基于CCMP的西北太平洋海面风场特征分析

Characteristics analysis of the sea surface wind in the Northwest Pacific based on CCMP satellite data

利用1988—2018年CCMP 10 m风场资料,对西北太平洋海表风场的气候态特征、线性变化趋势以及6级及以上风力的频率分布特征进行分析。结果表明:平均风速随季节变化显著,夏季风速偏小,冬季风速整体较大。海表风速的线性变化趋势同样呈现出较强的季节性差异,其中东海南部、台湾海峡、南海东北部以及巴士海峡海域季节平均风速在秋冬两季表现出相反的变化趋势,这可能与东亚大槽的强度变化以及累积气旋能量的年际变化有关。西北太平洋不同海域大风频率分布特征季节差异性显著,30°N以北的北太平洋海域除夏季外,其他3个季节大风过程频发,南海东北部海域、台湾海峡以及巴士海峡海域大风过程主要集中在秋、冬两季;南海中西部海域大风过程主要集中在夏、冬两季,夏季大风过程以西南风为主,冬季以东北风为主。

Using the Cross-Calibrated Multi-Platform 10 m wind field data from 1988 to 2018, the climatic characteristics, linear variation trend and the frequency distribution characteristics of wind force equals or beyond scale 6 are analyzed in this paper. The results show that the average wind speed changes significantly with the seasons, which is smaller in summer and generally larger in summer. The linear change variation trend of sea surface wind speed also shows strong seasonal variation. The most notable feature is that the seasonal mean wind speed in autumn and winter reveals opposite variation trend in the southern part of the East China Sea, the Taiwan Strait, the northeastern part of the South China Sea, and the Bashi Channel, which may be related to the changes in the intensity of the East Asian trough and the inter-annual variation of the Accumulated Cyclone Energy. The gale frequency shows significant seasonal differences in different areas of the Northwest Pacific. The gale processes occur frequently throughout the year except summer in the North Pacific area north of 30°N. The gale processes mainly occur in autumn and winter in the northeastern South China Sea, the Taiwan Strait and the Bashi Channel. The gale processes mainly occur in summer and winter in the central and western South China Sea with southwest gale prevailing in summer and northeast gale prevailing in winter.