2020年7月黑龙江极端少雨成因初探  

Preliminary study on the causes of extremely less precipitation in Heilongjiang Province in July 2020

作　　者：娄德君 李永生[2] 王永光[3] 陈晨 张健[2] LOU Dejun;LI Yongsheng;WANG Yongguang;CHEN Chen;ZHANG Jian(Qiqihar Meteorological Bureau of Heilongjiang Province,Qiqihar 161006,Heilongjiang,China;Heilongjiang Climate Center,Harbin 150030,China;National Climate Center,Beijing 100081,China)

机构地区：[1]黑龙江省齐齐哈尔市气象局,黑龙江齐齐哈尔161006 [2]黑龙江省气候中心,黑龙江哈尔滨150030 [3]国家气候中心,北京100081

出　　处：《干旱气象》2022年第3期396-405,共10页Journal of Arid Meteorology

基　　金：中央引导地方科技发展专项(ZY18C12)资助。

摘　　要：利用黑龙江省62个气象站月降水量观测资料和美国国家环境预报中心再分析资料、中国气象局国家气候中心环流指数资料等,对2020年7月黑龙江极端少雨成因进行初步诊断分析。结果表明:(1)2020年7月黑龙江降水异常偏少,全省平均降水量仅75.0 mm,为1961年以来历史同期第2少。(2)黑龙江7月异常少雨年,同期500 hPa东亚沿岸自低纬至高纬呈东亚-太平洋遥相关型(East Asia-Pacific teleconnection,EAP)负位相分布,东亚副热带西风急流(East Asia subtropical westerly jet,EASWJ)明显偏南,低层中国东北地区至黄海附近呈现异常的反气旋-气旋式环流,黑龙江上空整层水汽辐散。2020年7月环流特征与少雨年同期相似,但急流中心及其北侧负异常区较少雨年同期明显偏强,且中心略有东移,东亚沿岸对流层整层风场的经向波列更为清晰。EASWJ异常偏南是2020年7月黑龙江降水异常偏少的关键环流因子。(3)2020年5月南海附近异常偏弱的大气热源和7月负位相分布的北大西洋涛动,分别通过东亚沿岸经向EAP遥相关波列和欧亚中高纬地区纬向波列促使7月EASWJ异常南移,从而导致黑龙江省降水偏少。A preliminary cause analysis of extremely less precipitation in Heilongjiang Province in July 2020 was carried out by using the monthly precipitation data at 62 meteorological stations of Heilongjiang Province, reanalysis data from National Center for Environmental Prediction and circulation indices from National Climate Center of China Meteorological Administration, etc. Results are as follows:(1) The precipitation was abnormally less in Heilongjiang in July 2020, and the average precipitation in the whole province was only 75.0 mm, which was the second least since 1961.(2) When the precipitation was abnormally less in Heilongjiang Province in July,the negative phase distribution with East Asia-Pacific teleconnection(EAP) pattern appeared over the East Asian coast from low to high latitude at 500 hPa geopotential height anomaly field in the same period, the position of East Asian subtropical westerly jet(EASWJ) obviously leaned to south, and the anomalous anticyclone-cyclone circulation appeared over northeastern China to near the Yellow Sea at the lower level of troposphere, the integrated water vapor diverged over Heilongjiang Province. The circulation characteristics in July2020 were similar to those in the same period of less rain years, but the intensity of the jet center and its negative anomaly areas on the north side was significantly stronger than those in less rain years, and the center of the jet moved slightly to the east, the meridional wave train in troposphere over East Asian coast was more clearly. The abnormally southerly EASWJ played an important role on abnormally less precipitation in Heilongjiang Province in July 2020.(3) The atmospheric heat source near the South China Sea in May 2020was abnormally weak, and the distribution of the North Atlantic Oscillation(NAO) appeared negative phase in July 2020, which caused the EASWJ to move anomalously southward in July through the meridional wave train of EAP teleconnection over East Asian coast and zonal wave train over the middle-high latitude of

关 键 词：极端少雨 EASWJ 北大西洋涛动 大气热源 黑龙江省 

分 类 号：P467[天文地球—大气科学及气象学]