低空急流在一次区域性暴雨过程中的作用  

The Role of Low-level Jet in a Regional Heavy Rainfall

作　　者：闵涛[1] 吴筱 

机构地区：[1]雅安市气象局,四川雅安625000 [2]九寨沟气象局,四川九寨沟623400

出　　处：《安徽农业科学》2015年第35期280-284,共5页Journal of Anhui Agricultural Sciences

摘　　要：利用常规高空观测、地面加密自动站和NCEP再分析资料，对2015年8月3～4日发生在雅安的区域性暴雨过程进行分析，结果表明，此次过程雅安市位于两高之间的辐合带，这为高纬冷空气沿着辐合带迅速南下入侵该市并触发不稳定能量提供了有利的环流条件；南风低空急流有利于南海水汽向雅安市输送，并造成整个雅安范围内暴雨的产生；低空急流下产生的暴雨不要求强烈的气旋性扰动，低空急流可通过水汽输送来促进暴雨区的低层辐合和高层辐散，形成低层强辐合和高层辐散相耦合的有利动力结构，从而促进并加强大气的垂直上升运动；低空急流为暴雨的产生提供了有利的水汽条件和热力条件。A regional rainstorm occurred in Ya＇an during Aug 3rd to 4th 2015 was analyzed by using the conventional data, intensive surface ohservation data and NCEP reanalysis data. The resuhs showed thai： In this process, Ya＇an is located in the convergence zone between two high pressure, which form is conducive to the high latitude cold air down south quickly along the cunvergence zone and trigger instability energy ; The southerly low-level jet is conducive to transport water vapor from the South China Sea to Ya＇an and cause rainsturm in the whole range of Ya＇an; Strung cyclone disturbance is unwanted in the rainstorm which occun＇ed under luw-level jet for that the low-level jet can promote and strenglhen the vertical upward movement by transport water vapor to form the favorable dynamic structure in which the convergence at lower level and divergence at upper level; The low-level jel provides favorable water vapor conditions and thermal conditions for the rainstorm.

关 键 词：雅安 低空急流 暴雨 作用 

分 类 号：S161.6[农业科学—农业气象学]