Ocean Modelling最新文献

{"title":"Low power computation of transoceanic wave propagation for tsunami hazard mitigation","authors":"Mikhail Lavrentiev ,&nbsp;Andrey Marchuk ,&nbsp;Konstantin Oblaukhov","doi":"10.1016/j.ocemod.2024.102459","DOIUrl":"10.1016/j.ocemod.2024.102459","url":null,"abstract":"<div><div>This paper proposes the use of specialized hardware accelerator based on the Field Programmable Gates Array (FPGA) microchip to compute tsunami wave propagation to assess and manage risks of marine natural disasters, namely, tsunami waves caused by underwater earthquakes. After a sufficiently strong seismic event, many countries and research centres launch extensive computations to estimate the tsunami wave parameters in certain parts of the coast to determine if a declaration of a tsunami alarm is warranted. This requires high computating powers which leads to higher energy costs. The paper demonstrates how an FPGA-based special Calculator (architecture of which has been earlier proposed by the authors), installed on a Personal Computer (PC) could be used to calculate the propagation of a tsunami wave over the entire Pacific Ocean, from the subduction zone offshore Kamchatka Peninsula and Kuril Islands to the coast of Chile. Such calculations offer reliable results within a few minutes and make it possible to obtain the distribution of expected tsunami wave heights along the coast. If the obtained results indicate a danger to the population or possible destruction of infrastructure, it becomes paramount to carry out more detailed calculations to accurately estimate the wave parameters at specific locations along the coast where negative consequences are expected. This requires cluster and/or supercomputer systems, which consume significant energy and hence are expensive. In case the modelling results indicate small values of maximum wave heights at populated coastal areas, population of the near-shore regions can be immediately informed about low amplitude tsunami wave; more detailed studies are not needed. This hence leads to noticeable savings in energy consumption. The paper presents a calculation of the propagation of a tsunami wave across the Pacific Ocean on a personal computer using a FPGA-based hardware acceleration of a computer code execution.</div></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"192 ","pages":"Article 102459"},"PeriodicalIF":3.1,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142652228","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":"Discrete variance decay analysis of spurious mixing","authors":"Tridib Banerjee ,&nbsp;Sergey Danilov ,&nbsp;Knut Klingbeil ,&nbsp;Jean-Michel Campin","doi":"10.1016/j.ocemod.2024.102460","DOIUrl":"10.1016/j.ocemod.2024.102460","url":null,"abstract":"<div><div>This work examines the use of discrete variance decay of tracers to estimate locally in space and time the numerical mixing caused by different processes during a tracer transport step. Expressions for local discrete variance decay (DVD) rates are directly derived from discrete tracer equations without any assumptions on discrete fluxes of the second moment. They relate the DVD rates to the fluxes of the first moment through the faces of scalar control cell. Mixing associated with advective and diffusive fluxes is thus estimated. The new framework avoids the need for second-moment flux definition when solved directly on finite-volume cell faces but still invokes certain second-moment fluxes when the face DVD rates are partitioned to cells sharing the face. These implied discrete fluxes depend on the partitioning and are non-unique. For third- or higher-order advection schemes, the DVD rates are contaminated by dispersive errors intrinsic to the approach, introducing uncertainty to the locality of any estimates produced by it. Additional temporal averaging or coarse-graining is thus necessary. Through the application of this technique, numerical mixing is found to be correlated with the distribution of eddy kinetic energy. Numerical mixing induced by vertical advection is found to be relatively small and correlated with the distribution of buoyancy fluxes. The explored high-order schemes are found to demonstrate levels of spurious mixing which may locally exceed physical mixing.</div></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"192 ","pages":"Article 102460"},"PeriodicalIF":3.1,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142652230","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":"Global tsunami modelling on a spherical multiple-cell grid","authors":"Jian-Guo Li ,&nbsp;Peitao Wang","doi":"10.1016/j.ocemod.2024.102461","DOIUrl":"10.1016/j.ocemod.2024.102461","url":null,"abstract":"<div><div>A model of shallow water equations (SWEs) on a spherical multiple-cell (SMC) grid of 4-level (2.5–5–10–20 km) spatial resolutions is used to simulate tsunami propagation on global ocean surfaces. The unstructured SMC grid retains rectangular cells of the longitude-latitude grid so that efficient finite-difference schemes could be used. It also supports multi-resolutions like mesh refinement to