Ocean Modelling最新文献

{"title":"An effective parameterization of broadband ocean surface albedo applicable to all skies","authors":"Chuan Jiang Huang ,&nbsp;Gang Wang ,&nbsp;Siyu Chen ,&nbsp;Jingsong Guo ,&nbsp;Fangli Qiao","doi":"10.1016/j.ocemod.2024.102394","DOIUrl":"10.1016/j.ocemod.2024.102394","url":null,"abstract":"<div><p>The ocean surface albedo (OSA) is an important parameter in ocean and climate models for air-sea heat flux calculations. Current OSA schemes are either too simple, making them only suitable for clear sky conditions, or too complex, because they depend on parameters that are not often measured in conventional ocean observations. Using radiation observations at a fixed offshore platform, we propose a simple but effective parameterization scheme of OSA, in which the broadband OSA is an analytical function of both the solar zenith angle and atmospheric transparency. It depends only on the downward shortwave radiation measured at the ocean surface and applies to all sky conditions. During our 15-month radiation observations, the correlation coefficient between the calculated OSA and the observations reached 0.90 for all skies, and the root mean square deviation was 0.0130. Three other OSA observation datasets are also introduced to verify this scheme.</p></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"190 ","pages":"Article 102394"},"PeriodicalIF":3.2,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1463500324000817/pdfft?md5=80eb093a72adfe9fd300c9a2eae170df&pid=1-s2.0-S1463500324000817-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141275786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wavelet-based wavenumber spectral estimate of eddy kinetic energy: Application to the North Atlantic","authors":"Takaya Uchida ,&nbsp;Quentin Jamet ,&nbsp;Andrew C. Poje ,&nbsp;Nico Wienders ,&nbsp;William K. Dewar","doi":"10.1016/j.ocemod.2024.102392","DOIUrl":"https://doi.org/10.1016/j.ocemod.2024.102392","url":null,"abstract":"<div><p>An ensemble of eddy-rich North Atlantic simulations is analyzed, providing estimates of eddy kinetic energy (EKE) wavenumber spectra and spectral budgets below the mixed layer where energy input from surface convection and wind stress are negligible. A wavelet transform technique is used to estimate a spatially localized ‘pseudo-Fourier’ spectrum (Uchidaet al., 2023b), permitting comparisons to be made between spectra at different locations in a highly inhomogeneous and anisotropic environment. The EKE spectra tend to be stable in time but the spectral budgets are highly time dependent. We find evidence of a Gulf Stream imprint on the near Gulf Stream eddy field appearing as enhanced levels of EKE in the (nominally) North–South direction relative to the East–West direction. Surprisingly, this signature of anisotropy holds into the quiescent interior with a tendency of the orientation aligned with maximum EKE being associated with shallower spectral slopes and elevated levels of inverse EKE cascade. Conversely, the angle associated with minimum EKE is aligned with a steeper spectral slope and forward cascade of EKE. Our results also indicate that vertical motion non-negligibly affects the direction of EKE cascade. A summary conclusion is that the spectral characteristics of eddies in the wind-driven gyre below the mixed layer where submesoscale dynamics are expected to be weak tend to diverge from expectations built on inertial-range assumptions, which are stationary in time and horizontally isotropic in space.</p></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"190 ","pages":"Article 102392"},"PeriodicalIF":3.2,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1463500324000799/pdfft?md5=ca09141a3a43d2ac39f244cbc8d4c4c3&pid=1-s2.0-S1463500324000799-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141244806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A multi-faceted methodology for calibration of coastal vegetation drag coefficient","authors":"Erfan Amini ,&nbsp;Reza Marsooli ,&nbsp;Mehdi Neshat","doi":"10.1016/j.ocemod.2024.102391","DOIUrl":"https://doi.org/10.1016/j.ocemod.2024.102391","url":null,"abstract":"<div><p>The accurate prediction of wave height attenuation due to vegetation is crucial for designing effective and efficient natural and nature-based solutions for flood mitigation, shoreline protection, and coastal ecosystem preservation. Central to these predictions is the estimation of the vegetation drag coefficient (Cd). The present study undertakes a comprehensive evaluation of three distinct methodologies for estimating the drag coefficient: traditional manual calibration, calibration using a novel application of state-of-the-art metaheuristic optimization algorithms, and the integration of an empirical bulk drag coefficient formula (Tanino and Nepf, 2008) into