Model:Lake-Permafrost with Subsidence

Contact

Name	Nora Matell
Type of contact	Model developer
Institute / Organization	INSTAAR, University of Colorado
Postal address 1	450 UCB
Postal address 2
Town / City	Boulder
Postal code	80305
State	Colorado
Country	USA"USA" is not in the list (Afghanistan, Albania, Algeria, Andorra, Angola, Antigua and Barbuda, Argentina, Armenia, Australia, Austria, ...) of allowed values for the "Country" property.
Email address	nlmatell@gmail.com
Phone
Fax

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Lake-Permafrost with Subsidence

Metadata

Summary Also known as Model type Single Model part of larger framework Note on status model Date note status model Technical specs Supported platforms Windows Other platform Programming language Matlab Other program language Code optimized Single Processor Multiple processors implemented Nr of distributed processors Nr of shared processors Start year development 2008 Does model development still take place? No If above answer is no, provide end year model development 2009 Code development status When did you indicate the 'code development status'? Model availability As code Source code availability (Or provide future intension) Through owner"Through owner" is not in the list (Through web repository, Through CSDMS repository) of allowed values for the "Source code availability" property. Source web address Source csdms web address Program license type GPL v2 Program license type other Memory requirements -- Typical run time -- In/Output Describe input parameters Daily average solar radiation for location (at surface). Input format Other input format Matlab .mat file Describe output parameters Matlab variables, Matlab graphs Output format Other output format Matlab variables, Matlab graphs Pre-processing software needed? No Describe pre-processing software Post-processing software needed? No Describe post-processing software Visualization software needed? No If above answer is yes Other visualization software Process Describe processes represented by the model Heat conduction in permafrost, lake ice growth-decay, permafrost subsidence due to excess ice Describe key physical parameters and equations Heat conduction equations, lake ice growth-decay equations Describe length scale and resolution constraints Near surface, length scale should be 5-10 cm if subsidence occurring. Deeper in permafrost, 1+ m okay. Describe time scale and resolution constraints Model needs daily (or smaller) timesteps. Describe any numerical limitations and issues Runs slowly - iterates implicit scheme. Some sort of matrix algebra might improve speed. Testing Describe available calibration data sets -- Upload calibration data sets if available: Describe available test data sets Permafrost model can be tested with ground temperature time series at several depths. Lake model can be tested with known ice depths (though snow, not accounted for in model, can affect depth by several 10s of cm). Upload test data sets if available: Describe ideal data for testing Lake temperature time series, known lake depth, underlying permafrost time series. Surface temperature time series as input (not air temperature). Other Do you have current or future plans for collaborating with other researchers? -- Is there a manual available? No Upload manual if available: Model website if any Model forum / discussion board Comments Lake-Permafrost with Subsidence Introduction History Papers Lake-Permafrost with Subsidence Questionnaire Contact Information Model: Lake-Permafrost with Subsidence Contact person: Nora Matell Institute: CU Boulder - INSTAAR City: Boulder Country: USA Email: nlmatell@gmail.com 2nd person involved: -- 3rd person involved: -- Model description Model type: Single model for the terrestrial domain. Description: Models temperature of 1-D lake-permafrost system through time, given input surface temperature and solar radiation. Model is fully implicit control volume scheme, and cell size can vary with depth. Thermal conductivity and specific heat capacity are dependent on cell substrate (% soil and % ice) and temperature using the apparent heat capacity scheme where freezing/thawing occurs over a finite temperature range and constants are modified to account for latent heat. Lake freezes and thaws depending on temperature; when no ice is present lake is fully mixed and can absorb solar radiation. Upper 10 m substrate contains excess ice and, if thawed, can subside by this amount (lake then deepens by amount of subsidence). "Cell type" controls whether cell has excess ice, only pore space ice, or is lake water. Technical information Supported platforms: Windows Programming language: Matlab Model development started at: 2008 and ended in 2009 To what degree will the model become available: Source code will be available Current license type: GPLv2 Memory requirements: -- Typical run time: -- Input / Output description Input parameters: Daily average solar radiation for location (at surface). Input format: matlab .mat file Output parameters: Matlab variables, Matlab graphs Output format: Matlab variables, Matlab graphs Post-processing software (if needed): -- Visualization software (if needed): -- Process description Processes represented by model: Heat conduction in permafrost, lake ice growth-decay, permafrost subsidence due to excess ice Key physical parameters & equations: Heat conduction equations, lake ice growth-decay equations Length scale & resolution constraints: Near surface, length scale should be 5-10 cm if subsidence occurring. Deeper in permafrost, 1+ m okay. Time scale & resolution constraints: Model needs daily (or smaller) timesteps. Numerical limitations and issues : Runs slowly - iterates implicit scheme. Some sort of matrix algebra might improve speed. Testing Available calibration data sets: -- Available test data sets: Permafrost model can be tested with ground temperature time series at several depths. Lake model can be tested with known ice depths (though snow, not accounted for in model, can affect depth by several 10s of cm). Ideal data for testing: Lake temperature time series, known lake depth, underlying permafrost time series. Surface temperature time series as input (not air temperature). User groups Currently or plans for collaborating with: -- Documentation Key papers of the model: Model based on previous models by Ling and Zhang (2004), Plug and West (2008), Liston and Hall (1995). Model described in Matell et al. (in preparation) and Matell (2009, masters thesis). Is there a manual available: no Model website if any: -- Additional comments Comments: -- Issues Help Input Files Output Files Download Source