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张超美, 吴珊珊, 黄彩婷. 2021: 江西春季降水异常的环流特征及其对ENSO事件的响应. 暴雨灾害, 40(4): 410-418. DOI: 10.3969/j.issn.1004-9045.2021.04.009
引用本文: 张超美, 吴珊珊, 黄彩婷. 2021: 江西春季降水异常的环流特征及其对ENSO事件的响应. 暴雨灾害, 40(4): 410-418. DOI: 10.3969/j.issn.1004-9045.2021.04.009
ZHANG Chaomei, WU Shanshan, HUANG Caiting. 2021: Characteristics of atmospheric circulationforspring precipitation anomalies in Jiangxi Province and its response to ENSO Events. Torrential Rain and Disasters, 40(4): 410-418. DOI: 10.3969/j.issn.1004-9045.2021.04.009
Citation: ZHANG Chaomei, WU Shanshan, HUANG Caiting. 2021: Characteristics of atmospheric circulationforspring precipitation anomalies in Jiangxi Province and its response to ENSO Events. Torrential Rain and Disasters, 40(4): 410-418. DOI: 10.3969/j.issn.1004-9045.2021.04.009

江西春季降水异常的环流特征及其对ENSO事件的响应

Characteristics of atmospheric circulationforspring precipitation anomalies in Jiangxi Province and its response to ENSO Events

  • 摘要: 利用江西省83个气象观测站1961—2018年春季(3—5月)逐日降水资料和NCEP/NCAR逐日再分析资料,对江西春季降水异常的大气环流特征及其对ENSO事件的响应进行了研究。结果表明:江西春季降水异常偏多年,中层500 hPa中高纬地区受欧亚型环流(EU型)影响,乌拉尔山附近阻塞高压系统活动频繁,贝加尔湖地区低槽偏强,西太平洋副热带高压(简称西太副高,下同)偏强,有利于北方冷空气南下并与偏南暖湿气流在江西上空交汇;低层850 hPa菲律宾以东西太平洋地区为异常反气旋环流控制,造成南海水汽向江西地区输送加强。而江西春季降水异常偏少年,其环流特征表现则与之相反。ENSO是影响江西春季降水的重要强迫信号,厄尔尼诺(拉尼娜)衰减年,春季东亚地区低层850 hPa西太副高偏强(弱),有(不)利南海上空水汽向江西地区输送,低层辐合(辐散)和高层200 hPa辐散(辐合)形成的动力抬升条件是造成江西地区降水偏多(少)的主要原因。

     

    Abstract: Based on the daily precipitation data at the 83 national automatic weather stations over Jiangxi Province in spring (March to May) from 1961 to 2018 and the diurnal reanalysis data from NCEP/NCAR, we have performed an analysis on the characteristics of atmospheric circulation for the spring precipitation anomalies in Jiangxi and its response to ENSO events. The results show that in the years with abnormally more precipitation in spring in Jiangxi, as the mid-and high-latitudes in the middle layer 500 hPa is affected by the Eurasian circulation (EU type), the blocking high near the Ural Mountains is active, and both the low trough in the Baikal Lake area and the Western Pacific subtropical high (hereinafter referred to as WPSH) are stronger than the climatic mean state, which is conductive to the writhe of cold air from the north to south and southerly warm and wet airflow in Jiangxi. In addition, the western Pacific region in east of the Philippines in the low-level 850 hPa is controlled by the anomalous anticyclone circulation, causing the enhancement of water vapor transport from the South China Sea to Jiangxi. While the atmospheric circulation characteristics in the years with abnormally less precipitation in spring in Jiangxi are opposite to those in the above years with abnormally more precipitation. Moreover, ENSO is an important forcing signal affecting the spring precipitation in Jiangxi. In the year of El Niño (La Niña) decay, the WPSH at low level 850 hPa in East Asia in spring is stronger (weaker), which is (isn' t) favorable for the transportation of water vapor from the South China Sea to Jiangxi. More (less) precipitation in Jiangxi is due to the dynamic uplift formed by convergence (divergence) in the low-level and divergence (convergence) in the upper level 200 hPa.

     

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