resolve small islands and coastline details while keeping models compact enough to fit into available computers. Two earthquake-induced tsunami cases are simulated and compared with available observations. Results indicate that the modelled tsunami arrival times agree well with observations while tsunami wave heights are underestimated, particularly the observed runups on remote coastal lands. Possible reasons for this underestimation include the smoothing scheme used to suppress numerical oscillations and the missing of initial kinetic energy input from the earthquakes. Another reason is the limitation of the SWEs to describe coastal bores and breaking waves in coastal waters. A possible tsunami scenario induced by a landslide in the Canary Islands is also simulated to assess its potential impact on Atlantic coastal regions. Model results indicate that this kind of tsunami may cause severe damage to local areas but its effects on far fields, like the UK and American coastal regions are small. As the initial landslide disturbance is overly simplified, this study does not give a true representation of a real landslide tsunami but rather a qualitative assessment of its impact on the Atlantic Ocean. More realistic initial condition and improved model representation of coastal processes are needed for further studies of this possible landslide hazard.</div></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"192 ","pages":"Article 102461"},"PeriodicalIF":3.1,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142652229","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":"Accuracy assessment of recent global ocean tide models in coastal waters of the European North West Shelf","authors":"David E. Gregg ,&nbsp;Nigel T. Penna ,&nbsp;Christopher Jones ,&nbsp;Miguel A. Morales Maqueda","doi":"10.1016/j.ocemod.2024.102448","DOIUrl":"10.1016/j.ocemod.2024.102448","url":null,"abstract":"<div><div>The accuracy of global ocean tide models is assessed in coastal waters of the European North West Shelf to ascertain where higher resolution local (forecast) models are most needed for geophysical and navigational applications, and which global models are most suitable for providing boundary conditions for regional and local tide models. Five recent global ocean tide models (FES2014b, EOT20, TPXO9-atlas-v5, GOT4.10c, and DTU16) are considered, with the models first compared by interpolating them onto common grids and computing the mean absolute deviation at each grid point. Coastline tide gauge and offshore bottom pressure sensor data were collated from several sources to give a total of 279 observation sites for evaluating model accuracy, including observational values from 137 locations that have not previously been released and have therefore not been assimilated into any of the global models tested. The residual errors between each model’s predicted phasor and the corresponding observed phasor were calculated at each observation location, and quantified using the root mean square (RMS) and median absolute residual (MAR) for the eight tidal constituents M2, S2, N2, O1, K1, K2, P1, and Q1. To avoid RMS values being biased by observation point density, a Voronoi-weighted RMS based on the water area of the Voronoi polygon about each observation location was also developed and used. Four zones were defined based on ocean depth to gauge model performance, and model inaccuracy is again demonstrated in near-shore regions. Seven further zones were defined based on geographical areas, which reveals inhomogeneity among the global models. The smallest overall root sum square (RSS) RMS error across all eight constituents arises with FES2014b, although TPXO9-atlas-v5 has the best performance when using the MAR and Voronoi-weighted RMS metrics. Using only the 137 observation sites that have not been assimilated by any model and therefore provide an independent accuracy assessment, FES2014b exhibits the smallest errors at the coastline, with an RSS RMS of 24.46 cm. All models exhibit larger errors with the 137 independent observation sites than with all 279 observation sites, with an average overall increase in RSS RMS error of 12%, and an increase of 30% for coastline tide gauges, highlighting the need for local model development in these areas.</div></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"192 ","pages":"Article 102448"},"PeriodicalIF":3.1,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142527781","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":"Enhancing model temperature estimations in shallow, turbid, coastal regions: Mobile Bay, Alabama","authors":"Harikrishnan Sreeshylam ,&nbsp;Zhilong Liu ,&nbsp;Brian Dzwonkowski ,&nbsp;John Lehrter","doi":"10.1016/j.ocemod.2024.102455","DOIUrl":"10.1016/j.ocemod.2024.102455","url":null,"abstract":"<div><div>Accurate estimation of water column temperature is vital for modeling physical and biogeochemical processes. A key process in the thermal dynamics of the upper ocean is the attenuation of solar radiation. In shallow-turbid coastal systems, spatially and temporally varying optical characteristics