京津地区对流性和层状降水回波的特征分析  

Characteristics of Convective and Stratiform Echoes in Beijing-Tianjin Region

作　　者：林隐静[1] 王洪庆[1] 韩雷[2] 王玉[1] 郑永光 

机构地区：[1]北京大学物理学院大气与海洋科学系,北京100871 [2]中国海洋大学信息科学与工程学院,青岛266100 [3]国家气象中心,北京100081

出　　处：《北京大学学报（自然科学版）》2011年第2期258-262,共5页Acta Scientiarum Naturalium Universitatis Pekinensis

基　　金：国家自然科学基金(40875019)资助

摘　　要：利用自动分类算法,识别出2005—2007年5—8月京津地区雷达回波中的对流性和层状降水回波。在此基础上,分析了该地区对流性和层状降水回波的垂直廓线和回波面积的日变化特征。结果表明:京津地区层状降水回波的垂直廓线在4 km高度(0℃)附近,出现了明显的"零度层亮带",亮带强度在当地夜间最强,当地上午最弱;该区域内,两种类型的回波面积均呈明显的单峰型日变化特征,面积峰值出现在当地夜间,在当地午间面积最小;层状降水回波面积的变化比对流性降水回波的变化滞后了1～2 h;对流性回波与层状回波面积比的日变化存在两个明显的峰值,分别对应两类影响京津地区的主要对流系统:午后出现的热对流和具有夜发性的湿对流。The reflcctivity fields of Beijing-Tianjin region during 2005-2007 were classified into convective and stratiform components using an automatic algorithm, and then the vertical profiles and diurnal variation of convective and stratiform echoes in this region were analyzed. The results are as follows. 1 ） An obvious bright band was in the stratiform profile of Beijing-Tianjin region at about the 4 km altitude. The bright band was strongest in the night local time, while weakest in the morning. 2） In this region, the diurnal variations of both convective area and stratiform area were unimodal. The maximum areas occurred in the local evening, while the minimum occurred near local noon. The variation of stratiform area was about 1-2 hours later than convective area. 3 ） There were two peaks in the diurnal variation of the ratio between convective and stratiform area. One was associated with the thermal convection in the local afternoon, and the other was connected with the moist mass convection happens in the local evening. Both these two types of convection are typical convective systems in Beijing-Tianjin region.

关 键 词：天气雷达 对流性降水回波 层状降水回波 京津地区 

分 类 号：P412.25[天文地球—大气科学及气象学]