干旱气象
榦旱氣象
간한기상
Journal of Arid Meteorology
2015年
4期
626-634
,共9页
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
鞦季連陰雨%大呎度環流形勢特徵%南亞高壓%物理量場%Q矢量散度
추계련음우%대척도배류형세특정%남아고압%물리량장%Q시량산도
continuous rain in early autumn%large-scale circulation%South Asian High%physical quantity fields%Q-vector diver-gence
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。
利用常規氣象觀測資料和NCEP 1°×1°逐6 h再分析資料,對2010年9月2~10日(簡稱A過程)和2011年9月11~18日(簡稱B過程)魯西南2次初鞦連陰雨天氣過程的大呎度環流形勢特徵、影響天氣繫統及其物理量場特徵進行對比分析。結果錶明,2次過程均髮生在西太平洋副熱帶高壓異常偏彊、南亞高壓和副熱帶急流位置偏北的揹景下,副高邊緣的西南暖濕氣流和北方冷空氣在黃河中下遊地區長時間相互作用而形成連陰雨天氣。高低空急流的耦閤是暴雨髮生和維持的重要原因。不同的是,A過程南亞高壓和副熱帶急流在東亞地區軸線呈東北—西南走嚮,B過程呈東西走嚮,從而決定瞭連陰雨區的位置和走嚮。A過程在黃河上遊有一經嚮度較大的低槽,山東受西南氣流控製,且受低渦切變線影響,水汽輻閤、動力條件非常彊烈,降雨集中;B過程,烏拉爾山維持一穩定的阻塞高壓,亞洲中緯度多短波槽東移,有3次明顯的降雨過程,其中暴雨過程主要受低空急流和切變線影響,水汽輸送彊于A過程,動力條件較A過程弱,但持續時間長。Q矢量散度對暴雨落區有較好的指示意義。
이용상규기상관측자료화NCEP 1°×1°축6 h재분석자료,대2010년9월2~10일(간칭A과정)화2011년9월11~18일(간칭B과정)로서남2차초추련음우천기과정적대척도배류형세특정、영향천기계통급기물리량장특정진행대비분석。결과표명,2차과정균발생재서태평양부열대고압이상편강、남아고압화부열대급류위치편북적배경하,부고변연적서남난습기류화북방랭공기재황하중하유지구장시간상호작용이형성련음우천기。고저공급류적우합시폭우발생화유지적중요원인。불동적시,A과정남아고압화부열대급류재동아지구축선정동북—서남주향,B과정정동서주향,종이결정료련음우구적위치화주향。A과정재황하상유유일경향도교대적저조,산동수서남기류공제,차수저와절변선영향,수기복합、동력조건비상강렬,강우집중;B과정,오랍이산유지일은정적조새고압,아주중위도다단파조동이,유3차명현적강우과정,기중폭우과정주요수저공급류화절변선영향,수기수송강우A과정,동력조건교A과정약,단지속시간장。Q시량산도대폭우락구유교호적지시의의。
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.