present challenges for commonly used attenuation parameterization schemes. This study investigates the dependency of temperature with a ROMS model of Mobile Bay, a shallow, turbid estuary, using six different attenuation approaches including three base cases: Conventional approach PS77 based on water type-9; Novel approach SAL relating in situ PAR attenuation to salinity; and Surface trapped irradiance method ST. In addition, these base cases are also tested with surface atmospheric heat flux correction (QC). Simulations were validated against observations from various sources to identify the optimal approach at annual and synoptic scales. While all simulations showed effective temperature performance over an annual cycle, monthly analysis revealed some seasonality, with winter months typically performing better than summer months. The influence of QC notably enhanced temperature performance in both annual and synoptic scales, given that surface heat flux primarily drove temperature changes in this shallow system. The best overall performance was determined to be the ST approach incorporating QC. Conversely, PS77 without QC demonstrated the poorest performance. The SAL model with QC, notably improved performance over PS77 with QC, yet demonstrated comparable yet weaker performance compared to the ST model with QC. The study also implies that neglecting subseasonal validation in long-term regional climate modeling could introduce uncertainty into analyzing events tied to subseasonal temperatures.</div></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"192 ","pages":"Article 102455"},"PeriodicalIF":3.1,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142527780","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":"Total water level prediction at continental scale: Coastal ocean","authors":"Linlin Cui ,&nbsp;Fei Ye ,&nbsp;Y. Joseph Zhang ,&nbsp;Haocheng Yu ,&nbsp;Zhengui Wang ,&nbsp;Saeed Moghimi ,&nbsp;Gregory Seroka ,&nbsp;Jack Riley ,&nbsp;Shachak Pe'eri ,&nbsp;Soroosh Mani ,&nbsp;Edward Myers ,&nbsp;Kyungmin Park ,&nbsp;Liujuan Tang ,&nbsp;Zizang Yang ,&nbsp;Yan-Ming Wang","doi":"10.1016/j.ocemod.2024.102451","DOIUrl":"10.1016/j.ocemod.2024.102451","url":null,"abstract":"<div><div>We demonstrate recent progress made in the simulation of total water level (TWL) at continental scale, using the coastal ocean of US East Coast/Gulf of Mexico coast as an example. A key difference between the continental-scale and small-scale modeling is that the former requires a more accurate vertical datum. Using a geoid-based datum (xGEOID20b), a satellite altimetry product, and a state-of-the-art 3D unstructured-grid model, we significantly improve the accuracy for TWL both near- and off-shore. The average root-mean-square error at all NOAA stations is 14 cm. The non-tidal signals are found to be sensitive to the representation of a large-scale current system near the boundary and extending the domain extent to accommodate this system improves these signals.</div></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"192 ","pages":"Article 102451"},"PeriodicalIF":3.1,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142437825","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":"Variation of suspended-sediment caused by tidal asymmetry and wave effects","authors":"Jianbin Xie ,&nbsp;Xingru Feng ,&nbsp;Guandong Gao","doi":"10.1016/j.ocemod.2024.102454","DOIUrl":"10.1016/j.ocemod.2024.102454","url":null,"abstract":"<div><div>Suspended sediment plays an important role in coastal topography evolution and ecological environment change. To obtain a clear picture of the underlying mechanisms, we studied the response of suspended sediment dynamics to tidal current and wave-current interactions using the wave-current-sediment model of SCHISM. The results revealed evident tidal asymmetry in the study area, and showed that the suspended sediment concentration (SSC) markedly changes within a tidal cycle. We also disassembled the wave–current interactions to determine the contribution of each physical mechanism of the wave and hydrodynamic models. Regarding the importance of various effects of wave-current interactions on SSC, the wave-induced bottom shear stress and wave-induced radiation stress should be considered. The importance of advection in horizontal space is comparable to that of wave-induced bottom shear stress and wave-induced radiation stress, and is greater than that of the other types of wave energy advection. This study successfully explained all the mechanisms that influence the variation of SSC to the southwest of Hainan Island, which is helpful for coastal management and could provide a reference for other coastal areas.