海南岛沿海近地面风时空分布特征的观测分析

An observational analysis of spatial and temporal characteristics of near-surface wind over the coastal area of the Hainan Island

利用2012年海南岛沿海6个常规气象站、2个海岛站的逐时风向、风速资料,分别对全年以及不同季节内近地面风速大小、风速日变化以及风向频率分布等进行了统计分析.结果表明：2012年全年海南岛沿海近地面风速约在1.8~5.7 m/s之间,其中三亚站风速最大,冬季高达6.5 m/s,大部分站点夏季风速最弱,最大风速出现在春、冬季;海南岛南部沿海风速大于北部,东部大于西部;各站24 h风速基本呈现白天大、夜晚小的典型特征,由于所处地形、植被独特,三亚部分季节风速呈现相反的日变化特征;全年各站基本存在两个盛行风向,大部分站点近地面风向与南海季风的风向变化较为一致,夏季以南风、西南风为主,冬季以北风、东北风为主;各季沿海近地面风向南北部差异较大,东西部差异较小,随着季节转变,南部沿海盛行风转向最明显,东西部次之,北部则不明显.

The hourly observational data from 6 regular meteorological stations and 2 island stations in Hainan Island are used to statistically analyze the temporal and spatial characteristics of near-surface wind over the coastal areas of the Hainan Island during 2012,indexes including the distribution of wind speed and its daily change, and wind direction frequency.The results show that the yearly averaged wind speed over coastal areas is from 1.8 m/s to 5.7 m/s, with the highest wind speed appearing in Sanya, especially in winter with possible wind speed of 6. 5 m/s.Generally, the highest wind speed usually appears in winter or spring over most coastal stations, while the weakest wind appears in summer;the wind speed is higher in southern than in northern areas, and higher in western than in eastern coastal areas.The diurnal evolution of wind speed exhibits the canonical pattern,with high speed in daytime and low speed in nighttime ; however, Sanya exhibits the opposite pattern in wind speed as a result of its unique topography and vegetation.The dominant wind direction is south or southwest in summer and north or northeast in winter,which is similar to the pattern of South China Sea Monsoon.The seasonal variability of prevailing wind is significant over southern coastal areas, followed by eastern and western regions, and not obvious over northern coastal areas.