Modeling Ground Temperature with Thermal Conductivities based on Soil Classification and Moisture in High Mountain Asia

Permafrost in the HMA region requires careful attention because of its vulnerability to degradation and thaw under modern climate change scenarios. However, the lack of in-situ observations and the environment's complex topography continue to complicate its quantification. Although remotely sensed data products (i.e., land surface temperature from MODIS, Moderate Resolution Imaging Spectroradiometers) are valuable for obtaining initial estimates, the interim variable (i.e., MAGT, Mean Annual Ground Temperature) used to parameterize permafrost occurrence is highly sensitive to subsurface thermal conductivities by way of soil type and moisture conditions. Given the warmer nature of alpine permafrost at shallower depths, the MAGT is especially contested. In this study, we conduct a sensitivity analysis based on soil classifications from SoilGrids (250 m) and monthly soil moisture from ERA5-Land (9 km) to constrain the range of possible MAGT derived from MODIS (from 2003 to 2016 at 1 km), depending on the depths of the active layer and zero annual amplitude. Available borehole measurements and surface soil temperatures were used to assess for accuracy and context.