Wave parameters, such as wave height and wave period, are important for human activities, such as navigation, ocean engineering and sediment transport, etc. In this study, wave data from six buoys around Chinese water...Wave parameters, such as wave height and wave period, are important for human activities, such as navigation, ocean engineering and sediment transport, etc. In this study, wave data from six buoys around Chinese waters, are used to assess the quality of wave height and wave period in the ERA5 reanalysis of the European Centre for Medium-Range Weather Forecasts. Annual hourly data with temporal resolution are used. The difference between the significant wave height(SWH) of ERA 5 and that of the buoy varies from-0.35 m to 0.30 m for the three shallow locations;for the three deep locations, the variation ranges from-0.09 m to 0.09 m. The ERA5 SWH data show positive biases, indicating an overall overestimation for all locations, except for E2 and S1 where underestimation is observed. During the tropical cyclone period, a large(about 32%) underestimation of the maximum SWH in the ERA5 data is observed. Hence, the ERA5 SWH data cannot be used for design applications without site-specific validation. The difference between the annual wave period from ERA5 and the mean wave period from the buoys varies from-1.31 s to 0.4 s. Inter-comparisons suggest that the ERA5 dataset is consistent with the annual mean SWH. However, for the average period, the performance is not good, and half of the correlation coefficients in the four points are less 50%. Overall, the deep water area simulation effect is better than that in the shallow water.展开更多
We performed long-term wind-wave hindcast in the Yellow Sea and the Bohai Sea from the year 1988 to 2002, and then analyzed the regional wave climate. Comparisons between model results and satellite data are generally...We performed long-term wind-wave hindcast in the Yellow Sea and the Bohai Sea from the year 1988 to 2002, and then analyzed the regional wave climate. Comparisons between model results and satellite data are generally consistent on monthly mean significant wave height. Then we discuss the temporal and spatial characteristics of the climatological monthly mean significant wave heights and mean wave periods. The climatologically spatial patterns are observed as increasing from northwest to southeast and from offshore to deep-water area for both significant wave height and mean wave period, and the patterns are highly related to the wind forcing and local topography. Seasonal variations of wave parameters are also significant. Furthermore, we compute the extreme values of wind and significant wave height using statistical methods. Results reveal the spatial patterns of N-year return significant wave height in the Yellow Sea and the Bohai Sea, and we discuss the relationship between extreme values of significant wave height and wind forcing.展开更多
Reliable wave information is critical for marine engineering.Numerical wave models are useful tools to obtain wave information with continuous spatiotemporal distributions.However,the accuracy of model results highly ...Reliable wave information is critical for marine engineering.Numerical wave models are useful tools to obtain wave information with continuous spatiotemporal distributions.However,the accuracy of model results highly depends on the quality of wind forcing.In this study,we utilize observations from five buoys deployed in the northern South China Sea from August to September 2017.Notably,these buoys successfully recorded wind field and wave information during the passage of five tropical cyclones of different intensities without sustaining any damage.Based on these unique observations,we evaluated the quality of four widely used wind products,namely CFSv2,ERA5,CCMP,and ERAI.Our analysis showed that in the northern South China Sea,ERA5 performed best compared to buoy observations,especially in terms of maximum wind speed values at 10 m height(U10),extreme U10 occurrence time,and overall statistical indicators.CFSv2 tended to overestimate non-extreme U10 values.CCMP showed favorable statistical performance at only three of the five buoys,but underestimated extreme U10 values at all buoys.ERAI had the worst performance under both normal and tropical cyclone conditions.In terms of wave hindcast accuracy,ERA5 outperformed the other reanalysis products,with CFSv2 and CCMP following closely.ERAI showed poor performance especially in the upper significant wave heights.Furthermore,we found that the wave hindcasts did not improve with increasing spatiotemporal resolution,with spatial resolution up to 0.5°.These findings would help in improving wave hindcasts under extreme conditions.展开更多
A hindcast simulation of 75 typhoons and winter monsoons which affected the coastal areas of Korean Peninsula is performed by use of a third generation ocean wave prediction model, WAM-cycle 4 model, loosely coupled w...A hindcast simulation of 75 typhoons and winter monsoons which affected the coastal areas of Korean Peninsula is performed by use of a third generation ocean wave prediction model, WAM-cycle 4 model, loosely coupled with a com-bined tide and surge model. Typhoon wind fields are derived from the planetary marine boundary layer model for effective neutral winds embedding the vortical storm wind from the parameterized Rankin vortex type model in the limited areas of the overall modeled region. The hindcasted results illustrate that significant wave heights (SWH) considering the wave-tide-surge coupled process are significantly different from the results via the decoupled case especially in the region of the estuaries of the Changjiang Estuary, The Hangzhou Bay, and the southwestern tip of Korean Peninsula. This extensive model simulation is the first attempt to investigate the strong wave-tide-surge interaction for the shallow depth area along the coasts of the Yellow Sea and the East China Sea Continental shelf.展开更多
