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Evaluation of the simulation capability of the wavewatch Ⅲ model for Pacific Ocean wave

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Acta Oceanologica Sinica 2015年第9期34卷 43-57页

作者： BI Fan SONG Jinbao WU Kejian XU Yao Key Laboratory of Ocean Circulation and Waves Institute of OceanologyChinese Academy of Sciences College of Physical and Environmental Oceanography Ocean University of China Ocean College Zhejiang University Key Laboratory of Physical Oceanography (Ocean University of China) Ministry of Education

Wave climate analysis and other applications for the Pacific Ocean require a reliable wave hindcast. Five source and sink term packages in the wavewatch iii model （v3.14 and v4.18） are compared and assessed in this study through comprehensive observations, including altimeter significant wave height, advanced synthetic aperture radar swell, and buoy wave parameters and spectrum. In addition to the evaluation of typically used integral parameters, the spectra partitioning method contributes to the detailed wave system and wave maturity validation. The modified performance evaluation method （PS） effectively reduces attribute numbers and facilitates the overall assessment. To avoid possible misleading results in the root mean square error-based validations, another indicator called HH （indicating the two authors） is also calculated to guarantee the consistency of the results. The widely used Tolman and Chalikov （TC） package is still generally efficient in determining the integral properties of wave spectra but is physically deficient in explaining the dissipation processes. The ST4 package performs well in overall wave parameters and significantly improves the accuracy of wave systems in the open ocean. Meanwhile, the newly published ST6 package is slightly better in determining swell energy variations. The two packages （ACC350 and BIA） obtained from wavewatch iii v3.14 exhibit large scatters at different sea states. The three most ideal packages are further examined in terms of reproducing wave- induced momentum flux from the perspective of transport. Stokes transport analysis indicates that ST4 is the closest to the NDBC-buoy-spectrum-based transport values, and TC and ST6 tend to overestimate and underestimate the transport magnitude, respectively, in swell mixed areas. This difference must be considered, particularly in air-wave-current coupling research and upper ocean analysis. The assessment results provide guidance for the selection of ST4 for use in a backgrou

关键词： wavewatch iii evaluation Pacific Ocean source and sink term packages wave-induced flux Stokes transport

A speckle noise suppression method based on surface waves investigation and monitoring data

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Acta Oceanologica Sinica 2023年第1期42卷 131-141页

作者： Jingwei Gu Xiuzhong Li Yijun He School of Marine Sciences Nanjing University of Information Science&TechnologyNanjing210044China

The internal energy distribution of waves can be described using ocean-wave *** many ways,obtaining wave spectra on a global scale is *** waves investigation and monitoring onboard the Chinese-French oceanography satellite is the first space-borne instrument for detecting wave spectra specially,which was launched on October 29,*** can avoid the shortage of synthetic aperture radar detection results while still having some problems,especially with the effects of speckle *** this study,a method to suppress the speckle noise is ***,the empirical formula for background speckle noise is ***,many spatio-temporal representative fluctuation spectra are classified and ***,rational transfer function filtering is used to obtain speckle noise close to the along-track ***,a signal-to-noise ratio threshold is used to suppress the abnormal speckle *** method solves the problems existing in previous denoising methods,such as excessive denoising in the along-track direction and the inability of some abnormal noises to be denoised in the two-dimensional directional wave spectra.

关键词： speckle noise surface waves investigation and monitoring wavewatch iii wave spectra

An efficient algorithm for generating a spherical multiple-cell grid

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Acta Oceanologica Sinica 2022年第5期41卷 41-50页

作者： Fang Hou Zhiyi Gao Jianguo Li Fujiang Yu National Marine Environmental Forecasting Center Beijing100081China Met Office ExeterEX13PBUK

This paper presents an efficient algorithm for generating a spherical multiple-cell(SMC)*** algorithm adopts a recursive loop structure and provides two refinement methods:(1)an arbitrary area refinement method and(2)a nearshore refinement *** experiments are carried out,and the results show that compared with the existing grid generation algorithm,this algorithm is more flexible and operable.

关键词： spherical multiple-cell grid wave model wavewatch iii grid generation algorithm

Optimization of multi-model ensemble forecasting of typhoon waves

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Water Science and Engineering 2016年第1期9卷 52-57页

作者： Shun-qi Pan Yang-ming Fan Jia-ming Chen Chia-chuen Kao Hydro-environmental Research Centre School of Engineering Cardiff University Coastal Ocean Monitoring Center National Cheng Kung University Department of Hydraulic and Ocean Engineering National Cheng Kung University

