3种海面风场资料在台湾海峡的比较和评估

本文对3种海面风场资料(CCMP、NCEP、ERA)在台湾海峡风场的平面分布和时间变化特征进行了相互比较,并应用2011年浮标观测的风速和风向资料分别对3种风场的误差进行了分析及评估。主要结论如下:(1)3种资料风场的平面分布、季节变化和年际变化特征基本一致,差异主要表现在冬季NCEP资料在海峡中部和南部的风速相对CCMP和ERA资料较大;(2)CCMP资料的风速偏差、风速均方根误差和风向均方根误差分别为-0.62m/s、1.67m/s和31°,NCEP分别为0.15m/s、1.64m/s和31°,ERA分别为-1.36m/s、2.4m/s和33°;NCEP资料的风速整体略偏大、CCMP略偏小、ERA偏小明显,CCMP和NCEP资料比ERA资料更接近观测;(3)在西南季风影响期以及风速较小时(风速不大于10m/s)CCMP资料的风速可信度较高、NCEP资料的风速偏大;在东北季风影响期以及风速较大时(大于10m/s)NCEP资料的风速可信度较高、CCMP资料的风速偏小;(4)3种资料的风向误差接近,均在低风速时(风速小于5m/s)误差较大。本文的结论可以为台湾海峡的海洋和大气科学研究选择合适的海面风场资料提供借鉴和参考。

Comparison and evaluation of three sea surface wind products in Taiwan Strait

Three sea surface wind products(CCMP,NCEP,and ERA) have been cross compared and evaluated using moored-buoy observations in Taiwan Strait in 2011. The main conclusions are as follows: (1) The horizontal pattern of the surface wind from the three products are similar and the time variation are consistent with each other; the wind speed forecast of NCEP in the middle and southern Taiwan Strait in winter is bigger than that of CCMP and ERA. (2)The wind speed bias,wind speed RMSE and wind direction RMSE of CCMP are -0.62 m/s,1.67 m/s and 31° respectively,compared with those of NCEP being 0.15 m/s,1.64 m/s and 31°,and those of ERA being -1.36 m/s,2.4 m/s and 33°; CCMP and NCEP are found to be more close to observations than ERA. (3) During the south-west monsoon and at low wind speed range(≤10 m/s),CCMP shows higher credibility while NCEP's wind speed is over-estimated; during the east-north monsoon and at high wind speed range(>10 m/s),NCEP shows higher credibility while CCMP's wind speed is under-estimated. (4) The wind direction RMSE of the three products are close to each other and show the same characteristic that the RMSE is bigger at low wind speed range (<5 m/s). Those findings will provide references for choosing appropriate sea surface wind product in Taiwan Strait.