# CSN Examples

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# CSDMS Standard Names — Examples

• This document provides numerous examples, organized by the main object that is under consideration and its various parts or "subobjects". These examples were moved here from the CSDMS Quantity Templates page on 8/6/14.
• These names are a work in progress and are subject to change. The ones on this page are for Version 0.81 of the CSDMS Standard Names.
• A CSDMS Standard Name must have an object part and a quantity part, with adjectives and modifiers (as prefixes) being used to help avoid ambiguity and identify a specific object and a specific, associated quantity. The "quantity part" may include one or more operation prefixes that create a new quantity from an existing quantity.

## Variable Names for the Atmosphere

quantity = attribute

Objects, including Subobjects:
"atmosphere"
"atmosphere_aerosol"
"atmosphere_air"
"atmosphere_air-column"
"atmosphere_air_carbon-dioxide"
"atmosphere_air_flow"
"atmosphere_air_flow_sediment~suspended"
"atmosphere_air_flow_snow~suspended"
"atmosphere_air_water~vapor"
"atmosphere_bottom"
"atmosphere_bottom_air"
"atmosphere_bottom_air_sediment~suspended"
"atmosphere_bottom_air_snow~suspended"
"atmosphere_carbon-dioxide"
"atmosphere_clouds"
"atmosphere_hydrometeor"
"atmosphere_top"
"atmosphere_water~vapor"

Examples

atmosphere_aerosol_radiation~incoming~shortwave__absorptance

atmosphere_aerosol_dust__reduction_of_transmittance    (as compared to when there is no dust)

atmosphere_air__anomaly_of_pressure   (anomaly = difference from climatology)
atmosphere_air__anomaly_of_temperature
atmosphere_air__convective_available_potential_energy   (CAPE)
atmosphere_air__equivalent_potential_temperature
atmosphere_air__equivalent_temperature
atmosphere_air__heat_capacity_ratio       (Cp / Cv = cp / cv)
atmosphere_air__increment_of_pressure     (i.e. change after one time step)
atmosphere_air__increment_of_temperature
atmosphere_air__isentropic_compressibility
atmosphere_air__isothermal_compressibility
atmosphere_air__mass-per-volume_density
atmosphere_air__mass-specific_isobaric_heat_capacity    (isobaric = constant pressure)
atmosphere_air__mass-specific_isochoric_heat_capacity   (isochoric = constant volume)
atmosphere_air__potential_temperature
atmosphere_air__static_pressure   (i.e. weight of the air above)
atmosphere_air__static_pressure_environmental_lapse_rate    ### (or standard_pressure_lapse_rate ?)
atmosphere_air__temperature
atmosphere_air__temperature_dry_adiabatic_lapse_rate     ## ( ELR = minus_of_z_derivative_of_temperature)
atmosphere_air__temperature_environmental_lapse_rate    ## (based on the International Standard Atmosphere, with no moisture.)
atmosphere_air__thermal_conductivity
atmosphere_air__thermal_diffusivity
atmosphere_air__thermal_inertia
atmosphere_air__thermal_resistivity   (reciprocal of thermal_conductivity)
atmosphere_air__volume-specific_isobaric_heat_capacity    (isobaric = constant pressure)
atmosphere_air__volume-specific_isochoric_heat_capacity   (isochoric = constant volume)

atmosphere_air__east_derivative_of_temperature
atmosphere_air__north_derivative_of_temperature
atmosphere_air__x_derivative_of_temperature
atmosphere_air__y_derivative_of_temperature
atmosphere_air__z_derivative_of_temperature

atmosphere_air-column_acetic-acid__mass-per-area_density     (called "mass content" in CF names.  Also called "mass column density".)
atmosphere_air-column_aceto-nitrile__mass-per-area_density
atmosphere_air-column_alkanes__mass-per-area_density
atmosphere_air-column_alkenes__mass-per-area_density
atmosphere_air-column_alpha-hexachlorocyclohexane__mass-per-area_density
atmosphere_air-column_alpha-pinene__mass-per-area_density
atmosphere_air-column_ammonia__mass-per-area_density
atmosphere_air-column_aerosol~dry_ammonium__mass-per-area_density
atmosphere_air-column_water~vapor__mass-per-area_density
### The rest of the 90 or so atmospheric constituents in the CF names will be added soon.

atmosphere_air-column_water~vapor__liquid-equivalent_depth   (also called "precipitable depth";  see Note below)

atmosphere_air_carbon-dioxide__equilibrium_partial_pressure
atmosphere_air_carbon-dioxide__partial_pressure
atmosphere_air_carbon-dioxide__relative_saturation
atmosphere_air_carbon-dioxide__saturated_partial_pressure

atmosphere_air_flow__azimuth_angle_of_bolus_velocity
atmosphere_air_flow__east_component_of_bolus_velocity
atmosphere_air_flow__elevation_angle_of_bolus_velocity
atmosphere_air_flow__magnitude_of_bolus_velocity
atmosphere_air_flow__north_component_of_bolus_velocity
atmosphere_air_flow__up_component_of_bolus_velocity
atmosphere_air_flow__x_component_of_bolus_velocity
atmosphere_air_flow__y_component_of_bolus_velocity
atmosphere_air_flow__z_component_of_bolus_velocity

atmosphere_air_flow__east_derivative_of_potential_vorticity
atmosphere_air_flow__north_derivative_of_potential_vorticity
atmosphere_air_flow__x_derivative_of_potential_vorticity
atmosphere_air_flow__y_derivative_of_potential_vorticity
atmosphere_air_flow__z_derivative_of_potential_vorticity

atmosphere_air_flow__azimuth_angle_of_gradient_of_pressure      (static, dynamic or total ?) #########
atmosphere_air_flow__east_derivative_of_pressure
atmosphere_air_flow__north_derivative_of_pressure
atmosphere_air_flow__x_derivative_of_pressure
atmosphere_air_flow__y_derivative_of_pressure
atmosphere_air_flow__z_derivative_of_pressure

atmosphere_air_flow__azimuth_angle_of_momentum
atmosphere_air_flow__east_component_of_momentum
atmosphere_air_flow__elevation_angle_of_momentum
atmosphere_air_flow__magnitude_of_momentum
atmosphere_air_flow__north_component_of_momentum
atmosphere_air_flow__up_component_of_momentum
atmosphere_air_flow__x_component_of_momentum
atmosphere_air_flow__y_component_of_momentum
atmosphere_air_flow__z_component_of_momentum
atmosphere_air_flow__z_integral_of_u_component_of_momentum
atmosphere_air_flow__z_integral_of_v_component_of_momentum

atmosphere_air_flow__azimuth_angle_of_velocity
atmosphere_air_flow__east_component_of_velocity
atmosphere_air_flow__elevation_angle_of_velocity
atmosphere_air_flow__magnitude_of_velocity
atmosphere_air_flow__north_component_of_velocity
atmosphere_air_flow__x_component_of_velocity
atmosphere_air_flow__y_component_of_velocity
atmosphere_air_flow__z_component_of_velocity

atmosphere_air_flow__azimuth_angle_of_vorticity
atmosphere_air_flow__east_component_of_vorticity
atmosphere_air_flow__elevation_angle_of_vorticity
atmosphere_air_flow__magnitude_of_bolus_vorticity
atmosphere_air_flow__north_component_of_vorticity
atmosphere_air_flow__x_component_of_vorticity
atmosphere_air_flow__y_component_of_vorticity
atmosphere_air_flow__z_component_of_vorticity

atmosphere_air_flow__east_east_component_of_reynolds_stress
atmosphere_air_flow__east_north_component_of_reynolds_stress
atmosphere_air_flow__east_up_component_of_reynolds_stress
atmosphere_air_flow__north_north_component_of_reynolds_stress
atmosphere_air_flow__north_up_component_of_reynolds_stress
atmosphere_air_flow__up_up_component_of_reynolds_stress

atmosphere_air_flow__x_x_component_of_reynolds_stress
atmosphere_air_flow__x_y_component_of_reynolds_stress
atmosphere_air_flow__x_z_component_of_reynolds_stress
atmosphere_air_flow__y_y_component_of_reynolds_stress
atmosphere_air_flow__y_z_component_of_reynolds_stress
atmosphere_air_flow__z_z_component_of_reynolds_stress

atmosphere_air_flow__east_east_component_of_stress
atmosphere_air_flow__east_north_component_of_stress
atmosphere_air_flow__east_up_component_of_stress
atmosphere_air_flow__north_north_component_of_stress
atmosphere_air_flow__north_up_component_of_stress
atmosphere_air_flow__up_up_component_of_stress

atmosphere_air_flow__x_x_component_of_stress
atmosphere_air_flow__x_y_component_of_stress
atmosphere_air_flow__x_z_component_of_stress
atmosphere_air_flow__y_y_component_of_stress
atmosphere_air_flow__y_z_component_of_stress
atmosphere_air_flow__z_z_component_of_stress

atmosphere_air_flow__dynamic_pressure
atmosphere_air_flow__magnitude_of_stress   ####
atmosphere_air_flow__obukhov_length    ### (should we insert "boundary-layer" in object part?)
atmosphere_air_flow__potential_vorticity    ### (a scalar quantity, the dot product of potential temperature and absolute vorticity)
atmosphere_air_flow__time_derivative_of_potential_vorticity
atmosphere_air_flow__total_pressure

atmosphere_air_flow_sediment~suspended__mass_concentration
atmosphere_air_flow_sediment~suspended__volume_concentration

atmosphere_air_flow_snow~suspended__mass_concentration
atmosphere_air_flow_snow~suspended__volume_concentration

atmosphere_air_radiation__standard_refraction_index     (i.e. "standard" is based on a particular wavelength in the yellow visible range)

atmosphere_air_radiation_optical-path__length    ### (also called "air mass";  shorten optical-path to path ??)

atmosphere_air_water~vapor__dew_point_temperature
atmosphere_air_water~vapor__equilibrium_partial_pressure
atmosphere_air_water~vapor__frost_point_temperature
atmosphere_air_water~vapor__mass-per-volume_density    ### (usually called "absolute humidity" or "water vapor density" = mass of water per unit volume)
atmosphere_air_water~vapor__mass_mixing_ratio  ## (also called "mass ratio")
atmosphere_air_water~vapor__mole_mixing_ratio  ## (also called "mole ratio")
atmosphere_air_water~vapor__partial_pressure    ### (also called "vapor pressure" in meteorology)
atmosphere_air_water~vapor__psychrometric_constant   (varies between 0.00058 and 0.000648)
atmosphere_air_water~vapor__relative_saturation
atmosphere_air_water~vapor__saturated_partial_pressure      ### (also called "saturation vapor pressure" in meteorology)
atmosphere_air_water~vapor__virtual_potential_temperature
atmosphere_air_water~vapor__virtual_temperature

atmosphere_bottom_air__brutsaert_emissivity_canopy_factor
atmosphere_bottom_air__brutsaert_emissivity_cloud_factor
atmosphere_bottom_air__bulk_latent_heat_aerodynamic_conductance   [m s-1]
atmosphere_bottom_air__bulk_latent_heat_transfer_coefficient    [dimensionless]    ### (add "surface" after "bottom" ??)
atmosphere_bottom_air__bulk_momentum_aerodynamic_conductance   [m s-1]
atmosphere_bottom_air__bulk_momentum_transfer_coefficient    [dimensionless]
atmosphere_bottom_air__bulk_sensible_heat_aerodynamic_conductance   [m s-1]
atmosphere_bottom_air__bulk_sensible_heat_transfer_coefficient    [dimensionless]
atmosphere_bottom_air__emissivity   [dimensionless]      (for computing longwave radiation from the air toward the land surface)
atmosphere_bottom_air__mass-per-volume_density
atmosphere_bottom_air__mass-specific_isobaric_heat_capacity
atmosphere_bottom_air__neutral_bulk_latent_heat_transfer_coefficient    [dimensionless]    ### (add "surface" after "bottom" ??)
atmosphere_bottom_air__neutral_bulk_momentum_transfer_coefficient    [dimensionless]
atmosphere_bottom_air__neutral_bulk_sensible_heat_transfer_coefficient    [dimensionless]
atmosphere_bottom_air__static_pressure
atmosphere_bottom_air__temperature

atmosphere_bottom_air_carbon-dioxide__equilibrium_partial_pressure
atmosphere_bottom_air_carbon-dioxide__partial_pressure
atmosphere_bottom_air_carbon-dioxide__relative_saturation
atmosphere_bottom_air_carbon-dioxide__saturated_partial_pressure

atmosphere_bottom_air_flow__bulk_richardson_number
atmosphere_bottom_air_flow__dynamic_pressure
atmosphere_bottom_air_flow__flux_richardson_number
atmosphere_bottom_air_flow__log_law_displacement_length    ### (or "zero-plane displacement")
atmosphere_bottom_air_flow__log_law_roughness_length    ### can involve buildings, snowpack, terrain and vegetation.
atmosphere_bottom_air_flow__reference_height_speed
atmosphere_bottom_air_flow__speed_reference_height
atmosphere_bottom_air_flow__total_pressure

atmosphere_bottom_air_heat~advection__energy_flux    ### (e.g. carried by rain from atmosphere to land surface)
atmosphere_bottom_air_heat~convection__energy_flux   ### CHECK THIS
atmosphere_bottom_air_heat~diffusion__energy_flux    ### CHECK THIS
atmosphere_bottom_air_heat_flow__log_law_roughness_length     (See: Log wind profile.)

atmosphere_bottom_air_water~vapor_flow__log_law_roughness_length

atmosphere_bottom_air_flow__x_component_of_velocity     (i.e. surface wind)
atmosphere_bottom_air_flow__y_component_of_velocity
atmosphere_bottom_air_flow__z_component_of_velocity

atmosphere_bottom_air_flow_buildings__log_law_roughness_length   #### (i.e. z0.  "log_law" is added for clarity.  See: Roughness length.)
atmosphere_bottom_air_flow_snowpack__log_law_roughness_length
atmosphere_bottom_air_flow_terrain__log_law_roughness_length
atmosphere_bottom_air_flow_vegetation__log_law_roughness_length

atmosphere_bottom_air_land_heat~incoming~latent__energy_flux    [W m-2]
atmosphere_bottom_air_land_heat~incoming~sensible__energy_flux    [W m-2]
atmosphere_bottom_air_land_heat~net~latent__energy_flux    [W m-2]  (via mass transport, such as evaporation and condensation;  net = incoming-outgoing to surface)
atmosphere_bottom_air_land_heat~net~sensible__energy_flux   [W m-2]  (via conduction)

atmosphere_bottom_air_water~vapor__bulk_mass_aerodynamic_conductance   [m s-1]       ### (Maybe not needed;  see bulk_latent_heat_aerodynamic_conductance above.)
atmosphere_bottom_air_water~vapor__bulk_mass_transfer_coefficient    [dimensionless]     ### (Maybe not needed;  see bulk_latent_heat_transfer_coefficient above.)
atmosphere_bottom_air_water~vapor__dew_point_temperature
atmosphere_bottom_air_water~vapor__equilibrium_partial_pressure     (also called "equilibrium vapor pressure" in meteorology; see Pressure)
atmosphere_bottom_air_water~vapor__frost_point_temperature
atmosphere_bottom_air_water~vapor__mass-per-volume_density    ### (usually called "absolute humidity" or "water vapor density" = mass of water per unit volume)
atmosphere_bottom_air_water~vapor__neutral_bulk_mass_transfer_coefficient    [dimensionless]
atmosphere_bottom_air_water~vapor__partial_pressure      (also called "vapor pressure" in meteorology; see Pressure)
atmosphere_bottom_air_water~vapor__relative_saturation   (usually called "relative humidity")
atmosphere_bottom_air_water~vapor__saturated_partial_pressure   (usually called "saturated vapor pressure")

atmosphere_clouds_radiation~incoming~shortwave__absorbed_energy_flux  ## put "absorbed" after "shortwave"?

atmosphere_datum~vertical~tidal~msl_air__static_pressure
atmosphere_datum~vertical~tidal~msl_air_flow__dynamic_pressure
atmosphere_datum~vertical~tidal~msl_air_flow__total_pressure

atmosphere_graupel__mass-per-volume_density
atmosphere_graupel__precipitation_duration
atmosphere_graupel__precipitation_volume_flux

atmosphere_hail__mass-per-volume_density
atmosphere_hail__precipitation_duration
atmosphere_hail__precipitation_volume_flux

atmosphere_hydrometeor__mass-per-volume_density
atmosphere_hydrometeor__diameter
atmosphere_hydrometeor__fall_speed
atmosphere_hydrometeor__mass
atmosphere_hydrometeor__temperature
atmosphere_hydrometeor__terminal_fall_speed
atmosphere_hydrometeor__volume
# dbz = 10 x log of a ratio of reflectances, see:  DBZ (meteorology)

atmosphere_ice__mass-per-volume_density
atmosphere_ice__precipitation_duration
atmosphere_ice__precipitation_volume_flux

atmosphere_radiation~incoming~shortwave__absorbed_energy_flux       (by the atmosphere, i.e. by air, aerosols, clouds, etc.)
atmosphere_radiation~incoming~shortwave__reflected_energy_flux      (by aerosols or clouds, back into space)
atmosphere_radiation~incoming~shortwave__transmitted_energy_flux    (sent down to land surface)

atmosphere_raindrop__fall_speed
atmosphere_raindrop__terminal_fall_speed

atmosphere_sleet__mass-per-volume_density  # ("ice-pellet" may be preferable to "sleet")
atmosphere_sleet__precipitation_duration
atmosphere_sleet__precipitation_volume_flux

atmosphere_snow__mass-per-volume_density
atmosphere_snow__precipitation_duration
atmosphere_snow__precipitation_volume_flux

atmosphere_water__domain_time_integral_of_precipitation_leq-volume_flux     (i.e. over grid cell area and time. Here "water" includes frozen or liquid.)
atmosphere_water__domain_time_integral_of_rainfall_volume_flux
atmosphere_water__domain_time_integral_of_snowfall_leq-volume_flux
atmosphere_water__domain_time_max_of_precipitation_leq-volume_flux
atmosphere_water__geologic_time_average_of_rainfall_volume_flux    # (sometimes called "geomorphic rainrate")
atmosphere_water__globe_time_average_of_rainfall_volume_flux
atmosphere_water__icefall_leq-volume_flux      ### (this must only be used for precipitation know to be falling as ice)
atmosphere_water__icefall_mass-per-volume_density
atmosphere_water__mass-per-volume_density    ### (regardless whether frozen or liquid?)
atmosphere_water__one-day_time_integral_of_precipitation_leq-volume_flux
atmosphere_water__one-hour_time_integral_of_precipitation_leq-volume_flux
atmosphere_water__one-month_time_integral_of_precipitation_leq-volume_flux
atmosphere_water__one-year_time_integral_of_precipitation_leq-volume_flux
atmosphere_water__precipitation_duration
atmosphere_water__precipitation_leq-volume_flux      ######### ??
atmosphere_water__precipitation_mass_flux
atmosphere_water__rainfall_volume_flux        ### (this must only be used for precipitation know to be falling as liquid, perhaps masked)
atmosphere_water__snowfall_leq-volume_flux    ### (this must only be used for precipitation known to be falling as snow)
atmosphere_water__snowfall_mass-per-volume_density

• Water in the atmosphere may precipitate as rain (liquid), snow or ice (several types). Each of these has a different mass-per-volume density. Rain (liquid) contributes directly to runoff production, while snow contributes to the depth of the snowpack but may then be melted at a later time to contribute to runoff. Models must therefore handle precipitation carefully. The term "liquid-equivalent precipitation" (also liquid-water equivalent) is used in meteorology and hydrology to address this issue when working with "rates" (i.e. volume fluxes with units like mm/hr). This clarification refers to the volume flux that would result if all of the precipitation were converted to liquid form. In the CSDMS Standard Names, the abbreviation "leq" is used for "liquid-equivalent" in the quantity name "leq-volume_flux". A meteorology model component may be able to return both the "rainfall_volume_flux" and the "snowfall_leq-volume_flux" as two separate components of precipitation, by setting the former to zero for all model grid cells where the air temperature is below freezing and setting the latter to zero for all grid cells where it is above freezing. In other cases a model may only provide "precipitation_leq-volume_flux", leaving it to the caller to distinguish between rain and snow. Standard names are provided for all of these possible cases but must be selected carefully.
• The standard name "atmosphere_air-column_water_vapor" + "liquid-equivalent_depth" is sometimes called "precipitable water depth", "precipitable depth" or "total precipitable water". Alternate standard name constructions would be: "atmosphere_air_water~vapor" + "z_integral_from_bottom-to-top_of_volume_fraction" or "atmosphere_air-column_water~vapor" + "volume-per-area_density" or "atmosphere_air_water~vapor" + "column_density". However, the chosen name seems to be the best choice because "air column", "ice column", "soil column" and "water column" are familiar objects/concepts (try and internet search) and follow speech and it is helpful to indicate the necessary conversion from water~vapor to liquid with "liquid-equivalent" and the word "depth" is an appropriate base quantity. The hyphens bind the words to create one distinct object name. For the total mass of a substance in the air column, the standard name follows the pattern: "atmosphere_air-column_X" + "mass-per-area_density", where X is a substance name. In this case the concept of "liquid-equivalent" isn't needed, even for water vapor. In the CF Standard Names, the nonstandard term "mass_content" is used instead of "mass-per-area_density", with no reference to the "air column".
• In the examples above, the word "flow" is a shorthand for "flow_field", a mathematical model and 3D vector field. This is an example of the Object Name + Model Name Pattern.
• Note that "air_flow" takes the place of the word "wind", for cross-domain consistency. For example, "sea_water_flow" is analogous to "atmosphere_air_flow".
• The "mean-sea-level datum" is an idealized or "model" surface at which measurements can be made. This is an example of the Object Name + Model Name Pattern.
• "Air" is a particular mixture of gases that makes up the atmosphere of the Earth. However, for another planet, like Mars, we could use: "mars_atmosphere_air".
• There is a distinction between "static pressure" and "dynamic pressure". The first results from the weight of fluid above a location (called "hydrostatic" when the fluid is water) while the second is the kinetic energy per unit volume of a fluid flow. The "total pressure" is the sum of these two contributions. See: Bernoulli's principle, Dynamic pressure, Pressure, Stagnation pressure and Static pressure.
• According to Wikipedia: "In meteorology, the term "vapor pressure" is used to mean the partial pressure of water vapor in the atmosphere, even if it is not in equilibrium, and the term "equilibrium vapor pressure" is specified otherwise." See: Vapor pressure. In the CSDMS Standard Names, the standard names are therefore: "atmosphere_air_water~vapor" + "partial_pressure" and "atmosphere_air_water~vapor" + "equilibrium_partial_pressure".
• The word "radiation" is overloaded and is used in 2 different ways. It is used as a synonym for "electromagnetic waves" as well as for the process where something "radiates" energy. In the first case it will appear in the object part of the name, and in the second case in the quantity part of the name.