The risk of wind waves in a bay is often overlooked,owing to the belief that peninsulas and islands will inhibit high waves.However,during the passage of a tropical cyclone,a semi-enclosed bay is exposed to twodirecti...The risk of wind waves in a bay is often overlooked,owing to the belief that peninsulas and islands will inhibit high waves.However,during the passage of a tropical cyclone,a semi-enclosed bay is exposed to twodirectional waves:one generated inside the bay and the other propagated from the outer sea.Typhoon Faxai in 2019 resulted in the worst coastal disaster in Tokyo Bay in the last few decades.The authors conducted a post-disaster survey immediately after this typhoon.Numerical modeling was also performed to reveal the mechanisms of unusual high waves.No significant high-wave damage occurred on coasts facing the Pacific Ocean.By contrast,Fukuura-Yokohama,which faces Tokyo Bay,suffered overtopping waves that collapsed seawalls.To precisely reproduce multi-directional waves,the authors developed an extended parametric typhoon model,which was embedded in the JMA mesoscale meteorological model(JMA-MSM).The peak wave height was estimated to be 3.4 m off the coast of Fukuura,in which the contribution of the outer-sea waves was as low as 10%–20%.A fetchlimited wave developed over a short distance in the bay is considered the primary mechanism of the high wave.The maximum wave occurred on the left-hand side of the typhoon track in the bay,which appears to be contrary to the common understanding that it is safer within the semicircle of a storm than on the opposite side.Typhoon Faxai was a small typhoon;however,if the radius was tripled,it is estimated that the wave height would exceed 3 m over the entire bay and surpass 4 m off the coasts of Yokohama and Chiba.展开更多
基金supported by National Key R&D Program of China(No.2018YFB1501901)the National Natural Science Foundation of China(No.51909114)+2 种基金the Major Research Grant(Nos.U1806227 and U1906231)from the Natural Science Foundation of China and the Provincial Natural Science Foundation of Shandongthe Open Research Fund of the Key Laboratory of Ocean Circulation and Waves,Chinese Academy of Sciences(No.KLOCW1901)the Open Research Fund of State Key Laboratory of Tropical Oceanography,South China Sea Institute of Oceanology,Chinese Academy of Sciences(No.LTO1905).
文摘Wave parameters, such as wave height and wave period, are important for human activities, such as navigation, ocean engineering and sediment transport, etc. In this study, wave data from six buoys around Chinese waters, are used to assess the quality of wave height and wave period in the ERA5 reanalysis of the European Centre for Medium-Range Weather Forecasts. Annual hourly data with temporal resolution are used. The difference between the significant wave height(SWH) of ERA 5 and that of the buoy varies from-0.35 m to 0.30 m for the three shallow locations;for the three deep locations, the variation ranges from-0.09 m to 0.09 m. The ERA5 SWH data show positive biases, indicating an overall overestimation for all locations, except for E2 and S1 where underestimation is observed. During the tropical cyclone period, a large(about 32%) underestimation of the maximum SWH in the ERA5 data is observed. Hence, the ERA5 SWH data cannot be used for design applications without site-specific validation. The difference between the annual wave period from ERA5 and the mean wave period from the buoys varies from-1.31 s to 0.4 s. Inter-comparisons suggest that the ERA5 dataset is consistent with the annual mean SWH. However, for the average period, the performance is not good, and half of the correlation coefficients in the four points are less 50%. Overall, the deep water area simulation effect is better than that in the shallow water.
基金The National Natural Science Foundation of China under contract Nos 41476021 and 41321004the Strategic Priority Research Program of the Chinese Academy of Sciences under contract No.XDA11010104the project of Indo-Pacific Ocean Environment Variation and Air-sea Interaction under contract No.GASI-IPOVAI-04
文摘We performed long-term wind-wave hindcast in the Yellow Sea and the Bohai Sea from the year 1988 to 2002, and then analyzed the regional wave climate. Comparisons between model results and satellite data are generally consistent on monthly mean significant wave height. Then we discuss the temporal and spatial characteristics of the climatological monthly mean significant wave heights and mean wave periods. The climatologically spatial patterns are observed as increasing from northwest to southeast and from offshore to deep-water area for both significant wave height and mean wave period, and the patterns are highly related to the wind forcing and local topography. Seasonal variations of wave parameters are also significant. Furthermore, we compute the extreme values of wind and significant wave height using statistical methods. Results reveal the spatial patterns of N-year return significant wave height in the Yellow Sea and the Bohai Sea, and we discuss the relationship between extreme values of significant wave height and wind forcing.
