干、湿环境下中尺度对流系统发生的环流背景和地面特征分析  

Characteristics of Synoptic and Surface Circulation of Mesoscale Convective Systems in Dry and Moist Environmental Conditions

作　　者：郑淋淋[1,2] 孙建华[1] 

机构地区：[1]中国科学院大气物理研究所云降水物理与强风暴实验室,北京100029 [2]中国科学院大学,北京100049

出　　处：《大气科学》2013年第4期891-904,共14页Chinese Journal of Atmospheric Sciences

基　　金：国家自然科学基金项目41075032;中国气象局公益性行业(气象)科研专项经费项目GYHY200906004;国家重点基础研究规划项目2010CB951804

摘　　要：对2007～2010年暖季(6～9月)发生在江淮和黄淮流域46个对流天气过程的环流背景和地面特征进行了统计研究。根据整层可降水量小于或大于等于50mm将这些个例发生的环境分成干环境(10个个例)和湿环境(36个个例)。干环境下发生强对流的天气形势可以分为槽后型和副高边缘型,湿环境下的天气形势可分为槽前型、副高边缘型和槽后型,湿环境下有明显的暖湿区配合。湿环境下槽前型发生的概率最高,地面系统较为复杂,有静止锋、倒槽、冷锋和暖锋,而干环境下在本研究的个例中无槽前型发生。干、湿环境下副高边缘型的对流,从地面到500hPa都发生在副高后部的"S"流型的拐弯处,但部分湿环境个例低层有切变线。干环境下槽后型的发生概率较高,而湿环境下发生概率则相对较少。由这些研究表明,干、湿环境下强对流系统的触发和维持机制存在明显的差异。The synoptic circulation and surface characteristics of 46 convective events occurring over the Huaihe River and Yellow River basins from June to September during 2007-2010 are investigated. The related environmental conditions are classified as dry （10 cases） and moist （36 cases） environments according to whether precipitable water is less than, greater than or equal to 50 mm. The synoptic patterns in dry （moist） environments could be classified into post-trough and rim of subtropical high （pre-trough, post-trough, and rim of subtropical high） patterns. In addition, cases in moist environments are frequently accompanied by warm and moist flow. The pre-trough pattern in moist environments is characterized by various surface systems including a stationary front, inverted trough, cold front, and warm front. The pre-trough pattern occurs frequently in moist environments but does not occur in dry environments among the cases studied here. The convective cases are initialized at the corner of the ＂S＂ pattern from the surface to 500 hPa for the rim of subtropical high pattern in both dry and moist environments, but some cases in moist environments occur near the shear lines at low levels. The post-trough pattern occurs frequently in dry environments but rarely in moist environments. The aforementioned analyses show that significant differences exist between dry and moist environmental conditions where severe convective systems occur.

关 键 词：江淮和黄淮流域 环流形势 地面特征 "S"流型 

分 类 号：P448[天文地球—大气科学及气象学]