| 摘要: |
| 将基于最优插值 (OI) 的同化并行模块植入全谱空间的第三代海浪模式WAVEWATCH III version3.14,建立数据同化的海浪模式预报系统, 并通过实际的预报个例对同化系统进行检验。个例实验是以5°S 以北的印度洋海域为目标计算区域, 海面风场强迫采用业务单位的中尺度天气预报模式WRF(weather research and forecast) 提供的逐时海面风场预报产品。模式积分过程中连续同化2010 年12 月15 日、16 日和17 日过境北印度洋的Jason-2 卫星高度计沿轨有效波高 (SWH) 数据 (需要指出的是, 每次同化得到新的SWH 分析场后需重构相应的二维海浪谱用于谱模式)。SWH 同化分析值和无同化的对照组分别与高度计沿轨观测数据比较发现, 就日平均统计来看, 同化较无同化使SWH分析值的均方根误差减小约25%～50%。以SWH 同化分析场作为初始场的预报表明, 同化对预报影响的时效性可延长至48～60 h。本研究目的是通过将高度计测量的SWH 数据同化到海浪模式进一步提升海浪数值预报的准确度。 |
| 关键词: WAVEWATCH III 最优插值(OI) 数据同化 卫星高度计波高数据 |
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| 基金项目:海洋公益性行业科研专项经费项目(201005033, 201105002);国家高技术研究发展计划(863 计划)课题(2012AA091801); NSFC-广东联合基金重点项目(U1133001) |
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| The establishment and test of WAVEWATCH III data assimilation module |
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| Abstract: |
| A parallel module of data assimilation based on optimal interpolation (OI) was developed and implanted into the full-spectral third-generation wind-wave model WAVEWATCH III version3.14, turning it into a data assimilative wave forecasting model. The north of 5°S in the Indian Ocean was chosen as the target computational domain, with its open boundary conditions provided by the global implementation of WAVEWATCH III. Hourly sea-surface wind velocities from routine output of an atmosphere model WRF (weather research and forecasting) were employed as surface forcing on the wave model. In the process of the model integration, significant wave height (SWH) data observed by Jason-2 satellite altimeter were assimilated consecutively from Dec. 15 to Dec. 17, 2010. It’s needed to note that after finishing assimilation each time, the updated analysis of SWH fields must be used to reconstruct the corresponding two-dimensional wave spectrum. The SWH Model from the assimilation run and the control run was compared with Jason-2 along-track SWH data. It was found that consecutive assimilation of the observed SWH data in each day reduced the root-mean-square error of analyzed SWH by approximately 25%～50%. Furthermore, the forecast made using the analyzed SWH as the initial field indicated that the effect of assimilation on the forecast may be memorized and retained as long as 48~60 hours. The purpose of this paper is to further improve the accuracy of wave forecast model by assimilating altimeter SWH data into the wave model. |
| Key words: WAVEWATCH III optimal interpolation (OI) data assimilation satellite altimetric wave data |
