摘要
利用国家气候中心实时和历史气象观测数据,对我国2021年汛期(4月1日至10月16日)气候特点进行了综合分析。分析结果显示,2021年汛期,我国气候特征总体雨多温高、旱涝并重,且气候异常特征突出、极端事件频发。一是我国降水“北多南少”,暴雨过程多,强度强、极端性显著;二是高温日数多、南方地区“秋老虎”明显;三是登陆台风数量少,出现了1949年以来在我国陆地滞留时间最长的台风;四是南北方气象干旱并发,阶段性区域性明显。分析还显示,2020年8月至2021年3月,赤道中东太平洋发生了一次中等强度的拉尼娜事件,热带西太平洋对流活动持续异常活跃,对副热带高压的持续偏北有重要作用。由此共同导致来自西北太平洋的东南暖湿气流和来自印度洋的西南暖湿气流异常强盛,并随着副热带高压北上,为北方降水提供了充沛的水汽条件。同时,欧亚中高纬环流经向度大,冷空气活动频繁,冷暖空气在我国北方地区频频交汇,导致北方地区降水持续偏多。
Based on the real-time and historical meteorological observation data from national meteorological stations in China,the climate characteristics of China during 2021 flood season(from April 1th to October 16th)were comprehensively analyzed.The results show that during the flood season of 2021,the climate characteristics of China are generally more rain and higher temperature,severe drought and flood,prominent climate anomalies,and frequent extreme events.Firstly,the characteristic of spatial distribution of precipitation in flood season was more in the north and less in the south.The rainstorm processes occurred frequently,with strong intensity and significant extremes.Secondly,the high temperature days in China were more than normal,and the Indian summer occurred in the south.Thirdly,the number of landfall typhoon was less than normal,and Typhoon"In-fa"had the longest detention time on land in China since 1949.Finally,the regional and phased meteorological drought occurred in the south and north simultaneously.From August 2020 to March 2021,La Nina occurred in the equatorial central and eastern Pacific with a moderate intensity.The convective activity in tropical western Pacific was abnormally active and played an important role in the northward of subtropical high.The warm and humid air flows from Northwest Pacific and Indian Ocean were strong and moved northward,providing abundant water vapor for precipitation in the north.At the same time,the meridional gradient of Eurasian circulation in middle and high latitude is large,and cold air activities are frequent,resulting in more precipitation in the north than normal.
作者
石帅
李威
赵珊珊
艾婉秀
尹宜舟
翟建青
周星妍
赵俊虎
孙林海
曾红玲
赵琳
SHI Shuai;LI Wei;ZHAO Shanshan;AI Wanxiu;YIN Yizhou;ZHAI Jianqing;ZHOU Xingyan;ZHAO Junhu;SUN Linhai;ZENG Hongling;ZHAO Lin(National Climate Center,Beijing 100081)
出处
《中国防汛抗旱》
2022年第2期10-15,35,共7页
China Flood & Drought Management
基金
中国长江三峡集团有限公司项目(0704182)资助。
关键词
暴雨
汛期
高温
台风
气象干旱
拉尼娜
2021年
rainstorm
flood season
high temperature
typhoon
meteorological drought
LaNina
2021
