1970-2020年青藏高原近地面风速时空变化特征

Spatio-temporal variation of near-surface wind speed over Qinghai-Tibet Plateau from 1970 to 2020

基于1970-2020年青藏高原区域及其附近154个气象站点的风速风向观测数据,采用线性拟合等方法,分析该地区年平均和季节平均近地面风速的时空分布特征和日变化特征.结果表明:(1)青藏高原区域1970-2020年年均风速在0.6-4.2m/s之间,青藏高原主体年均风速较高,高原周边地区风速较低;(2)青藏高原区域1970-2020年间近地面风速呈极显著下降趋势,2000年以后呈极显著增加趋势;(3)青藏高原区域1970-2020年间近地面风速春季最大,冬、夏次之,秋季最小,不同季节平均风速均是高原主体大于高原周边,4个季节的平均风速均呈极显著降低趋势,春季平均风速降低的速率最大;(4)大气环流驱动力的减弱可能是青藏高原区域地面风速呈减弱趋势的主导性因素.青藏高原近地面风速显著的变化特征可为青藏高原风能资源开发利用、农林生态系统开发与保护等提供科学依据.(图5参46)

The annual and seasonal average spatial-temporal distribution characteristics and daily variation characteristics of near-surface wind speed were analyzed using a linear fitting method based on observational data of wind speed and direction from 154 meteorological stations in and around Qinghai-Tibet Plateau from 1970 to 2020.(1) The average annual wind speed over Qinghai-Tibet Plateau was between 0.6 m/s and 4.2m/s from 1970 to 2020, and the average annual wind speed over the main part of Qinghai-Tibet Plateau was higher than the surrounding areas.(2) The near-surface wind speed over Qinghai-Tibet Plateau decreased significantly from 1970 to 2020, and increased significantly after 2000.(3) The near-surface wind speed in Qinghai-Tibet Plateau was the highest in spring, followed by winter and summer, and then autumn. The average wind speed during different seasons was higher in the main part of the plateau than in the surrounding areas.The average wind speed of the four seasons in Qinghai-Tibet Plateau showed a very significant decreasing trend, and the decreasing rate of average wind speed was maximum in spring.(4) The weakening of the driving force of atmospheric circulation may be the dominant factor for the weakening trend of near-surface wind speed over Qinghai-Tibet Plateau. Significant variation characteristics of near-surface wind speed over QinghaiTibet Pleteau can provide a reference for the development and utilization of wind energy resources and the development and protection of the agroforestry ecosystem in Qinghai-Tibet Plateau.