Long-term trend of near-surface air temperature lapse rate over the Chinese mainland during 1961-2018

The near-surface air temperature lapse rate (SATLR) is a result of surface energy balance, and the long-term trend of SATLR is linked to elevation-dependent warming (EDW). The long-term trend of SATLR in China's mainland was examined in the present study. It was found that the regional average values of annual, autumn, and winter SATLR anomalies in Tmean, Tmax, and Tmin decreased significantly during the period of 1961-2018. In terms of spatial distribution, most of the annual SATLR trends in Tmean across China's mainland are negative. In spring, positive SATLR trends in Tmean are widespread in the northern mountainous areas of China, while in winter, strong negative trends are found in some areas of the central and eastern parts of the Tibetan Plateau and the Yunnan-Guizhou Plateau. Most of the negative annual SATLR trends in Tmax occur in the central part of China, but in the southwestern part of China for Tmin. Widespread negative SATLR trends in Tmin are usually found in winter, especially in the Hengduan Mountains of Southwestern China and the eastern part of the Tibetan Plateau. The significant positive SATLR trends in Tmax are observed in spring, mostly distributed in northern mountainous areas. In the context of global and regional warming, the long-term trend of SATLR has the potential to detect differences in altitude responses to climate change on a small spatial scale, and to explore the local effect of EDW.