Some issues on the GIPL-DOS-TEM permafrost dynamics modeling

Soil column we been using for permafrost dynamics simulation

The DOS-TEM layersMOSSDZ = moss layer SHLWDZ = fibric organic layer DEEPDZ = humic organic layer MINETOP = mineral soil layer 1MINEBOT = mineral soil layer 2

Additional layersSILTBEDROCK

Upper Boundary Conditions:Mean Monthly Air TemperatureMean Monthly SWE

From SWE the GIPL generated snow properties:• Depth• Density• Thermal Conductivity

At the Lower Boundary:

Heat Flux calculated at the particular grid cell geospatially referenced by Latitude and Longitude, using spherical harmonic of order 12

described in: Pollack, H.N., Hurter, S.J., & Johnson, J.R., 1993. Heat flow from the earth's interior: analysis of the global data set, Reviews of Geophysics 31(3), 267-280.

Conditionally named Soil Moisture Deficiency (SMD)

VWC - Volumetric Water Content

SMD = GIPL(VWC) – DOS-TEM(VWC)

Daily soil temperature modeled in two ways: GIPL-Standalone and GIPL-DOS-TEM dynamics

The GIPL-DOS-TEM modeled daily soil temperature at 5 m depth (cccma_a1b)

Our findings:

Soil moisture dynamics are very important for permafrost modeling because soil moisture affects seasonally depended processes such as freezing, thawing, time of freeze-up due to thermal conductivity and latent heat. However, seasonal processes could have impact on the long-term process of permafrost dynamics due to cumulative effect.

One of the important ecosystem component for permafrost modeling are organic layer. An organic matter accumulation dynamics or their destruction, directly affect accuracy of prediction of permafrost behavior.