## Variable Names for Atoms

quantity = attribute
quantity = "atomic_mass"
quantity = "emission_frequency"
quantity = "relative_atomic_mass" (dimensionless ratio to carbon-12)
quantity = "mass_number" (number of protons + neutrons)
quantity = "neutron_number" (number of neutrons)
quantity = "proton_number" (number of protons)

Examples

carbon_isotope__neutron_number  (use "isotope" like this ??)
cesium_atom__mass_number
cesium_atom__neutron_number
cesium_atom__proton_number
cesium_atom__relative_atomic_mass

• There is controversy over the term "atomic_weight" and the term "relative_atomic_mass" seems preferable and more precise.
• While "atomic number" is a standard term, the synonym "proton_number" is winning favor because it is more specific and because "neutron_number" is also used.
• A specific frequency in the emission spectrum of cesium-133 is used for the ISU definition of the "second", so cesium is used in atomic clocks. It is not really a characteristic vibration frequency of the atom. (But molecules do have vibration frequencies; see Variable Names for Molecules below.) It is a transition or resonance frequency between two hyperfine ground states of cesium-133. A CSDMS standard name for this frequency could be something like: "cesium-133_isotope_state1-to-state2_hyperfine_transition_frequency", where "state1" and "state2" would be replaced with appropriate names for the two states involved.

## Variable Names for Automobiles

quantity = attribute

Objects, including Subobjects:
"automobile"
"automobile_alternator"
"automobile_battery"
"automobile_bottom"
"automobile_bumper"
"automobile_chassis"
"automobile_dashboard"
"automobile_differential"
"automobile_distributor"
"automobile_door"
"automobile_driver"
"automobile_engine"
"automobile_frame"
"automobile_engine_camshaft"
"automobile_engine_camshaft_sprocket"
"automobile_engine_crankshaft"
"automobile_engine_crankshaft_sprocket"
"automobile_engine_cylinder"
"automobile_engine_cylinder_piston"
"automobile_engine_cylinder_piston_connecting-rod"
"automobile_engine_cylinder_spark-plug"
"automobile_engine_cylinder_valves"
"automobile_exhaust-system"
"automobile_fan_belt"
"automobile_front"
"automobile_front_axle"
"automobile_fuel"
"automobile_fuel_tank"
"automobile_hood"
"automobile_muffler"
"automobile_rear"
"automobile_rear_axle"
"automobile_seatbelt"
"automobile_steering-box"
"automobile_steering-wheel"
"automobile_suspension"
"automobile_tire"
"automobile_top"
"automobile_transmission"
"automobile_wheel"
"automobile_windshield"

Examples:

automobile__0-to-60mph_acceleration_time   (seconds)
automobile__acceleration
automobile__braking_distance
automobile__braking_force
automobile__cargo_capacity   (a volume;  use the word "volume" ?)
automobile__drag_coefficient
automobile__fuel-economy    (measured as "miles per gallon")
automobile__kelley-blue-book_price
automobile__length
automobile__lift_coefficient
automobile__manufacture_year
automobile__mass
automobile__msrp_price
automobile__new_price
automobile__safety_rating
automobile__seating_capacity
automobile__speed
automobile__top_speed
automobile__total_stopping_distance   (perception-reaction + braking)
automobile__total_stopping_time
automobile__total_travel_distance  # (from time of manufacture to present time; distance travelled. odometer reading?)
automobile__vehicle_identification_number
automobile__weight  (or "earth_weight")
automobile__wheelbase_length
automobile__width
automobile__x_component_of_velocity
automobile__y_component_of_velocity
automobile__z_component_of_velocity

automobile_axis~vertical__rotational_inertia

automobile_battery__height
automobile_battery__length
automobile_battery__voltage
automobile_battery__weight
automobile_battery__width

automobile_bottom__approach_angle
automobile_bottom__breakover_angle
automobile_bottom__departure_angle
automobile_bottom_ground__clearance_height   ## (also called "ride height")

automobile_bumper_bottom__above-ground_height

automobile_carbon-dioxide__emission_rate  (by mass?)

automobile_door__count

automobile_driver__reaction_distance
automobile_driver__reaction_time

automobile_engine__max_of_output_power
automobile_engine__power-to-weight_ratio

automobile_engine_crankshaft__rotation_rate   (measured with RPMs, revolutions per minute)
automobile_engine_crankshaft__torque   (often expressed as "horsepower")

automobile_engine_cylinder__count
automobile_engine_cylinder__diameter   ### (called the "cylinder bore")
automobile_engine_cylinder__length    (or depth ??)
automobile_engine_cylinder__stroke_ratio     (i.e. cylinder diameter to piston stroke length)
automobile_engine_cylinder__volume

automobile_engine_cylinder_piston__diameter
automobile_engine_cylinder_piston__stroke_length

automobile_front_axle_weight  ## (still ambiguous;  could also be weight of the axle itself.)

automobile_front_x-section__area

automobile_fuel__consumption_rate
automobile_fuel__volume

automobile_fuel_tank__volume

automobile_rear_axle__weight    ## (still ambiguous;  could also be weight of the axle itself.)

automobile_seat_belt__count  ## (often determines the legal max number of passengers)

automobile_tire__contact_area
automobile_tire__diameter
automobile_tire__inflation_pressure

automobile_wheel__camber_angle
automobile_wheel__camber_force
automobile_wheel__caster_angle
automobile_wheel__diameter

automobile_wheelbase__distance   (between centers of front and rear wheels;  "track" is sometimes used for distance between the front or rear wheels)


• There are an almost endless number of quantities that can be associated with an automobile and is various parts. The purpose of this section is not to be exhaustive but to provide examples -- or a "scoping exercise" -- to help assess the robustness of the patterns and naming conventions of the CSDMS Standard Names.
• The term "automobile" is fairly general and includes: cars, jeeps, SUVs, trucks, etc.
• The term "motor vehicle" is generally used to include automobiles and motorcycles, etc.
• The word "vehicle" is the most general, and includes airplanes, ships, trains, etc.
• In the examples above, we are assuming the vehicle has in internal combustion engine (ICE), as opposed to an electric vehicle (EV). Perhaps this should also be indicated.
• There is a distinction between sprockets and gears -- sprockets are never meshed together directly; they use a roller chain or track. So "camshaft_sprocket" and "crankshaft_sprocket" are correct.
• Moving vehicles (e.g. cars and planes) have 3 natural, orthogonal axes with their center of mass at the origin: a longitudinal axis, lateral axis and vertical axis. For airplanes, these are also called the roll, pitch and yaw axes, respectively. The longitudinal axis lies in the vehicle's longitudinal plane of symmetry (or left-right symmetry plane) and is everywhere equidistant from the ground (if it is horizontal and planar). If the vehicle is not drifting or skidding, then this will also be the direction of motion. However, a car's "roll axis" is tilted (due to braking?), so it is lower toward the front and higher toward the rear of the car. Is a car's "centerline" well-defined?
• Many additional variable names can be found in the List of Symbols of: Gillespie, T.D. (1992) Fundamentals of Vehicle Dynamics, Society of Automotive Engineers, Warrendale, PA, 495 pp.

## Variable Names for Basins

quantity = attribute

Objects, including Subobjects:
"basin"
"basin_boundary"
"basin_land~burned"
"basin_centroid"
"basin_channels"
"basin_channel-network" ### for Horton ratios, etc. ??
"basin_land~forested"
"basin_channel~longest"
"basin_channel~longest_centerline"
"basin_channel~main"
"basin_outlet"
"basin_outlet_channel"
"basin_outlet_channel_x-section"
"basin_outlet_bank~left"
"basin_outlet_bank~right"
"basin_outlet_water"
"basin_outlet_water_sediment~suspended"
"basin_rain-gauge"
"basin_sediment"
"basin_soil"
"basin_sources"
"basin_outlet~terminal"
"basin_weather-station"

Examples

basin__area
basin__d8_total_contributing_area             (i.e. upstream, contributing area)
basin__d-infinity_total_contributing_area
basin__flint_law_exponent      (vs. "flint_law_concavity_exponent")
basin__flint_law_coefficient   (vs. "flint_law_steepness_parameter")
basin__mass-flux_total_contributing_area     ####
basin__max_of_elevation
basin__mean_of_elevation
basin__min_of_elevation
basin__range_of_elevation   (also called the "relief")

basin_boundary__aspect_ratio   # (also called "max-min chord shape factor")
basin_boundary__diameter
basin_boundary__normalized_area-diameter_shape_factor
basin_boundary__normalized_area-perimeter_shape_factor
basin_boundary__normalized_diameter-perimeter_shape_factor
basin_boundary__perimeter

basin_centroid__elevation
basin_centroid__latitude
basin_centroid__longitude

basin_channel-network__graph_diameter  (i.e. path to root with greatest number of links)
basin_channel-network__horton_bifurcation_ratio
basin_channel-network__horton-strahler_order
basin_channel-network__pfafstetter_code
basin_channel-network__shreve_magnitude   (or water_channel-network_source__count ??)
basin_channel-network__total_length
basin_channel-network__total-length-to-area_ratio   ### (usually called "drainage density")
basin_channel-network__usgs_hydrologic_unit_code

basin_channel-network_source__count    # (same as shreve magnitude)

basin_land~burned__area_fraction
basin_land~forested__area_fraction

basin_channel~longest__hack_law_coefficient
basin_channel~longest__hack_law_exponent
basin_channel~longest__length
basin_channel~longest_centerline__downvalley_sinuosity
basin_channel~longest_centerline__sinuosity

basin_outlet_bank~left__latitude
basin_outlet_bank~left__longitude
basin_outlet_bank~right__latitude
basin_outlet_bank~right__longitude

basin_outlet__bankfull_width

basin_outlet_center__elevation
basin_outlet_center__latitude
basin_outlet_center__longitude

basin_outlet_channel_bottom__slope

basin_outlet_sediment__yield

basin_outlet_water_flow__half_of_fanning_friction_factor

basin_outlet_water_sediment~suspended__mass_flow_rate
basin_outlet_water_sediment~suspended__volume_flow_rate
basin_outlet_water_sediment~total__mass_flow_rate
basin_outlet_water_sediment~total__volume_flow_rate

basin_outlet_water_x-section__mean_depth
basin_outlet_water_x-section__volume_flow_rate    # (usually called "discharge")
basin_outlet_water_x-section__time_integral_of_volume_flow_rate
basin_outlet_water_x-section__time_max_of_mean_depth
basin_outlet_water_x-section__time_max_of_volume_flow_rate
basin_outlet_water_x-section__time_max_of_volume_flux
basin_outlet_water_x-section__volume_flux    #  (usually called "mean flow speed" or similar)
basin_outlet_water_x-section__peak_time_of_depth    # (for any depth, including mean depth)
basin_outlet_water_x-section__peak_time_of_volume_flow_rate
basin_outlet_water_x-section__peak_time_of_volume_flux
basin_outlet_water_x-section__width-to-depth_ratio

basin_outlet_water_x-section_top__width
basin_outlet~terminal_water__mass_flow_rate    ### (here "terminal" indicates an outlet that drains to the ultimate receiving water body, e.g. the sea)
basin_outlet~terminal_water__volume_flow_rate

basin_rain-gauge__count

basin_sources__number-per-area_density

basin_weather-station__count

• The expressions "drainage basin", "river basin", "catchment" and "watershed" are synonyms, but the word "watershed" means "drainage divide" in English speaking countries other than the US. The word "catchment" has another meaning in Human Geography.
• For the CSDMS Standard Names, the word "basin" was chosen to represent drainage basin, or basin~drainage. In order to avoid ambiguity, however, other names will need to be used for other types of basins. For example, basin~oceanic, basin~sedimentary and basin~structural (or basin~geologic) could be used. The adjective closed can also be used with basin.
• "basin_boundary" seems better than "basin_drainage_divide". We could introduce "basin_interior" also, if needed.
• "basin_polygon" would be another example of our Object_name + Model_name Pattern.

## Variable Names for Bedrock

quantity = attribute

Objects, including Subobjects:
"bedrock"
"bedrock_material"
"bedrock_surface"
"bedrock_surface_sediment"

Examples

bedrock__mass-per-volume_density
bedrock__permeability
bedrock__uplift_rate   [mm yr-1]

bedrock_below-land-surface__depth

bedrock_material__poisson_ratio
bedrock_material__young_modulus

bedrock_surface__elevation
bedrock_surface__slope
bedrock_surface__time_derivative_of_elevation
bedrock_surface__time_derivative_of_slope
bedrock_surface__x_derivative_of_elevation
bedrock_surface__x_derivative_of_slope
bedrock_surface__y_derivative_of_elevation
bedrock_surface__y_derivative_of_slope


• Bedrock is consolidated rock that is usually covered by soil on land and by sediment on the sea floor. Outcrops are places where the bedrock is exposed.
• Bedrock may be igneous, sedimentary or metamorphic. Igneous bedrock may be classified as plutonic (gabbro or granite) or volcanic (basalt or rhyolite). Sedimentary rock may be classified as clastic (sandstone or shale) or chemical (limestone). Metamorphic rock may be classified as foliated (slate or schist) or nonfoliated (quartzite or marble).

## Variable Names for Channels

quantity = attribute

Objects, including Subobjects:
"channel_bank"
"channel_bank_soil"
"channel_bank_water"
"channel_bottom" ### (used instead of "channel_bed")
"channel_bottom_water"
"channel_bottom_water_flow"
"channel_bottom_water_sediment"
"channel_bottom_sediment"
"channel_bottom_sediment_grain"
"channel_bottom_surface"
"channel_centerline"
"channel_centerline_endpoints"
"channel_entrance"
"channel_entrance_center" (center or centroid ??)
"channel_entrance_water"
"channel_entrance_basin"
"channel_exit"
"channel_exit_center" (center or centroid ??)
"channel_exit_water"
"channel_exit_basin"
"channel_water"
"channel_water_flow"
"channel_water_hydraulic-jump"
"channel_water_oxygen~photosynthetic"
"channel_water_sediment~suspended"
"channel_water_sediment~total"
"channel_water_sediment_grain"
"channel_water_surface"
"channel_water_wave~bore"
"channel_water_wave~diffusive"
"channel_water_wave~dynamic"
"channel_water_wave~kinematic"
"channel_water_wave~solitary"
"channel_water_wave~standing"
"channel_weir"
"channel_x-section"
"channel_x-section_centroid"
"channel_x-section_top"
"channel_x-section_trapezoid"
"channel_x-section_trapezoid_bank~left"
"channel_x-section_trapezoid_bank~right"
"channel_x-section_water"

Examples

channel__downstream_hydraulic_geometry_depth-vs-discharge_coefficient   ###  (add the word "law" ??)
channel__downstream_hydraulic_geometry_depth-vs-discharge_exponent
channel__downstream_hydraulic_geometry_slope-vs-discharge_coefficient
channel__downstream_hydraulic_geometry_slope-vs-discharge_exponent
channel__downstream_hydraulic_geometry_speed-vs-discharge_coefficient
channel__downstream_hydraulic_geometry_speed-vs-discharge_exponent
channel__downstream_hydraulic_geometry_width-vs-discharge_coefficient
channel__downstream_hydraulic_geometry_width-vs-discharge_exponent

channel__station_hydraulic_geometry_depth-vs-discharge_coefficient
channel__station_hydraulic_geometry_depth-vs-discharge_exponent
channel__station_hydraulic_geometry_slope-vs-discharge_coefficient
channel__station_hydraulic_geometry_slope-vs-discharge_exponent
channel__station_hydraulic_geometry_speed-vs-discharge_coefficient
channel__station_hydraulic_geometry_speed-vs-discharge_exponent
channel__station_hydraulic_geometry_width-vs-discharge_coefficient
channel__station_hydraulic_geometry_width-vs-discharge_exponent

channel__meander_amplitude    ("meander" is treated as a process name vs. an object)
channel__meander_migration_rate
channel__meander_wavelength

channel_bank_sediment_water__saturated_hydraulic_conductivity   ### (for PIHM.  use soil or sediment here ??)

channel_bank_water__volume-per-length_flow_rate    ("lateral flow" into side of channel)

channel_bottom_sediment__thickness

channel_bottom_sediment_grain__d50_diameter    (same as "median diameter")
channel_bottom_sediment_grain__d84_diameter

channel_bottom_sediment_oxygen~dissolved__consumption_rate
channel_bottom_sediment_water__saturated_hydraulic_conductivity   (for PIHM)

channel_bottom_surface__cross-stream_derivative_of_elevation   ### (or allow "cross-stream_slope" ?)
channel_bottom_surface__downstream_derivative_of_elevation    ### (or allow "downstream_slope" ?)
channel_bottom_surface__slope
channel_bottom_surface__x_derivative_of_elevation
channel_bottom_surface__y_derivative_of_elevation

channel_bottom_water__static_pressure
channel_bottom_water__temperature

channel_bottom_water_flow__domain_max_of_log_law_roughness_length
channel_bottom_water_flow__domain_min_of_log_law_roughness_length
channel_bottom_water_flow__dynamic_pressure
channel_bottom_water_flow__log_law_roughness_length   (i.e. z0.  See: Roughness length.)
channel_bottom_water_flow__magnitude_of_shear_stress
channel_bottom_water_flow__relative_roughness_ratio        (dimensionless ratio of z0 roughness length to water depth;  maybe: log_law_z0_length ??)   #####
channel_bottom_water_flow__relative_smoothness_ratio       (dimensionless ratio of water depth to z0 roughness length)  #####
channel_bottom_water_flow__shear_speed    (shear speed = magnitude of shear velocity)
channel_bottom_water_flow__speed        ####  (use "near-bottom" vs. "bottom"  ??)
channel_bottom_water_flow__total_pressure
channel_bottom_water_flow__x_component_of_shear_velocity
channel_bottom_water_flow__x_component_of_velocity
channel_bottom_water_flow__y_component_of_shear_velocity
channel_bottom_water_flow__y_component_of_velocity

channel_bottom_water_flow_sediment_grain__shields_critical_shear_stress    (to initiate transport grains of a given size)
channel_bottom_water_flow_sediment_grain__shields_number    (a nondimensional stress;  also called "shields_parameter")

channel_centerline__length
channel_centerline__downvalley_sinuosity   (also called the "sinuosity index"; see: Sinuosity)
channel_centerline__sinuosity  (same as Tortuosity ??) #####

channel_centerline_endpoints__difference_of_elevation
channel_centerline_endpoints__separation_distance    (also called: "chord length", "shortest distance" or "euclidean distance")

channel_entrance_basin__total_contributing_area

channel_entrance_center__elevation
channel_entrance_center__latitude
channel_entrance_center__longitude

channel_entrance_water_x-section__volume_flow_rate     ## ("water" or "water~incoming"?)
channel_entrance_water_x-section__volume_flux

channel_exit_basin__total_contributing_area

channel_exit_center__elevation
channel_exit_center__latitude
channel_exit_center__longitude

channel_exit_water_x-section__volume_flow_rate  ## ("water" or "water~outgoing"?)
channel_exit_water_x-section__volume_flow_rate_law_area_exponent
channel_exit_water_x-section__volume_flow_rate_law_coefficient
channel_exit_water_x-section__volume-per-width_flow_rate  (i.e. "q", or unit-width discharge)  #######

channel_water__depth-times-bottom-surface-slope  ### (not clear how is depth defined here.)
channel_water__dynamic_shear_viscosity    (can be different than pure water)
channel_water__dynamic_volume_viscosity
channel_water__mass-per-volume_density    (can be different than pure water)
channel_water__initial_volume
channel_water__kinematic_shear_viscosity
channel_water__kinematic_volume_viscosity
channel_water__mass_flow_rate
channel_water__reaeration_coefficient
channel_water__static_pressure     (anywhere in the channel vs. at channel bottom)
channel_water__temperature
channel_water__time_derivative_of_volume
channel_water__volume

channel_water_flow__chezy_formula_coefficient
channel_water_flow__cross-stream_component_of_velocity
channel_water_flow__darcy_friction_factor
channel_water_flow__domain_max_of_manning_n_parameter
channel_water_flow__domain_min_of_manning_n_parameter
channel_water_flow__downstream_component_of_velocity
channel_water_flow__energy-per-volume_dissipation_rate     ### (energy or kinetic_energy ?)
channel_water_flow__dynamic_pressure
channel_water_flow__fanning_friction_factor   (also called the "skin friction coefficient"; not just for pipes)
channel_water_flow__froude_number
channel_water_flow__half_of_fanning_friction_factor    ### There doesn't seem to be another name for this.
channel_water_flow__manning_k_parameter
channel_water_flow__manning_n_parameter
channel_water_flow__reynolds_number
channel_water_flow__speed   (magnitude of velocity vector)
channel_water_flow__total_pressure
channel_water_flow__x_component_of_velocity
channel_water_flow__y_component_of_velocity
channel_water_flow__z_component_of_velocity

channel_water_flow__x_component_of_vorticity
channel_water_flow__y_component_of_vorticity
channel_water_flow__z_component_of_vorticity

channel_water_flow__x_x_component_of_stress
channel_water_flow__x_y_component_of_stress
channel_water_flow__x_z_component_of_stress

channel_water_hydraulic-jump__height
channel_water_hydraulic-jump__loss_of_energy    ###  (or "drop_of" ??)

