Abstract
Enabling the rational use of energy and the realization of the "dual carbon goals" across China will require systematic analysis of temporal and spatial changes in surface wind speed (SWS), determination of key factors influencing SWS, and quantification of wind energy resources. We investigated changes of SWS and their potential impact on wind energy resources using daily SWS data from meteorological observations and based on wind power density (WPD) across China during 1961-2021. The SWS changes were related to atmospheric circulation, surface friction (urbanization and vegetation changes), aerosol emissions and the replacement of observation instruments. The increase of SWS after 2015 was closely related to changes of atmospheric circulation that were reflected by changes of Asian Meridional Circulation Index, North Atlantic Oscillation, and Arctic Oscillation. Compared with the mean SWS, the extreme SWS exhibited a more obvious downward trend and earlier abrupt change. The annual mean SWS decreased by 16.80% in the last six decades, resulting in a decrease of 47.78% in wind energy potential. Regions with annual WPD more than 100 W · m(-2) were mainly in western China, northeastern China, northwestern China and some coastal areas. The WPD decreased mainly in northeastern China, northern China, and some coastal areas during the last six decades; it increased mainly in western China. Regions with annual WPD more than 100 W · m(-2) and robust coefficient of variation less than 0.5 are high-quality wind energy resource areas and were found mainly in western China, northern China, northeast China, and coastal areas.