the XBeach non-hydrostatic wave model. These methodologies were tested using a series of existing laboratory experiments involving nearshore vegetation on a sloping beach. A key innovation of the study is the first application of metaheuristic optimization algorithms for calibrating the drag coefficient, which enables efficient automated searches to identify optimal values aligning with measurements. We found that the optimization algorithms rapidly converge to precise drag coefficients, enhancing accuracy and overcoming limitations in manual calibration which can be laborious and inconsistent. While the integrated empirical formula also demonstrates reasonable performance, the optimization approach exemplifies the potential of computational techniques to transform traditional practices of model calibration. Comparing these strategies provides a framework to determine effective methodology based on constraints in determining the vegetation drag coefficient.</p></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"190 ","pages":"Article 102391"},"PeriodicalIF":3.2,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141291157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to “Dispersion diagrams of linear damped waves on the equatorial beta plane” [Volume 188 (2024) 102336]","authors":"P. Amol ,&nbsp;D. Shankar","doi":"10.1016/j.ocemod.2024.102389","DOIUrl":"https://doi.org/10.1016/j.ocemod.2024.102389","url":null,"abstract":"","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"190 ","pages":"Article 102389"},"PeriodicalIF":3.2,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1463500324000763/pdfft?md5=76bd6b70d34e9beae40a167bb9c51bb5&pid=1-s2.0-S1463500324000763-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141241740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A statistical analysis method for significant wave height and spectral peak frequency considering the random and time-varying effects based on copula function and Bayesian inference","authors":"Xiaochuan Duan ,&nbsp;Shaoping Wang ,&nbsp;Di Liu ,&nbsp;Jian Shi ,&nbsp;Yinghua Wu ,&nbsp;Xiaobao Zhou","doi":"10.1016/j.ocemod.2024.102390","DOIUrl":"https://doi.org/10.1016/j.ocemod.2024.102390","url":null,"abstract":"<div><p>Random and time-varying effects are important factors for statistical analysis of wave characteristic variables, including the significant wave height and spectral peak frequency. This paper proposes a statistical analysis method for the accurate statistical analysis of the state of the ocean. Several common distributions are applied as candidates for describing a specific variable, denoted as the marginal distribution. The joint distribution for the wave characteristic variables is constructed using copula functions based on the marginal distributions. The probability and unknown parameters of the marginal distributions are then determined by fully Bayesian inference. The best-fitting marginal distribution is selected based on the posterior probabilities of the candidates. Then, unknown parameters of the candidate copula functions are estimated by maximum likelihood estimation. The best-fitting copula function is selected based on Akaike information criterion, root mean squared error and Nash Sutcliffe efficiency. The proposed method is verified using the National Data Buoy Center dataset for 2019. However, this dataset, collected from a network of almost 100 moored buoys and Coastal-Marine Automated Network (CMAN) stations, contains incomplete data. The results reveal that the best-fitting marginal distribution and copula function may vary with the month. The average and maximum values of the improved RMSE using the proposed method are only 0.0064 and 0.0187, respectively. This indicates the high accuracy of the proposed method for the statistical analysis of wave states even though missing some data.</p></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"190 ","pages":"Article 102390"},"PeriodicalIF":3.2,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141241739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Model validation and applications of wave and current forecasts from the Hong Kong Observatory's Operational Marine Forecasting System","authors":"Wai Kong ,&nbsp;Ching-chi Lam ,&nbsp;Dick-shum Lau ,&nbsp;Chi-kin Chow ,&nbsp;Sze-ning Chong ,&nbsp;Pak-wai Chan ,&nbsp;Ngo-ching Leung","doi":"10.1016/j.ocemod.2024.102393","DOIUrl":"https://doi.org/10.1016/j.ocemod.2024.102393","url":null,"abstract":"<div><p>The Hong Kong Observatory has been running an Operational Marine Forecasting System (OMFS) adapted from the Regional Ocean Modelling System (ROMS) coupled with the WaveWatch III and SWAN wave models to provide wave, current and sea temperature forecasts up to 144 h twice a day since December 2021. To facilitate users’ interpretation of