channel_water_oxygen~photosynthetic__production_rate

channel_water_sediment_grain__stokes_settling_speed

channel_water_sediment~suspended__mass_concentration
channel_water_sediment~suspended__mass_flow_rate
channel_water_sediment~suspended__rouse_number
channel_water_sediment~suspended__volume_flow_rate
channel_water_sediment~total__volume_flow_rate  (i.e. "Qs" or "sediment discharge")
channel_water_sediment~total__volume_flow_rate_law_area_exponent
channel_water_sediment~total__volume_flow_rate_law_coefficient
channel_water_sediment~total__volume_flow_rate_law_slope_exponent

channel_water_surface__cross-stream_derivative_of_elevation   ### (or allow "cross-stream_slope" ?)  (Remove "top" here?) ##########
channel_water_surface__downstream_derivative_of_elevation     ### (or allow "downstream_slope" ?)
channel_water_surface__elevation
channel_water_surface__slope
channel_water_surface__x_derivative_of_elevation
channel_water_surface__y_derivative_of_elevation

channel_water_surface_air__temperature
channel_water_surface_water__temperature

channel_water_x-section__depth-vs-half-width_coefficient  (in PIHM)
channel_water_x-section__depth-vs-half-width_exponent   (in PIHM)
channel_water_x-section__domain_max_of_mean_depth
channel_water_x-section__domain_min_of_mean_depth
channel_water_x-section__domain_max_of_volume_flow_rate
channel_water_x-section__domain_min_of_volume_flow_rate
channel_water_x-section__domain_max_of_volume_flux
channel_water_x-section__domain_min_of_volume_flux
channel_water_x-section__initial_mean_depth
channel_water_x-section__max_of_depth
channel_water_x-section__mean_depth
channel_water_x-section__time_derivative_of_mean_depth    (could drop "mean" in this case?)
channel_water_x-section__volume_flow_rate  (also called "discharge" in hydrology)
channel_water_x-section__volume_flow_rate_law_area_exponent
channel_water_x-section__volume_flow_rate_law_coefficient
channel_water_x-section__volume_flux     (also called "mean speed", but this is more precise)
channel_water_x-section__wetted_area       ## (or just area)
channel_water_x-section__wetted_perimeter  ## (exlcuding the top edge)
channel_water_x-section__width-to-depth_ratio

channel_water_x-section_top__width   ## (not same as "channel_x-section_top + width"  below)

channel_weir__discharge_coefficient  (in PIHM)

channel_x-section__area
channel_x-section__depth-vs-half-width_coefficient  (in PIHM)
channel_x-section__depth-vs-half-width_exponent   (in PIHM)
channel_x-section__diameter
channel_x-section__max_of_depth
channel_x-section__max_of_elevation    ## (elevation of the bank, assumed same for both sides)
channel_x-section__min_of_elevation     ## (elevation of the lowest point in the x-section, where max depth occurs)
channel_x-section__perimeter
channel_x-section__width-to-depth_ratio   #### (for the channel itself)

channel_x-section_top__width   (for any x-section shape, incl. trapezoid;  also called bankfull_width)

channel_x-section_parabola__coefficient

channel_x-section_trapezoid_side~left__flare_angle
channel_x-section_trapezoid_side~right__flare_angle
channel_x-section_trapezoid_side__flare_angle        ##### (if same for both sides)
channel_x-section_trapezoid_bottom__width

• The word "channel" seems preferable as a generic term to words like "creek", "stream" and "river" because it doesn't have a size connotation. For example, there are textbooks on "open channel flow", we talk of "channelized flow" and then there is the English Channel. The CSDMS Standard Names is meant to function as a lingua franca for coupling resources (e.g. model-to-model or model-to-data), so allowing synonyms is counterproductive as it prevents otherwise valid matches.
• Although the term "mean flow speed" (or similar) is often used for the cross-section average of the downstream (axial) component of the flow velocity, it is not precise or self-explanatory. By contrast, the term "volume_flux" (volume per unit area per unit time) when applied to the channel cross-section is a precise quantity name. Similarly, the term "volume_flow_rate" is precise, cross-domain and preferable to discharge -- discharge is sometimes used to mean "mass_flow_rate" and has other meanings outside of hydrology. These two quantities are related through the equation u = Q/A, where u = volume flux, Q = volume flow rate and A = area of the cross-section.
• Note that "mean_depth" is used instead of "mean_of_depth". While the operation name "mean_of" must usually be specialized to "time_average_of" or "domain_mean_of", etc. we allow "mean_depth" to be used when the base object is "x-section". In general, applying the words "mean" or "average" as an adjective to a base quantity is avoided to prevent ambiguity. Clarifications on how quantities are computed can also be provided using <assume> tags in an associated Model Coupling Metadata (MCM) file.
• A "x-section" (short for "cross-section") through a channel (or other object) can be at any angle; see Cross section. When unqualified, however, a channel x-section is generally assumed to be at right angles to the streamwise axis (flow direction). In anatomical terminology, the terms "transverse plane", "coronal plane" and "sagittal plane" are used to specify x-sections. The terms "longitudinal" and "lateral" are also used, more for axes than planes. For tree trunks, the terms "horizontal section" (or transverse section), "radial section" and "tangential section" are used. The term "transverse-section" is basically a synonym for "x-section" and could also be used for channels. Terms like "plan-view" (or top-view), "side-view" and "symmetry planes" are closely related.
• Note that "entrance" and "exit" are used instead of "high_end" and "low_end" because it is possible for the "exit" to be the "high end".
• Instead of "channel_entrance_basin" + "total_contributing_area", we could just use: "channel_entrance_basin" + "area". There are several different methods for computing contributing area (or drainage area) and the method should be indicated using an <assume> tag in a Model Coupling Metadata (MCM) file, such as "d8_flow_direction_method", "d_infinity_flow_direction_method" or "mass_flux_flow_direction_method".
• It appears that Howard (1980) may have been the first to parameterize sediment discharge as Qs = K * A^m * S^n, where A is contributing area and S is channel slope. (Or perhaps Carson and Kirkby or Kirkby were first.) If so, then we could use the standard names:
channel_water_sediment~total + howard_law_coefficient  (K)
channel_water_sediment~total + howard_law_area_exponent (m)
channel_water_sediment~total + howard_law_slope_exponent (n)

Note that "geomorphic_transport_law" could also be used but is more general than "howard_law".
• It would be nice to have a short, unambiguous standard name for:
"channel_entrance-to-exit" + "difference_of_elevation.
Note that "drop_of" could be used as an operation prefix for this purpose (similar to "increment_of"). We currently use: "channel_centerline_endpoints" + "difference_of_elevation".
• Note that "bank_angle" by itself would be ambiguous; is it the angle the bank makes with the vertical z-axis or with a horizontal x-axis? However, "channel_x-section_trapezoid_side~left" + "flare_angle" is clear. A "flare_angle" of zero (no flare) corresponds to a rectangular x-section. When "left" and "right" are used as adjectives, they are taken relative to the direction of travel or flow, by convention. See "side~left" and "side~right" above. Would "left-edge" and "right-edge" be better?
• A quantity like "bottom" + "width" or "flare_angle" may only be well-defined for x-sections of a particular shape, like a trapezoid. In such cases we use the Object_name + model_name Pattern.
• We can use "basin_channel-network"; the hyphen must be included (to indicate a distinct object) since the network is not a part of a channel.
• An outlet would be considered part of a drainage basin and not part of a channel.
• Note that the channel itself has a bottom surface but no "top surface". It is the water in the channel that has a top surface. This is different than the case where the main object is "sea". So we use "sea_surface" and "sea_surface_water", and we also use "channel_water_surface" as well as "channel_water_surface_water". (We can refer to the "bottom surface" or the "top surface", but the latter is usually shortened to "surface" for water bodies.) The choice depends on whether the quantity is an attribute of the surface (e.g. elevation) or of the water near the surface (e.g. temperature).
• The phrase "hydraulic geometry" appears to have been introduced in: Leopold, L.B. and T. Maddock Jr. (1953) The hydraulic geometry of stream channels and some physiographic implications, USGS Professional Paper 252. A set of power laws is used to relate variables such as width, depth, slope and Manning's n to the stream discharge (volume flow rate). A distinction is made between "downstream" and "at-a-station" formulas.
• The Darcy friction factor and Fanning friction factor are primarily defined for flow in pipes, but are also applied to open-channel flow (sometimes with modifications). The Darcy friction factor is defined in terms of pressure drop while the Fanning friction factor is defined in terms of wall shear stress. At least for pipes, the Darcy friction factor turns out to be 4 times larger than the Fanning friction factor. The Drag coefficient is very similar to the Fanning friction factor but is defined for an object moving through a fluid (or fluid moving around an object). The term skin friction coefficient is a synonym for the Fanning friction factor. In open-channel flow, dimensional analysis and other contexts, the simple ratio of the wall shear stress and the product of fluid mass density times the square of mean velocity arises naturally. While this fundamental ratio is half of the Fanning friction factor, there appears to be no special name for it. On the web (but rarely) this has been described as the "basic friction factor" or "European friction factor".

## Variable Names for Chocolate

quantity = attribute

Objects, including Subobjects:
"chocolate"
"chocolate_cacao"
"chocolate_fat"
"chocolate_lecithin"
"chocolate~liquid
"chocolate_sugar"

Examples
chocolate__conching_time
chocolate__heat_capacity_ratio    (cp/cv = Cp/Cv)
chocolate__mass-per-volume_density
chocolate__mass-specific_isobaric_heat_capacity    (isobaric = constant pressure)
chocolate__mass-specific_isochoric_heat_capacity   (isochoric = constant volume)
chocolate__melting_point_temperature
chocolate__metabolizable-energy-per-mass_density   [kJ g-1] or [kcal g-1]
chocolate__thermal_conductivity
chocolate__thermal_diffusivity
chocolate__thermal_inertia
chocolate__thermal_resistivity
chocolate__tempering_time
chocolate__volume-specific_isobaric_heat_capacity    (isobaric = constant pressure)
chocolate__volume-specific_isochoric_heat_capacity   (isochoric = constant volume)

chocolate_cacao__mass_concentration    ("by weight")
chocolate_caffeine__mass_concentration
chocolate_carbohydrate~total__mass_concentration
chocolate_cholesterol__mass_concentration
chocolate_fat~monounsaturated__mass_concentration
chocolate_fat~polyunsaturated__mass_concentration
chocolate_fat~saturated__mass_concentration
chocolate_fat~total__mass_concentration
chocolate_flavanol__mass_concentration
chocolate_lecithin__mass_concentration
chocolate~liquid__apparent_viscosity
chocolate~liquid__casson_model_k_parameter
chocolate~liquid__herschel_bulkley_exponent
chocolate~liquid__kinematic_shear_viscosity
chocolate~liquid__yield_stress
chocolate_liquor__mass_concentration

chocolate~liquid_water__volume_fraction

• Molten chocolate is a non-Newtonian fluid. Both the Herschel-Bulkley and Casson models have been used to model its rheology (i.e. relationship between shear stress and strain rate), but the Casson model is the official model used in the industry. It has two parameters, the yield stress (not adjustable) and "the viscosity coefficient", or "k parameter".
• The object name: "chocolate~liquid" has been used to specify the phase of matter, following one of the name-construction rules. It does not indicate a liquid mixed with chocolate (e.g. chocolate milk). The construction is used instead of "molten_chocolate" to preserve alphabetical grouping.
• Types of chocolate include dark, milk and white.

## Variable Names for Compounds and Mixtures

quantity = attribute

Examples

air~dry__mass-specific_gas_constant  [J kg-1 K-1]
water~vapor__mass-specific_gas_constant  [J kg-1 K-1]

air~dry_water~vapor__gas_constant_ratio   [unitless]
water~vapor_air~dry__relative_molecular_mass_ratio   [unitless]

atmosphere_air_mercury~gaseous~elemental__mole_concentration  # (gaseous vs. vapor ??)
atmosphere_air_mercury~gaseous~divalent__mole_concentration
atmosphere_air_mercury~gaseous~monovalent__mole_concentration

atmosphere_air_nitrogen~atomic__mole_concentration   # (atomic vs. elemental ??)
atmosphere_air_nmvoc~anthropogenic_carbon__mole_concentration
atmosphere_air_nmvoc~biogenic_carbon__mole_concentration

ice__mass-specific_isobaric_heat_capacity    (isobaric = constant pressure)    ## (ice, or "water-solid" ?)
ice__mass-specific_isochoric_heat_capacity   (isochoric = constant volume)
ice__volume-specific_isobaric_heat_capacity    (isobaric = constant pressure)
ice__volume-specific_isochoric_heat_capacity   (isochoric = constant volume)

water~liquid__antoine_vapor_pressure_a_parameter
water~liquid__antoine_vapor_pressure_b_parameter
water~liquid__antoine_vapor_pressure_c_parameter
water~liquid__mass-per-volume_density                  #### (for some standard temperature?)

water~liquid~20C__dynamic_shear_viscosity
water~liquid~20C__dynamic_volume_viscosity
water~liquid~20C__mass-per-volume_density
water~liquid~20C__kinematic_shear_viscosity
water~liquid~20C__kinematic_volume_viscosity
water~liquid~20C__mass-per-volume_density
water~liquid~20C__vapor_pressure

water~liquid~20C_air__surface_tension    (force per length = energy per area;  depends on two substances)

water~liquid_carbon~dissolved~inorganic__mole_concentration
water~liquid_carbon~dissolved~organic__mole_concentration
water~liquid_oxygen~dissolved~molecular__mole_concentration

water__mass-specific_latent_fusion_heat   # Lf     [J kg-1]
water__mass-specific_latent_sublimation_heat  # Ls  [J kg-1]
water__mass-specific_latent_vaporization_heat   # Lv     [J kg-1]

water__mole-specific_latent_fusion_heat   #  [J mole-1]
water__mole-specific_latent_sublimation_heat  #  [J mole-1]
water__mole-specific_latent_vaporization_heat   #  [J mole-1]

• Compounds (pure chemical substances that contain two or more elements) like water can occur in association with many possible objects. However, some quantities are intrinsic properties of the substance, and then only the compound name is needed for the object part.
• A variety of adjectives are used in these names. Some of the main ones are: alkyl, ambient, anthropogenic (nmvoc), atomic, biogenic (nmvoc, silica), carbonaceous, coarse-mode, chlorinated (hydrocarbons), colloidal, condensed, dissolved, divalent, dry, elemental, ferric, ferrous, fixed, free, gaseous, gross, inorganic, ionized, kjeldahl, long-chain, molecular (hydrogen), monovalent, nitrogenous, nucleation-mode, organic, oxygenated, particulate (matter), photosynthetic (oxygen), primary, pyritic (sulfur), secondary, short-chain, solid-phase, stable, suspended, total, vapor and volatile.
• The latent heat of fusion (also called enthalpy of fusion) is the change in enthalpy that results as a substance changes state from solid to liquid (or the other way, with a minus sign).
• The latent heat of vaporization (also called enthalpy of vaporization) is the change in enthalpy that results as a substance changes state from liquid to gas (or the other way, with a minus sign).
• The latent heat of sublimation (also called enthalpy of sublimation) is the change in enthalpy that results as a substance changes state from solid to gas (or the other way, with a minus sign).
• Air (or dry air) is a mixture of gases, not a compound.
• Mass-specific gas constants are computed by dividing the ideal gas constant (also called "universal gas constant"), R, by the molar mass of a particular gas.
• Surface tension acts at the interface between two substances. (Laplace pressure and contact angle are similar.) There are liquid-solid, liquid-gas and solid-gas surface tensions.
• Vapor pressure (or "equilibrium vapor pressure") is a property of a pure liquid or solid substance (partial pressure is used for gas mixtures). It is a function of temperature that can be modeled with the Antoine Equation. The same term is used in meteorology to refer to a partial pressure of one gas in a mixture, such as water vapor in air. In the CSDMS Standard Names, the term "vapor pressure" is only used in its strict sense.

## Variable Names for Earthquakes

quantity = attribute

Objects, including Subobjects:
earth_interior_earthquake
earth_interior_earthquake_auxiliary-plane
earth_interior_earthquake_fault
earth_interior_earthquake_fault_plane
earth_interior_earthquake_fault_plane_asperity
earth_interior_earthquake_block~foot-wall
earth_interior_earthquake_block~hanging-wall
earth_interior_earthquake_hypocenter
earth_interior_earthquake_swarm
earth_interior_earthquake_wave~p
earth_interior_earthquake_wave~s
earth_interior_wave~p
earth_interior_wave~s

earth_surface_earthquake_epicenter # (surface vs. interior)
earth_surface_earthquake_station
seismic_wave

Examples

earth_interior_earthquake__count      (number of earthquakes, or N in Gutenberg-Richter law)
earth_interior_earthquake__critical_slip_distance
earth_interior_earthquake__duration   (overall duration of the event)
earth_interior_earthquake__drop_of_dynamic_stress   ????
earth_interior_earthquake__drop_of_static_stress  ???
earth_interior_earthquake__east_component_of_seismic_slip    (slip is a 2D vector, a displacement, units of length)
earth_interior_earthquake__gutenberg-richter_law_a_parameter
earth_interior_earthquake__gutenberg-richter_law_b_parameter
earth_interior_earthquake__modified_mercali_intensity      (for ground motion instead ??)
earth_interior_earthquake__modified_omori_law_c_parameter
earth_interior_earthquake__modified_omori_law_k_parameter
earth_interior_earthquake__modified_omori_law_p_parameter
earth_interior_earthquake__magnitude_of_seismic_moment   ### (Same as "moment_magnitude" ?)
earth_interior_earthquake__moment_magnitude              ### (Same as "magnitude_of_seismic_moment" ?)
earth_interior_earthquake__seismic_moment   ## (this is a tensor, in general)
earth_interior_earthquake__north_component_of_seismic_slip      ( slip is a 2D vector, a displacement, units of length)
earth_interior_earthquake__origin_time
earth_interior_earthquake__radiated_seismic_energy   (measured by seismometers.  How does this compare to release_energy ??)
earth_interior_earthquake__release_energy      (same as the "seismic moment" ??)
earth_interior_earthquake__richter_magnitude
earth_interior_earthquake__rupture_speed     (or rupture_velocity ??)
earth_interior_earthquake__slip_angle           (angle between slip vector and horizontal)
earth_interior_earthquake__slip_distance
earth_interior_earthquake__slip_duration     (also known as the "rise time", as seen on a seismograph, from rupture time to peak moment release.)
earth_interior_earthquake__slip_speed    (slip is a 2D vector)

earth_interior_earthquake__east_east_component_of_seismic_moment       (notation Mpp;  r = up, p = east, t = south; tensor is symmetric)
earth_interior_earthquake__east_up_component_of_seismic_moment         (notation Mpr;  moment = Force x distance,  [Newton meters = Joules])
earth_interior_earthquake__south_east_component_of_seismic_moment      (notation Mtp)
earth_interior_earthquake__south_south_component_of_seismic_moment      (notation Mtt)
earth_interior_earthquake__up_south_component_of_seismic_moment        (notation Mrt)
earth_interior_earthquake__up_up_component_of_seismic_moment            (notation Mrr)

earth_interior_earthquake_auxiliary-plane__**

earth_interior_earthquake_block~foot-wall__**
earth_interior_earthquake_block~hanging-wall__**

earth_interior_earthquake_fault__length

earth_interior_earthquake_fault_plane__dip_angle   (angle between fault plane and horizontal)
earth_interior_earthquake_fault_plane__length
earth_interior_earthquake_fault_plane__rake_angle  (direction that hanging wall block moves from, measured on the fault plane)
earth_interior_earthquake_fault_plane__rupture_area
earth_interior_earthquake_fault_plane__rupture_length
earth_interior_earthquake_fault_plane__rupture_time    (time that rupture event begins)
earth_interior_earthquake_fault_plane__rupture_width
earth_interior_earthquake_fault_plane__slip-rake_angle   ???
earth_interior_earthquake_fault_plane__strike_angle  (angle in plane of Earth's surface
earth_interior_earthquake_fault_plane__width

earth_interior_earthquake_fault_plane_asperity__contact_area   (perhaps 0.22 times the fault plane rupture_area ??)

earth_interior_earthquake_hypocenter__depth      (hypocenter is also called the "focus")
earth_interior_earthquake_hypocenter__latitude
earth_interior_earthquake_hypocenter__longitude
earth_interior_earthquake_hypocenter-to-station__distance

earth_interior_earthquake_wave~p__amplitude    ## (p = primary, pressure or push-pull)
earth_interior_earthquake_wave~p__angular_frequency
earth_interior_earthquake_wave~p__angular_wavenumber
earth_interior_earthquake_wave~p__frequency
earth_interior_earthquake_wave~p__period
earth_interior_earthquake_wave~p__speed
earth_interior_earthquake_wave~p__takeoff_angle          (angle from the vertical of a seismic ray as it leaves the focus)
earth_interior_earthquake_wave~p__wavelength
earth_interior_earthquake_wave~p__wavenumber

earth_interior_earthquake_wave~s__amplitude   ## (s = secondary, shear or shake)
earth_interior_earthquake_wave~s__angular_frequency
earth_interior_earthquake_wave~s__angular_wavenumber
earth_interior_earthquake_wave~s__frequency
earth_interior_earthquake_wave~s__period
earth_interior_earthquake_wave~s__speed
earth_interior_earthquake_wave~s__takeoff_angle          (angle from the vertical of a seismic ray as it leaves the focus)
earth_interior_earthquake_wave~s__wavelength
earth_interior_earthquake_wave~s__wavenumber

earth_surface_earthquake_epicenter__elevation
earth_surface_earthquake_epicenter__latitude       (equal to the earthquake_hypocenter__latitude)
earth_surface_earthquake_epicenter__longitude      (equal to the earthquake_hypocenter__longitude)

earth_surface_earthquake_wave~p_station__arrival_time
earth_surface_earthquake_wave~p_station__travel_time
earth_surface_earthquake_wave~s_station__arrival_time
earth_surface_earthquake_wave~s_station__travel_time

earth_surface_station~seismic__elevation
earth_surface_station~seismic__latitude
earth_surface_station~seismic__longitude
earth_surface_station~seismic_seismograph__shaking_amplitude    (is this an attribute of a seismograph ?)


