Using the daily maximum temperature datasets from 664 observational stations during the period of 1961-2022,this paper systematically analyzed the spatio-temporal distribution and variations of the extreme heat events as well as their start and end dates.The results showed that nearly 90％of the extreme heat events in China occurred in summer,of which 39.3％occurred in July.The extreme heat events increased significantly in the past 62 years in China,characterized by increasing days and maximum temperature of extreme heat events at over 90％of the stations.The average days and maximum temperature of extreme heat events increased by 2.1 d and 0.18 ℃ every 10 years in China,respectively.The increase of extreme heat events was more obvious in high altitude ar-eas,with more than 90％stations showing a significant increasing trend in extreme heat days,and more than 87％stations showing a significant increasing trend in maximum temperature in Qinghai-Tibetan Plateau.The increas-ing trends of days and maximum temperature were up to 2.9 d·(10a)-1 and 0.34 ℃·(10a)-1 in Qinghai-Tibetan Pla-teau,respectively.The start and end dates of extreme heat events showed obvious advance and delay trend in most stations in China.The duration of extreme heat events increased more distinctly due to the reverse variations of the start and end dates,characterized by increasing duration of extreme heat events at over 90％of the stations in all re-gions.Southwest China was characterized by the fastest growth of extreme heat events in all regions,with the larg-est rate of 10.8 d·(10a)-1.Persistent extreme heat events maintained for a long time posed a serious threat to peo-ple's production and life,which occurred frequently in 21 century.Similar to the variation of extreme heat events,the persistent extreme heat events also showed a significant increasing trend in most stations in China.The persis-tent extreme heat events increased rapidly in South China and Southwest China.Specifically,the largest increase was observed in South China,with the trends up to 0.5 times(10a)-1 and 2.5 d·(10a)-1,respectively.In addition,the increase of persistent extreme heat events was also obvious in Qinghai-Tibetan Plateau,with trends of frequen-cies and accumulated days up to 0.3 times·(10a)-1 and2.1 d·(10a)-1,respectively.
关键词
极端高温事件/连续性极端高温过程/起讫日期/时空演变
Key words
extreme heat events/persistent extreme heat events/start and end dates/spatio-temporal variations
维普
万方数据