气象科学2017，Vol.37Issue(4)：505-513,9.DOI:10.3969/2016jms.0045
2013年长江中下游夏季高温干旱演变过程及环流异常成因简析
Evolution and abnormal causes for high temperature and drought in the middle and lower reaches of Yangtze River in summer of 2013
摘要
Abstract
Based on the improved drought index of CIn and the NCEP/NCAR reanalysis data,the evolution and the causes of summer droughts over the middle and lower reaches of Yangtze River in 2013 were analyzed.Results show that the improved drought index of CIn is good for monitoring the duration of the drought,which lasted for a month.The event began from the fourth pentad in July in the southern Hunan province,and the third pentad in August had the heaviest drought whose center was located in the middle and eastern Hunan province.Zhejiang province was the high temperature center and the drought alleviated at the fourth pentad in August.It was shown that the extremely westerly extension of polar vortex led to the weak cold air in the middle and lower reaches of Yangtze River.As a result,the South Asia high pressure moved abnormally eastward while the Western Pacific Subtropical High (WPSH) moved obviously westward.The area covered from Okhosk Sea to the Philippines showed strong EAP teleconnection patterns,in which,the geopotential height of the positive phase in the middle and lower reaches of Yangtze River strengthened the center of WPSH and made its location westerly.When the blocking high over Ural Mountains and WPSH confront each other,which was favorable to control stably the middle and lower reaches of Yangtze River for a long term.Meanwhile,the temperature difference between the Eurasian continent and the West Pacific ocean increased,the East Asian summer monsoon became strong,the northward extension of WPSH became anomalous,and the sinking air current in the middle and lower reaches of Yangtze River was strong,all of which caused the continuous high temperature and drought.关键词
长江中下游地区/干旱指数应用/高温干旱/环流异常Key words
The middle and lower reaches of Changjiang River/Drought index application/High temperature and drought/Circulation anomalies分类
天文与地球科学引用本文复制引用
李瞳,王文,蔡晓军..2013年长江中下游夏季高温干旱演变过程及环流异常成因简析[J].气象科学,2017,37(4):505-513,9.基金项目
国家自然科学基金资助项目(41275091) （41275091）