• Seismic moment = M0 = shear_modulus (rigidity) x slip_distance (displacement) x rupture_area. Units of energy and sometimes called "seismic moment energy".
• Moment magnitude = Mw = (2/3) log10( M0 ) - 6.0 [dimensionless].
• Should we use "aki_seismic_moment" for clarity instead of just "seismic_moment", after Aki (1972) ??
• The "takeoff_angle" and "azimuth_angle" give the direction in which a seismic (wave) ray leaves the focus or hypocenter.
• Seismic wave travel times are from source to station.
• How are the following terms defined? rupture azimuth, source duration, apparent source duration, particle velocity, static stress drop, dynamic stress drop, radiated seismic energy, rupture top depth, rupture down dip width?
• Some mathematical earthquake models are the Burridge-Knopoff (1D spring-block or "slider-block") model (and variants) and the Olami-Feder-Christensen model.
• Also see the section called: Variable Names for Planets.

## Variable Names for Glaciers

quantity = attribute

Objects, including Subobjects:
glacier
glacier_ablation-zone
glacier_accumulation-zone
glacier_bed (see Notes about "bed" vs. "bottom")
glacier_bed_surface
glacier_bottom (see Notes about "bed" vs. "bottom")
glacier_bottom_ice
glacier_bottom_ice_flow
glacier_bottom_surface
glacier_bergschrund
glacier_crevasse
glacier_equilibrium-line
glacier_firn-line
glacier_forefield
glacier_ice
glacier_ice~above-bed
glacier_ice_flow
glacier_ice_meltwater
glacier_margin (is this the entire boundary, or just the terminus?) ########
glacier_melt-pond
glacier_meltwater
glacier_moraine
glacier_moulin
glacier_ogive
glacier_percolation-zone (same as "unsaturated zone" ??) #####
glacier_randkluft
glacier_serac
glacier_sill
glacier_tarn
glacier_terminus
glacier_till
glacier_top
glacier_top_ice
glacier_top_ice_flow
glacier_top_surface
glacier_valley~hanging
glacier_valley~main

Examples

glacier_ablation-zone__area
glacier_ablation-zone__area_fraction   (or ablation_zone-to-total_area_fraction ?  Usually called: AAR=accumulation-area ratio)

glacier_accumulation-zone__area
glacier_accumulation-zone__area_fraction

glacier_bed__down_z_derivative_of_temperature   (also called the "geothermal gradient".  ##### glacier_bed is wrong object
glacier_bed_heat~geothermal__energy_flux   (through bed;  see Notes about "bed" vs. "bottom")

glacier_bed_surface__aspect_angle    (see Notes about "bed" vs. "bottom")
glacier_bed_surface__elevation
glacier_bed_surface__slope       (See: Surface template.)
glacier_bed_surface__slope_angle

glacier_bottom_ice__magnitude_of_shear_stress
glacier_bottom_ice__sliding_speed
glacier_bottom_ice__static_pressure
glacier_bottom_ice__temperature

glacier_bottom_ice_flow__east_component_of_velocity
glacier_bottom_ice_flow__north_component_of_velocity
glacier_bottom_ice_flow__x_component_of_velocity
glacier_bottom_ice_flow__y_component_of_velocity
glacier_bottom_ice_flow__z_component_of_velocity

glacier_bottom_ice_flow__east_down_component_of_stress
glacier_bottom_ice_flow__north_down_component_of_stress
glacier_bottom_ice_flow__x_z_component_of_stress
glacier_bottom_ice_flow__y_z_component_of_stress

glacier_bottom_surface__aspect_angle    (use "bottom" vs. "bed" here ??)
glacier_bottom_surface__elevation
glacier_bottom_surface__slope       (See: Surface template.)
glacier_bottom_surface__slope_angle

glacier_bottom_surface_heat~conduction~frictional__energy_flux   [W m-2]   ## CHECK
glacier_bottom_surface_heat~conduction~geothermal__energy_flux   [W m-2]
glacier_bottom_surface_heat~conduction~net__energy_flux     [W m-2]

glacier_equilibrium-line__altitude   ## (vs. elevation in this case)

glacier_ice__ablation_rate      [m s-1]
glacier_ice__accumulation_rate  [m s-1]
glacier_ice__change_from_annual_min_of_mass      ### (new operation prefix: 8/12/14;  "annual_min" used here vs. "summer")
glacier_ice__change_from_annual_min_of_thickness  ## (better to specify a date, vs. "summer"?)
glacier_ice__change_from_annual_min_of_volume  ###############
glacier_ice__depression_of_melting_point_temperature
glacier_ice__domain_time_integral_of_melt_volume_flux
glacier_ice__dynamic_shear_viscosity
glacier_ice__dynamic_volume_viscosity
glacier_ice__glen_law_coefficient      (From "Glen's flow law", also called "creep parameter".) #####
glacier_ice__glen_law_exponent        (From "Glen's flow law", also called "creep_exponent".)
glacier_ice__heat_capacity_ratio       (Cp / Cv = cp / cv)
glacier_ice__initial_thickness
glacier_ice__isothermal_compressibility
glacier_ice__kinematic_shear_viscosity
glacier_ice__kinematic_volume_viscosity
glacier_ice__mass
glacier_ice__mass-per-volume_density
glacier_ice__mass-specific_isobaric_heat_capacity     (isobaric = constant pressure)
glacier_ice__mass-specific_isochoric_heat_capacity    (isochoric = constant volume)
glacier_ice__mass-specific_latent_fusion_heat         (solid to liquid; melting)
glacier_ice__mass-specific_latent_sublimation_heat    (solid to gas)
glacier_ice__mass-specific_latent_vaporization_heat   (liquid to gas)
glacier_ice__melt_mass_flux
glacier_ice__melt_volume_flux
glacier_ice__melting_point_temperature
glacier_ice__peclet_number      (defined as:  (H * w_s / kappa), where H=thickness, w_s = ice surface vertical speed and kappa=thermal diffusivity)
glacier_ice__pressure_melting_point_temperature
glacier_ice__relative_permittivity     (also called "relative dielectric constant", but not a constant)
glacier_ice__temperature
glacier_ice__thermal_conductivity     ## (already intensive property; don't need specific)
glacier_ice__thermal_diffusivity
glacier_ice__thermal_inertia
glacier_ice__thermal_resistivity    (reciprocal of thermal_conductivity)
glacier_ice__thermal_volume_expansion_coefficient     (there are also coefficients for area and length expansion)
glacier_ice__thickness
glacier_ice__time_derivative_of_mass
glacier_ice__time_derivative_of_thickness
glacier_ice__time_derivative_of_volume
glacier_ice__volume
glacier_ice__volume-specific_isobaric_heat_capacity    (isobaric = constant pressure)
glacier_ice__volume-specific_isochoric_heat_capacity   (isochoric = constant volume)
glacier_ice__volume-vs-area_law_coefficient
glacier_ice__volume-vs-area_law_exponent

glacier_ice~above-bed__distance    (See Notes about "bed" vs. "bottom")
glacier_ice~above-bed__normalized_distance   (divided by ice thickness, also called "scaled distance")

glacier_ice__down_derivative_of_temperature
glacier_ice__east_derivative_of_temperature
glacier_ice__north_derivative_of_temperature
glacier_ice__x_derivative_of_temperature
glacier_ice__y_derivative_of_temperature
glacier_ice__z_derivative_of_temperature

glacier_ice_flow__down_derivative_of_static_pressure
glacier_ice_flow__east_derivative_of_static_pressure
glacier_ice_flow__north_derivative_of_static_pressure
glacier_ice_flow__x_derivative_of_static_pressure
glacier_ice_flow__y_derivative_of_static_pressure
glacier_ice_flow__z_derivative_of_static_pressure

glacier_ice_flow__azimuth_angle_of_velocity
glacier_ice_flow__down_component_of_velocity
glacier_ice_flow__dynamic_pressure
glacier_ice_flow__east_component_of_velocity
glacier_ice_flow__elevation_angle_of_velocity
glacier_ice_flow__north_component_of_velocity
glacier_ice_flow__south_component_of_velocity
glacier_ice_flow__speed     (magnitude_of_velocity)
glacier_ice_flow__west_component_of_velocity
glacier_ice_flow__total_pressure
glacier_ice_flow__up_component_of_velocity
glacier_ice_flow__x_component_of_velocity
glacier_ice_flow__y_component_of_velocity
glacier_ice_flow__z_component_of_velocity

glacier_ice_meltwater__domain_time_integral_of_volume_flux     # (cumulative meltwater volume)
glacier_ice_meltwater__mass_flux      [kg m-2 s-1]
glacier_ice_meltwater__volume_flux    [m s-1]

glacier_terminus__advance_rate   (opposite of retreat rate;  should we allow both?)
glacier_terminus__calving_rate    (use "terminus_ice" here ?   Units of velocity.  Do we need to specify mass or volume flux also?)  ######
glacier_terminus__retreat_rate      (See: Glacier retreat; perhaps a terminus speed)
glacier_terminus_side~left__latitude    (See Note below regarding "side~left".)
glacier_terminus_side~left__longitude
glacier_terminus_side~right__latitude
glacier_terminus_side~right__longitude

glacier_top_ice__desublimation_mass_flux   # (desublimation, deposition and resublimation are synonyms)
glacier_top_ice__desublimation_volume_flux
glacier_top_ice__sublimation_mass_flux
glacier_top_ice__sublimation_volume_flux
glacier_top_ice__temperature
glacier_top_ice__time_derivative_of_temperature
glacier_top_ice_heat~net__time_max_of_energy_flux

glacier_top_ice_wind__scour_rate     (always a loss?  wind or "air_flow")  #########

glacier_top_ice_flow__x_component_of_velocity
glacier_top_ice_flow__y_component_of_velocity

glacier_top_surface__area
glacier_top_surface__aspect_angle
glacier_top_surface__elevation
glacier_top_surface__emissivity
glacier_top_surface__max_of_elevation
glacier_top_surface__mean_of_elevation
glacier_top_surface__mid-range_of_elevation   (also called the "mid-range altitude")
glacier_top_surface__min_of_elevation

glacier_top_surface__range_of_elevation
glacier_top_surface__slope       (see glacier_bed_surface_slope)
glacier_top_surface__slope_angle
glacier_top_surface__temperature    ### (or just glacier_top__temperature ??)
glacier_top_surface__time_derivative_of_elevation

glacier_top_surface_heat~net~latent__energy_flux       ## (net flux could be into the air or the ice)
glacier_top_surface_heat~net~sensible__energy_flux


• In glaciology, "mass_balance" has a specific meaning that can be confusing to scientists from other disciplines. See: Glacier mass balance. It is the difference between accumulation and ablation (melting and sublimation) and therefore the net rate at which ice is being "added" to the glacier. The quantity name: "glacier_ice__time_derivative_of_thickness" is unambiguous (it avoids domain-specific terms) and is more consistent with other standard names.
• Note that we distinguish between the "glacier_bed" and the "glacier_bottom" because they can be two different surfaces, separated by gaps or voids. (This doesn't happen for liquid water.) The glacier "bottom" is "in the ice" while the glacier bed isn't. For consistency across domains, "top" and "bottom" should be preferred over terms like "sea_floor" or "sea_bed", unless this kind of distinction exists.
• Glaciers are classified into 3 distinct types: cold, temperate and polythermal.
• Glacier processes include (among others): ablation, accumulation, advance, calving, congelation, deflation, deformation, desublimation, flotation, flow, infiltration/percolation, melting, wind scour, recrystallization, refreezing, resublimation, sliding, sublimation, retreat.
• When "left" and "right" are used as adjectives, they are taken relative to the direction of travel or flow, by convention.
• Within the CSDMS Standard Names, quantity names "altitude" and "elevation" are taken to have distinct meanings. See Altitude and Elevation. However, the quantity name equilibrium_line_altitude is allowed since it is a standard term in glaciology and otherwise follows the naming rules.
• Note that the word "glacier" is used here to indicate a place or a "main object", sometimes in addition to the word "ice" (what the glacier is made of), even though a glacier is a persistent body of ice, by definition. This allows us to identify parts of the glacier, like the top and bottom, and then refer to properties of the air or ice at this interface. It also allows a "flow field" (shortened to flow) to be associated with the ice. For a glacier on another planet (e.g. Mars) that is not made of water, the word "ice" can be replaced with "dry-ice" or "carbon-dioxide-ice", but "dry-ice" is clear and shorter.
• We may need an additional adjective before "area" in order to distinguish between a "surface area" and "projected area".

## Variable Names for Materials

quantity = attribute
quantity = "bulk_modulus" (See Notes below.)
quantity = "lame_first_parameter"
quantity = "p_wave_modulus"
quantity = "poisson_ratio"
quantity = "shear_modulus"
quantity = "young_modulus" ("tensile" elastic modulus)

Examples:

earth_material__bulk_modulus
earth_material__down_component_of_electric-d-field   (
earth_material__down_component_of_electric-e-field   (volts / meter)
earth_material__down_component_of_electric-p-field   (
earth_material__down_component_of_magnetic-b-field   (newtons / (meter * ampere))
earth_material__down_component_of_magnetic-h-field   (amperes / meter)
earth_material__down_component_of_magnetic-m-field  (amperes / meter)
earth_material__east_component_of_electric-d-field   (
earth_material__east_component_of_electric-e-field   (volts / meter)
earth_material__east_component_of_electric-p-field   (
earth_material__east_component_of_magnetic-b-field   (newtons / (meter * ampere))
earth_material__east_component_of_magnetic-h-field   (amperes / meter)
earth_material__east_component_of_magnetic-m-field   (amperes / meter)
earth_material__electrical_conductivity   (siemens / meter)   ## electrical or electric ??
earth_material__electric_susceptibility
earth_material__lame_first_parameter
earth_material__magnetic_susceptibility
earth_material__north_component_of_electric-d-field   (
earth_material__north_component_of_electric-e-field   (volts / meter)
earth_material__north_component_of_electric-p-field   (
earth_material__north_component_of_magnetic-b-field   (newtons / (meter * ampere))
earth_material__north_component_of_magnetic-h-field   (amperes / meter)
earth_material__north_component_of_magnetic-m-field   (amperes / meter)
earth_material__p_wave_modulus
earth_material__poisson_ratio
earth_material__relative_electric_permittivity
earth_material__relative_magnetic_permeability
earth_material__shear_modulus
earth_material__young_modulus

• The 6 elastic moduli above are all related through simple equations. Given any two, the other four can be computed. See the table at: Elastic modulus.
• Maxwell's equations also use two universal constants; in the CSN, these are called "physics + vacuum_electric_permittivity_constant" and "physics__vacuum_magnetic_permeability_constant".

## Variable Names for Models

quantity = attribute

Objects, including Subobjects:
"model"
"model_domain-boundary"
"model_grid"
"model_grid_axis~x"
"model_grid_axis~x_axis~east"
"model_grid_axis~y"
"model_grid_axis~z"
"model_grid_edge~east"
"model_grid_edge~north"
"model_grid_edge~south"
"model_grid_edge~west"
"model_grid_cell"
"model_grid_cell_centroid"
"model_grid_cell_edge~east"
"model_grid_cell_edge~north"
"model_grid_cell_edge~south"
"model_grid_cell_edge~west"
"model_grid_cell_water"
"model_grid_cell_water~incoming"
"model_grid_cell_water~outgoing"
"model_grid_column"
"model_grid_row"

Examples

model__courant_number
model__initial_time_step   (for PIHM)
model__max_allowed_time_step
model__min_allowed_time_step
model__run_time
model__spinup_time
model__start_time
model__stop_time
model__time
model__time_step
model__time_step_count   #####

model_grid_cell__area
model_grid_cell__column_index
model_grid_cell__count
model_grid_cell__d8_total_contributing_area
model_grid_cell__d8_flow_length
model_grid_cell__d8_flow_width
model_grid_cell__d8_slope
model_grid_cell__d_infinity_total_contributing_area
model_grid_cell__d_infinity_slope
model_grid_cell__diameter
model_grid_cell__perimeter
model_grid_cell__row_index
model_grid_cell__row-major-offset_index
model_grid_cell__total_contributing_area   #####

model_grid_cell_centroid__latitude
model_grid_cell_centroid__longitude
model_grid_cell_centroid__x_coordinate
model_grid_cell_centroid__y_coordinate

model_grid_cell_edge~east__longitude
model_grid_cell_edge~west__longitude
model_grid_cell_edge~south__latitude
model_grid_cell_edge~north__latitude

model_grid_cell_edge~east__length
model_grid_cell_edge~west__length
model_grid_cell_edge~south__length
model_grid_cell_edge~north__length
model_grid_cell_edge~x__length     # or x_length ?
model_grid_cell_edge~y__length     # or y_length ?

model_grid_cell_water__azimuth_angle_of_velocity
model_grid_cell_water__time_derivative_of_volume
model_grid_cell_water~incoming__volume_flow_rate
model_grid_cell_water~outgoing__volume_flow_rate

model_grid_column__count   # (number of columns)
model_grid_row__count      # (number of rows)

model_grid_edge~east__longitude
model_grid_edge~north__latitude
model_grid_edge~south__latitude
model_grid_edge~west__longitude

model_grid_axis~x_axis~east__rotation_angle

model_soil_layer__count

model_soil_layer~0__porosity
model_soil_layer~0__saturated_thickness
model_soil_layer~0__thickness
model_soil_layer~1__porosity
model_soil_layer~1__saturated_thickness
model_soil_layer~1__thickness
model_soil_layer~2__porosity
model_soil_layer~2__saturated_thickness
model_soil_layer~2__thickness

• A model of a physical process will typically discretize both the spatial domain and time. This introduces several quantities that do not exist in the "real world", but only within the context of the model, as shown in the examples above. Note that "total_contributing_area" is a quantity that is technically associated with a segment of a contour line, but is typically attributed to a grid cell.
• While CSDMS component models often request variables from one another (i.e. a model tells the framework it needs a variable using the BMI function get_output_var_names()), CSDMS does not support (and discourages) models requesting model attributes from one another. Model attributes (i.e. output variables that start with the word "model") that are listed among a model's output variables are only intended for use by the modeling framework. Part of the CSDMS philosophy is the idea that model components should not need to know anything about the internal details of other models that they want to obtain output variables from --- this is viewed as the job of the modeling framework (which calls service components or mediators when needed). Another part of this philosophy (more of a design decision) is that model components should not need to be grouped into "types" (e.g. based on the physical process they model, such as "infiltration"). All matching should be based on what each model needs from others or can provide to others.
• Many of the possible model attributes will be "provided" by most or all of the models in a "component set". For example, "model__time_step" would typically be listed as an output variable for every model in a component set. This means that model attribute names cannot be used to automatically match users to providers. For this to be possible, models would need to be grouped into named "types", model developers would need to be aware of these types, and the type name (e.g. perhaps a process name like "infiltration") would need to be inserted before the word "model" in model output variable names. While individual component models therefore have no way to ask for model attributes from another model in the component set, the framework "sees everything" and can keep track of which component it retrieved a model attribute from. For example, the service component that performs time interpolation for the models in a component set needs to know the individual time steps of each model in the set. (But actually gets this directly from the BMI "get_time_step()" function instead of using a "get_values()" call for the variable called "model__time_step".)

## Variable Names for Molecules

quantity = attribute
quantity = "bond_angle"
quantity = "bond_dissociation_energy"
quantity = "bond_energy"
quantity = "bond_length"
quantity = "proton_number" (total number of protons)
quantity = "torsion_angle"
quantity = "vibration_frequency"

Examples
benzene_molecule_c_c_c__bond_angle

dihydrogen_molecule_h-h__bond_length  (dihydrogen = H2)
dinitrogen_molecule_n-n__bond_length  (dinitrogen = N2)
dioxygen_molecule_o-o__bond_length    (dioxygen = O2)

ethane_molecule_h-c-c-h__torsion_angle

ozone_molecule_o-o__bond_length  (trioxygen = O3 is another name for ozone.)

water_molecule__hydrogen_number  (?? number of hydrogen atoms)
water_molecule_h-o__bond_dissociation_energy
water_molecule_h-o__bond_length
water_molecule_h-o-h__actual_bond_angle
water_molecule_h-o-h__ideal_bond_angle  (or replace "ideal" by "VSEPR" ?)

