夏季东北冷涡异常对淮河流域降水影响机制的数值模拟  

Numerical Studies of Affection of Northeast Cold Vortex Abnormal on Rainfall over Huaihe River Valley in Summer

作　　者：孙燕[1] 韩桂荣[1] 李超[1] 

机构地区：[1]江苏省气象台,南京210008

出　　处：《高原气象》2015年第4期1149-1157,共9页Plateau Meteorology

基　　金：江苏省科技厅科技支撑计划社会发展项目(BE2011818);淮河流域气象开放研究基金(HRM201006);江苏省气象科研开放基金(K201006)

摘　　要：利用NCEP/NCAR月平均再分析资料分析了1960-2009年夏季东北冷涡异常特征及其与同期淮河流域降水的关系,结果表明:当东北冷涡偏强时,淮河流域降水可能偏多;当东北冷涡偏弱时,淮河流域降水可能偏少。选取夏季东北冷涡典型异常强年(2003年)进行数值模拟,人为添加扰动热源后,高层出现东南差值气流,低层出现西北差值气流,这种环流形势不利于高层冷空气与低层西南暖湿气流在淮河流域交汇,不利于淮河流域降水的发生、发展,最终使得淮河流域降水减少。夏季东北冷涡通过热源异常影响淮河流域降水的可能机制为东北冷涡强(弱)年,东北冷涡持续性活动偏多(少),导致东北—朝鲜半岛—日本以东洋面热力状况异常冷(暖),使得35°N-50°N纬带的海陆热力差异更大(小),引起夏季风及其他环流系统异常,有(不)利于淮河流域降水发生、发展,从而导致淮河流域降水异常偏多(少)。By using the NCEP / NCAR reanalysis data,the anomalous features of the northeast cold vortex and relationship between it and rainfall in the Huaihe River valley in summer from 1960 to 2009 was analyzed. It was found that stronger northeast cold vortex possibly related to more rainfall in the Huaihe River,and vice versa.2003 was chose as a strong northeast cold vortex year,and a heat source was artificially added in the numerical studies. As a result of that,different southeast airflowoccurred in high levels,and difference northwest airflowin lowlevels. This circulation situation was not conducive to high-level cold air and the low-level warm and humid air joined over the Huaihe River valley,therefore the precipitation over the Huaihe River valley deceased.The formation mechanism of rainfall reaction over the Huaihe River valley in the northeast cold vortex was found that it was abnormal warm in the Northeast-the Korean Peninsula-the ocean east of Japan in strong NECVI years,which made more obvious sea-land thermal contrast in the 35°N- 50° N and caused abnormal summer monsoon circulation systems. The anomalies resulted in abnormal more precipitation over the Huaihe River valley,and vice versa.

关 键 词：淮河流域 东北冷涡 海陆热力差异 数值模拟 

分 类 号：P461[天文地球—大气科学及气象学]