摘要: |
模式集合样本的代表性和观测信息的可靠性是制约数据同化效果的重要因素,而前者对海浪模式同化的影响尤为显著。由于海浪模式对初始场的敏感性较弱,来自大气的风输入源函数是海浪的重要能量输入,如何合理地对风输入进行扰动,构造海浪的集合模式运行,是实现和改进海浪模式集合Kalman滤波同化的关键问题。为了实现海浪模式集合运行,本文提出了风场的三种集合扰动方案,分别为:纯随机数、随机场和时间滞后的风场扰动方法。本研究利用2014年1月ECMWF全球风场,基于这三种风场扰动方法开展了集合海浪模式的集合运行实验,并统计分析了海浪特征要素(有效波高)和二维波数谱对风场扰动的响应。结果表明,随机场集合扰动方案所构造的风场集合效果最佳,所得海浪模拟结果的集合样本发散度适中,能够较为合理地反映背景误差的统计特征,可用于进一步的集合Kalman滤波海浪数据同化实验。 |
关键词: 风场扰动 集合样本 海浪同化 |
DOI:10.11693/hyhz20160500098 |
分类号: |
基金项目:国家高技术研究发展计划(863)项目,2013AA09A506号;海洋可再生能源专项项目,GHME2011ZC07号;海洋水文资料同化方法与业务化应用研究项目。 |
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ON ENKF DATA ASSIMILATION BASED ON MASNUM-WAMI. INFLUENCE ON WAVE SIMULATION OF ENSEMBLE-DISTURBANCE WIND FIELD |
SUN Meng1,2, YIN Xun-Qiang2,3, YANG Yong-Zeng2,3, WU Ke-Jian1
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1.College of Oceanic and Atmospheric Sciences, Ocean University of China, Qingdao 266100, China;2.Key Lab of Marine Science and Numerical Modeling, First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China;3.Laboratory for Regional Oceanography and Numerical Modeling, National Laboratory for Marine Science and Technology, Qingdao 266071, China
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Abstract: |
Representativeness of model ensemble samples and reliability of observations,especially the former one,are key factors affecting data assimilation.Wave model is not very sensitive to initial field.Wind energy input is an important primitive function.To implement and improve wave data assimilation of EnKF,disturbance-ensemble wind fields that force wave models are essential.Three schemes to construct the disturbance-ensemble wind fields are proposed for pure random-number,random-field and time-delay method.ECMWF reanalysis wind data and MASNUM-WAM were adopted here.Global ensemble wave numerical experiments were carried out in January,2014.To understand the influence of ensemble-disturbance wind field on MASNUM-WAM,an ensemble sample statistics of significant wave height and wave spectrum is implemented.The results show that the random-field scheme reflects the information of background error reasonably and performed best.Therefore,the scheme can be used for further research on wave data assimilation. |
Key words: disturbance wind field ensemble sample wave assimilation |