Drivers of the Severity of the Extreme Hot Summer of 2015 in Western China  

作　　者：Wei CHEN Buwen DONG 

机构地区：[1]State Key Laboratory of Numerical Modelling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics,Chinese Academy of Sciences [2]National Centre for Atmospheric Science, Department of Meteorology, University of Reading

出　　处：《Journal of Meteorological Research》2018年第6期1002-1010,共9页气象学报（英文版）

基　　金：Supported by the National Natural Science Foundation of China(416750788,U1502233,and 41320104007);Youth Innovation Promotion Association of Chinese Academy of Sciences(2018102);Natural Environment Research Council via National Centre for Atmospheric Science of UK

摘　　要：Western China experienced an extreme hot summer in 2015,breaking a number of temperature records.The summer mean surface air temperature(SAT)anomaly was twice the interannual variability.The hottest daytime temperature(TXx)and warmest night-time temperature(TNx)were the highest in China since 1964.This extreme hot summer occurred in the context of steadily increasing temperatures in recent decades.We carried out a set of experiments to evaluate the extent to which the changes in sea surface temperature(SST)/sea ice extent(SIE)and anthropogenic forcing drove the severity of the extreme summer of 2015 in western China.Our results indicate that about 65%–72% of the observed changes in the seasonal mean SAT and the daily maximumand daily minimum(Tmin)temperatures over western China resulted from changes in boundary forcings,including the SST/SIE and anthropogenic forcing.For the relative role of individual forcing,the direct impact of changes in anthropogenic forcing explain about 42% of the SAT warming and 60%(40%)of the increase in TNxand Tmin(TXxand Tmax)in the model response.The changes in SST/SIE contributed to the remaining surface warming and the increase in hot extremes,which are mainly the result of changes in the SST over the Pacific Ocean,where a super El Ni?o event occurred.Our study indicates a prominent role for the direct impact of anthropogenic forcing in the severity of the extreme hot summer in western China in 2015,although the changes in SST/SIE,as well as the internal variability of the atmosphere,also made a contribution.Western China experienced an extreme hot summer in 2015,breaking a number of temperature records.The summer mean surface air temperature(SAT)anomaly was twice the interannual variability.The hottest daytime temperature(T_(Xx))and warmest night-time temperature(T_(Nx))were the highest in China since 1964.This extreme hot summer occurred in the context of steadily increasing temperatures in recent decades.We carried out a set of experiments to evaluate the extent to which the changes in sea surface temperature(SST)/sea ice extent(SIE)and anthropogenic forcing drove the severity of the extreme summer of 2015 in western China.Our results indicate that about 65%–72% of the observed changes in the seasonal mean SAT and the daily maximumand daily minimum(T_(min))temperatures over western China resulted from changes in boundary forcings,including the SST/SIE and anthropogenic forcing.For the relative role of individual forcing,the direct impact of changes in anthropogenic forcing explain about 42% of the SAT warming and 60%(40%)of the increase in T_(Nx) and T_(min)(T_(Xx) and T_(max))in the model response.The changes in SST/SIE contributed to the remaining surface warming and the increase in hot extremes,which are mainly the result of changes in the SST over the Pacific Ocean,where a super El Ni?o event occurred.Our study indicates a prominent role for the direct impact of anthropogenic forcing in the severity of the extreme hot summer in western China in 2015,although the changes in SST/SIE,as well as the internal variability of the atmosphere,also made a contribution.

关 键 词：severity of temperature extremes summer 2015 western China anthropogenic forcing 

分 类 号：P[天文地球]