• A molecule is an electrically neutral group of two or more atoms held together by covalent chemical bonds.
• CSDMS Standard Names allow using the standard symbol for atoms of a particular element that occur in a molecule (but in lower case).
• There is distinction between "bond energy" and "bond dissociation energy".
• It seems that the bond energy, bond dissociation energy and bond length all depend on the molecule that the atoms are in and not just which two types of atoms are involved. If this is the case, then names should use the Part-of-another-Object Pattern (and perhaps the Object-to-object Quantity Pattern for the atoms), as in: "water_molecule_h_o" + bond_length" and "water_molecule_h_o" + "bond_dissociation_energy".
• Bond angles and lengths in molecules are defined as time averages.
• A bond_angle can be defined for 2 consecutive bonds and 3 atoms, as in "water_molecule_h_o_h" + "bond_angle". For a molecule in which all bond angles are the same, like benzene, we could have "benzene_molecule_c_c_c" + "bond_angle". See: Benzene.
• A torsion_angle can be defined for 3 consecutive bonds and 4 atoms, as in "ethane_molecule_h_c_c_h" + torsion_angle". A synonym is "dihedral_angle". See: Dihedral angle.
• Note that we use "benzene_molecule", "ethane_molecule" and "water_molecule" vs. "benzene", "ethane" and "water" in these examples. This is to distinguish between the bulk substance (for which these quantities don't make sense) and a single molecule.
• Molecules have "vibration frequencies" associated with all the different ways in which the atoms in the molecule can undergo a periodic motion relative to one another. (These relative positions don't change when the molecule rotates or translates as a whole.) See: Molecular vibration. (Individual atoms don't have vibration frequencies but they do have "emission frequencies".) In the so-called: rocking, scissoring, twisting and wagging vibrations, the bond lengths between atoms don't change. In stretching vibrations (symmetric or antisymmetric), the bond lengths change. For the CSDMS standard names we may be able to use names such as "ethylene + wagging_vibration_frequency".
• We could use "hydrogen_number" to quantify the number of hydrogen atoms in a molecule, but that term is also used in a medical context to mean the quantity of hydrogen that 1 gram of fat will absorb.

## Variable Names for Oceans

quantity = attribute

Objects, including Subobjects:
"sea_bed" ### (is bed also needed, or just bottom ??)
"sea_bottom"
"sea_bottom_sediment"
"sea_bottom_sediment_clay"
"sea_bottom_sediment_grain"
"sea_bottom_sediment_mud"
"sea_bottom_sediment_sand"
"sea_bottom_sediment_silt"
"sea_bottom_surface"
"sea_bottom_water"
"sea_bottom_water_sediment~suspended"
"sea_bottom_water_flow"

"sea_coast # (inland of high-tide shoreline)
"sea_coastline # (boundary between coast and shore)
"sea_shore # (same as intertidal zone)
"sea_shoreline" # (boundary between sea and land; changes with tides)
"sea_shoreline~high-tide"
"sea_shoreline~low-tide"
"sea_shoreline_wave~breaking" ##### water_wave ??
"sea_shoreline_wave~breaking_crestline"
"sea_shoreline_wave~breaking_ray"
"sea_shoreline_wave~incoming~deepwater"
"sea_shoreline_wave~incoming~deepwater_crestline"
"sea_shoreline_wave~incoming~deepwater_ray"
"sea_shoreline_wave~incoming" ### (to include both deep and shallow-water waves)
"sea_shoreline_wave~incoming-crestline"
"sea_shoreline_wave~incoming-ray"
"sea_shoreline_axis~x"
"sea_shoreline_axis~y"

"sea_surface"
"sea_surface_air"
"sea_surface_air_carbon-dioxide"
"sea_surface_air_flow"
"sea_surface_water"
"sea_surface_water_sediment~suspended"
"sea_surface_water_tide"
"sea_surface_water_tide_constituents~all"
"sea_surface_water_tide_" + [short name] + "_constituent" (e.g. short name = "m4")
"sea_surface_water_wave"
"sea_surface_water_wave_crest"
"sea_surface_water_wave_crest_line"
"sea_surface_water_wave_ray"
"sea_surface_water_wave_trough"

"sea_water"
"sea_water_above-bottom"
"sea_water_below-surface" ###### (use "subsurface" vs. "below-surface" ??)
"sea_water_biota"
"sea_water_carbon-dioxide"
"sea_water_flow"
"sea_water_magnesium-chloride"
"sea_water_magnesium-sulphate
"sea_water_potassium-chloride"
"sea_water_current~feeder"
"sea_water_current~longshore"
"sea_water_current~rip"
"sea_water_current~rip_neck"
"sea_water_current~undertow"
"sea_water_sodium-chloride"
"sea_water_sediment~suspended"
"sea_water_wave~internal"
"sea_water_wave~surface"
"sea_water_wave~tsunami"
"sea_water_zone~abyssal"
"sea_water_zone~aphotic"
"sea_water_zone~aphotic_top"
"sea_water_zone~benthic"
"sea_water_zone~intertidal"
"sea_water_zone~littoral"
"sea_water_zone~neritic"
"sea_water_zone~oceanic"
"sea_water_zone~pelagic"
"sea_water_zone~photic"
"sea_water_zone~photic_bottom"
"sea_water_zone~surf"

Examples
model_grid_edge~west_sea_water__elevation  (a boundary condition)

sea_bed_freshwater__net_volume_flux    (net = incoming - outgoing)

sea_bottom_sediment__immersed_weight
sea_bottom_sediment__mass-per-volume_bulk_density  (also called "dry density")
sea_bottom_sediment__mass-per-volume_density   (i.e. "total density" or "wet density")
sea_bottom_sediment__mass-per-volume_particle_density
sea_bottom_sediment__permeability
sea_bottom_sediment__porosity
sea_bottom_sediment__thickness
sea_bottom_sediment__thickness-to-depth_ratio

sea_bottom_sediment_clay__volume_fraction
sea_bottom_sediment_grain__mean_of_diameter
sea_bottom_sediment_mud__volume_fraction
sea_bottom_sediment_sand__volume_fraction
sea_bottom_sediment_silt__volume_fraction

sea_bottom_surface__elevation    (Replace "floor" with "bottom" for cross-domain consistency?)
sea_bottom_surface__latitude
sea_bottom_surface__longitude
sea_bottom_surface_heat~net__energy_flux
sea_bottom_surface__slope
sea_bottom_surface__time_derivative_of_elevation
sea_bottom_surface__x_derivative_of_elevation
sea_bottom_surface__y_derivative_of_elevation

sea_bottom_water__magnitude_of_shear_stress
sea_bottom_water__mass-per-volume_density
sea_bottom_water_heat~net__energy_flux
sea_bottom_water__salinity
sea_bottom_water__temperature

sea_shoreline__azimuth_angle_of_normal-vector    ## (Only use "azimuth_angle" as an operator.)
sea_shoreline__azimuth_angle_tangent-vector
sea_shoreline__closure_depth   ####
sea_shoreline__curvature

sea_shoreline_axis~x-to-axis~east__rotation_angle

sea_shoreline_wave~breaking__azimuth_angle_of_phase_velocity
sea_shoreline_wave~breaking__height
sea_shoreline_wave~breaking__period

sea_shoreline_wave~incoming__azimuth_angle_of_group_velocity
sea_shoreline_wave~incoming__azimuth_angle_of_phase_velocity
sea_shoreline_wave~incoming__azimuth_angle_of_left_normal_of_phase_velocity

sea_shoreline_wave~incoming~deepwater__ashton_et_al_approach_angle_asymmetry_parameter
sea_shoreline_wave~incoming~deepwater__ashton_et_al_approach_angle_highness_parameter
sea_shoreline_wave~incoming~deepwater__azimuth_angle_of_group_velocity
sea_shoreline_wave~incoming~deepwater__azimuth_angle_of_phase_velocity
(CCW from x-axis, between -180 and 0;  "rays" = phase velocity field)
sea_shoreline_wave~incoming~deepwater__azimuth_angle_of_left_normal_of_phase_velocity
(between -90 and 90, used by Ashton et al. 2001, x-axis alongshore)
sea_shoreline_wave~incoming~deepwater__height   ### (add "water" after "sea" ??)
sea_shoreline_wave~incoming~deepwater__period
sea_shoreline_wave~incoming~deepwater__significant_height

sea_surface__elevation
sea_surface__latitude   (this is a local value, like all others)
sea_surface__longitude  (this is a local value, like all others)
sea_surface__slope

sea_surface_air__magnitude_of_shear_stress   (wind)
sea_surface_air__pressure
sea_surface_air__temperature

sea_surface_air_flow__shear_speed       (air_flow = "wind";  shear_speed = magnitude_of_shear_velocity)
sea_surface_air_flow__speed
sea_surface_air_flow__x_component_of_shear_velocity
sea_surface_air_flow__x_component_of_velocity
sea_surface_air_flow__y_component_of_shear_velocity
sea_surface_air_flow__y_component_of_velocity
sea_surface_air_flow__z_component_of_velocity     (should be zero)

sea_surface_air_carbon-dioxide__partial_pressure
sea_surface_air_water~vapor__partial_pressure
sea_surface_air_water~vapor__relative_saturation  (relative humidity)

sea_surface_air-vs-water__difference_of_temperature        ####(use "air_and" or "air_vs" ?)

sea_surface_water__anomaly_of_geopotential_height
sea_surface_water__anomaly_of_temperature
sea_surface_water__evaporation_mass_flux    [kg m-2 s-1]
sea_surface_water__evaporation_volume_flux    [m s-1]
sea_surface_water__geopotential_height
sea_surface_water__precipitation_leq-volume_flux
sea_surface_water__mass-per-volume_density
sea_surface_water__precipitation_mass_flux
sea_surface_water__salinity
sea_surface_water__temperature

sea_surface_water_heat~net~latent__energy_flux
sea_surface_water_heat~net~sensible__energy_flux

sea_surface_water_tide_constituents~all__amplitude    ####  (added to mean sea level)

sea_surface_water_tide_constituent~2mk3__amplitude
sea_surface_water_tide_constituent~2mk3__degrees-per-hour_speed    ####### (or just "phase_speed" ??)
sea_surface_water_tide_constituent~2mk3__period
sea_surface_water_tide_constituent~2mk3_amphidromic-points__latitude    (there are multiple points for each constituent)
sea_surface_water_tide_constituent~2mk3_amphidromic-points__longitude
sea_surface_water_tide_constituent~2mk3__phase_angle
sea_surface_water_tide_constituent~2q1__amplitude
sea_surface_water_tide_constituent~2q1__degrees-per-hour_speed
sea_surface_water_tide_constituent~2q1__period
sea_surface_water_tide_constituent~2q1__phase_angle
sea_surface_water_tide_constituent~2sm2__amplitude
sea_surface_water_tide_constituent~2sm2__degrees-per-hour_speed
sea_surface_water_tide_constituent~2sm2__period
sea_surface_water_tide_constituent~2sm2__phase_angle
sea_surface_water_tide_constituent~2n2__amplitude
sea_surface_water_tide_constituent~2n2__degrees-per-hour_speed
sea_surface_water_tide_constituent~2n2__period
sea_surface_water_tide_constituent~2n2__phase_angle
sea_surface_water_tide_constituent~2q1__amplitude
sea_surface_water_tide_constituent~2q1__degrees-per-hour_speed
sea_surface_water_tide_constituent~2q1__period
sea_surface_water_tide_constituent~2q1__phase_angle
sea_surface_water_tide_constituent~j1__amplitude
sea_surface_water_tide_constituent~j1__degrees-per-hour_speed
sea_surface_water_tide_constituent~j1__period
sea_surface_water_tide_constituent~j1__phase_angle
sea_surface_water_tide_constituent~k1__amplitude
sea_surface_water_tide_constituent~k1__degrees-per-hour_speed
sea_surface_water_tide_constituent~k1__period
sea_surface_water_tide_constituent~k1__phase_angle
sea_surface_water_tide_constituent~k2__amplitude
sea_surface_water_tide_constituent~k2__degrees-per-hour_speed
sea_surface_water_tide_constituent~k2__period
sea_surface_water_tide_constituent~k2__phase_angle
sea_surface_water_tide_constituent~l2__amplitude
sea_surface_water_tide_constituent~l2__degrees-per-hour_speed
sea_surface_water_tide_constituent~l2__period
sea_surface_water_tide_constituent~l2__phase_angle
sea_surface_water_tide_constituent~lam2__amplitude
sea_surface_water_tide_constituent~lam2__degrees-per-hour_speed
sea_surface_water_tide_constituent~lam2__period
sea_surface_water_tide_constituent~lam2__phase_angle
sea_surface_water_tide_constituent~m1__amplitude
sea_surface_water_tide_constituent~m1__degrees-per-hour_speed
sea_surface_water_tide_constituent~m1__period
sea_surface_water_tide_constituent~m1__phase_angle
sea_surface_water_tide_constituent~m2__amplitude
sea_surface_water_tide_constituent~m2__degrees-per-hour_speed
sea_surface_water_tide_constituent~m2__period
sea_surface_water_tide_constituent~m2__phase_angle
sea_surface_water_tide_constituent~m3__amplitude
sea_surface_water_tide_constituent~m3__degrees-per-hour_speed
sea_surface_water_tide_constituent~m3__period
sea_surface_water_tide_constituent~m3__phase_angle
sea_surface_water_tide_constituent~m4__amplitude
sea_surface_water_tide_constituent~m4__degrees-per-hour_speed
sea_surface_water_tide_constituent~m4__period
sea_surface_water_tide_constituent~m4__phase_angle
sea_surface_water_tide_constituent~m6__amplitude
sea_surface_water_tide_constituent~m6__degrees-per-hour_speed
sea_surface_water_tide_constituent~m6__period
sea_surface_water_tide_constituent~m6__phase_angle
sea_surface_water_tide_constituent~m8__amplitude
sea_surface_water_tide_constituent~m8__degrees-per-hour_speed
sea_surface_water_tide_constituent~m8__period
sea_surface_water_tide_constituent~m8__phase_angle
sea_surface_water_tide_constituent~mf__amplitude
sea_surface_water_tide_constituent~mf__degrees-per-hour_speed
sea_surface_water_tide_constituent~mf__period
sea_surface_water_tide_constituent~mf__phase_angle
sea_surface_water_tide_constituent~mk3__amplitude
sea_surface_water_tide_constituent~mk3__degrees-per-hour_speed
sea_surface_water_tide_constituent~mk3__period
sea_surface_water_tide_constituent~mk3__phase_angle
sea_surface_water_tide_constituent~mm__amplitude
sea_surface_water_tide_constituent~mm__degrees-per-hour_speed
sea_surface_water_tide_constituent~mm__period
sea_surface_water_tide_constituent~mm__phase_angle
sea_surface_water_tide_constituent~mn4__amplitude
sea_surface_water_tide_constituent~mn4__degrees-per-hour_speed
sea_surface_water_tide_constituent~mn4__period
sea_surface_water_tide_constituent~mn4__phase_angle
sea_surface_water_tide_constituent~ms4__amplitude
sea_surface_water_tide_constituent~ms4__degrees-per-hour_speed
sea_surface_water_tide_constituent~ms4__period
sea_surface_water_tide_constituent~ms4__phase_angle
sea_surface_water_tide_constituent~msf__amplitude
sea_surface_water_tide_constituent~msf__degrees-per-hour_speed
sea_surface_water_tide_constituent~msf__period
sea_surface_water_tide_constituent~msf__phase_angle
sea_surface_water_tide_constituent~mu2__amplitude
sea_surface_water_tide_constituent~mu2__degrees-per-hour_speed
sea_surface_water_tide_constituent~mu2__period
sea_surface_water_tide_constituent~mu2__phase_angle
sea_surface_water_tide_constituent~n2__amplitude
sea_surface_water_tide_constituent~n2__degrees-per-hour_speed
sea_surface_water_tide_constituent~n2__period
sea_surface_water_tide_constituent~n2__phase_angle
sea_surface_water_tide_constituent~nu2__amplitude
sea_surface_water_tide_constituent~nu2__degrees-per-hour_speed
sea_surface_water_tide_constituent~nu2__period
sea_surface_water_tide_constituent~nu2__phase_angle
sea_surface_water_tide_constituent~o1__amplitude
sea_surface_water_tide_constituent~o1__degrees-per-hour_speed
sea_surface_water_tide_constituent~o1__period
sea_surface_water_tide_constituent~o1__phase_angle
sea_surface_water_tide_constituent~oo1__amplitude
sea_surface_water_tide_constituent~oo1__degrees-per-hour_speed
sea_surface_water_tide_constituent~oo1__period
sea_surface_water_tide_constituent~oo1__phase_angle
sea_surface_water_tide_constituent~oo2__amplitude
sea_surface_water_tide_constituent~oo2__degrees-per-hour_speed
sea_surface_water_tide_constituent~oo2__period
sea_surface_water_tide_constituent~oo2__phase_angle
sea_surface_water_tide_constituent~p1__amplitude
sea_surface_water_tide_constituent~p1__degrees-per-hour_speed
sea_surface_water_tide_constituent~p1__period
sea_surface_water_tide_constituent~p1__phase_angle
sea_surface_water_tide_constituent~q1__amplitude
sea_surface_water_tide_constituent~q1__degrees-per-hour_speed
sea_surface_water_tide_constituent~q1__period
sea_surface_water_tide_constituent~q1__phase_angle
sea_surface_water_tide_constituent~r2__amplitude
sea_surface_water_tide_constituent~r2__degrees-per-hour_speed
sea_surface_water_tide_constituent~r2__period
sea_surface_water_tide_constituent~r2__phase_angle
sea_surface_water_tide_constituent~rho__amplitude
sea_surface_water_tide_constituent~rho__degrees-per-hour_speed
sea_surface_water_tide_constituent~rho__period
sea_surface_water_tide_constituent~rho__phase_angle
sea_surface_water_tide_constituent~s1__amplitude
sea_surface_water_tide_constituent~s1__degrees-per-hour_speed
sea_surface_water_tide_constituent~s1__period
sea_surface_water_tide_constituent~s1__phase_angle
sea_surface_water_tide_constituent~s2__amplitude
sea_surface_water_tide_constituent~s2__degrees-per-hour_speed
sea_surface_water_tide_constituent~s2__period
sea_surface_water_tide_constituent~s2__phase_angle
sea_surface_water_tide_constituent~s4__amplitude
sea_surface_water_tide_constituent~s4__degrees-per-hour_speed
sea_surface_water_tide_constituent~s4__period
sea_surface_water_tide_constituent~s4__phase_angle
sea_surface_water_tide_constituent~s6__amplitude
sea_surface_water_tide_constituent~s6__degrees-per-hour_speed
sea_surface_water_tide_constituent~s6__period
sea_surface_water_tide_constituent~s6__phase_angle
sea_surface_water_tide_constituent~sa__amplitude
sea_surface_water_tide_constituent~sa__degrees-per-hour_speed
sea_surface_water_tide_constituent~sa__period
sea_surface_water_tide_constituent~sa__phase_angle
sea_surface_water_tide_constituent~ssa__amplitude
sea_surface_water_tide_constituent~ssa__degrees-per-hour_speed
sea_surface_water_tide_constituent~ssa__period
sea_surface_water_tide_constituent~ssa__phase_angle
sea_surface_water_tide_constituent~t2__amplitude
sea_surface_water_tide_constituent~t2__degrees-per-hour_speed
sea_surface_water_tide_constituent~t2__period
sea_surface_water_tide_constituent~t2__phase_angle

sea_surface_storm_water__surge_height   #####

sea_surface_water_wave__amplitude
sea_surface_water_wave__angular_frequency    (frequency means "temporal frequency")
sea_surface_water_wave__angular_wavenumber  (wavenumber means "spatial frequency")
sea_surface_water_wave__breaking_height
sea_surface_water_wave__breaking_height-to-depth_ratio   (also called the "breaker index")
sea_surface_water_wave__energy-per-unit-area_density
sea_surface_water_wave__frequency
sea_surface_water_wave__group_speed
sea_surface_water_wave__group-speed-to-phase-speed_ratio    (usually called "wave speed ratio")
sea_surface_water_wave__height
sea_surface_water_wave__intrinsic_angular_frequency    (vs. observed_angular_frequency)
sea_surface_water_wave__max_of_orbital_speed
sea_surface_water_wave__observed_angular_frequency    (vs. intrinsic_angular_frequency)
sea_surface_water_wave__orbital_speed
sea_surface_water_wave__period
sea_surface_water_wave__phase_angle   (usually just called the "phase")
sea_surface_water_wave__phase_speed
sea_surface_water_wave__power    (between wave rays)  ####
sea_surface_water_wave__refraction_angle   (acute angle between wave crest line and tangent to bathymetric contour line)  ####
sea_surface_water_wave__significant_height
sea_surface_water_wave__steepness    (wave height over wavelength)
sea_surface_water_wave__time_integral_from_start_of_cos_of_angular_frequency_times_time  ### or maybe somehow allow TeX for complex math?  e.g. $\cos(\omega(k)*t)$
sea_surface_water_wave__time_mean_of_height
sea_surface_water_wave__time_median_of_height
sea_surface_water_wave__wavelength
sea_surface_water_wave__wavenumber

sea_surface_water_wave_crest_x-section__vertex_angle

sea_surface_water_wave_ray__incidence_angle   (in deep water, before refraction)

sea_surface_water_carbon-dioxide__partial_pressure

sea_surface_water_wave__breaking_fraction

sea_water_above-bottom__height

sea_water_below-surface__depth    ## (could use "subsurface" vs. "below-surface", but "above-bottom" is better than "superbottom".)

