A CASE STUDY OF COLD WAVE IN EAST ASIA USING TRAJECTORY TECHNIQUES

By using the data of FGGE Ⅲ SOP(I),the three-dimensional tra jectorie of air parcels in a East Asia cold wave case occurring during 24 Jan. -31 Jan. 1979 are calculated and analysed. The results show that: the cold wave high, over Balchas Lake and its neighbouring region (Area B),did not generate from the upstream cold high (named early stage cold high),which developed in the juncture of Europe and Asia and moved slowly eastward. The cold wave high formed and developed as the cold air in polar region around Jamal Peninsula moved down southward to Area B and amassed over there. Furthermore, adiabatic cooling of ascending air over Area B facilitated the formation of the cold wave high. During cold wave breaking out period, the cold air parcels scattered in shape of so called "sector spread" in the lower troposphere. The whole process of cold air movement in this event is characterized by amassing, scattering, amassing again and scattering again.