</div></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"192 ","pages":"Article 102454"},"PeriodicalIF":3.1,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441822","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":"A dynamically adaptive Langmuir turbulence parameterization scheme for variable wind wave conditions: Model application","authors":"Fangrui Xiu ,&nbsp;Zengan Deng","doi":"10.1016/j.ocemod.2024.102453","DOIUrl":"10.1016/j.ocemod.2024.102453","url":null,"abstract":"<div><div>Langmuir circulations and turbulence (LT) are crucial in the upper ocean mixed layer, significantly affecting the air-sea exchange of momentum, heat, and mass. The development of an appropriate LT parameterization scheme is vital for ocean modeling. This study employed the Large-eddy Simulation (LES) and the Physics-informed Neural Network (PINN) to optimize the KC04 Langmuir turbulence scheme by dynamically adjusting E₆ as a key parameter determined by winds and waves. The LES simulations under different wind wave states indicated the PINN-inferred values for E₆. Modelling results from GOTM in OCSPapa station demonstrated that the optimized scheme outperformed the original KC04 scheme in simulating the vertical eddy diffusivity and temperature, with an ∼6.24% annual reduction in the root mean square error (RMSE) for the temperature and an ∼8.23% reduction in the RMSE during autumn. Furthermore, the optimized scheme resulted in a thicker mixed layer, reaching 4.9 m. This enhanced LT parameterization scheme exhibited the improved robustness for variable spatiotemporal resolutions, significantly improving the modeling accuracy.</div></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"192 ","pages":"Article 102453"},"PeriodicalIF":3.1,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421567","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":"Improving the accuracy of global ECMWF wave height forecasts with machine learning","authors":"Shuyi Zhou ,&nbsp;Jiuke Wang ,&nbsp;Yuhan Cao ,&nbsp;Brandon J. Bethel ,&nbsp;Wenhong Xie ,&nbsp;Guangjun Xu ,&nbsp;Wenjin Sun ,&nbsp;Yang Yu ,&nbsp;Hongchun Zhang ,&nbsp;Changming Dong","doi":"10.1016/j.ocemod.2024.102450","DOIUrl":"10.1016/j.ocemod.2024.102450","url":null,"abstract":"<div><div>Significant wave height (SWH) stands as one of the most crucial parameters for maritime activities. However, even the SWH data from the widely utilized European Centre for Medium-Range Weather Forecast Integrated Forecasting System (ECMWF-IFS) carries errors and uncertainties. In this study, the Light Gradient Boosting Machine (LightGBM) is used to inference the global ECMWF-IFS SWH forecast biases. The results demonstrate that globally, the LightGBM reduces the root mean square error by 10–20 %. Particularly noteworthy is the enhanced forecast accuracy observed in the western Pacific during late summers. Furthermore, the corrected forecast results during Super Typhoon Lekima in 2019 showcase the capability of model to effectively enhance the forecast accuracy of typhoon-induced wind waves, even when four typhoons occur concurrently. This study establishes the feasibility of LightGBM in inferencing single-step SWH forecast bias and presents a cost-effective model for enhancing global wave forecasts.</div></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"192 ","pages":"Article 102450"},"PeriodicalIF":3.1,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441821","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":"Contribution of high-mode near-inertial waves to enhanced typhoon-induced sea surface temperature cooling in the South China Sea","authors":"Shukui Cheng ,&nbsp;Anzhou Cao ,&nbsp;Jinbao Song ,&nbsp;Xinyu Guo","doi":"10.1016/j.ocemod.2024.102452","DOIUrl":"10.1016/j.ocemod.2024.102452","url":null,"abstract":"<div><div>Sea surface temperature cooling (SSTC) is an important indicator of the ocean response to typhoons and is a factor in the evolution of typhoons. Understanding the intricate mechanisms underlying the SSTC induced by different typhoons is important. Based on the numerical simulation, we investigated the SSTC induced by typhoons Megi (2010), Linfa (2015), and Sarika (2011), which had relatively similar tracks in the South China Sea. As the strongest (weakest) typhoon, Megi (Sarika) induced the largest (smallest) SSTC, which is consistent with the traditional understanding that stronger typhoons usually induce larger SSTC than weaker typhoons. However, the SSTC induced by the moderate typhoon Linfa was nearly comparable to that induced by Megi, while Linfa had a wind power input an order of magnitude smaller. A comparison of near-inertial waves (NIWs) induced by Linfa and Megi showed that the former contained a larger proportion of high modes, substantially contributing to vertical shear. Consequently, the vertical mixing coefficient during Linfa reached one third of that during Megi. Because the SSTC is primarily influenced by vertical mixing, which is dominated by vertical diffusion at the mixed layer depth, the relatively strong vertical mixing coefficient and large temperature gradient during Linfa ultimately resulted in the SSTC nearly comparable to that induced by Megi. The results of this study enhance the understanding of typhoon-induced SSTC.</div></div>","PeriodicalId":19457,"journal":{"name":"Ocean Modelling","volume":"192 ","pages":"Article 102452"},"PeriodicalIF":3.1,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421565","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}