乌鲁木齐春季两类东南大风个例的对比分析  

Analysis of Comparison Between the Two Kinds of the Southeasterly Gale Cases in Spring in Urumqi

作　　者：孙鸣婧 李如琦 刘俊哲 肉孜.阿基 

机构地区：[1]新疆气象台,新疆乌鲁木齐830002 [2]和静县气象局,新疆和静841300

出　　处：《沙漠与绿洲气象》2017年第5期38-45,共8页Desert and Oasis Meteorology

基　　金：国家自然科学基金(41575011);中央级公益性科研院所基本科研业务费专项资金项目(IDM201501);新疆气象局气象科技研究课题(MS2015001)共同资助

摘　　要：运用NCEP逐6 h再分析资料、乌鲁木齐自动站逐时常规观测资料、微波辐射计及边界层风廓线雷达资料,对比分析了发生在乌鲁木齐春季的两次接地型东南风和一次低空型东南大风过程。结果表明:无论是接地型还是低空型,峡谷两端南高北低的海平面气压场是必要的地面形势;地面蒙古冷高越强,东南风不一定越强,乌鲁木齐与达坂城的气压梯度也不一定越大;东南大风很大程度上受温度平流影响,水平方向乌鲁木齐与其以东或以南形成较大温度梯度、垂直方向乌鲁木齐上空对流层中下层暖气团越深厚、温度越高,越利于地面东南大风的发生;进一步分析发现地面乌鲁木齐东南大风较大时刻都伴随着高空的动量下传,一方面动量下传为地面风提供动量,另一方面向下输送的暖平流利于乌鲁木齐局地升温减压,确保乌鲁木齐与峡谷南端气压差和温度差的维持。Based on the NCEP reanalysis data, the weather station conventional observation data,data derived from the microwave radiometer and boundary layer wind profile radar, comparativeanalysis of two ground-based southeasterly gale cases and one elevated southeasterly gale case inUrumqi are performed. The results show that the sea level pressure patterns such as the lowpressure in north of Xinjiang matching the high in south of Xinjiang or the low pressure in west ofXinjiang matching the high pressure in east of Xinjiang are necessary for the formation of the twokinds of southeasterly gale. Under control by the strong Mongolia high, the southeasterly gales maynot occur although there is a pressure gradient around Urumqi. The southeasterly gales alsodepended on horizontal temperature gradient in the south-north direction. In combination with thickand warm air mass over Urumqi city, it is favorable for the onset of the southeasterly gale. Furtheranalysis also found that the downward momentum transport can not only provide kinetic energy tothe low- level flow, but also heat the low-level flow by the dry adiabatic sinking movement, causingthe pressure over Urumqi to be low. Such situation is conducive to keep the pressure difference andthe temperature difference across the valley.

关 键 词：乌鲁木齐 东南大风 气压梯度 温度平流 动量下传 

分 类 号：P458.123[天文地球—大气科学及气象学]