model forecasts of significant wave height and current speed in coastal predictions and open seas which are of particular significance in high wind situations, model forecasts were validated against moored buoy observations and wave recorder measurements near the shores of Hong Kong and drifting buoy data over the South China Sea, as well as Mercator Ocean model reanalysis in 2022. The validation results showed that the wave forecasts generally agreed well with the buoy observations with coefficient of determination (R²) of around 0.7 and root-mean-square error (RMSE) of less than 0.2 m up to 72 h ahead. The R² for sea current forecasts ranged between 0.4 and 0.6, and the RMSE was around 8 to 11 cm/s in near shores up to <em>T</em> + 144 forecast hours. Validation against drifting buoy demonstrated that the trend of current forecasts generally agreed well with the measurements. RMSE of surface current forecasts over open seas ranged from 19 cm/s for 24-hour forecast to around 30 cm/s for 144-hour forecast when compared against Mercator Ocean reanalysis. Results from the current downscaling approach could serve as a benchmark reference for HKO to enhance OMFS in the future. In this paper, applications of model forecasts in the provision of marine weather services in Hong Kong are also introduced.</p></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"190 ","pages":"Article 102393"},"PeriodicalIF":3.2,"publicationDate":"2024-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1463500324000805/pdfft?md5=266e2969315d211d062c13bff82cb79a&pid=1-s2.0-S1463500324000805-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141324166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficacy of reduced order source terms for a coupled wave-circulation model in the Gulf of Mexico","authors":"Mark Loveland ,&nbsp;Jessica Meixner ,&nbsp;Eirik Valseth ,&nbsp;Clint Dawson","doi":"10.1016/j.ocemod.2024.102387","DOIUrl":"https://doi.org/10.1016/j.ocemod.2024.102387","url":null,"abstract":"<div><p>During hurricanes, coupled wave-circulation models are critical tools for public safety. The standard approach is to use a high fidelity circulation model coupled with a wave model that uses the most advanced source terms. As a result, the models can be computationally expensive and so this study investigates the potential consequences of using simplified (reduced order) source terms within the wave model component of the coupled wave-circulation model. The trade-off between run time and accuracy with respect to observations is quantified for a set of two storms that impacted the Gulf of Mexico, Hurricane Ike and Hurricane Ida. Water surface elevations as well as wave statistics (significant wave height, peak period, and mean wave direction) are compared to observations. The usage of the reduced order source terms yielded significant savings in computational cost. Additionally, relatively low amounts of additional error with respect to observations during the simulations with reduced order source terms are observed in our computational experiments. However, large changes in global model outputs of the wave statistics were observed based on the choice of source terms particularly near the track of each hurricane.</p></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"190 ","pages":"Article 102387"},"PeriodicalIF":3.2,"publicationDate":"2024-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141164112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Water mass circulation and residence time using Eulerian approach in a large coastal lagoon (Nokoué Lagoon, Benin, West Africa)","authors":"Kodjo Jules Honfo ,&nbsp;Alexis Chaigneau ,&nbsp;Yves Morel ,&nbsp;Thomas Duhaut ,&nbsp;Patrick Marsaleix ,&nbsp;Olaègbè Victor Okpeitcha ,&nbsp;Thomas Stieglitz ,&nbsp;Sylvain Ouillon ,&nbsp;Ezinvi Baloitcha ,&nbsp;Fabien Rétif","doi":"10.1016/j.ocemod.2024.102388","DOIUrl":"10.1016/j.ocemod.2024.102388","url":null,"abstract":"<div><p>Seasonal water circulation and residence times in the large (150 km²) and shallow (1.3 m average dry season depth) Nokoué Lagoon (Benin) are analyzed by means of numerical simulations using the three-dimensional SYMPHONIE model. The average circulation during the four primary hydrological periods throughout the year are studied in detail. Despite the lagoon's shallowness, significant disparities between surface and bottom conditions are observed. During the flood season (September-November), substantial river inflow (∼1200 m³/s) leads to nearly barotropic currents (∼7 cm/s), ‘directly’ linking rivers to the Atlantic Ocean. Rapid flushing results in short water residence times ranging from 3 to 16 days, with freshwater inflow and winds driving lagoon dynamics. During the salinization period (December-January) the circulation transforms into an estuarine