Spatial distribution mapping of permafrost in Mongolia using TTOP

This study presents the results of permafrost mapping in Mongolia based on the TTOP (temperature-on-top-of-permafrost) approach, which were validated against in situ measurements at various locations. In situ measurements indicated that the mean annual ground temperature (MAGT) ranged from 0.6 to 2.2 degrees C interannually, showing the greatest variability when furthest from 0 degrees C. The differences between the modeled and measured MAGTs exceeded +/- 1 degrees C in locations where permafrost was in a nonequilibrium state and was controlled predominantly by local factors. It was estimated that permafrost occupies one-third of Mongolia. We divided the extent of the permafrost into five zones: continuous, discontinuous, sporadic, isolated, and seasonally frozen ground. In total, the permafrost zones cover similar to 462.8 x 10(3) km(2), accounting for 29.3% of Mongolia. Of this total area, continuous permafrost accounted for 118.3 x 10(3) km(2) (7.5%), discontinuous permafrost 127.7 x 10(3) km(2) (8.1%), sporadic permafrost 112.4 x 10(3) km(2) (7.1%), and isolated permafrost 104.4 x 10(3) km(2) (6.6%).