摘要
利用天气图和T63资料分析 1 996年 1月中旬青海牧区降雪过程 ,指出这场暴雪是由于北支冷空气和南支暖湿气流结合形成具有中 α尺度结构的高原切变线引发的暴雪过程 ,其主要触发信号是切变线高层正变涡。诊断表明 ,对高层正变涡起主要贡献的是平流项和扭转项 ,此两项正贡献都与背景场上青藏高原南北两支西风急流适当配置相互作用有关。
The synoptic chart and T63 data were used to analyse the heavy snow event in the middle of January 1996 in Qinghai Province. The result suggests that the heavy snow event was caused by the plateau's shear line on meso α scale which was generated by the combination of northerly airflow areas with coldness and dryness and southerly airflow areas with warmness and humidity. The positive vorticity on the shear line was the main trigger signal. The diagnosis shows that the advection and the twisting terms were the main contribution for the high level positive changing vorticity, and the two term positive contributions were relative to the proper allocation and interaction of the westerly jets on the south and north sides over Plateau background field.
出处
《高原气象》
CSCD
北大核心
2000年第2期187-197,共11页
Plateau Meteorology
基金
国家自然科学基金!"我国西部灾害性暴雪机理的诊断和数值模拟研究"( 497752 71 )资助
关键词
青藏高原
暴雪
中-α尺度切变线
涡源诊断
Qinghai Xizang Plateau snow storm Meso α scale shear line Study of vortex source
