不同下垫面垂直风切变特征对比

A contrast study on vertical wind shear characteristics of different underlying surfaces

利用中国西北、北方东部和南方地区的10个测风塔风速资料,研究了不同区域风切变的特征及差异.结果表明,西北、北方东部和南方垂直风切变存在明显的年变化和日变化,秋冬季大、春夏季小;夜间大,白天小;风切变的年变化和日变化与边界层稳定度的年变化、日变化有关.风切变的大小与下垫面有关,下垫面平缓地区风切变比较小,地形起伏大的地区风切变比较大.海滨地区的垂直风切变值明显大于内陆.

The wind speed data of 10 wind towers in northwestern China,east of northern China and southern China were used to study the characteristics and differences of wind shear in different regions and the main results were:in general,the vertical wind shear of 10 wind towers in the three representative regions of the northwest,eastern part and southern part of the country showed obvious annual and diurnal changes,large in fall and winter seasons and small in spring and summer seasons;large at night and small in the daytime.The annual and diurnal variations of wind shear were related to the annual and diurnal changes in boundary layer stability.The values of wind shear were also related to the underlying surfaces.The wind shear was relatively small in the areas with a low underlying surface,and larger in the regions with large undulations.The vertical wind shear in coastal areas was significantly greater than inland.