内蒙古东部地区夏季降水年代际突变及其可能成因  

Decadal Variation of Summer Precipitation in Inner Mongolia and its Analysis

作　　者：董祝雷 Dong Zhulei(Inner Mongolia Climate Centre,Inner Mongolia Hohhot 010051)

机构地区：[1]内蒙古气候中心,内蒙古呼和浩特010051

出　　处：《内蒙古气象》2021年第1期3-9,共7页Meteorology Journal of Inner Mongolia

摘　　要：近些年来,内蒙古呈现出干旱趋势。文章利用1961—2019年内蒙古107个气象站逐月降水资料和NCEP/NCAR逐月再分析数据,研究了内蒙古夏季降水的年代际变化特征,指出内蒙古夏季降水,尤其是东部地区(110°E以东)夏季降水在20世纪90年代中后期发生突变,夏季降水由前期(1983—1998年,P1阶段)偏多阶段转变为后期(1999—2011年,P2阶段)偏少阶段。分析表明:亚洲中高纬地区气温异常可能对内蒙古东部地区夏季降水年代际突变有显著影响,一方面,内蒙古东部地区夏季降水与亚洲中高纬地区气温有显著的负相关;另一方面,亚洲中高纬地区气温在20世纪末显著增高,升温幅度明显超过趋势变化。进一步分析表明,亚洲中高纬地区气温对我国北方大气环流有调制作用,在P1阶段,亚洲中高纬地区为负的温度距平,我国北方为气旋性环流异常,这一环流形势有利于内蒙古东部地区夏季降水增多;而在P2阶段,亚洲中高纬地区增暖显著,内蒙古上空被异常反气旋性环流控制,大陆高压偏强,导致内蒙古东部地区偏旱。In recent years,the drought in Inner Mongolia shows an upward trend.Decadal variation of summer precipitation in Inner Mongolia is analyzed by using 107 stations of Inner Mongolia monthly precipitation data and NCEP/NCAR monthly reanalysis data from 1961 to 2019.It is found that summer precipitation in Inner Mongolia,especially in the eastern(110 degrees east)showed an obvious abrupt changes during the mid-to late 20th century.More summer precipitation in Inner Mongolia was observed in 1983-1998(P1),while less during 1999-2011(P2).Analysis showed that the mid-high latitude temperature of Asia may had an import influence on abrupt changes of summer precipitation in eastern Inner Mongolia.On the one hand,summer precipitation in eastern Inner Monglia had a significant negative correlation between mid-high latitude temperature of Asia.On the other hand,the temperature in the mid-high latitude of Asia increased significantly at the end of the 20th century,and the warming range was obviously higher than the trend.Further analysis showed that the temperature anomaly in the mid-high latitude of Asia had a modulating effect on the atmospheric circulation in the north of China.When there was a negative temperature anomaly in the mid-high latitude of Asia and cyclonic circulation anomaly in the north of China,this circulation pattern was conducive to the increase of summer precipitation in the eastern region of Inner Mongolia.In the stage of P2,the warming of middle and high latitude in Asia was significant,and the air over Inner Mongolia was controlled by the abnormal anticyclonic circulation,and the continental high was relatively strong,resulting in the drought in the eastern part of Inner Mongolia.

关 键 词：内蒙古 夏季降水 年代际变率 亚洲中高纬 地表气温 

分 类 号：P426.6[天文地球—大气科学及气象学] P434