用过程透雨量确定的东亚夏季风北边缘特征  

Determination on the North Boundary of Summer Monsoon in East Asian with Soaking Rainfall

作　　者：黄菲[1] 李栋梁[1,2] 汤绪[1,3] 王式功[1] 王慧[2] 

机构地区：[1]兰州大学大气科学学院,兰州730000 [2]南京信息工程大学大气科学学院,南京210044 [3]上海市气象局,上海200030

出　　处：《应用气象学报》2009年第5期530-538,共9页Journal of Applied Meteorological Science

基　　金：国家自然科学基金项目(40875059和40875056);上海市气象局研究型业务专项"东亚副热带夏季风北边缘带变化及其成因分析"共同资助

摘　　要：利用1951—2006年全国715个站逐日降水资料及NCEP/NCAR逐日和月平均再分析资料,以农作物生长角度为出发点,采用过程透雨量(20 mm)标准确定4—10月出现6次及6次以上过程透雨量作为东亚夏季风区,以北边缘历年波动范围确定夏季风边缘带,根据连续透雨过程达到无旱标准来判断东亚夏季风的开始时间。主要分析了夏季风北边缘的年际、年代际变化特征和夏季风边缘带的变化范围以及夏季风边缘的推进过程和北边缘变化机制及其对我国降水的影响。结果表明:透雨标准较好地确定了边缘带位置,夏季风北边缘呈现向南偏移的趋势,边缘带范围有所扩大;北边缘变化与偏南风强弱和水汽输送联系紧密,并且对我国雨带的分布以及北方降水有一定影响,北边缘偏北,雨带偏北,则华北降水偏多。The summer monsoon brings plentiful water vapor,which is important for vegetation＇s growth and people＇s subsistence.The relation between monsoon＇s northward advance and north boundary＇s location is consanguineous.There are many monsoon indexes,and northward advancing of summer monsoon has also been investigated a lot.The research method considering vegetation growth angles proves to be accordant with the monsoon＇s influences on China.Station data and grid data including the daily rainfall data of 715 stations of China from 1951 to 2006 are used to depict the summer monsoon＇s advancing process.Moisture transport is also investigated using NCEP/NCAR monthly mean and daily reanalysis data.First,the soaking rainfall index is defined to determine the East Asian summer monsoon area.It takes appearing six times and more soaking rainfall（20 mm） processes during April to October as the standard,then the boundary belt positions for summer monsoon are defined according to the range of six times soaking rainfall lines waving variance annually,and wind vector changes in the boundary belt.Analyzing the continual soaking rainfall processes,the time when periods of drought ends is defined as the start time for summer monsoon in East Asian.This start time can represent the summer monsoon＇s northward advance.Besides,the characteristics of annual and decade variance of East Asian summer monsoon＇s north boundary and the variance of boundary belt＇s scopes are analyzed.Furthermore,the advanced process of East Asian summer monsoon＇s north boundary and its influence to the rainfall in China are investigated.To seek the cause about north boundary for summer monsoon waving unconventionally,it is important to analyze moisture transport which maybe one important gene.The results show that： the soaking rainfall standard ascertains boundary belt location for East Asian summer monsoon preferably,and it appears a tendency of southward moving and the scopes of boundary belt are enlarged.In brief,the location variance of

关 键 词：过程透雨量 夏季风北边缘带 雨带类型 北界位置 水汽输送 

分 类 号：P425.42[天文地球—大气科学及气象学] TP391.41[自动化与计算机技术—计算机应用技术]