ABSTRACT

The actual ground temperature is a result of the heat balance on the surface of the Earth. This is dependent on two main factors, viz., the geothermal heat flow and the solar radiation reaching the surface of the Earth. The difference between the energy reaching the surface and that emitted from the surface radiation by reradiation is called the net solar radiation (Rn). One of the main causes of precipitation is the interaction between cold, dense, polar or sub-polar air and warm, humid temperate or tropical air, so the movements of the air masses are critical in maintaining the precipitation at any given location. The Earth surface and the atmosphere also exchange heat through convection between the surface and the air (the sensible heat flux, H) as well as through evaporation and transpiration (latent heat, LE). Permafrost distribution is closely related to the distribution of the Arctic and Antarctic air masses as well as the polar air masses.