基金The Major Projects of the National Natural Science Foundation of China under contract No.U21A6001the Program of Marine Economy Development Special Fund under Department of Natural Resources of Guangdong Province under contract No.GDNRC[2022]18+1 种基金the Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)under contract No.SML2021SP207the Fund of State Key Laboratory of Tropical Oceanography,South China Sea Institute of Oceanology,Chinese Academy of Sciences under contract No.LTO2001.
文摘Reliable wave information is critical for marine engineering.Numerical wave models are useful tools to obtain wave information with continuous spatiotemporal distributions.However,the accuracy of model results highly depends on the quality of wind forcing.In this study,we utilize observations from five buoys deployed in the northern South China Sea from August to September 2017.Notably,these buoys successfully recorded wind field and wave information during the passage of five tropical cyclones of different intensities without sustaining any damage.Based on these unique observations,we evaluated the quality of four widely used wind products,namely CFSv2,ERA5,CCMP,and ERAI.Our analysis showed that in the northern South China Sea,ERA5 performed best compared to buoy observations,especially in terms of maximum wind speed values at 10 m height(U10),extreme U10 occurrence time,and overall statistical indicators.CFSv2 tended to overestimate non-extreme U10 values.CCMP showed favorable statistical performance at only three of the five buoys,but underestimated extreme U10 values at all buoys.ERAI had the worst performance under both normal and tropical cyclone conditions.In terms of wave hindcast accuracy,ERA5 outperformed the other reanalysis products,with CFSv2 and CCMP following closely.ERAI showed poor performance especially in the upper significant wave heights.Furthermore,we found that the wave hindcasts did not improve with increasing spatiotemporal resolution,with spatial resolution up to 0.5°.These findings would help in improving wave hindcasts under extreme conditions.
基金The research is a part of the second phase(1998-2000)of Natural Hazard Prevention Research funded by the Ministry of Science and Technology through Korea Institute of Science and Technology Evaluation and Planning (KISTEP) and Group for Natural Hazard Pr
文摘A hindcast simulation of 75 typhoons and winter monsoons which affected the coastal areas of Korean Peninsula is performed by use of a third generation ocean wave prediction model, WAM-cycle 4 model, loosely coupled with a com-bined tide and surge model. Typhoon wind fields are derived from the planetary marine boundary layer model for effective neutral winds embedding the vortical storm wind from the parameterized Rankin vortex type model in the limited areas of the overall modeled region. The hindcasted results illustrate that significant wave heights (SWH) considering the wave-tide-surge coupled process are significantly different from the results via the decoupled case especially in the region of the estuaries of the Changjiang Estuary, The Hangzhou Bay, and the southwestern tip of Korean Peninsula. This extensive model simulation is the first attempt to investigate the strong wave-tide-surge interaction for the shallow depth area along the coasts of the Yellow Sea and the East China Sea Continental shelf.
基金funded by grants awarded to Tokyo Institute of Technology(Japan Society for the Promotion of Science,Nos.16KK0121,19K04964 and 19K24677).
文摘The risk of wind waves in a bay is often overlooked,owing to the belief that peninsulas and islands will inhibit high waves.However,during the passage of a tropical cyclone,a semi-enclosed bay is exposed to twodirectional waves:one generated inside the bay and the other propagated from the outer sea.Typhoon Faxai in 2019 resulted in the worst coastal disaster in Tokyo Bay in the last few decades.The authors conducted a post-disaster survey immediately after this typhoon.Numerical modeling was also performed to reveal the mechanisms of unusual high waves.No significant high-wave damage occurred on coasts facing the Pacific Ocean.By contrast,Fukuura-Yokohama,which faces Tokyo Bay,suffered overtopping waves that collapsed seawalls.To precisely reproduce multi-directional waves,the authors developed an extended parametric typhoon model,which was embedded in the JMA mesoscale meteorological model(JMA-MSM).The peak wave height was estimated to be 3.4 m off the coast of Fukuura,in which the contribution of the outer-sea waves was as low as 10%–20%.A fetchlimited wave developed over a short distance in the bay is considered the primary mechanism of the high wave.The maximum wave occurred on the left-hand side of the typhoon track in the bay,which appears to be contrary to the common understanding that it is safer within the semicircle of a storm than on the opposite side.Typhoon Faxai was a small typhoon;however,if the radius was tripled,it is estimated that the wave height would exceed 3 m over the entire bay and surpass 4 m off the coasts of Yokohama and Chiba.
