Projection Of Temperature In Guangdong Province Based On Copula-based Ensemble Downscaling Method

Guangdong Province is affected by the alternation of low-latitude tropical and mid-high latitude weather systems,resulting in a complex and changeable climate.The low resolution of Global Climate Models(GCMs)makes it impossible to accurately output the possible changes in Guangdong's future climate.Therefore,in this study,a Copula-based ensemble downscaling(CED)method is employed to explore the possible changes of future temperature in Guangdong,China.First,temperature variables from 1995 to 2005 are reproduced and compared with historical observation data to evaluate the performance of the CED method.Based on the verification of Taylor diagrams and correlation coefficients,the CED method has better performance in reproducing historical data and can reduce the uncertainty of a single model.Then,the CED method is used to project the daily maximum,minimum and mean temperature in Guangdong Province from 2025 to 2099 under RCPs 4.5 and 8.5 emission scenarios.Subsequently,the projected temperature changes in Guangdong Province are divided into three periods(i.e.,2025?2049,2050?2074 and 2075?2099)and are analyzed based on different time scales(i.e.,annual,seasonal,and monthly).The results indicate that the temperature of the selected 32 stations in Guangdong Province all show an upward trend.Under the RCP4.5 scenario,the increasing rate of the average annual mean temperature of the 32 stations in Guangdong Province is 0.24? per decade,while such rate under the RCP8.5 scenario is 0.45? per decade.Moreover,it is found that the average increasing rate and range of temperature in winter are much greater than that in summer.The results from this study will help policy makers in Guangdong's economic,agricultural,social and environmental sectors to identify appropriate adaptation strategies to cope with the adverse impacts of heat stress brought by future climate change.