sea_water__anomaly_of_mass-to-volume_density
sea_water__brunt_vaisala_frequency     (also called "buoyancy_frequency"
sea_water__depth     (or "sea_water_bottom" + "depth" ??)  ###########
sea_water__electrical_conductivity
sea_water__flow_speed
sea_water__heat_capacity_ratio    (cp/cv = Cp/Cv)
sea_water__isothermal_compressibility
sea_water__mass-specific_isobaric_heat_capacity      (isobaric = constant pressure, cp)
sea_water__mass-specific_isochoric_heat_capacity     (isochoric = constant volume, cv)
sea_water__mass-specific_latent_fusion_heat          (solid to liquid; melting)
sea_water__mass-specific_latent_vaporization_heat    (liquid to gas)
sea_water__mass-to-volume_density
sea_water__osmotic_pressure
sea_water__potential_temperature
sea_water__salinity
sea_water__secchi_depth
sea_water__static_pressure
sea_water__temperature
sea_water__thermal_conductivity
sea_water__thermal_inertia
sea_water__thermal_resistivity    (reciprocal of thermal_conductivity)
sea_water__thermal_volume_expansion_coefficient     (there are also coefficients for area and length expansion)
sea_water__time_average_of_square_of_potential_temperature
sea_water__time_average_of_square_of_salinity
sea_water__time_derivative_of_temperature
sea_water__time_derivative_of_total_pressure
sea_water__volume-specific_isobaric_heat_capacity    (isobaric = constant pressure)
sea_water__volume-specific_isochoric_heat_capacity   (isochoric = constant volume)

sea_water__east_derivative_of_salinity
sea_water__north_derivative_of_salinity
sea_water__x_derivative_of_salinity
sea_water__y_derivative_of_salinity
sea_water__z_derivative_of_salinity

sea_water__east_derivative_of_temperature
sea_water__north_derivative_of_temperature
sea_water__x_derivative_of_temperature
sea_water__y_derivative_of_temperature
sea_water__z_derivative_of_temperature

sea_water_biota__mass_concentration
sea_water_biota__mass-per-volume_density   (biomass)

sea_water_carbon-dioxide__mass_concentration
sea_water_carbon-dioxide__partial_pressure
sea_water_carbon-dioxide__solubility
sea_water_carbon-dioxide__volume_concentration

sea_water_current~longshore__speed
sea_water_current~longshore__thickness
sea_water_current~longshore__width
sea_water_current~rip__length
sea_water_current~rip__mean_flow_speed
sea_water_current~rip__thickness
sea_water_current~rip_neck__width

sea_water_flow__azimuth_angle_of_bolus_velocity
sea_water_flow__east_component_of_bolus_velocity
sea_water_flow__elevation_angle_of_bolus_velocity
sea_water_flow__magnitude_of_bolus_velocity
sea_water_flow__north_component_of_bolus_velocity
sea_water_flow__up_component_of_bolus_velocity
sea_water_flow__x_component_of_bolus_velocity
sea_water_flow__y_component_of_bolus_velocity
sea_water_flow__z_component_of_bolus_velocity

sea_water_flow__east_derivative_of_pressure
sea_water_flow__north_derivative_of_pressure
sea_water_flow__up_derivative_of_pressure
sea_water_flow__x_derivative_of_pressure
sea_water_flow__y_derivative_of_pressure
sea_water_flow__z_derivative_of_pressure

sea_water_flow__azimuth_angle_of_momentum
sea_water_flow__east_component_of_momentum
sea_water_flow__elevation_angle_of_momentum
sea_water_flow__magnitude_of_momentum
sea_water_flow__north_component_of_momentum
sea_water_flow__up_component_of_momentum
sea_water_flow__x_component_of_momentum
sea_water_flow__y_component_of_momentum
sea_water_flow__z_component_of_momentum
sea_water_flow__z_integral_of_u_component_of_momentum
sea_water_flow__z_integral_of_v_component_of_momentum

sea_water_flow__azimuth_angle_of_velocity
sea_water_flow__east_component_of_velocity
sea_water_flow__elevation_angle_of_velocity
sea_water_flow__magnitude_of_velocity
sea_water_flow__north_component_of_velocity
sea_water_flow__up_component_of_velocity
sea_water_flow__x_component_of_velocity
sea_water_flow__y_component_of_velocity
sea_water_flow__z_component_of_velocity

sea_water_flow__azimuth_angle_of_vorticity
sea_water_flow__east_component_of_vorticity
sea_water_flow__elevation_angle_of_vorticity
sea_water_flow__magnitude_of_vorticity
sea_water_flow__north_component_of_vorticity
sea_water_flow__up_component_of_vorticity
sea_water_flow__x_component_of_vorticity
sea_water_flow__y_component_of_vorticity
sea_water_flow__z_component_of_vorticity

sea_water_flow__east_east_component_of_reynolds_stress
sea_water_flow__east_north_component_of_reynolds_stress
sea_water_flow__east_up_component_of_reynolds_stress
sea_water_flow__north_north_component_of_reynolds_stress
sea_water_flow__north_up_component_of_reynolds_stress
sea_water_flow__up_up_component_of_reynolds_stress

sea_water_flow__x_x_component_of_reynolds_stress
sea_water_flow__x_y_component_of_reynolds_stress
sea_water_flow__x_z_component_of_reynolds_stress
sea_water_flow__y_y_component_of_reynolds_stress
sea_water_flow__y_z_component_of_reynolds_stress
sea_water_flow__z_z_component_of_reynolds_stress

sea_water_flow__east_east_component_of_stress
sea_water_flow__east_north_component_of_stress
sea_water_flow__east_up_component_of_stress
sea_water_flow__north_north_component_of_stress
sea_water_flow__north_up_component_of_stress
sea_water_flow__up_up_component_of_stress

sea_water_flow__x_x_component_of_stress
sea_water_flow__x_y_component_of_stress
sea_water_flow__x_z_component_of_stress
sea_water_flow__y_y_component_of_stress
sea_water_flow__y_z_component_of_stress
sea_water_flow__z_z_component_of_stress

sea_water_flow__east_east_component_of_viscous_stress
sea_water_flow__east_north_component_of_viscous_stress
sea_water_flow__east_up_component_of_viscous_stress
sea_water_flow__north_north_component_of_viscous_stress
sea_water_flow__north_up_component_of_viscous_stress
sea_water_flow__up_up_component_of_viscous_stress

sea_water_flow__x_x_component_of_viscous_stress
sea_water_flow__x_y_component_of_viscous_stress
sea_water_flow__x_z_component_of_viscous_stress
sea_water_flow__y_y_component_of_viscous_stress
sea_water_flow__y_z_component_of_viscous_stress
sea_water_flow__z_z_component_of_viscous_stress

sea_water_flow__dynamic_pressure
sea_water_flow__magnitude_of_stress
sea_water_flow__total_pressure

sea_water_flow__azimuth_angle_of_stokes_drift_velocity
sea_water_flow__elevation_angle_of_stokes_drift_velocity
sea_water_flow__magnitude_of_stokes_drift_velocity
sea_water_flow__x_component_of_stokes_drift_velocity
sea_water_flow__y_component_of_stokes_drift_velocity
sea_water_flow__z_component_of_stokes_drift_velocity

sea_water_flow__time_average_of_z_integral_of_square_of_x_component_of_momentum
sea_water_flow__time_average_of_z_integral_of_square_of_y_component_of_momentum
sea_water_flow__turbulent_kinetic_energy  (or sea_water_turbulence ??)

sea_water_heat__horizontal_diffusion_coefficient    (vertical or upward or "z" ??)
sea_water_heat__vertical_diffusion_coefficient    (vertical or upward or "z" ??)

sea_water_magnesium-sulfate__mass_concentration
sea_water_magnesium-sulfate__molar_concentration
sea_water_magnesium-sulfate__solubility
sea_water_magnesium-sulfate__volume_concentration

sea_water_potassium-chloride__mass_concentration
sea_water_potassium-chloride__molar_concentration
sea_water_potassium-chloride__solubility
sea_water_potassium-chloride__volume_concentration

sea_water_salt__horizontal_diffusion_coefficient
sea_water_salt__vertical_diffusion_coefficient

sea_water_sodium-chloride__mass_concentration
sea_water_sodium-chloride__molar_concentration
sea_water_sodium-chloride__solubility
sea_water_sodium-chloride__volume_concentration

sea_water_sediment~suspended__mass_concentration
sea_water_sediment~suspended__volume_concentration

sea_water_tide__period
sea_water_tide__range_of_depth

sea_water_energy~kinetic~turbulent__diffusion_coefficient
sea_water_energy~kinetic~turbulent__horizontal_diffusion_coefficient
sea_water_energy~kinetic~turbulent__vertical_diffusion_coefficient

sea_water_wave~internal__amplitude
sea_water_wave~internal__angular_frequency
sea_water_wave~internal__angular_wavenumber
sea_water_wave~internal__frequency
sea_water_wave~internal__period
sea_water_wave~internal__wavelength
sea_water_wave~internal__wavenumber

sea_water_zone~aphotic_top__depth
sea_water_zone~photic_bottom__depth
sea_water_zone~surf__width    ####

• The word "flow" is used in the object part of these names to mean "flow field". This is another example of the Object Name + Model Name Pattern, because a flow field is a mathematical model that is "imposed" on the sea water.
• Should we allow "surface" to be used here as a shorthand for "top_surface" (e.g. used for glaciers)?
• Many of the variables represented here are actually used within ROMS (Regional Ocean Modeling System), but with a different "long name".
• The term "bolus velocity" dates to about 1967 and is also called the "eddy-induced transport velocity". However, the term is used to refer to the speed at which chewed food travels down the esophagus!
• Longuet-Higgins (1962, 1970ab) developed the mathematical theory of "radiation stress" in the context of ocean waves. These stresses are the cause of longshore currents. Note that "stress" has the same units as "momentum flux", since flux means "per unit area and per unit time).
• Several other properties of water waves are listed and discussed at: Airy wave theory.
• There is a technical distinction between the words "coastline" and "shoreline".

## Variable Names for Planets

quantity = attribute

Objects, including Subobjects:
earth_asthenosphere
earth_atmosphere
earth_axis
earth_black-body
earth_circle~antarctic ## (circle or "parallel" ?)
earth_circle~arctic
earth_circle~tropic-of-cancer
earth_circle~tropic-of-capricorn
earth_core
earth_core~inner (solid iron core)
earth_core-mantle_boundary (known in geophysics as "cmb")
earth_core~outer (liquid iron core)
earth_crust (move to planet attributes ??)
earth_crust-mantle_boundary (known in geophysics as "moho", for Mohorovicic discontinuity, about 50 km depth)
earth_datum~vertical~geodetic   earth_datum~vertical~gravimetric   earth_datum~vertical~tidal~msl   earth_datum_ellipsoid
earth_datum_ellipsoid_origin #### (not all ellipsoid origins are at center of Earth. How is this quantified?
earth_datum_ellipsoid_surface
earth_datum_ellipsoid_surface_point-pair_geodesic ## (not always a "great circle". Use "point-to-point" vs. "point-pair"?)
earth_equator
earth_equator_plane
earth_equator_plane-to-sun
earth_exosphere # (outermost part of atmosphere)
earth_exosphere_geocorona
earth_hemisphere~north
earth_hemisphere~south
earth_interior
earth_lithosphere
earth_lithosphere-asthenosphere_boundary (known in geophysics as "lab")
earth_magnetosphere
earth_mantle
earth_mantle~lower
earth_mantle_plume
earth_mantle~upper
earth_mantle_transition-zone
earth_mesopause (
earth_mesosphere
earth_orbit
earth_parallel~antarctic-circle
earth_parallel~arctic-circle
earth_parallel~tropic-of-cancer
earth_parallel~tropic-of-capricorn
earth_pole~north~geographic
earth_pole~north~magnetic
earth_pole~south~geographic
earth_pole~south~magnetic
earth_prime-meridian ## (or meridian~prime ?)
earth_stratopause ## (mesosphere - stratosphere boundary)
earth_stratosphere
earth_surface
earth_surface_viewpoint
earth_thermopause ## (also called "exobase")
earth_thermosphere
earth_thermosphere_ionosphere
earth_tropopause ## (troposphere - stratosphere boundary)
earth_troposphere

Examples

earth__bond_albedo  (named after George Phillips Bond)
earth__coriolis_frequency
earth__escape_speed   #### (or use earth_gravity__escape_speed?  Direction of velocity doesn't matter, just speed.)
earth__geometric_albedo
earth__mass
earth__mean_mass-to-volume_density
earth__range_of_elevation
earth__rotation_angular_speed   ### (or angular_frequency ??)
earth__rotation_kinetic_energy
earth__rotation_rate
earth__rotation_period      (see "Process_name + Quantity Pattern")
earth__rotational_inertia    ### (also called "moment of inertia")
earth__sidereal_day
earth__solar_azimuth_angle
earth__solar_irradiation_constant    ( or just "solar constant"?  See notes.)
earth__solar_elevation_angle
earth__solar_zenith_angle
earth__synodic_day
earth__standard_gravity_constant    (see the Constant template)
earth__visual_geometric_albedo
earth__volume

earth__max_of_orbital_speed   (i.e. "orbit following speed").
earth__mean_of_orbital_speed
earth__min_of_orbital_speed
earth__orbital_energy
earth__orbital_period
earth__orbital_speed
earth__precise_orbital_speed
earth__transverse_orbital_speed

earth_atmosphere__thickness
earth_atmosphere__volume

earth_axis__nutation_period   ### (CHECK TERM)
earth_axis__nutation_rate      # ## (CHECK TERM)
earth_axis__precession_period
earth_axis__precession_rate
earth_axis__tilt_angle     (see "Object vs. Adjective Rule")

earth_black-body__temperature

earth_core-mantle_boundary__depth
earth_crust-mantle_boundary__depth

earth_datum_ellipsoid__eccentricity   (e = sqrt[ 1 - (b/a)^2 ].)
earth_datum_ellipsoid__equatorial_radius  (often denoted as "a", the semi-major axis length)
earth_datum_ellipsoid__flattening_ratio   (f = (a-b)/a)
earth_datum_ellipsoid__inverse_of_flattening_ratio    ### (use "reciprocal", or "multiplicative inverse" instead ?)
earth_datum_ellipsoid__polar_radius  (often denoted as "b", the semi-minor axis length)
earth_datum_ellipsoid__second_flattening_ratio   (f = (a-b)/b, but rarely used)
earth_datum_ellipsoid__third_flattening_ratio   (f = (a-b)/(a+b), used in some geodetic calculations)

earth_datum_ellipsoid_surface_point-pair_geodesic__distance     ## (also called "geographic distance")

earth_equator__average_temperature
earth_equator__circumference
earth_equator_plane-to-sun__declination_angle   (also called "solar declination angle"; varies over the year)

earth_interior__down_z_derivative_of_temperature   (also called the "geothermal gradient")

earth_lithosphere-asthenosphere_boundary__depth

earth_pole~north~magnetic__latitude    ## (magnetic vs. geographic)
earth_pole~north~magnetic__longitude
earth_pole~south~magnetic__latitude
earth_pole~south~magnetic__longitude

earth_surface_land__area_fraction
earth_surface_ocean__area_fraction

earth_orbit__aphelion_distance
earth_orbit__perihelion_distance

earth_orbit_ellipse__eccentricity            (see "Object vs. Adjective Rule")
earth_orbit_ellipse_axis~semi-major__length
earth_orbit_ellipse_axis~semi-minor__length
earth_orbit_ellipse_foci__separation_distance

earth_surface__average_temperature    ##### (how computed ??)
earth_surface__range_of_diurnal_temperature

earth_surface_land__area_fraction
earth_surface_ocean__area_fraction
earth_surface_wind__range_of_speed

earth_surface_viewpoint__elevation
earth_surface_viewpoint__latitude
earth_surface_viewpoint__longitude
earth_surface_viewpoint__solar_noon_time   (local clock time when sun is highest in the sky; also called "true solar noon" or "local apparent noon")

earth_surface_viewpoint_jupiter__subtended_angle     (also called "visual_angle" or "angular_diameter"; see below)
earth_surface_viewpoint_jupiter__apparent_magnitude   (a measure of "brightness";  include in the name?)  #####
earth_surface_viewpoint_jupiter__rise_time
earth_surface_viewpoint_jupiter__set_time

earth_surface_viewpoint_mars__subtended_angle
earth_surface_viewpoint_mars__apparent_magnitude
earth_surface_viewpoint_mars__rise_time
earth_surface_viewpoint_mars__set_time

earth_surface_viewpoint_mercury__subtended_angle
earth_surface_viewpoint_mercury__apparent_magnitude
earth_surface_viewpoint_mercury__rise_time
earth_surface_viewpoint_mercury__set_time

earth_surface_viewpoint_moon__subtended_angle
earth_surface_viewpoint_moon__apparent_magnitude
earth_surface_viewpoint_moon__rise_time
earth_surface_viewpoint_moon__set_time

earth_surface_viewpoint_neptune__subtended_angle
earth_surface_viewpoint_neptune__apparent_magnitude
earth_surface_viewpoint_neptune__rise_time
earth_surface_viewpoint_neptune__set_time

earth_surface_viewpoint_saturn__subtended_angle
earth_surface_viewpoint_saturn__apparent_magnitude
earth_surface_viewpoint_saturn__rise_time
earth_surface_viewpoint_saturn__set_time

earth_surface_viewpoint_sun__subtended_angle
earth_surface_viewpoint_sun__apparent_magnitude
earth_surface_viewpoint_sun__azimuth_angle
earth_surface_viewpoint_sun__elevation_angle
earth_surface_viewpoint_sun__rise_time
earth_surface_viewpoint_sun__set_time
earth_surface_viewpoint_sun__zenith_angle

earth_surface_viewpoint_uranus__subtended_angle
earth_surface_viewpoint_uranus__apparent_magnitude
earth_surface_viewpoint_uranus__rise_time
earth_surface_viewpoint_uranus__set_time

earth_surface_viewpoint_venus__subtended_angle
earth_surface_viewpoint_venus__apparent_magnitude
earth_surface_viewpoint_venus__rise_time
earth_surface_viewpoint_venus__set_time

mars__mean_diameter
mars__standard_gravity_constant
mars_axis__tilt_angle
mars_moon__count  (it is 2, Deimos and Phobos)
mars_surface_viewpoint_venus__rise_time
mars_surface_viewpoint_venus__set_time

mercury_axis__precession_period
mercury_axis__precession_rate

venus_axis__tilt_angle
venus_orbit__aphelion_distance
venus_orbit__perihelion_distance
venus_orbit-to-ecliptic__inclination_angle  (or "venus_orbit_ecliptic" ?)
venus__standard_gravity_constant  (8.83 m s-2)

• Some of these are needed for proper georeferencing or modeling solar radiation via celestial mechanics.
• Notice that the word "ellipsoid" was inserted in three examples above. This is an example of the Object_name + Model_name pattern that is explained at the top of the document: CSDMS Object Templates.
• Solid earth geophysicists use the following acronyms/abbreviations: CMB = core-mantle boundary, LAB = lithosphere-asthenosphere boundary and "moho" = crust-mantle boundary, also called the Mohorovicic discontinuity, at about 50 km depth.
• Note that a "black body" is an idealized version of an object, see: Black body. It is therefore an example of the Object Name + Model Name Pattern.
• See: Orbital elements for a discussion of the 6 parameters (including "inclination angle") that uniquely specify a specific orbit in astronomy.
• Note that Insolation refers to the solar irradiance measured at a given location on Earth, typically around 1000 W/m^2. The Solar irradiation constant is measured at the outer surface of Earth's atmosphere and is roughly 1366 W/m^2. Due to scattering and absorption in the atmosphere, the "insolation" is less than the "solar irradiation constant".
• See: Apparent diameter, Subtended angle and Visual angle. While these three terms are equivalent, the term apparent diameter' suggests units of length when the quantity is actually an angle. The term visual angle makes implicit reference to a viewer". The term subtended angle is a mathematically well-defined concept that involves a point and a distant object, and does not have these other issues.

## Variable Names for Products of a Company

quantity = attribute

Examples
gm_hummer__weight
porsche~911__mrsp_price
porsche~911__top_speed
toyota_corolla~2008__kelly-blue-book_price    ###
toyota_corolla~2008_engine__volume
toyota_corolla~2008_fuel-tank__volume
toyota_corolla~2008__fuel-economy   [mpg]
toyota_corolla~2008__motor-trend-magazine_safety_rating
(or "motor_trend_magazine" could go into metadata; how measured)

• We would do something similar for organizations contained within other organizations, such as "us_noaa_nws" (country_agency_program). The general pattern is to go from the general to the specific.

