Model help:GIPL

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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

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

Parameter	Description	Unit
First parameter	Description parameter	[Units]

Uses ports

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Provides ports

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Main equations

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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

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Developer(s)

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References

Key papers

Links

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