LAUSR

ABSTRACT In the paper, daily near-surface wind speed data from 462 stations are used to study the spatiotemporal characteristics of the annual and seasonal mean wind speed (MWS) and effective wind energy density (EWED) from 1960 to 2016, through the methods of kriging interpolation, least-squares, correlation coefficient testing, and empirical orthogonal function (EOF) analysis. The results show that the annual MWS is larger than 3 m s−1 and the EWED is larger than 75 W m−2 in northern China and parts of coastal areas. However, the MWS and EWED values in southern China are all smaller than in northern China. Over the past 50 years, the annual and seasonal MWS in China has shown a significant decreasing trend, with the largest rate of decline in spring for northern China and winter for coastal areas. The annual MWS in some areas of Guangdong has an increasing trend, but it shows little change in southwestern China, South China, and west of Central China. Where the MWS is high, the rate of decline is also high. The main spatial distributions of the annual MWS and the annual EWED show high consistency, with a decreasing trend year by year. The decreasing trend of wind speed and wind energy resources in China is mainly related to global warming and land use/cover change. Graphical abstract Key figure (only for graphical abstract online):