气象2018，Vol.44Issue(4)：556-564,9.DOI:10.7519/j.issn.1000-0526.2018.04.009
2017年全球重大天气气候事件及其成因
Global Major Weather and Climate Events in 2017 and the Possible Causes
摘要
Abstract
The concentration of greenhouse gases continued to increase in 2017,and the global mean tem-perature was 1.1℃ above the pre-industrial levels,making the year 2017 become the second warmest year on record and the warmest year not influenced by El Ni~no event.The cryosphere continued its contraction. The maximum sea-ice extent of Arctic sea in winter broke the lowest record while the sea-ice extent of Antarctic was near the record low level throughout the year.Global sea surface temperatures were signifi-cantly above the 1981-2010 average,and the global mean sea level kept rising steadily.The ocean heat content reached new record highs due to the intensified impact of ocean acidification.Many significant weather and climate events occurred in 2017,including a very active North Atlantic hurricane season,ma-jor monsoon floods in the Indian subcontinent,severe droughts in East Africa as well as some torrential rains,heat waves,cold waves and severe convective weather at regional or local scale worldwide.Econo-mic losses from the weather and climate related disasters set a new record in 2017.This paper summarizes the major events and its impact in 2017,and analyzes the formation causes of typical events including the exceptionally destructive hurricanes that occurred in rapid succession in the North Atlantic and the significant summer heat waves in the United States.Analysis of atmospheric circulation and external forc-ing shows that the positive SST anomalies of Caribbean and western tropical Atlantic enhanced the convec-tive activity and decreased the vertical shear of wind speed,providing favorable background conditions for the development of hurricanes.In addition,the stage weakening of North American subtropical high caused four destructive hurricanes to make landfall successively in southern United States and the Caribbe-an region.In early July,the North American subtropical high that was influenced by the eastward exten-sion and enhancement of subtropical westerly jet and the maintaining of Northeast Pacific cut-off low con-tinued controlling the southwestern United States.This was the major reason for the summer heat wave on the west coast of the United States.关键词
表面温度/降水量/极端事件/气象灾害Key words
surface temperature/precipitation/extreme events/meteorological disaster分类
天文与地球科学引用本文复制引用
孙劭,王东阡,尹宜舟,王国复,柯宗建..2017年全球重大天气气候事件及其成因[J].气象,2018,44(4):556-564,9.基金项目
国家自然科学基金项目(41701103)和公益性行业(气象)科研专项(GYHY201506002)共同资助 （41701103）
