Mathematical modeling of the atmosphere-cryolitic zone interaction

The main factors controlling the ground thermal regime characteristic of cold regions are analyzed with the use of a one-dimensional model of heat and moisture transport in the soil and its interaction with the atmosphere. The influence of these factors on the state of permafrost and the present-day climate as a whole is investigated on the basis of numerical experiments with a global model of general atmospheric circulation. It is shown that a decrease in the heat conductivity coefficient of the upper soil level, which can be interpreted as a layer of nondecomposed litter and moss, considerably increases the area occupied by permafrost. The introduction of the dependence of the heat conductivity coefficient on the phase state of water in the ground also increases the area occupied by permafrost and decreases the depth of the layer of its seasonal thawing in this territory. It is also established that the larger the relative amount of water which can be contained in the ground in a supercooled state is, the higher its temperature is, the lager the active layer depth is, and the smaller the area occupied by perennially frozen rocks is.