琼州海峡海面风场特征的观测分析

OBSERVATION AND ANALYSIS OF SEA SURFACE WIND OVER THE QIONGZHOU STRAIT

在检验资料可靠性的基础上,利用船载自动站、浮标站与岸基自动站测风资料分析了琼州海峡海面风速空间变化规律,以及秋冬季节的海面风场的日变化特征。结果表明:(1)琼州海峡海面风速平均比沿岸风速大3～4 m/s,当沿岸风速≥8.0 m/s(5级)时,海面风速比沿岸大5～6 m/s;(2)海峡海面阵风系数随着风速加大而减小。沿岸风速<5级时,海面平均阵风系数在1.4～1.5之间,风速≥5级时,平均阵风系数为1.35左右;(3)秋冬季节,海面的平均风速日较差与风一致率均小于沿岸,当海面出现≥10.8 m/s(6级)强风时,海面与沿岸的风速日较差减小,风一致率增加。

The spatial variation and diurnal fluctuation of sea surface wind over the Qiongzhou Strait were described using datasets from ship-borne automatic meteorological observing station,buoy and automatic weather station after the verification of it.It is demonstrated that：（1） The sea surface wind speed is 3～4 m/s larger than the coastal area over the Qiongzhou Strait on average.When the surface wind speed in the coastal area is up to 8.0 m/s（level 5） or above,the sea surface wind speed over the Qiongzhou Strait is 5～6 m/s greater than the coastal area.（2） The gust coefficient over Qiongzhou Strait decreases with increasing wind speed.When the coastal wind speed is less than level 5,the average gust coefficient over sea surface is between 1.4～1.5,when the wind speed equal to level 5 or above,the average gust coefficient is about 1.35;（3） In autumn and winter season,the diurnal range of average wind speed and wind constancy over the strait is less than the coastal area,when the wind speed is up to 10.8 m/s（level 6） or above,the diurnal range of average wind speed decrease while wind constancy increase over both strait and coast.