内蒙古河套地区极端降水特征分析  

Analysis on Characteristic of Extreme Precipitation in Hetao Area,Inner Mongolia

作　　者：刘林春 刘炜[2] 孙鑫 刘新[2] 董祝雷 张宇 LIU Linchun;LIU Wei;SUN Xin;LIU Xin;DONG Zhulei;ZHANG Yu(Inner Mongolia Meteorological Observatory,Hohhot 010051,China;Climatic Center of Inner Mongolia,Hohhot 010051,China)

机构地区：[1]内蒙古自治区气象台,内蒙古呼和浩特010051 [2]内蒙古自治区气候中心,内蒙古呼和浩特010051

出　　处：《干旱气象》2020年第4期535-542,共8页Journal of Arid Meteorology

基　　金：国家重点研发计划(2018YFC1506800);中国气象局预报员专项(CMAYBY2019-023);内蒙古自治区气象局科研项目(nmqxkjcx201908)共同资助。

摘　　要：基于内蒙古河套地区34个国家气象站1961—2018年逐日降水量,分析近58 a极端降水事件和降水过程的时空分布特征,并选取典型过程分析极端降水过程环流背景场特征。结果表明:(1)平均年降水量自东南向西北递减,7—8月降水最丰沛。8月降水量显著减少,5、6和12月降水量显著增加。(2)极端降水阈值东南高西北低,鄂尔多斯市乌审召降水量历史极值最大,巴彦淖尔市海力素最小。大部地区极端降水事件频次在5次以上,强度东南强西北弱。(3)极端降水事件7—8月最多,平均强度8月最强。9月极端降水事件显著增加,强度显著增强。(4)年平均极端降水过程强度减弱趋势显著,过程降水大值区多集中在土默特左旗、伊金霍洛旗和呼和浩特市区。(5)极端降水过程多受槽前西南气流影响,充足的水汽条件配合异常强盛的上升气流,易发生强降水事件。Based on daily rainfall from 34 national meteorological observation stations in the Hetao area,Inner Mongolia during 1961-2018,extreme precipitation events and extreme precipitation processes were analyzed in the past 58 years.Atmospheric circulation features of typical extreme precipitation processes were aslo analyzed.The main results are as follows:(1)Average annual precipitation decreased from southeast to northwest,and precipitation was rich from July to August.The precipitation decreased significantly in August and increased significantly in May,June and December.(2)The thresholds of extreme precipitation became lower from southeast to northwest,the historical maximum extremum occurred in Wushenzhao of Ordos,the historical minimum extremum occurred in Hailisu of Bayannur.The frequency of extreme precipitation events was more than five times in most areas,the intensity became weaker from southeast to northwest.(3)The extreme precipitation events was most from July to August,and its intensity was strongest in August.The frequency of extreme precipitation events and the intensity increased significantly in September.(4)The annual average extreme precipitation process intensity decreased significantly,the process precipitation was concentrated in Tumote Zuo Banner,Ejin Horo Banner and the city of Huhhot.(5)The extreme precipitation processes were influenced by the southwest flow at the front of trough,and the plentiful vapor and exceptionally strong updraft flow could easily cause extreme precipitation events.

关 键 词：内蒙古河套地区 极端降水特征 极端降水事件 极端降水过程 环流背景场 

分 类 号：P426.61[天文地球—大气科学及气象学]