CAJ | 학술논문

利用NCEP再分析资料和观测资料，对2012年2月20日至3月10日江南地区出现的历史罕见的持续连阴雨天气过程发生时的环流形势进行了分析。结果表明，伴随此次过程的异常环流特征为：（1）连阴雨期间，乌拉尔山阻塞高压稳定维持，强度偏强，我国北方地区长期由槽后脊前的西北气流控制，为连阴雨天气提供了持续的冷空气；（2）里海低涡不断分裂的小槽分成南北两支：北支加强了中纬度冷空气的输送；南支到达孟加拉湾后使得西南气流加强。（3）西太平洋副热带高压异常偏北以及青藏高原南缘的南支低槽系统活跃，使得西南暖湿气流北上与冷空气在长江中下游一带交汇产生降水；（4）雨带位于水汽通量湿舌区北侧，大致与相当位温能量锋区重合，冷空气活动在连阴雨雨势加剧中起了重要作用。（5）连阴雨期间维持着低层辐合、高层辐散的动力配置，这对上升运动的加强和气旋性涡度柱上空抽吸作用的加强起了主导作用。
이용NCEP재분석자료화관측자료，대2012년2월20일지3월10일강남지구출현적역사한견적지속련음우천기과정발생시적배류형세진행료분석。결과표명，반수차차과정적이상배류특정위：（1）련음우기간，오랍이산조새고압은정유지，강도편강，아국북방지구장기유조후척전적서북기류공제，위련음우천기제공료지속적랭공기；（2）리해저와불단분렬적소조분성남북량지：북지가강료중위도랭공기적수송；남지도체맹가랍만후사득서남기류가강。（3）서태평양부열대고압이상편북이급청장고원남연적남지저조계통활약，사득서남난습기류북상여랭공기재장강중하유일대교회산생강수；（4）우대위우수기통량습설구북측，대치여상당위온능량봉구중합，랭공기활동재련음우우세가극중기료중요작용。（5）련음우기간유지착저층복합、고층복산적동력배치，저대상승운동적가강화기선성와도주상공추흡작용적가강기료주도작용。
Based on the reanalysis data from NCEP and observational data, the circulation situation of rarely continuous rainy weather in the regions south of the Yangtze River from 20 February to 10 March in 2012 were analyzed. The results show that: (1)During the period of continuous rainy days, The Ural mountains blocking high was stronger and stability maintained, north China was controlled by northwest airflow which behind trough and before ridge former for a long time ,which provided continuous cold air for the continuous rainy weather.(2)The small trough separating from low vortex of Caspian sea is divided into south and north branches: the north branch strengthen cold air transport from the mid-latitude;The south branch strengthen the southwest airflow after arrived at the bay of Bengal ( 2)The west Pacific subtropical high is anomaly north and the south trough which lies the south of Tibet plateau is actively. Under these stable circulations, the cold dry air from the north contacts the warm wet air flows from the south over the middle lower reaches of Yangze River for a long time. (3)Rain belt is on the north side of water vapor flux moist tongue area, which roughly concides with frontal zone of equivalent potential temperature energy. The cold air activity plays an important action in aggravation of rainfall intensity during the continuous rainy process.(4)The dynamic structure of the continuous rainy weather is typical configuration of upper-level divergence and lower-level convergence, which play a leading role in the strengthen of ascending motion and pumping action upper the cyclonic vorticity column.