Prediction Of Future Temperature Changes In Shandong,China Through A Stepwise Cluster Analysis Approach

As a coastal province in China,Shandong has experienced an average temperature of 14.4? in 2016 which is 1.0 ? higher than normal.Shandong has also suffered more frequent extreme weather events in recent years as a result of climate change.In order to provide scientific support for developing appropriate adaptation policies to protect human communities,agriculture systems,and ecosystems from climatic changes,this research will be focused on investigating future temperature changes in Shandong Province.In detail,we will employ a stepwise cluster analysis method(named rSCA)to simulate the current climate and project the future climate over the study area.The rSCA model will first be calibrated and validated under different significance levels to verify the suitability of the model in simulating local temperatures(Tmean,Tmin,and Tmax)at eight weather stations across the province.The validated rSCA model will then be used to develop future temperature scenarios in 2050s and 2080s under RCP4.5 and RCP8.5.The time series of daily temperature from 2018 to 2099 is analyzed to quantify the magnitude of local warming trend at RCP4.5 and RCP8.5.Finally,the extreme temperature index of the future temperature at eight sites in Shandong Province was calculated and analyzed by trend analysis and Mann-Kendall mutation test.Based on rSCA model the stepwise clustering analysis method is suitable for simulating the future temperature of eight stations in Shandong Province,and the range of coefficient is 0.7-0.9.The results indicate that the near-surface temperatures at all stations are very likely to increase throughout the 21st century,leading to an average warming-up trend of 0.34 ? per 10 years in Shandong Province,where the degree of increase in winter and spring temperatures are relatively large about 2-3 ?,summer and autumn temperatures rose about 1-3 ?.The days of frost,freezing,the temperature range of day and night at eight stations in Shandong province showed a downward trend,and the other extreme climatic indices showed an upward trend.These trends are consistent with the forecast of the future temperature increase in Shandong Province.In addition,under the condition of high emission level,the rate of temperature change at each station is lower than RCP4.5.