Ocean Modelling最新文献

Low power computation of transoceanic wave propagation for tsunami hazard mitigation 低功耗计算跨洋波传播，减轻海啸危害

IF 3.1 3区地球科学 Q2 METEOROLOGY & ATMOSPHERIC SCIENCES

Ocean Modelling

Pub Date : 2024-11-12 DOI: 10.1016/j.ocemod.2024.102459

Mikhail Lavrentiev , Andrey Marchuk , Konstantin Oblaukhov

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.

本文提出使用基于现场可编程门阵列（FPGA）微芯片的专用硬件加速器来计算海啸波的传播，以评估和管理海洋自然灾害的风险，即水下地震引起的海啸波。在发生足够强烈的地震事件后，许多国家和研究中心会进行大量计算，估算海岸某些地区的海啸波参数，以确定是否有必要宣布海啸警报。这需要很高的计算能力，从而导致更高的能源成本。本文展示了如何利用安装在个人电脑（PC）上的基于 FPGA 的特殊计算器（作者早先已提出该计算器的结构）来计算海啸波在整个太平洋（从堪察加半岛和千岛群岛近海的俯冲带到智利海岸）的传播。这种计算在几分钟内就能得出可靠的结果，并能获得沿岸海啸波高的预期分布。如果得到的结果表明海啸会对居民造成危害或可能破坏基础设施，就必须进行更详细的计算，以准确估算预计会产生负面影响的沿岸特定地点的波浪参数。这需要集群和/或超级计算机系统，这些系统耗能巨大，因此价格昂贵。如果模拟结果表明沿海人口稠密地区的最大波高值较小，就可以立即通知近岸地区的居民海啸波幅较小，不需要进行更详细的研究。因此，这可以明显节省能源消耗。本文介绍了利用基于 FPGA 的硬件加速计算机代码执行，在个人计算机上计算海啸波在太平洋上传播的情况。

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引用次数: 0

Discrete variance decay analysis of spurious mixing 杂散混合的离散方差衰减分析

IF 3.1 3区地球科学 Q2 METEOROLOGY & ATMOSPHERIC SCIENCES

Ocean Modelling

Pub Date : 2024-11-09 DOI: 10.1016/j.ocemod.2024.102460

Tridib Banerjee , Sergey Danilov , Knut Klingbeil , Jean-Michel Campin

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.

这项研究利用示踪剂的离散方差衰减来估算示踪剂传输步骤中不同过程在空间和时间上造成的局部数值混合。局部离散方差衰减（DVD）率的表达式直接来自离散示踪剂方程，无需对第二时刻的离散通量做任何假设。它们将 DVD 率与通过标量控制单元面的第一时刻通量联系起来。这样就可以估算出与平流和扩散通量相关的混合情况。当直接求解有限体积单元面时，新框架避免了第二时刻通量定义的需要，但当面的 DVD 率被分割到共享面的单元时，仍会调用某些第二时刻通量。这些隐含的离散通量取决于分区，并且是非唯一的。对于三阶或更高阶的平流方案，DVD 率会受到该方法固有的分散误差的污染，从而为其产生的任何估计值的定位带来不确定性。因此，有必要进行额外的时间平均或粗粒化。通过应用这种技术，发现数值混合与涡旋动能的分布相关。垂直平流引起的数值混合相对较小，并且与浮力通量的分布相关。研究发现，所探讨的高阶方案显示的虚假混合程度可能会局部超过物理混合程度。

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引用次数: 0

Global tsunami modelling on a spherical multiple-cell grid 在球形多单元网格上建立全球海啸模型

IF 3.1 3区地球科学 Q2 METEOROLOGY & ATMOSPHERIC SCIENCES

Ocean Modelling

Pub Date : 2024-11-02 DOI: 10.1016/j.ocemod.2024.102461

Jian-Guo Li , Peitao Wang

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.