Accurately forecasting ocean waves during typhoon events is extremely important in aiding the mitigation and minimization of their potential damage to the coastal infrastructure, and the protection of coastal communities. However, due to the complex hydrological and meteorological interaction and uncertainties arising from different modeling systems, quantifying the uncertainties and improving the forecasting accuracy of modeled typhoon-induced waves remain challenging. This paper presents a practical approach to optimizing model-ensemble wave heights in an attempt to improve the accuracy of real-time typhoon wave forecasting. A locally weighted learning algorithm is used to obtain the weights for the wave heights computed by the wavewatch iii wave model driven by winds from four different weather models （model-ensembles）. The optimized weights are subsequently used to calculate the resulting wave heights from the model-ensembles. The results show that the opti- mization is capable of capturing the different behavioral effects of the different weather models on wave generation. Comparison with the measurements at the selected wave buoy locations shows that the optimized weights, obtained through a training process, can significantly improve the accuracy of the forecasted wave heights over the standard mean values, particularly for typhoon-induced peak waves. The results also indicate that the algorithm is easy to imnlement and practieal for real-time wave forecasting.

关键词： Wave modeling Optimization Forecasting Typhoon waves wavewatch iii Locally weighted learning algorithm

Effect of wave-induced Stokes drift on the dynamics of ocean mixed layer

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Chinese Journal of Oceanology and Limnology 2015年第1期33卷 233-242页

作者：王智峰吴克俭董胜邓增安张晓爽 College of Engineering Ocean University of China College of Physical and Environmental Oceanography Ocean University of China National Marine Data and Information Service State Oceanic Administration

The wave-forcing 'Coriolis-Stokes forcing' and 'Stokes-vortex force' induced by Stokes drift affect the upper ocean *** study the effect of the wave-induced Stokes drift on the dynamics of the ocean mixed layer,a new three-dimensional(3D) numerical model is derived using the primitive basic equations and Eulerian wave *** Princeton Ocean Model(POM),a 3D primitive equation ocean model is used with the upper wave-averaged basic *** global ocean circulation is simulated using the POM model,and the Stokes drift is evaluated based on the wave data generated by wavewatch *** compared simulations with and without the Stokes *** results show that the magnitude of the Stokes drift is comparable with the Eulerian mean *** the Stokes drift in the ocean model affects both the Eulerian current and the Lagranian drift and causes the vertical mixing coefficients to increase.

关键词： Stokes drift wavewatch iii Princeton Ocean Model (POM) Coriolis-Stokes forcing Stokes-vortex force

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再分析风场驱动下的南海波浪模拟误差

中国海洋大学学报（自然科学版） 2020年第11期50卷 96-104页

作者：王绿卿梁丙臣夏运强邵珠晓高慧君中国海洋大学工程学院山东青岛266100 中国海洋大学山东省海洋工程重点实验室山东青岛266100 海军研究院海防工程设计研究所北京100070

本文采用国际上广泛应用的3种再分析风场驱动wavewatch iii模型得到了南海波浪后报数据,并基于全球卫星高度计波高数据和我国沿海浮标实测数据对不同的风场计算结果进行了对比分析,分析表明3种风场的误差特征相差明显,其中ERA-40风场偏... 详细信息

本文采用国际上广泛应用的3种再分析风场驱动wavewatch iii模型得到了南海波浪后报数据,并基于全球卫星高度计波高数据和我国沿海浮标实测数据对不同的风场计算结果进行了对比分析,分析表明3种风场的误差特征相差明显,其中ERA-40风场偏小,CFSR风场非常适合模拟常见天气的波浪过程,NCDC风场适合模拟大浪过程。论文重点以NCDC风场后报波浪数据分析了波浪模型模拟误差特点,发现在台风频发的的南海北部海域,再分析风场易低估大值波高,而在季风影响明显的南海南部海域,再分析风场易高估波高。浮标周边2°范围海域内的卫星高度计波高模拟误差趋势与浮标波高模拟误差趋势相似,浮标波高数据的统计特征值与“2度法”提取的卫星高度计数据统计特征值具有较高一致性。

关键词：再分析风场 wavewatch iii 模拟误差分析南中国海波浪模拟

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集合同化方法在海浪同化中的试验

集合同化方法在海浪同化中的试验

作者：吴萌萌国家海洋环境预报中心

学位级别：硕士

目前，集合同化方法在海浪同化中还未得到全面深入的应用。本文基于第三代海浪数值预报模式wavewatch iii，设计了全球区域海浪同化系统，开展了集合最优插值（Ensemble Optimal Interpolation，简称EnOI）三天海浪预报及长期的同化试... 详细信息