## Variable Names for Projectiles

quantity = attribute

Objects, including Subobjects:
projectile
projectile_barycenter
projectile_impact-crater
projectile_origin
projectile_origin_land_surface
projectile_origin_wind
projectile_rotation-axis
projectile_shaft # arrows are also called "shafted projectiles"
projectile_target
projectile_target_land_surface
projectile_trajectory
projectile_x-section

Examples

projectile__acceleration  (a vector)
projectile__altitude   (distance above the ground.  preferable to projectile_height)
projectile__angular_momentum
projectile__angular_velocity  (a vector)
projectile__azimuth_angle_of_impact_velocity
projectile__azimuth_angle_of_initial_velocity   (or of_firing_velocity ??)
projectile__azimuth_angle_of_velocity
projectile__diameter     (if spherical)
projectile__drag_coefficient
projectile__drag_force   (a vector)
projectile__elevation_angle_of_impact_velocity     (also called "impact angle" or "terminal angle")
projectile__elevation_angle_of_initial_velocity    (also called  "launch angle" or "firing angle")
projectile__elevation_angle_of_velocity
projectile__firing_speed
projectile__firing_time
projectile__flight_duration
projectile__impact_depth
projectile__impact_force
projectile__impact_time
projectile__impact_velocity   (a vector)
projectile__initial_altitude      (this would be zero if fired from the ground or nonzero if fired from aloft)
projectile__initial_angular_momentum
projectile__initial_elevation    (this would be undefined if fired from aloft)
projectile__initial_latitude
projectile__initial_longitude
projectile__initial_velocity   (a vector)
projectile__kinetic_energy
projectile__kinetic_energy_plus_potential_energy
projectile__length    (if cylindrical)
projectile__lift_coefficient
projectile__lift_force  (a vector)
projectile__mach_number
projectile__magnitude_of_drag_force
projectile__magnitude_of_lift_force
projectile__mass
projectile__mass-per-volume_density   #####
projectile__max_of_altitude    (highest point on the trajectory)
projectile__momentum
projectile__peak_time_of_altitude
projectile__potential_energy
projectile__potential_range_distance   (max possible, if fired at 45 degree angle)
projectile__propelling_force
projectile__range_distance   (i.e. horizontal travel distance)
projectile__reynolds_number
projectile__roll_rotation_rate     #####
projectile__rotational_inertia
projectile__specific_kinetic_energy  [J kg-1]
projectile__specific_potential_energy [J kg-1]
projectile__speed
projectile__thermal_energy
projectile__velocity    (a vector)
projectile__weight
projectile__x_component_of_acceleration
projectile__x_component_of_velocity
projectile__y_component_of_acceleration
projectile__y_component_of_velocity
projectile__z_component_of_acceleration
projectile__z_component_of_velocity

projectile_origin__elevation
projectile_origin__latitude
projectile_origin__longitude
projectile_origin__speed
projectile_origin__velocity  (a vector)
projectile_origin__x_component_of_acceleration
projectile_origin__x_component_of_velocity
projectile_origin__y_component_of_acceleration
projectile_origin__y_component_of_velocity
projectile_origin__z_component_of_acceleration
projectile_origin__z_component_of_velocity

projectile_origin_land_surface__aspect_angle
projectile_origin_land_surface__slope
projectile_origin_land_surface__slope_angle

projectile_origin_wind__azimuth_angle_of_velocity
projectile_origin_wind__elevation_angle_of_velocity
projectile_origin_wind__speed
projectile_origin_wind__velocity  (a vector)
projectile_origin_wind__x_component_of_velocity
projectile_origin_wind__y_component_of_velocity
projectile_origin_wind__z_component_of_velocity

projectile_impact-crater__depth         (insert "land_surface"  ??)
projectile_impact-crater__diameter

projectile_shaft__length
projectile_shaft_x-section__diameter

projectile_target__elevation
projectile_target__latitude
projectile_target__longitude
projectile_target__speed
projectile_target__velocity  (a vector)
projectile_target__x_component_of_acceleration
projectile_target__x_component_of_velocity
projectile_target__y_component_of_acceleration
projectile_target__y_component_of_velocity
projectile_target__z_component_of_acceleration
projectile_target__z_component_of_velocity

projectile_target_land_surface__aspect_angle
projectile_target_land_surface__slope
projectile_target_land_surface__slope_angle

projectile_trajectory__curvature
projectile_trajectory__length

projectile_x-section__area

• "Projectile" is a generic object name that could refer to a cannonball, bullet, arrow, crossbow bolt, spear, missile, etc. We may want to make a distinction between projectiles (that are fired or launched) and meteors (that "just arrive"). Arrows are also called "shafted projectiles".
• We could use "initial_elevation", "initial_latitude" and "initial_longitude" as quantity names with "projectile" as the object. However, using "projectile_origin" as the object name makes it possible to specify additional attributes (other than elevation, latitude and longitude) of the firing site, such as the topographic slope or aspect. It is also possible for the "firing site" to be moving (e.g. aircraft or ship), and then we need to be able to specify its velocity as well.
• Roll_angle, pitch_angle and yaw_angle are used for aircraft and perhaps could be used to describe rotation of a projectile in flight.

quantity = attribute
quantity = "absorbance"
quantity = "albedo"
quantity = "amplitude"
quantity = "emission_angle"
quantity = "emissivity"
quantity = "energy_flux"
quantity = "frequency"
quantity = "incidence_angle"
quantity = "intensity"
quantity = "period"
quantity = "phase_angle"
quantity = "reflectance"
quantity = "standard_refraction_index"
quantity = "transmittance"
quantity = "wavelength"

Examples:

See examples in Attributes of the Atmosphere, Attributes of Oceans and Attributes of Topography.

• Albedo is also called "diffuse reflectivity" or "reflectance coefficient".
• Note that "refraction_index" is an example of a quantity that really requires two objects to be specified, electromagnetic radiation or light of a particular wavelength and the medium that it is traveling through (e.g. air, water, vacuum). However, standard refractive index measurements (see List of refractive indices) are taken at the yellow doublet sodium D line, with a wavelength of 589 nanometers. So in CSDMS standard names the insertion of the adjective "standard" means that only one object, the medium, needs to be specified. So "air_radiation" + "standard_refraction_index" would be a valid and unambiguous name, but an <assume> tag should be included in the Model Coupling Metadata (MCM) file that specifies: "at_reference_wavelength_of_589_nm" (and maybe also "yellow_doublet_sodium_d_line_reference".) We may also want to allow names such as "550_nm_light_in_air_refraction_index".

## Variable Names for River Deltas

quantity = attribute

Objects, including Subobjects:
"delta~river-dominated"
"delta~tide-dominated"
"delta~wave-dominated"
"delta_apex" ## (also called the "delta head")
"delta_bar~mouth"
"delta_beds~bottomset"
"delta_beds~bottomset_sediment"
"delta_beds~foreset" ## (foreset is also called "frontset")
"delta_beds~foreset_sediment"
"delta_beds~topset"
"delta_beds~topset~lower" ## (lower = affected by tide)
"delta_beds~topset~upper" ## (upper = unaffected by tide)
"delta_beds~topset_sediment"
"delta_channel~abandoned"
"delta_channel~active"
"delta_channel~distributary" ## or just "delta_distributary" ?
"delta_channel~main" ## (or apex_channel ??)
"delta_channel~main_entrance"
"delta_distributary"
"delta_distributary_outlet" ## or "outlet~terminal" ?
"delta_distributary-network"
"delta_facies" ## (is this needed?)
"delta_front"
"delta_front_toe"
"delta_front_toe-thrust_belt" ## (hyphen ??)
"delta_land~vegetated"
"delta_levee~subaerial"
"delta_levee~subaqueous"
"delta_lobe"
"delta_lobe_sediment"
"delta_margin~seaward"
"delta_plain~lower" # can be inundated by tide
"delta_plain~upper" # not inundated by tide; subaerial
"delta_plain~upper_vegetation"
"delta_plain~subaqueous" ## (also called the "prodelta")
"delta_plain~total" ## (also called the "delta platform" ?)
"delta_platform" ## (is this upper + lower + subaqueous plain?)
"delta_shoreline" ## (compare to margin)
"delta_strata" ## (is this needed?)
"delta_x-section"

Examples

delta__mass
delta__mean_subsidence_rate
delta__volume
delta~subaerial__volume
delta~subaqueous__volume
delta_apex__elevation
delta_apex__latitude
delta_apex__longitude
delta_apex__opening_angle
delta_apex-to-shoreline__min_of_distance
delta_beds~bottomset_sediment_clay__volume_fraction
delta_beds~bottomset_sediment_sand__volume_fraction
delta_beds~bottomset_sediment_silt__volume_fraction
delta_beds~foreset_sediment_clay__volume_fraction
delta_beds~foreset_sediment_sand__volume_fraction
delta_beds~foreset_sediment_silt__volume_fraction
delta_beds~foreset__mean_of_slope
delta_beds~topset_sediment_clay__volume_fraction
delta_beds~topset_sediment_sand__volume_fraction
delta_beds~topset_sediment_silt__volume_fraction
delta_beds~topset~lower_sediment_silt__volume_fraction   ####
delta_beds~topset~upper_sediment_silt__volume_fraction
delta_channel~main_entrance__azimuth_angle_of_velocity
delta_channel~main_entrance__elevation_angle_of_velocity
delta_channel~main_entrance__max_of_depth
delta_channel~main_entrance__mean_depth
delta_channel~main_entrance__width
delta_channel~main_entrance_center__elevation
delta_channel~main_entrance_center__latitude
delta_channel~main_entrance_center__longitude
delta_channel~main_entrance_water_sediment~suspended__mass_concentration
delta_channel~main_entrance_water_sediment~suspended__mass_flow_rate
delta_channel~main_entrance_water_sediment~suspended__mass_transport_rate
delta_channel~main_entrance_water_sediment~suspended__volume_concentration
delta_channel~main_entrance_water_sediment_clay__volume_fraction
delta_channel~main_entrance_water_sediment_sand__volume_fraction
delta_channel~main_entrance_water_sediment_sand_grain__mean_of_diameter
delta_channel~main_entrance_water_sediment_silt__volume_fraction
delta_channel~main_entrance_water_x-section__volume_flow_rate
delta_channel~main_entrance_water_x-section__volume_flux
delta_channel~main_entrance_water_x-section__wetted_area
delta_channel~main_entrance_water_x-section__wetted_perimeter
delta_channel~main_entrance_water_x-section__width-to-depth_ratio
delta_channel~main_entrance_water_x_section_top__width
delta_channel~main_entrance_x-section__area
delta_channel~main_entrance_x_section_top__width
delta_distributary__length
delta_distributary__slope   #####
delta_distributary_outlet__count    ## (See Notes section below)
delta_distributary_outlet__top_width
delta_distributary_outlet_water_x-section__mean_of_depth
delta_distributary_outlet_water_x-section__volume_flow_rate
delta_distributary_outlet_water_x-section__volume_flux
delta_distributary_outlet_center__elevation
delta_distributary_outlet_center__latitude
delta_distributary_outlet_center__longitude
delta_distributary_outlet_side~left__elevation
delta_distributary_outlet_side~left__latitude
delta_distributary_outlet_side~left__longitude
delta_distributary_outlet_side~right__elevation
delta_distributary_outlet_side~right__latitude
delta_distributary_outlet_side~right__longitude
delta_distributary-network__drainage_density
delta_distributary-network__total_length
delta_distributary-network_water__max_of_depth
delta_front__mean_of_slope
delta_front_sediment__repose_angle
delta_front_sediment_grain__mean_diameter
delta_front_toe__mean_of_elevation
delta_plain~lower__area     # (inundated by tides; semi-subaerial?)
delta_plain~lower__mean_of_slope
delta_plain~lower-and-upper__area
delta_plain~subaqueous__area  # (seaward of shoreline)
delta_plain~subaqueous__mean_of_slope
delta_plain~subaqueous_plain~total__area_ratio
delta_plain~total__area   # (upper and lower and subaqueous)
delta_plain~total_boundary__diameter
delta_plain~total_boundary__perimeter
delta_plain~upper__area     # (not inundated by tides)
delta_plain~upper__mean_of_slope
delta_plain~upper_boundary~seaward__length
delta_plain~upper~farmed__area_fraction
delta_plain~upper~residential__area_fraction
delta_plain~upper~urban__area_fraction
delta_plain~upper~vegetated__area_fraction
delta_plain~upper_vegetation__mean_of_height
delta_shoreline__geodetic_latitude
delta_shoreline__length
delta_shoreline__longitude
delta_shoreline__x_coordinate
delta_shoreline__y_coordinate
delta_shoreline_sediment_wave~ocean__reworking_depth   #### CHECK
delta_x-section__area
delta_x-section__dip_angle   ## (between plane and horizontal)
delta_x-section__strike_angle   ## (azimuth angle in plane of Earth's surface)

• Since there are multiple distributaries and distributary outlets that flow into the ocean, many of these standard names will be associated with 1D arrays. The size of these arrays is given by "delta_distributary_outlet__count".

## Variable Names for Sea Ice

quantity = attribute

Objects, including Subobjects:
"sea_ice"
"sea_ice_bottom"
"sea_ice_bottom_water"
"sea_ice_meltwater"
"sea_ice_salt"
"sea_ice_surface"
"sea_ice_surface_air"
"sea_ice_surface_air_flow"

Examples

sea_ice__age
sea_ice__albedo
sea_ice__area
sea_ice__area_fraction   (vs. "sea_ice_concentration"; see Concentration)
sea_ice__depression_of_melting_point_temperature
sea_ice__draft_depth     (i.e. depth below water surface)
sea_ice__dynamic_shear_viscosity
sea_ice__dynamic_volume_viscosity
sea_ice__emissivity
sea_ice__extent        (see Notes below)
sea_ice__freeboard_height    (i.e. height above water surface)
sea_ice__heat_capacity_ratio    (cp/cv = Cp/Cv)
sea_ice__isothermal_compressibility
sea_ice__kinematic_shear_viscosity
sea_ice__kinematic_volume_viscosity
sea_ice__mass-per-volume_density
sea_ice__mass-specific_isobaric_heat_capacity     (isobaric = constant pressure)
sea_ice__mass-specific_isochoric_heat_capacity    (isochoric = constant volume)
sea_ice__mass-specific_latent_fusion_heat         (solid to liquid; melting)
sea_ice__mass-specific_latent_sublimation_heat    (solid to gas)
sea_ice__melt_mass_flux      #####  ([kg m-2 s-1], instead of ambiguous melt_rate)
sea_ice__melt_volume_flux  ([m s-1], instead of ambiguous melt_rate)
sea_ice__melting_point_temperature
sea_ice__relative_permittivity     (also called "relative dielectric constant", but not a constant)
sea_ice__salinity    (parts per thousand?)
sea_ice__sublimation_mass_flux
sea_ice__sublimation_volume_flux
sea_ice__thermal_conductivity
sea_ice__thermal_diffusivity
sea_ice__thermal_inertia
sea_ice__thermal_resistivity   (reciprocal of thermal_conductivity)
sea_ice__thermal_volume_expansion_coefficient     (there are also coefficients for area and length expansion)
sea_ice__thickness
sea_ice__time_derivative_of_area_fraction
sea_ice__time_derivative_of_extent
sea_ice__time_derivative_of_thickness
sea_ice__time_derivative_of_volume
sea_ice__volume
sea_ice__volume-specific_isobaric_heat_capacity    (isobaric = constant pressure)
sea_ice__volume-specific_isochoric_heat_capacity   (isochoric = constant volume)

sea_ice_bottom_water__salinity
sea_ice_bottom_water__temperature
sea_ice_bottom_water_salt__mass_flux

sea_ice_radiation~incoming~longwave__transmitted_energy_flux    (sent down to sea water below)

sea_ice_radiation~incoming~shortwave__transmitted_energy_flux    (sent down to sea water below)

sea_ice_radiation~incoming~total__transmitted_energy_flux    (sent down to sea water below)

sea_ice_radiation~outgoing~longwave~downward__energy_flux    (emitted downward into sea water)

sea_ice_salt__mass_concentration     ### (or use sea_ice + salinity ??)
sea_ice_salt__volume_concentration

sea_ice_surface_air__temperature

• The quantity "sea_ice_extent" is related to "sea_ice_area" but involves a "reference threshold" (as a percentage, usually 15%) that must be specified with an <assume> tag in a Model Coupling Metadata (MCM) file. See Measurement of sea ice. Also see Reference Quantities.
• What about "sea_ice_mass_balance" ? The term "mass_balance" is also used in glaciology but is confusing outside of that domain.
• What about latent and sensible heat flux?
• Some processes that affect sea ice are: brine rejection, freezing, melting and radiation.
• See Concentration, Fraction and Thickness.

## Variable Names for Snow

quantity = attribute

Objects, including Subobjects:
snow
snow_grain
snowpack
snowpack_bottom
snowpack_bottom_ice_layer
snowpack_bottom_surface
snowpack_core
snowpack_crust~first #### or ice_first-layer ??
snowpack_crust~second #### or ice_second-layer ??
snowpack_layer
snowpack_meltwater
snowpack_snow~new
snowpack_snow_grain
snowpack_soil
snowpack_top
snowpack_top_surface

Examples

snow__blowing_speed    #### ??
snow__energy-per-area_cold_content       ## (energy required to raise snowpack temperature to the melting point; a deficit)
snow__heat_capacity_ratio    (cp/cv = Cp/Cv)
snow__mass-per-volume_density
snow__mass-specific_isobaric_heat_capacity    (isobaric = constant pressure)
snow__mass-specific_isochoric_heat_capacity   (isochoric = constant volume)
snow__thermal_conductivity
snow__thermal_diffusivity
snow__thermal_inertia
snow__thermal_resistivity    (reciprocal of thermal_conductivity)
snow__volume-specific_isobaric_heat_capacity    (isobaric = constant pressure)
snow__volume-specific_isochoric_heat_capacity   (isochoric = constant volume)

snowpack__age
snowpack__degree-day_coefficient
snowpack__degree-day_threshold_temperature
snowpack__depth   (chosen instead of "thickness", based on common usage and "water depth") #####
snowpack__desublimation_mass_flux
snowpack__desublimation_volume_flux
snowpack__domain_time_integral_of_desublimation_volume_flux
snowpack__domain_time_integral_of_melt_volume_flux
snowpack__domain_time_integral_of_sublimation_volume_flux
snowpack__diurnal_max_of_temperature
snowpack__diurnal_min_of_temperature
snowpack__diurnal_range_of_temperature
snowpack__initial_depth
snowpack__initial_liquid-equivalent_depth
snowpack__isothermal_compressibility
snowpack__liquid-equivalent_depth     ### (usually called "snow water equivalent" depth)
snowpack__mass-per-volume_density
snowpack__mean_of_temperature
snowpack__melt_mass_flux      ### (or snowpack_meltwater__mass_flux, but what about sublimation, etc. ?)
snowpack__melt_volume_flux   ### (or snowpack_meltwater__volume_flux ?)
snowpack__sublimation_mass_flux
snowpack__sublimation_volume_flux
snowpack__thermal_quality_ratio # (energy required to melt unit mass of snow over energy required to melt unit mass of ice at 0 degC, unitless)
snowpack__time_derivative_of_depth
snowpack__time_derivative_of_temperature
snowpack__z_mean_of_mass-per-volume_density    ### (include initial and final prefixes ??)
snowpack__z_mean_of_mass-specific_isobaric_heat_capacity

snowpack_bottom__temperature

snowpack_bottom_heat~net~conduction__energy_flux  [W m-2]   (into or out of the land surface or soil)

snowpack_core__diameter
snowpack_core__length
snowpack_core__volume

snowpack_crust_layer~first__depth    #### (or snowpack_top-ice-layer + depth  ??)
snowpack_crust_layer~second__depth

snowpack_grains__mean_of_diameter

snowpack_ice-layer__count

snowpack_snow~new__depth

snowpack_top__albedo
snowpack_top__emissivity
snowpack_top_heat~net~latent__energy_flux    [W m-2]
snowpack_top_heat~net~sensible__energy_flux   [W m-2]
snowpack_top__temperature

snowpack_top_air__temperature

snowpack_top_surface__indentation_hardness

snowpack_water~liquid__mass_fraction   # (also called "liquid water content")
snowpack_water~liquid__volume_fraction

snow~wet_rubber__kinetic_friction_coefficient
snow~wet_rubber__static_friction_coefficient
snow~wet_ski~waxed__kinetic_friction_coefficient
snow~wet_ski~waxed__static_friction_coefficient

• The use of "snowpack" here is directly analogous to the use of "glacier" in the CSDMS Standard Names. The first is an entity made of snow; the second made of ice. Both "snowpack" and "snowcover" are widely-used terms for the same thing.
• Here we take "snowpack" to mean any mass of snow that has accumulated on the ground, whether or not it has been "compressed" or "packed".
• The concept of "snow" generalizes to frozen precipitation of other substances like carbon dioxide (on Mars) and methane (on Jupiter's moon, Titan). The current and natural trend is to simply call these "carbon-dioxide_snow" and "methane_snow". The word "snow" used by itself then means "water_snow". Similarly, we could use "carbon-dioxide_ice" and "methane_ice", even though the former is also known as "dry ice".
• Do we need to use "land_snow" and "ice_snow", etc. ??

