海面与海岸陆面风速廓线特征

利用位于江苏海岸陆地的两座测风塔以及福建海面的一座测风塔气象要素资料,分析了这两种下垫面风速、湍流等要素的日变化规律及廓线特征,探讨了这两种不同下垫面特征导致的风力特征差异。结果表明:海岸陆面日最大风速出现时间较内陆滞后,最小风速出现时间与内陆相差不大,风速日变化位相随高度滞后,日振幅随高度减小,冬季70 m高度风速日变化特征与10 m高度风速日变化特征相反,夜间大于白天,说明冬季的过渡层转换高度低于夏季;海面风速的日变化位相、日振幅等特征随高度变化很小。两种下垫面的风廓线用对数律、指数律拟合的效果相当,海岸陆面的风廓线指数呈现的规律为离岸风组大于向岸风组,冬季大于夏季;海面风廓线指数呈现的规律则是向岸风组大于离岸风组,夏季大于冬季。

Wind profile features of surface layer over ocean and coast

Based on the data of two anemometer towers located on Jiangsu coastal land and one on Fujian sea surface,the daily variation and profile features of wind velocity and turbulence intensity are analyzed,and the differences of wind features resulted by two different underlying surfaces are discussed.Results show that the daily maximum wind speed in coastal land occurrs later than that in inland,but the minimum wind occurrs nearly at the same time.The phase of daily variation of wind velocity delays along with altitude and the daily swing grows down.Wind speed of 70 m-height at night is bigger than that in daytime in winter,which is opposite to that of 10 m-height,showing that the height of transition layer in winter is lower than that in summer.The differences of daily variation phase of wind velocity are tiny among different altitudes over sea.Both exponential law and logarithm law can fit wind profiles of two different underlying surfaces.The law of wind profile exponent over coastal land shows that the exponent of group of wind from coast is greater than that of group of wind toward coast,and the exponent in winter is bigger than that in summer.The law of wind profile exponent over sea shows that the exponent of group of wind toward coast is bigger than that of group of wind from coast,and the exponent in summer is bigger than that in winter.