台湾海峡有效波高的SWAN模式与ERA-Interim数据对比分析

Comparative analysis of SWAN model and ERA-Interim data on significant wave height in the Taiwan Strait

有效波高是描述海浪的关键参数。欧洲中期天气预报中心(ECMWF)提供的ERA-Interim再分析数据提供了全球海浪的有效波高,本文选取该数据在台湾海峡2013年3月份的有效波高结果,分别与浮标观测数据以及海浪数值模式SWAN(Simulating Waves Nearshore)的数值模拟结果相对比,来分析其预报效果。结果显示:在浮标点,ERA-Interim数据和SWAN模拟浪高数据与浮标浪高数据的时间相关系数分别为0.94和0.98,ERA-Interim数据的浪高均值约为浮标的51%,为SWAN模拟数据的70%。在台湾海峡区域,ERA-Interim数据与SWAN模拟浪高之间的空间异常相关系数(ACC)月均值为0.51,时序ACC曲线显示,一般在海峡东北口风初起时刻ACC值最小,在风吹遍海峡并增长的过程中,ACC迅速增加,在风速达到最大值之后,ACC开始下降,但ERA-Interim数据与SWAN数值模拟结果在整个海峡区域的浪高最大值与最小值分布位置基本一致。综合分析,ERA-Interim数据能够反映台湾海峡区域此时间段的有效波高的时空变化趋势,在数值上有明显低估。

The significant wave height(SWH)is a key parameter for describing the ocean waves.In this paper,the SWH in the Taiwan Strait provided by the ERA-Interim reanalysis data from the European Centre for MediumRange Weather Forecasts(ECMWF)in March 2013 is compared with the buoy observations and the simulation results of the SWAN(Simulating Waves Nearshore)model.The results showed that the correlation coefficient of SWH between the buoy data and the ERA-Interim as well as the SWAN results is 0.94 and 0.98,respectively.The average SWH of the ERA-Interim data is about 51%of the buoy data and 70%of the SWAN results.The monthly averaged values of the spatial anomaly correlation coefficient(ACC)of the SWH between the ERA-Interim data and the SWAN results is 0.51.The ACC was minimal when the wind started,it boosted rapidly with increasing of the wind speed and reached the maximum before the wind speed reached the peak.Then the ACC turned to decrease at the peak wind speed.Integrated analysis imply that the ERA-Interim data can reflect the spatial distribution and the temporal variations trend of the SWH over the Taiwan Strait during this period,but it’s evidently smaller than the SWAN model data.