1980—2012年春末夏初江淮气旋活动的气候特征及其年际、年代际变化  

Climatic characteristics and interannual( interdecadal)variations of cyclones over Changjiang-Huaihe River basin during late spring and early summer from 1980 to 2012

作　　者：王艳玲[1,2] 管兆勇[2] 金大超[2] 柯丹[2] 

机构地区：[1]江苏海事职业技术学院航海学院,江苏南京211170 [2]南京信息工程大学气象灾害预报预警与评估协同创新中心,江苏南京210044

出　　处：《大气科学学报》2015年第3期354-361,共8页Transactions of Atmospheric Sciences

基　　金：公益性行业(气象)科研专项(GYHY201406024);江苏省高等职业院校国内高级访问学者计划资助项目(2013)

摘　　要：利用1980—2012年NCEP/NCAR逐6 h海平面气压再分析资料及定义的气旋客观识别方法,统计分析了春末夏初江淮地区气旋活动频数和强度的气候特征及其年际、年代际变化。结果表明:5—7月江淮地区存在明显的气旋活动高频中心,5、6月高频中心位于两湖盆地之间;7月北移,淮河以南频数较高。20世纪80—90年代江淮气旋活动频数偏少,强度偏弱;21世纪初期的10 a间气旋活动频数偏多,强度偏强。气旋活动频数多发年与少发年500 h Pa均出现稳定的长波环流结构,但仍存在显著差异。多发年两个南支槽向南伸展直达阿拉伯海和孟加拉湾地区,少发年仅出现孟加拉湾南支槽。多发年,对流层低层华南至江淮地区存在气旋式环流辐合异常中心,高层则出现辐散异常。西风带上的异常扰动沿着副热带急流向东亚地区传播能量,导致东部地区出现异常气旋式环流,为江淮气旋的发生提供了有利的环流背景。Based on the NCEP / NCAR 6-hourly sea level pressure reanalysis data from 1980 to 2012 and a defined method to objectively identify cyclones,this paper has analyzed the climatic characteristics and interannual（ interdecadal） variations of frequency and intensity of cyclone activities over the Changjiang-Huaihe River basin in late spring and early summer. Results showthat there is an obvious high-frequency cyclone activity center in Changjiang-Huaihe River basin from May to July. It lies between Dongting Lake and Poyang Lake from May to June,and moves northward in July,with a higher frequency to the south of Huaihe River. The frequency and intensity of cyclones over Changjiang-Huaihe River basin decrease from 1980 s to 1990 s,and increase in the first decade of 21 st century. The stable longwave circulation structure appears at 500 hPa in whether more cyclone frequency years or less,but there are obvious differences between them. Two southern troughs appear in the Arabian Sea and theBay of Bengal in the more cyclone years,while only one appears in the Bay of Bengal in the less cyclone years. In the more cyclone years,there is an abnormal convergence center with cyclonic circulation in the lower troposphere from South China to Changjiang-Huaihe River basin,while an abnormal divergence appears in the upper troposphere. Because the abnormal disturbance of westerlies along subtropical jet stream spreads energy to East Asia,the abnormal cyclonic circulation appears in eastern regions. Such circulation structure provides some advantages for the cyclones over Changjiang-Huaihe River basin.

关 键 词：江淮气旋 春末夏初 气候特征 大气环流 

分 类 号：P444[天文地球—大气科学及气象学]