pattern, characterized by surface water exiting and oceanic water entering the lagoon at the bottom. Average currents (∼2 cm/s) and recirculation cells are relatively weak, resulting in a prolonged residence time of approximately 4 months. Circulation during this time is dominated by tides, the ocean-lagoon salinity gradient, wind, and river discharge (∼100 m³/s). During low-water months (February to June), minimal river inflow and low lagoon water-levels prevail. Predominant southwest winds generate a small-scale circulation (∼3 cm/s) with a complex pattern of multiple recirculation and retention cells. Residence times vary from 1 to 4 months, declining from February to June. During the lagoon's desalination season (July-August), increasing river inflows again establish a direct river-ocean connection, and average residence times reduce to ∼20 days. Notably, a critical river discharge threshold (∼50-100 m³/s) is identified, beyond which the lagoon empties within days. This study highlights how wind-driven circulation between December and June can trap water along with potential pollutants, while river inflows, tides, and the ocean-lagoon salinity gradient facilitate water discharge. Additionally, it explores the differences between residence and flushing times, as well as some of the limitations identified in the simulations used.</p></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"190 ","pages":"Article 102388"},"PeriodicalIF":3.2,"publicationDate":"2024-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141139083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antarctic sea ice prediction with A convolutional long short-term memory network","authors":"Xiaoran Dong ,&nbsp;Qinghua Yang ,&nbsp;Yafei Nie ,&nbsp;Lorenzo Zampieri ,&nbsp;Jiuke Wang ,&nbsp;Jiping Liu ,&nbsp;Dake Chen","doi":"10.1016/j.ocemod.2024.102386","DOIUrl":"10.1016/j.ocemod.2024.102386","url":null,"abstract":"<div><p>Antarctic sea ice predictions are becoming increasingly important scientifically and operationally due to climate change and increased human activities in the region. Conventional numerical models typically require extensive computational resources and exhibit limited predictive skill on the subseasonal-to-seasonal scale. In this study, a convolutional long short-term memory (ConvLSTM) deep neural network is constructed to predict the 60-day future Antarctic sea ice evolution using only satellite-derived sea ice concentration (SIC) from 1989 to 2016. The network is skillful for approximately one month in predicting the daily spatial distribution of Antarctic SIC between 2018 and 2022, with the best predictive skill found in austral autumn (MAM) and winter (JJA). ConvLSTM also performs well in real-time prediction in February and September when the Antarctic sea ice extent (SIE) reaches the seasonal maximum and minimum, with the monthly mean SIE error mostly below 0.2 million km². The results suggest substantial potential for applying machine learning techniques for skillful Antarctic sea ice prediction.</p></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"190 ","pages":"Article 102386"},"PeriodicalIF":3.2,"publicationDate":"2024-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141133265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection of three-dimensional structures of oceanic eddies using artificial intelligence","authors":"Guangjun Xu ,&nbsp;Wenhong Xie ,&nbsp;Xiayan Lin ,&nbsp;Yu Liu ,&nbsp;Renlong Hang ,&nbsp;Wenjin Sun ,&nbsp;Dazhao Liu ,&nbsp;Changming Dong","doi":"10.1016/j.ocemod.2024.102385","DOIUrl":"https://doi.org/10.1016/j.ocemod.2024.102385","url":null,"abstract":"<div><p>Oceanic mesoscale eddies play an important role in transports of heat, freshwater, mass in the ocean, therefore understanding three-dimensional structure of oceanic eddies is of significance to climate study and oceanic applications. However, detection of three-dimensional (3D) structures is a big challenge though many algorithms of sea surface 2D eddy detection are developed. In this study, we present a novel approach by using 3D U-Net residual architecture (3D-U-Res-Net) to identify 3D structure of oceanic eddies. The sensitivity tests to input variables are conducted to optimalize the input setting. Trained by 3D eddy data provided by a kinetic eddy detection method, the AI-based method can identify different kinds of eddy vertical structures and moreover can dig out more eddy information in deeper layers. This study has significant implications for the further application of the AI-based algorithm in oceanic study.</p></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"190 ","pages":"Article 102385"},"PeriodicalIF":3.2,"publicationDate":"2024-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141073387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}