Spatial Distribution and Trends of Wind Energy at Various Time Scales over the South China Sea

Abstract

In this study, the spatial distribution and trends of wind energy (as measured by wind and wind power density) were investigated from 1979 to 2021 across various time scales over the South China Sea (SCS)by utilizing ERA5 reanalysis data. The results indicate that the SCS possesses abundant wind energy. In addition, due to the fact that the East Asian monsoon dominates the SCS, the wind energy exhibits obvious seasonal changes. It is in winter and autumn that the winter monsoon (i.e., the northeast wind) prevails over the SCS. Here, the wind energy is abundant and reaches its maximum in December. In summer, the summer monsoon (i.e., the southwest wind) prevails over the SCS. Here, the wind energy is abundant over the southwestern SCS. In spring, however, the wind energy is poor. The annual mean wind energy shows a decreasing trend along the northern coast and an increasing trend over the central SCS. The trends of seasonal mean wind energy in winter, spring, and summer demonstrate a similar pattern to the annual mean wind energy. With respect to the intensity of the trends, they are strongest in winter, followed by spring and autumn, and weakest in summer. The trend of wind energy in autumn almost demonstrates the opposite pattern in comparison with the other seasons, i.e., both decreasing and increasing trends over the northern and southern SCS, respectively. The decreasing trend of wind energy along the northern coast of the SCS occurs in February, April, July, September, and November, whereas the increasing trend over the central SCS appears from the period of December to June. The spatial distribution and trends of wind energy over the SCS can help with issuing a more informed recommendation with respect to offshore wind energy planning.