资源环境科技发展态势分析平台

The Tibetan Plateau (TP) affects its surroundings significantly through thermal and dynamic processes. Reductions in near-surface wind speed (W-s) have been observed from ground measurements but how the trends of Ws vary with the elevation is less clear. Trends of W-s with respect to elevation were investigated using long-term daily records taken from 1970 to 2012 of W-s and maximum (T-max), minimum (T-min), and mean (T-mean) air temperatures from 139 stations over and around the TP. The major findings are as follows. (1) Pronounced reductions in W-s can be observed in all seasons and annually across the TP. Spring demonstrates the most prominent weakening. The rate of reductions in W-s was amplified with elevation, and higher-elevation environments experienced greater changes in W-s than lower-elevation areas. Elevation-dependent reductions in W-s have intensified from 1970 to 2012. (2) Statistically significant negative correlations between W-s and corresponding near-surface temperatures were detected. We suggested that the elevation-dependent warming and thereby the increased surface roughness at higher-elevation environments may contribute to the elevation-dependent reductions in W-s over and around the TP. More detailed mechanisms causing this pattern are to be further explored.