Terrestrial Near-Surface Wind Speed Variations in China: Research Progress and Prospects

Changes in terrestrial near-surface wind speed (NSWS) are indicative of the concentrated net effect of climate change and anthropogenic activities. Investigating change mechanisms of NSWS not only furthers the understanding of how the atmosphere changes and improves the climate analysis and projection, but also aids the evaluation and application of wind energy resources. Recent advances in studies of the changes and associated mechanisms of the NSWS over China are reviewed in this paper. Some new results have been achieved in understanding the behaviors of the NSWS changes. The NSWS over China has experienced a decrease in the past 40 years and a recovery in the recent decade, exhibiting large regional and seasonal differences. Understanding of the mechanisms of the NSWS changes has been improved in several aspects; for example, it is found that the reduced NSWS over China is due to the weakening of the pressure-gradient force (PGF) attributed to variations in large-scale ocean-atmosphere circulations (LOACs) as well as the increase of surface roughness due to the land use and cover change (LUCC). The main methods used to analyze the NSWS changes and corresponding mechanisms are also elucidated and discussed. However, studies are still lacking on the mechanisms for multi-timescale (seasonal, interannual, decadal, multi-decadal) variations in the NSWS over China, and it remains unknown about the contributions of different forcing factors to the NSWS changes. Finally, key scientific issues regarding our understanding of the NSWS changes are proposed for future investigation.