GEOGRAPHICAL SIGNATURES FOR THERMAL CONVECTION CLIMATOLOGY

Abstract

Maps for the qualification of thermal convection over different areas have been used by glider pilots especially for Westem Germany for more than fifteen years. They are based on data about water table distance, soil kind and quality, vegetation and evapotranspiration, or on cumulus cloud cover statistic partly out of satellite data, and on other parameters. After the reunification of Germany, thermal convection maps havebeen constructed by similar methods for Eastem Germany. All these construction methods are based on the idea, that available maps can be combined in that manner to represent the thermal convection potential. One of the results of experience and measurements was that deciduous forests (after development of their leaves in spring) have large evapotranspiration and thus bad thermals. Such forests exist to a great extent in Westem Germany. On the other hand, East German and Polish pilots experience in their areas a high thermal convection potential over forests (here mostly pine forests) even greater than over agricultural fields. This special thermal behavior and an advanced method for a more automatic evaluation of thermal convection potential will be discussed.