Causes of a Heavy Snowfall Process in Eastern Yunnan in 2022  

作　　者：Menglin TIAN Tao ZHANG Puli ZHANG Mingyong YU 

机构地区：[1]Qujing Meteorological Bureau,Qujing 655000,China [2]Zhanyi Meteorological Bureau,Zhanyi 655331,China

出　　处：《Meteorological and Environmental Research》2023年第6期16-22,28,共8页气象与环境研究（英文版）

基　　金：Supported by the Project of Meteorological Science and Technology Innovation and Capacity Improvement Program for Young Scholars of Basic Stations in Yunnan(STIAP202210).

摘　　要：Based on NCEP/NCAR reanalysis data, Micaps data and ground observation data, the physical characteristics of a heavy snowfall process in eastern Yunnan from January 31 to February 3, 2022 were analyzed. The results show that the circulation background of the heavy snowfall process was "north-ridge and south-trough" type, and the cold air accumulated in the deep East Asian transverse trough. The cold advection behind the trough moved southwards into eastern Yunnan under the movement of the transverse trough. The establishment of upper and lower air jet provided abundant water vapor, and the snowfall area coincided with the strong water vapor convergence area. The strong cold center near the ground was maintained, and the cold air moved southwards. As a result, the cold pad was lasting and deep, and the ground temperature was 0 ℃ or below, which was conducive to snow accumulation on the ground. Seen from the spatial distribution of pseudo-equivalent potential temperature, the low layer always had certain warm and wet conditions during the heavy snowfall, which was conducive to the establishment of unstable energy. The snowfall occurred near the θ se steep area and the warm and wet unstable area. The vertical distribution of temperature had a good indication of precipitation form. The upper layer was controlled by strong cold advection, while the middle and lower troposphere was controlled by warm advection, and there was a warm inversion layer, which was conducive to the transformation of ice crystals into snowflakes, so that ice crystals fell to the ground in the form of snowflakes.

关 键 词：Heavy snowfall "North-ridge and south-trough"type Torrent Characteristics of physical quantities 

分 类 号：P73[天文地球—海洋科学]