## Variable Names for Soil

quantity = attribute

Objects, including Subobjects:
soil
soil_active-layer
soil_air
soil_capillary-fringe
soil_clay
soil_column
soil_epiphreatic-zone
soil_x-section~horizontal
soil_ice
soil_ice_lense
soil_ice_thawing-front
soil_inactive-layer
soil_laterite-layer
soil_layer
soil_loam
soil_macropores
soil_parent-material
soil_permafrost
soil_permafrost_bottom
soil_permafrost_top
soil_profile
soil_regolith-layer
soil_root-zone
soil_sand
soil_saprolite-layer
soil_silt
soil_surface
soil_surface_water
soil_x-section~vertical
soil_water
soil_water_flow
soil_water_frost-front ####
soil_water_sat-zone (also called the "phreatic zone")
soil_water_sat-zone_top (i.e. the water table)
soil_water_unsat-zone (also called the "vadose zone"
soil_water_wetting-front (as water infiltrates down into dry soil)

soil_horizon~a
soil_horizon~b
soil_horizon~c
soil_horizon~d
soil_horizon~e
soil_horizon_l
soil_horizon~o
soil_horizon~p
soil_horizon_r
soil_solum

Examples

### See variables names for "model_soil_layer" in the Attributes of Models section.
soil__freeze_depth  ###  (use "soil_water" instead ?)
soil__heat_capacity_ratio   (cp/cv = Cp/Cv)
soil__mass-per_volume_bulk_density    (also called "dry density")
soil__mass-per-volume_density   (also called "total density" or "wet density")
soil__mass-per-volume_particle_density
soil__mass-specific_isobaric_heat_capacity    (isobaric = constant pressure)
soil__mass-specific_isochoric_heat_capacity   (isochoric = constant volume)
soil__permeability
soil__porosity
soil__reference_depth_temperature
soil__specific_permeability   (function of medium only, not fluid)
soil__temperature
soil__temperature_reference_depth
soil__thaw_depth   ###  (use "soil_water" for object?  thaw depth = annual average thickness of active layer)
soil__thermal_conductivity
soil__thermal_diffusivity
soil__thermal_inertia
soil__thermal_resistivity   (reciprocal of thermal_conductivity)
soil__thickness
soil__void_ratio   (not same as porosity.  Same as "soil_air__volume_fraction" ?)
soil__volume-specific_isobaric_heat_capacity    (isobaric = constant pressure)
soil__volume-specific_isochoric_heat_capacity   (isochoric = constant volume)

soil_bedrock_top__depth    # (same as "soil_bottom" + "depth" ?)

soil_horizon~a__thickness
soil_horizon~b__thickness
soil_horizon~c__thickness
soil_horizon~d__thickness
soil_horizon~e__thickness
soil_horizon~l__thickness
soil_horizon~o__thickness
soil_horizon~p__thickness
soil_horizon~r__thickness

soil_active-layer__porosity
soil_active-layer__saturated_thickness
soil_active-layer__thickness

soil_layer~top__porosity
soil_layer~top__saturated_thickness
soil_layer~top__thickness

soil_macropores__horizontal_saturated_hydraulic_conductivity  (in PIHM)
soil_macropores__cutoff_depth   ### (or "max_of_penetration_depth" ?)
soil_macropores__vertical_saturated_hydraulic_conductivity  (in PIHM)
soil_macropores__volume_fraction

soil_permafrost__thickness
soil_permafrost_bottom__depth
soil_permafrost_top__depth

soil_regolith-layer__thickness

soil_root-zone__thickness

soil_surface_water__domain_time_integral_of_infiltration_volume_flux  [m3]    (for checking mass conservation)
soil_surface_water__infiltration_mass_flux      [kg m-2 s-1]
soil_surface_water__infiltration_volume_flux    [m s-1]     ### (usually called "infiltration_rate")
soil_surface_water__potential_infiltration_volume_flux
soil_surface_water__time_integral_of_infiltration_volume_flux  [m]    ### (sometimes called "cumulative infiltrated depth";  from start of run)
soil_surface_water__volume_fraction   ###  (also called "water content")

soil_x-section~horizontal_macropores__area_fraction   (in PIHM)  #####
soil_x-section~vertical_macropores__area_fraction  (in PIHM)   ########

soil_clay__mass_fraction
soil_ice__mass_fraction
soil_loam__mass_fraction
soil_matter~organic__mass_fraction
soil_sand__mass_fraction
soil_silt__mass_fraction
soil_water__mass_fraction

soil_clay__oven-dried_mass_fraction
soil_loam__oven-dried_mass_fraction
soil_matter~organic__oven-dried_mass_fraction
soil_sand__oven-dried_mass_fraction
soil_silt__oven-dried_mass_fraction
soil_water__oven-dried_mass_fraction

soil_air__volume_fraction    (not same as porosity)
soil_clay__volume_fraction
soil_ice__volume_fraction
soil_loam__volume_fraction
soil_matter~organic__volume_fraction
soil_sand__volume_fraction
soil_silt__volume_fraction
soil_water__volume_fraction

soil_water__atterberg_activity_index
soil_water__atterberg_liquid_limit_volume_fraction
soil_water__atterberg_liquidity_index
soil_water__atterberg_plastic_limit_volume_fraction
soil_water__atterberg_plasticity_index
soil_water__atterberg_shrinkage_limit_volume_fraction
soil_water__brooks-corey_b_parameter   (lambda = 1/b)
soil_water__brooks-corey_eta_parameter
soil_water__brooks-corey_lambda_parameter
soil_water__brooks-corey-smith_c_parameter
soil_water__diffusivity    ### (better to use "richards_diffusivity" ??)
soil_water__effective_hydraulic_conductivity
soil_water__effective_saturated_hydraulic_conductivity     ("effective" indicates a representative value for a region, e.g. grid cell)
soil_water__field-capacity_volume_fraction  (usually called "field-capacity water content)
soil_water__green-ampt_capillary_length    (denoted as G.  could use "green_ampt_g_parameter".)
soil_water__hydraulic_conductivity    (function of medium and fluid)
soil_water__hygroscopic_volume_fraction   (usually called "hygroscopic water content")
soil_water__infiltration_mass_flux
soil_water__infiltration_volume_flux   ### (at any depth below surface;  downward is implied ? OR z_component_of_darcy_velocity)
soil_water__initial_hydraulic_conductivity
soil_water__initial_normalized_volume_fraction
soil_water__initial_volume_fraction       (water content or soil moisture)
soil_water__mass_fraction
soil_water__normalized_hydraulic_conductivity
soil_water__normalized_volume_fraction    (also called "normalized water content" or "effective saturation")
soil_water__philip_sorptivity      ### (a parameter in an older empirical treatment)
soil_water__potential_infiltration_volume_flux    (less standard term for fc = infiltrability; max possible rate, given sufficient supply)
soil_water__relative_hydraulic_conductivity   (K/Ks)
soil_water__residual_volume_fraction      (water content)
soil_water__saturated_hydraulic_conductivity   (function of medium and fluid)
soil_water__saturated_volume_fraction   (usually called "saturated water content")
soil_water__smith-parlange_gamma_parameter
soil_water__van-genuchten_alpha_parameter   ##### (should this be for soil or "soil_water" ??)
soil_water__van-genuchten_m_parameter
soil_water__van-genuchten_n_parameter
soil_water__wilting-point_volume_fraction  (usually called "wilting-point water content")

soil_water_flow__azimuth_angle_of_darcy_velocity
soil_water_flow__elevation_angle_of_darcy_velocity
soil_water_flow__x_component_of_darcy_velocity    (darcy_velocity = specific_discharge, macroscopic = volume flux)
soil_water_flow__y_component_of_darcy_velocity
soil_water_flow__z_component_of_darcy_velocity

soil_water_sat-zone__thickness   (if underlaid by an impermeable surface)

soil_water_sat-zone_top__domain_time_integral_of_recharge_volume_flux  [m3]    (for checking mass conservation)
soil_water_sat-zone_top__depth      (i.e. depth to the water table)
soil_water_sat-zone_top__offset_depth  (i.e. depth below the water table;  compare to just "depth")
soil_water_sat-zone_top__recharge_mass_flux
soil_water_sat-zone_top__recharge_volume_flux
soil_water_sat-zone_top__time_integral_of_recharge_volume_flux  [m]

soil_water_sat-zone_top_surface__elevation    (i.e. water table elevation)   ## (what about "land_subsurface_water_sat-zone"   ?)
soil_water_sat-zone_top_surface__initial_elevation
soil_water_sat-zone_top_surface__slope
soil_water_sat-zone_top_surface__x_derivative_of_elevation
soil_water_sat-zone_top_surface__y_derivative_of_elevation

soil_water_unsat-zone__thickness

soil_ice_thawing-front__depth
soil_water_frost-front__depth
soil_water_wetting-front__depth


• The quantity name darcy_velocity is used for the volume flux that is otherwise known as the specific discharge. Freeze and Cherry (1979) mention both names, but emphasize the latter in order to make a clear distinction between it and the microscopic fluid velocity within pores. It has units of velocity and in the general case is modeled as a (macroscopic) three-dimensional velocity field (i.e. 3 components). Retaining the adjective "darcy" serves as a reminder of its origins and macroscopic nature.
• The quantity name volume_fraction is used instead of the more standard term water content. By keeping the word "water" in the (compound) object name "soil_water" and out of the quantity name, we maintain consistency with other standard names. "Volume_fraction" is also more self-explanatory.
• Some of the objects and quantities identified here do not require there to be an actual "soil". For example, "land_subsurface_water" is also allowed and could be used in place of "soil_water" in "soil_water_sat-zone_top" + "depth".
• The Brooks-Corey, van Genuchten and modified Brooks-Corey (or Brooks-Corey-Smith) equations are empirical and contain several parameters. They are referred to as "soil water retention curves", and therefore involve both the soil and the water.
• The quantity name potential_infiltration_rate is used instead of the alternate name infiltrability since it is the max possible infiltration rate.
• The term "baseflow" refers to the process where the water table rises locally above the land surface which results in a positive contribution to the surface water budget. It cannot be negative. The rate at which baseflow contributes water to the surface water can be quantified with either a mass flux [kg m-2 s-1] or a volume flux [m s-1].
• Note that "soil_surface_water" and "land_surface_water" are very similar. The CSDMS standard names use "soil_surface_water" to describe attributes of the movement of water through soil just below the land surface and "land_surface_water" to describe the water above the land surface.
• See Variable Names for Topography that start with "land_surface_water" for several that are relevant for infiltration.

## Variable Names for Sea Floor Debris Flows

quantity = attribute

Objects, including Subobjects:
"sea_bottom_surface"
"sea_bottom_water_debris_deposit"
"sea_bottom_water_debris_flow"
"sea_bottom_water_debris_flow_plug-layer"
"sea_bottom_water_debris_flow_shear-layer"
"sea_bottom_water_debris_flow_top"

Examples
sea_bottom_surface__slope
sea_bottom_water__mass-per-volume_density
sea_bottom_water_debris_deposit__initial_length
sea_bottom_water_debris_flow__dynamic_shear_viscosity
sea_bottom_water_debris_flow__herschel_bulkley_coefficient
sea_bottom_water_debris_flow__herschel_bulkley_exponent
sea_bottom_water_debris_flow__mass-per-volume_density
sea_bottom_water_debris_flow__thickness
sea_bottom_water_debris_flow__yield_stress
sea_bottom_water_debris_flow_plug-layer__thickness
sea_bottom_water_debris_flow_shear-layer__flow_speed
sea_bottom_water_debris_flow_shear-layer__thickness
sea_bottom_water_debris_flow_top__speed
sea_water__depth

• Subaqueous debris flows have been modeled as Herschel-Bulkley fluids with an exponent of 1 (i.e. the special case of a Bingham plastic). See: Imran, J., P. Harff and G. Parker (2001) A numerical model of submarine debris flow with graphical user interface, Computers and Geosciences, 27, 717-729. (The name of the model is BING.)

## Variable Names for Topography

quantity = attribute
quantity = "aspect_angle" (aspect is not used by itself)
quantity = "elevation"
quantity = "mean_curvature"
quantity = "plan_curvature"
quantity = "profile_curvature"
quantity = "slope" [unitless = rise/run = L/L]
quantity = "slope_angle" [radians or degrees]
quantity = "specific_contributing_area"
quantity = "streamline_curvature"
quantity = "tangential_curvature"
quantity = "total_contributing_area"

Objects, including Subobjects:
"land"
"land_subsurface"
"land_subsurface_water_sat-zone"
"land_subsurface_water_sat-zone_top" (i.e. surface of groundwater table)
"land_subsurface_water_unsat-zone"
"land_surface"
"land_surface~10m-above" #########
"land_surface_air"
"land_surface_base-level"
"land_surface_contour_segment"
"land_surface_ice"
"land_surface_polygon"
"land_surface_soil"
"land_surface_water"
"land_surface_water_sink"
"land_surface_water_source"
"land_vegetation"
"land_vegetation_canopy"
"land_vegetation_floor"

Examples

land_domain_boundary__elevation_lowering_rate

land_subsurface_water_sat-zone_top__depth

land_surface__albedo
land_surface__anomaly_of_temperature
land_surface__aspect_angle   # (azimuth angle of opposite of gradient of elevation)
land_surface__domain_max_of_elevation   # (should we allow just "max_of_elevation"?)
land_surface__domain_max_of_increment_of_elevation
land_surface__domain_min_of_elevation
land_surface__domain_min_of_increment_of_elevation
land_surface__domain_range_of_elevation
land_surface__domain_time_max_of_elevation
land_surface__domain_time_min_of_elevation
land_surface__elevation
land_surface__emissivity
land_surface__gaussian_curvature
land_surface__increment_of_elevation
land_surface__initial_elevation
land_surface__laplacian_of_elevation       (Is "laplacian curvature" a synonym ??)
land_surface__latitude    # (geodetic latitude, since unqualified)
land_surface__longitude
land_surface__max_normal_curvature     # (in each grid cell;  not a "domain max")
land_surface__mean_curvature
land_surface__min_normal_curvature  # (in each grid cell;  not a "domain min")
land_surface__plan_curvature
land_surface__profile_curvature
land_surface__slope
land_surface__slope_angle
land_surface__specific_contributing_area   (measured by D8, D-inf, etc.)
land_surface__streamline_curvature
land_surface__sunshine_duration       (or "daylight_duration")
land_surface__tangential_curvature
land_surface__temperature
land_surface__thermal_inertia
land_surface__time_derivative_of_elevation
land_surface__time_max_of_elevation   # (each grid cell has a max over time)
land_surface__time_min_of_elevation
land_surface__topographic_wetness_index
land_surface__x_x_derivative_of_elevation
land_surface__x_y_derivative_of_elevation
land_surface__y_y_derivative_of_elevation

land_surface_air__temperature   ##  (See variable names starting with "atmosphere_bottom_air";  same as "atmosphere_bottom_air__temperature")
land_surface_air__pressure  ## (same as "atmosphere_bottom_air__pressure")

###  See: atmosphere_bottom_air_land_heat~net~latent__energy_flux  ###
land_surface_air_heat~incoming~latent__energy_flux    [W m-2]       (incoming to the *air*, since air is last)
land_surface_air_heat~incoming~sensible__energy_flux    [W m-2]
land_surface_air_heat~net~latent__energy_flux    [W m-2] (via mass transport, such as evaporation, sublimation or condensation;  net = incoming-outgoing to the *air* )
land_surface_air_heat~net~sensible__energy_flux   [W m-2]  (via turbulent conduction)    ### (use "conducted_energy_flux"  ??)

land_surface_base-level__elevation
land_surface_base-level__initial_elevation
land_surface_base-level__time_derivative_of_elevation    # (also called the "base-level lowering rate")

land_surface_contour_segment__total_contributing_area  (measured by: D8, D-inf., mass flux algorithm, etc.)  ######
land_surface_polygon__total_contributing_area   ## (maybe use "parcel" vs. "polygon" ?)
land_surface_transect__total_contributing_area    ## use transect or "line_segment" ?

land_surface~10m-above_air__temperature         (if land or sea, use "earth")
land_surface~10m-above_air_flow__speed
land_surface~10m-above_air_flow__x_component_of_velocity
land_surface~10m-above_air_flow__y_component_of_velocity

land_surface_energy~net~total__energy_flux     ## (includes all energy fluxes: radiation, sensible heat, latent heat, conduction heat, etc.)

land_surface_radiation~outgoing~longwave__emittance      ### (is it good to keep "outgoing" in these 2 names?)
land_surface_radiation~outgoing~longwave__emitted_energy_flux     ###### (use "emitted"  to exclude "incoming reflected" from outgoing)

######  Maybe add these also:   #######
land_surface_ice  + melt_volume_flux      (vs. glacier_ice + melt_volume_flux)
land_surface_snow + melt_volume_flux   (vs. snowpack + melt_volume_flux)

land_surface_soil_heat~conduction__energy_flux  [W m-2]  (from land surface into the soil)

land_surface_water__baseflow_mass_flux   [kg m-2 s-1]     (baseflow is always nonnegative and "incoming")
land_surface_water__baseflow_volume_flux  [m s-1]
land_surface_water__depth
land_surface_water__domain_time_integral_of_baseflow_volume_flux
land_surface_water__domain_time_integral_of_evaporation_volume_flux
land_surface_water__domain_time_integral_of_runoff_volume_flux
land_surface_water__east_derivative_of_depth
land_surface_water__evaporation_mass_flux      [kg m-2 s-1]
land_surface_water__evaporation_volume_flux     [m s-1]
land_surface_water__infiltration_ponding_depth        ## (the word "infiltration" is added here for clarity)
land_surface_water__infiltration_ponding_time      ## See "soil_surface_water__infiltration_volume_flux" and related terms)
land_surface_water__north_derivative_of_depth
land_surface_water__potential_evaporation_volume_flux   [m s-1]
land_surface_water__priestley-taylor_alpha_coefficient  [unitless]
land_surface_water__runoff_mass_flux          [kg m-2 s-1]     ### (sometimes called "excess rainrate")
land_surface_water__runoff_volume_flux          [m s-1]
land_surface_water__time_derivative_of_depth   [m s-1]
land_surface_water__x_derivative_of_depth
land_surface_water__y_derivative_of_depth

land_surface_water_flow__azimuth_angle_of_z_integral_of_velocity   # (z_integral_of_velocity = unit-width discharge = volume flow rate per unit contour length)
land_surface_water_flow__east_component_of_z_integral_of_velocity
land_surface_water_flow__east_derivative_of_east_component_of_z_integral_of_velocity
land_surface_water_flow__east_derivative_of_north_component_of_z_integral_of_velocity
land_surface_water_flow__magnitude_of_z_integral_of_velocity
land_surface_water_flow__north_component_of_z_integral_of_velocity
land_surface_water_flow__north_derivative_of_east_component_of_z_integral_of_velocity
land_surface_water_flow__north_derivative_of_north_component_of_z_integral_of_velocity
land_surface_water_flow__time_derivative_of_east_component_of_z_integral_of_velocity
land_surface_water_flow__time_derivative_of_north_component_of_z_integral_of_velocity
land_surface_water_flow__time_derivative_of_x_component_of_z_integral_of_velocity
land_surface_water_flow__time_derivative_of_y_component_of_z_integral_of_velocity
land_surface_water_flow__x_component_of_z_integral_of_velocity
land_surface_water_flow__x_derivative_of_x_component_of_z_integral_of_velocity
land_surface_water_flow__x_derivative_of_y_component_of_z_integral_of_velocity
land_surface_water_flow__y_component_of_z_integral_of_velocity
land_surface_water_flow__y_derivative_of_x_component_of_z_integral_of_velocity
land_surface_water_flow__y_derivative_of_y_component_of_z_integral_of_velocity

land_surface_water_flow__azimuth_angle_of_velocity
land_surface_water_flow__depth    ####  (overland flow depth)  (in PIHM)
land_surface_water_flow__down_component_of_velocity
land_surface_water_flow__east_component_of_velocity
land_surface_water_flow__elevation_angle_of_velocity
land_surface_water_flow__north_component_of_velocity
land_surface_water_flow__speed    ### (a scalar field throughout the 3D flow; not depth-integrated)
land_surface_water_flow__time_derivative_of_down_component_of_velocity
land_surface_water_flow__time_derivative_of_east_component_of_velocity
land_surface_water_flow__time_derivative_of_north_component_of_velocity
land_surface_water_flow__time_derivative_of_x_component_of_velocity
land_surface_water_flow__time_derivative_of_y_component_of_velocity
land_surface_water_flow__time_derivative_of_z_component_of_velocity
land_surface_water_flow__x_component_of_velocity
land_surface_water_flow__y_component_of_velocity
land_surface_water_flow__z_component_of_velocity

land_surface_water_sink__volume_flow_rate
land_surface_water_source__volume_flow_rate

land_surface_water_surface__elevation
land_surface_water_surface__time_derivative_of_elevation
land_surface_water_surface__x_derivative_of_elevation
land_surface_water_surface__y_derivative_of_elevation

land_vegetation__annual_time_max_of_leaf-area_index  (in PIHM)
land_vegetation__leaf-area_index  (in PIHM)
land_vegetation__reference_stomatal_resistance  (in PIHM)
land_vegetation__time_min_of_stomatal_resistance  (in PIHM)

land_vegetation_canopy__area_fraction
land_vegetation_canopy_water__interception_capacity  (in PIHM)   (i.e. max that can be intercepted and stored)
land_vegetation_canopy_water__interception_volume_flux  (in PIHM)
land_vegetation_canopy_water__throughfall_volume_flux  (in PIHM)
land_vegetation_canopy_water__transpiration_volume_flux
land_vegetation_floor_water__interception_volume_flux    ### (could use "understory" instead of "floor")

• The term runoff can be confusing, because it sounds like a lateral flow of water over the land surface (i.e. volume flow rate). However, it is computed as: R = (P + BF + SM + IM) - (ET + IN), where P = liquid precipitation, BF = baseflow (transport from subsurface to surface), SM = snowmelt, IM = ice melt, ET = evapotranspiration and IN = infiltration. Since each of these contributions is a vertical volume flux (a volume appearing per unit area per unit time), so is runoff. It has units of [m s-1], as a local contributor to change of water depth. It is technically not the same as overland flow, contrary what the current Wikipedia article on surface runoff says. Overland flow corresponds to lateral (not vertical) transport and can be quantified with unit-width discharge (or z-integral of velocity), which has units of [m2 s-1]. The amount of overland flow leaving a control volume has both a vertical contribution from runoff and a lateral contribution that results from (overland) flow into the other sides of the control volume. There can therefore be overland flow even if the runoff volume flux is zero.
• When evaporation (liquid to gas) or sublimation (solid to gas) occur, mass (e.g. water) is transferred from the land surface to the air. This mass (e.g. water molecules) transfers energy from the land surface to the air, but without a change in temperature. This energy is known as latent heat, and in this case there is an energy flux from the land surface to the air.
• When condensation (gas to liquid) or desublimation (gas to solid) occur, mass (e.g. water) is transferred from the air to the land surface. As before, this mass transfers energy, now from the air to the land surface, with no change in temperature. This is a latent heat flux from the air to the land surface. The net latent heat flux is the difference between the incoming and outgoing energy fluxes, relative to the last object listed in the object part of the standard name.
• The standard names: "atmosphere_bottom_air_land_heat~net~latent" + "energy_flux" and "land_surface_air_heat~net~latent" + "energy_flux" have the same magnitude but different signs.
• Sensible heat flux is the transport of heat between the land surface and the air by the process of turbulent conduction (vs. much slower molecular conduction). Sensible heat can be "sensed" with a thermometer. The direction of sensible heat flux is from the hotter to the cooler object.
• The standard names: "atmosphere_bottom_air_land_heat~net~sensible" + "energy_flux" and "land_surface_air_heat~net~sensible" + "energy_flux" have the same magnitude but different signs.
• Note that many of these quantities are defined in terms of first or second derivatives, which requires a certain degree of smoothness (differentiable or twice differentiable). Real topography is generally not this smooth, especially at small scales, but these quantities are nevertheless useful and can be computed from DEMs. In the CSDMS Standard Names, the Object_name + Model_name Pattern indicates that the word "surface" should be inserted in front of the quantity name when the quantity is only defined for some kind of idealized "model" surface. See the Surface template.
• "Specific contributing area" (SCA) is a quantity that can be defined for each point on a mathematical surface as the (upstream) contributing area per unit contour length. "Total contributing area" (TCA) is a quantity obtained from integrating SCA over a line segment, such as the width of a grid cell projected in the direction of the surface gradient. The relationship between TCA and SCA is similar to that between water discharge (Q) and unit-width water discharge (q, also called the depth-integral of velocity).
• "Contour curvature" is a synonym for "plan curvature". "streamline curvature" is not well-known. See: Peckham (2011).
• Also see Variable Names for Bedrock above.

## Variable Names for a Water Tank

quantity = attribute

Examples

atmosphere_water__precipitation_duration
atmosphere_water__precipitation_leq-volume_flux
tank~storage~open-top_x-section~horizontal__area       ### (add "interior" after "tank" ??)