我国暖季深对流云分布与日变化特征分析  

Distribution and Spatiotemporal Variations of Deep Convective Clouds over China During the Warm Season

作　　者：陈国春[1,2] 郑永光 肖天贵[1] 

机构地区：[1]成都信息工程学院,成都610225 [2]国家气象中心,北京100081

出　　处：《气象》2011年第1期75-84,共10页Meteorological Monthly

基　　金：公益性行业(气象)科研专项(GYHY200906003;GYHY200906004);国家自然科学基金项目40875019共同资助

摘　　要：本文利用1996—2008年近12年3—10月(无2004年资料,部分时段资料缺失)的地球静止卫星逐时多通道(红外1、红外2和水汽通道)数字云图资料给出了我国及周边地区暖季深对流云时空演变特征,并对比分析了相关文献中的雷暴日数分布及低轨卫星观测的闪电密度分布。本文以TB_(ir1)(红外1通道亮温)≤-52℃、TB_(ir1)-TB_(ir2)(红外2通道亮温)<3 K、TB_(ir1)-TB_(wv)(水汽通道亮温)≤8 K来识别深对流云。分析结果表明:我国暖季有4个深对流云活跃区域,分别为青藏高原中东部、华南和云贵高原东北部、新疆伊犁河谷及周边区域、浙闽赣大部分区域;总体来看深对流云夏季(6—8月)最活跃,春季(3—5月)次之,秋季(9—10月)最不活跃;不同季节深对流云地理分布特征显著不同;不同季节、不同地区的深对流云日变化特征具有明显差异,秋季日变化最不显著;由于春季日落时间早于夏季,一般说来深对流云日变化主峰时段春季早于夏季;青藏高原中东部、两广丘陵与浙闽丘陵地区深对流云都为单峰型日变化;四川盆地深对流云具有显著的夜发性特征;江淮地区春夏季节深对流云日变化都为双峰型,这可能与该区域较多MαCS密切相关;青藏高原中东部热对流比较活跃;夏季两广丘陵、四川盆地和江淮地区不仅热对流活动频繁,其他天气系统(比如台风、梅雨锋等)触发和维持的对流活动也非常活跃。Based on the nearly-twelve-year hourly geostationary satellite multi-channel（IR1,IR2 and water vapor channels） digital infrared image dataset,the distribution and spatiotemporal variations of deep convective clouds over China and its vicinity during the warm season（March -October） from 1996 to 2008 （lacking 2004 data,part data missing） are analyzed,and comparative analysis is conducted on the distribution of thunderstorm days and the density distribution of lightning obtained from low-orbit satellites.In this paper,TB_（ir1）≤-52℃（Infrared 1-channel brightness temperature）,TB_（ir1）-TB_（ir2）3 K（Infrared 2- channel brightness temperature）,and TB_（ir1）-TB_（wv）≤8 K（water vapor channel brightness temperature） are used to identify the deep convetive clouds.The results show that：There are four active regions of deep convective clouds during the warm season,i.e.,the middle-east of Qinghai-Tibetan Plateau,South China and Northeast of Yunnan-Guizhou Plateau,Xinjiang Ili River Valley and its surrounding area,and the most parts of Zhejiang-Fujian-Jiangxi regions;Overall,deep convective clouds over summer（June-August） are the most active;in spring（March-May） followed by;the autumn（September-October） are the least;The geographical distribution of deep convective clouds in different seasons is significantly different;The feature of diurnal variations of deep convective clouds has a significantly difference in different seasons and regions;Autumn diurnal variation is the least significant;As spring sunset time is earlier than the summer,in general,the diurnal variation of deep convective clouds in the spring is earlier than the summer peak hours;Deep convective clouds in the middle-east of Qinghai-Tibetan Plateau,Guangdong and Guangxi hills and the Zhejiang and Fujian hilly regions are of the single peak diurnal variation;At Sichuan Basin,the deep convective clouds often have nocturnal occurrence;In spring and summer,the diurnal variations of deep convective clouds ar

关 键 词：深对流云 时空分布 季节变化 日变化 

分 类 号：P426.62[天文地球—大气科学及气象学]