目前，集合同化方法在海浪同化中还未得到全面深入的应用。本文基于第三代海浪数值预报模式wavewatch iii，设计了全球区域海浪同化系统，开展了集合最优插值（Ensemble Optimal Interpolation，简称EnOI）三天海浪预报及长期的同化试验，并与最优插值（Optimal Interpolation，简称OI）同化结果进行了比较。发现，EnOI同化方法在改善海浪预报中起到了很好的作用。考虑到EnOI中的历史样本会夸大背景误差且引起虚假相关，为解决这一问题，本文又首次尝试了通过在风场叠加随机扰动的方法生成一组动态样本，评估了历史样本与动态样本的优劣，为今后继续开展集合卡尔曼滤波（Ensemble Kalman Filter，简称EnKF）同化的研究做好了准备。主要开展了以下工作：（1）背景误差信息在资料同化中是至关重要的，在开展同化前须对模式误差有充分的认识。为此，首先对模式进行了10年的积分，通过NDBC浮标数据及Jason-1高度计资料对模式模拟结果的检验，发现模式对全球海浪模拟效果较好，并得到了有效的模式误差，为后面同化工作中背景误差协方差矩阵的构建及集合样本的选取提供了依据。（2）由于在全球范围内同化观测点资料较多，且模式网格设置较粗，为节省计算时间，对比分析了四种同化观测点选取方案。发现观测稀疏后并不会明显削弱同化效果，采用五点平均的减薄方案滤去高频扰动，能够在不影响同化效果的前提下缩短同化计算时间。（3）为了评估OI、EnOI同化在短期海浪预报中的改进效果，开展了三天海浪预报同化试验。发现，数据同化能够很好地订正初始场的偏差，并对初始化过程及三天预报过程有明显改进。EnOI对模式的改进效果在时间序列上更为稳定，对于36小时以内的预报，采用EnOI同化方案能够获得比OI更理想的同化效果。（4）为了进一步考察EnOI在长时间序列上对海浪预报的同化效果，设计了为期一年的同化试验。发现与OI相比，EnOI具有绝对的优势。采用EnOI同化方案后，全球海浪有效波高预报绝对误差小于0.5m的概率达到83.79%，小于1m的概率高达96.03%，预报精度非常可观。（5）由于EnOI是通过预先存储好的历史样本来估计背景误差，在积分过程中始终保持不变，这往往会夸大背景误差并且引起较长时间尺度上大范围的虚假相关。为解决这一问题，通过设计多组敏感性试验继续探讨了EnKF初始样本生成的最佳方法，并将其与EnOI历史样本做了比较。发现，相对于历史样本，扰动样本能够较好的呈现出模式误差的结构和相关性。

关键词： wavewatch iii 海浪同化 OI EnOI 历史样本扰动样本

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西北太平洋台风浪后报

西北太平洋台风浪后报

作者：杨洋上海交通大学

学位级别：硕士

西北太平洋是全球热带气旋活动最活跃的海域,该海域每年发生热带气旋的次数约占全球的1/3。而台风引起的大风浪和涌浪对船舶航行、海洋和近岸建筑物有重要的影响。1997年台风9711(Winnie)和台风0008(Jelawat)曾经对我国东部海域产生较... 详细信息

西北太平洋是全球热带气旋活动最活跃的海域,该海域每年发生热带气旋的次数约占全球的1/3。而台风引起的大风浪和涌浪对船舶航行、海洋和近岸建筑物有重要的影响。1997年台风9711(Winnie)和台风0008(Jelawat)曾经对我国东部海域产生较大的影响,文章描述了台风Winnie和Jelawat以及台风浪的发展、运移过程,其中台风风场由Jelesnianski2型风场模式模拟结果和NCAR背景风场合成得到,海浪模式采用第三代深海波浪模型(wavewatch iii)。首先,在模型风场中,台风的最大风速半径是一个重要而复杂的参数,它对模型风场的影响起着至关重要的作用。一般的气象台站台风参数实况分析并不包括最大风速半径R,而代之以近中心最大风速和某一风速的风圈半径等常规参数,文章应用经验公式(MEF)和大风风圈反推( MGCR )两种方法计算最大风速半径。基于Jelesnianski2型风场模式、藤田气压模式导出风场模式,并将模拟结果与NCAR资料的背景风场进行合成得出整个计算域的风场。然后,利用第三代深海波浪模型(wavewatch iii)计算台风浪。海底地形利用数字化仪将海图数字化,并与美国全球水下地形资料西北太平洋海域进行插值整合。考虑到台风过程是一个大尺度的大气系统模拟范围,模型采用经纬度网格,网格大小为0.2经度×0.2纬度,共201×201个网格。考虑到计算水域水深较大,模型中忽略地形底部摩擦、潮流、冰等因素的影响,从而使计算简便、快速。计算时间步长为15分钟,计算结果每小时输出一次最后,利用以上模型对台风9711(Winnie)和台风0008(Jelawat)进行数值模拟.将计算结果与实测资料进行比较得到:台风期间,用MEF模拟的西北太平洋海域风浪场变化较为合理;三个波浪测站计算和实测的有效波高对比表明MEF的模拟结果吻合更好,误差约为10%。因此根据合成风场应用第三代深海波浪模型(wavewatch iii)模拟的西北太平洋台风浪是可应用于船舶与海洋工程。

关键词：最大风速半径台风9711 台风0008 数值模型台风浪后报 wavewatch iii

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次网格数据对台风浪数值模拟结果的影响

次网格数据对台风浪数值模拟结果的影响