Model help:GIPL

The CSDMS Help System

GIPL

GIPL is a heat flow with phase change model use to model permafrost thermal state and active layer depth, can be used for site specific and regional ground temperature distribution modeling.

Model introduction

GIPL(Geophysical Institute Permafrost Laboratory) is an implicit finite difference transient one-dimensional heat flow model. The model simulates ground temperature dynamics and the depth of the active layer by solving non-linear heat equation with phase change numerically. The model employs the Enthalpy method which does not require explicit treatment of the freeze/thaw moving boundary. In this model the process of freezing or thawing is occurring in accordance with unfrozen water content and soil thermal properties, and depends on the degree of soil saturation.

Model parameters

Input files and Directories

Second tab header

Etc. tab header

Parameter	Description	Unit
Switcher	1 runs new simulation reading initial temperature distribution from initial.txt file in input folder, 0 continues simulation by reading initial temperatures from dump/start_001.txt file	-
Output time step	Output calculated temperatures based on output time step input. For example, 1 correspond to 1 day time interval. The result.txt file has the temperature distribution output based on the output time interval.	days
Calculation step	Calculation time step used in Stefan subroutine.	-
Minimal time step	Minimum time step is a constrain for calculation time step used in Stefan subroutine.	-
Number of years	If the number is greater than 1 then the model simulates the ground temperature distribution and write mean annual temperature distribution with depth into mean_001.txt file.	years
Max distance between next temperature iterations (E1) (0.001-0.1)	If the absolute difference between current and next temperature iteration is greater than E1 progonka continuous. Used in Stefan subroutine.	-
Error of saturation for next iteration (UWK)	If the absolute difference between current and next saturated unfrozen water coefficient is greater than UWK progonka continuous. Used in Stefan subroutine.	-
Max number of iterations before dividing time step	If the current and next temperature iteration do not converge i.e. absolute difference is greater than E1 then time step divided by 2. Used in Stefan subroutine.	-
Number of seconds per step	For output time step 1 day number of seconds is equal to 86400.	sec
Average number	The average number of days in one year 365.	day
depth of earth surface		meters
maximum number of freezing fronts	For example if there case of a talik there are more than 2 freezing fronts	-
min depth of freezing front		meters
max depth of freezing front		meters
The saturation coefficient	Used for freeze/thaw front calculation	percent

Parameter	Description	Unit
First parameter	Description parameter	[Units]

Uses ports

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Provides ports

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Main equations

A list of the key equations. HTML format is supported; latex format will be supported in the future

Notes

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Numerical scheme

Examples

An example run with input parameters, BLD files, as well as a figure / movie of the output

Follow the next steps to include images / movies of simulations:

• Upload file: http://csdms.colorado.edu/wiki/Special:Upload
• Create link to the file on your page: [[Image:<file name>]].

See also: Help:Images or Help:Movies

Developer(s)

Name of the module developer(s)

References

Key papers

Links

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