2010年和2011年鲁西南初秋罕见连阴雨天气对比分析  

Comparative Analysis of Two Rare Continuous Rains in Early Autumn in Southwest Shandong in 2010 and 2011

作　　者：魏秀兰 赵熙 黄玉芳 

机构地区：[1]山东省菏泽市气象局,山东菏泽274000 [2]民航山东空管分局气象台,山东济南250107

出　　处：《干旱气象》2015年第4期626-634,共9页Journal of Arid Meteorology

基　　金：2012年山东省气象局预报员专项(sdyby2012-17)资助

摘　　要：利用常规气象观测资料和NCEP 1°×1°逐6 h再分析资料，对2010年9月2~10日（简称A过程）和2011年9月11~18日（简称B过程）鲁西南2次初秋连阴雨天气过程的大尺度环流形势特征、影响天气系统及其物理量场特征进行对比分析。结果表明，2次过程均发生在西太平洋副热带高压异常偏强、南亚高压和副热带急流位置偏北的背景下，副高边缘的西南暖湿气流和北方冷空气在黄河中下游地区长时间相互作用而形成连阴雨天气。高低空急流的耦合是暴雨发生和维持的重要原因。不同的是，A过程南亚高压和副热带急流在东亚地区轴线呈东北—西南走向，B过程呈东西走向，从而决定了连阴雨区的位置和走向。A过程在黄河上游有一经向度较大的低槽，山东受西南气流控制，且受低涡切变线影响，水汽辐合、动力条件非常强烈，降雨集中；B过程，乌拉尔山维持一稳定的阻塞高压，亚洲中纬度多短波槽东移，有3次明显的降雨过程，其中暴雨过程主要受低空急流和切变线影响，水汽输送强于A过程，动力条件较A过程弱，但持续时间长。Q矢量散度对暴雨落区有较好的指示意义。Based on the conventional observation data and NCEP reanalysis data with 1° × 1° spatial resolution,the characteristics of large-scale circulation,weather system and physical quantity fields of two continuous rain processes from 2 to 10 September 2010 （ named A process）and from 11 to 19 September 2011（ named B process）occurring in southwest Shandong were contrastively ana-lyzed. The results indicated that two continuous rains occurred under the background of anomalous strong Western Pacific Subtropical High（WPSH）,northerly locations of South Asian High（SAH）and Subtropical Westerly Jet（SWJ）,and the southwest warm and moist air flow on the edge of subtropical high and cold air from the north continuously interacted in the middle and lower reaches of the Yellow River for a long time,which formed the continuous rainy weather. The coupling of the high and low level jet played an important role in two continuous heavy rains. The difference was,the jet axis of SAH and SWJ over East Asian exhibited NE-SW direction dur-ing A process,while that was E-W direction during B process,which determined the position and orientation of two continuous rainy areas. There was a low trough with bigger meridians over the upper reaches of the Yellow River during A process,and the southwest airflow and low vertex shear line controlled over Shandong,which caused extremely strong moisture convergence and dynamic lifting, thus the rainfall was concentrated. During B process,a stable blocking high had been maintained near the Ural Mountains,and the short wave trough was continuously split up to move eastward in mid-latitudes of Asia. In this case,there were three times obvious rain processes,and the heavy rain process was mainly affected by the low-level jet and the shear line,the moisture transport was stronger than that of A process and the duration was longer,while the dynamic condition was weaker than the latter. The divergence of Q-vector had better indicative significance for the heavy rain area.

关 键 词：秋季连阴雨 大尺度环流形势特征 南亚高压 物理量场 Q矢量散度 

分 类 号：P458.121[天文地球—大气科学及气象学]