摘要
应用常规观测资料、灾情资料、NCAR/NCEP再分析资料(2.5×2.5经纬度),对近40年发生在内蒙古地区(草原牧区为主)的21次较强暴风雪天气过程,就暴风雪天气进行了天气学分型和成因分析。同时,针对内蒙古暴风雪天气主要影响系统-蒙古冷涡的结构、发展演变特征进行了分析研究。分析研究表明:强冷空气活动是暴风雪天气形成的主要原因;强盛的高空急流及与之配合的高空辐散区的强迫作用是地面蒙古气旋强烈发展和强风形成的动力条件;远程的较好的水汽输送配合对流层低层冷涡辐合对较强的降雪至关重要;对流层高层辐散强迫、中低层温度差异、中层涡度平流作用对蒙古气旋的爆发性发展起到关键作用;对流层低层偏南暖湿急流与偏西干冷急流在蒙古气旋控制区交汇是暴风雪天气发生的重要特征;对流层中层强上升运动配合对流层低层强风区的结构特征对确定暴风雪天气落区有很好的指示意义。
Using normal observational data , information of disaster and NCAR/NCEP reanalysis data（2.5 ＊ 2.5 longitude/latitude） we analyzed synoptic process of 21 times of strong snowstorms happened in Inner Mongolia （mainly in the grassland） in recent 40 years. We classified the snowstorm in different synoptic types and ana- lysed the cause of the snowstorms. At the same time, we did research in the main influencing factor of Mongolia snowstorm, which are Mongolia cold vortex structure and the developing features. Analysis showed that strong cold weather is the main cause of the snowstorm; the strong upeer level jet stream meet with the forced role of high - altitude area divergence not only is the dynamic conditions of strong development Mongolia cyclone on the ground, but also forms strong wind; Remote rich water vapor transport cooperating with cold vortex convergence in low - level of tropospheric is essential to strong snowfall ; Divergence force in upper troposphere , temperature differences in middle and lower troposphere and vorticity advection in the middle has a pivotal effect on the explo- sive developing of Mongolia cyclone; In lower troposphere southern warm wet jet stream always meets with the western dry cold jet stream in the area controlled by Mongolia cyclone, this is an important feature of snowstorm ; Strong ascending motion in mid troposphere cooperating with the structure feature of strong breeze area in lower troposphere is a good indicator for confirmin~ the ~tc^rrn fnllln ~o,~
出处
《干旱区资源与环境》
CSSCI
CSCD
北大核心
2012年第5期18-27,共10页
Journal of Arid Land Resources and Environment
关键词
暴风雪
蒙古气旋
诊断分析
snowstorm
the Mongolian cyclone
diagnostic analysis
