Linkage of extreme temperature change with atmospheric and locally anthropogenic factors in China mainland

Abstract

Much attention has been given to the large-scale anthropogenic influence on extreme temperature changes. However, the possible effects of atmospheric factors and the role of the locally anthropogenic driver on the observed regional change in extreme temperatures have not been well understood. Datasets of the China Meteorological Administration (CMA) were used to examine the possible influence. The data include the homogenized surface air maximum/minimum temperature, surface sunshine duration (SSD), water vapor pressure (VAP), and total cloud cover (CLO) during 1961–2020. We calculated the seasonal means of maximum temperature (Tx(mean)), minimum temperature (Tn(mean)) and diurnal temperature range (DTR) to analyze the characteristics of extreme surface air temperature (ESAT) changes in winter and summer, and their relationship to SSD, VAP, and CLO, as well as the urbanization effect in the extreme temperature indices series. The changes in the trends for SSD and VAP were more closely correlated with ESAT in winter and summer, respectively. The decreasing of SSD led to a slowing of the ESAT warming, while an increase of the VAP led to the intensification of ESAT warming. In addition, CLO also had an important role in the change of ESAT. The seasonal mean correlation coefficient over China mainland between Tn(mean) and VAP were statistically significant and higher than those with SSD and CLO. The seasonal mean correlation between Tx(mean)/DTR and SSD were also statistically significant. The SSD and VAP strongly influenced the Tx(mean) in winter. The urbanization contribution to the DTR trends reached >25% in both winter and summer. SSD strongly influenced the trend of ESAT in urban area whereas CLO/VAP had larger influence on the trend of ESAT in rural area, which were all related to the urbanization effect as observed in the data series.