Has the stilling of the surface wind speed ended in China

Since the 1960s, the global land surface wind speed (SWS) has significantly weakened, a phenomenon known as global terrestrial stilling. The latest research found that the stilling reversed around 2010, and since then the global SWS has been strengthening. However, there is still a lack of systematic quantitative analysis in China. We analyzed the transition and regional differences in the long-term trends of the SWS in China based on observational SWS data from 1971 to 2019. The results showed that annual mean SWS in China underwent a reversal from a continuously weakening trend to a significantly strengthening trend around 2014 and implying that stilling may have ended in 2014. The reversal had obvious regional and seasonal variations. In Northeast China, Western Xinjiang as well as on the Tibetan Plateau, the years with both annual and seasonal mean SWS changing from weakening to strengthening were around 2013/2014, 1993/1994, and 2000. However, in the west of North China, SWS showed an obviously strengthening trend only in autumn and winter after 2007; while only autumn mean SWS showed a strengthening trend after 2012 in South China. It should be noted that stilling is ongoing in the eastern and southern coastal areas, North China and Eastern Xinjiang.