采用空间分辨率为 4 级（2.5-5-10-20 公里）的球形多单元网格（SMC）上的浅水方程（SWE）模型，模拟海啸在全球海洋表面的传播。非结构化 SMC 网格保留了经纬度网格的矩形单元，因此可以使用高效的有限差分方案。它还支持多分辨率，如网格细化，以解决小岛屿和海岸线细节问题，同时保持模型足够紧凑，以适应现有计算机。模拟了两个地震引发海啸的案例，并与现有观测数据进行了比较。结果表明，模拟的海啸到达时间与观测结果吻合，但海啸波高被低估了，特别是在偏远沿海地区观测到的海啸波高。造成这种低估的可能原因包括为抑制数值振荡而采用的平滑方案，以及地震初始动能输入的缺失。另一个原因是，SWEs 在描述沿岸水域的沿岸膛线和断裂波方面存在局限性。还模拟了加那利群岛山体滑坡可能引发的海啸，以评估其对大西洋沿岸地区的潜在影响。模型结果表明，这种海啸可能会对局部地区造成严重破坏，但对远距离地区，如英国和美国沿海地区的影响较小。由于初始滑坡扰动过于简化，这项研究并不能真实地反映真实的滑坡海啸，只能对其对大西洋的影响进行定性评估。在进一步研究这种可能的滑坡灾害时，需要更真实的初始条件和更好的沿岸过程模型。

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引用次数: 0

Accuracy assessment of recent global ocean tide models in coastal waters of the European North West Shelf 欧洲西北大陆架沿岸水域近期全球海洋潮汐模型的精度评估

IF 3.1 3区地球科学 Q2 METEOROLOGY & ATMOSPHERIC SCIENCES

Ocean Modelling

Pub Date : 2024-10-17 DOI: 10.1016/j.ocemod.2024.102448

David E. Gregg , Nigel T. Penna , Christopher Jones , Miguel A. Morales Maqueda

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.

在欧洲西北大陆架沿岸水域评估了全球海洋潮汐模式的精度，以确定在哪些地方最需要更高分辨率的本地（预报）模式来进行地球物理和导航应用，以及哪些全球模式最适合为区域和本地潮汐模式提供边界条件。研究考虑了五个最新的全球海洋潮汐模式（FES2014b、EOT20、TPXO9-atlas-v5、GOT4.10c 和 DTU16），首先将这些模式插值到共同网格上，然后计算每个网格点的平均绝对偏差，以此进行比较。海岸线验潮仪和近海底压传感器数据来自多个来源，共 279 个观测点，用于评估模式的准确性，其中包括 137 个地点的观测值，这些观测值以前没有发布过，因此没有被同化到任何测试的全球模式中。每个观测点都计算了每个模式的预测相位与相应观测相位之间的残差，并使用均方根（RMS）和绝对残差中值（MAR）对 M2、S2、N2、O1、K1、K2、P1 和 Q1 这八个潮汐成分进行量化。为避免均方根值受观测点密度的影响，还根据每个观测点的沃罗诺多边形的水域面积开发并使用了沃罗诺加权均方根值。根据海洋深度定义了四个区域以衡量模型性能，在近海区域再次证明了模型的不准确性。根据地理区域又定义了七个区域，这显示了全球模式之间的不均匀性。虽然 TPXO9-atlas-v5 在使用 MAR 和 Voronoi-weighted RMS 指标时性能最佳，但 FES2014b 在所有八个成分中的总均方根误差最小。FES2014b 仅使用未被任何模式同化的 137 个观测点，因此可提供独立的精度评估，其海岸线误差最小，RSS 均方根误差为 24.46 厘米。与全部 279 个观测站点相比，所有模式与 137 个独立观测站点的误差都较大，RSS 均方根误差总体平均增加了 12%，海岸线验潮仪的误差增加了 30%，这凸显了在这些地区开发本地模式的必要性。

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引用次数: 0

Enhancing model temperature estimations in shallow, turbid, coastal regions: Mobile Bay, Alabama 加强浅海、浑浊沿岸地区的模型温度估算：阿拉巴马州莫比尔湾

IF 3.1 3区地球科学 Q2 METEOROLOGY & ATMOSPHERIC SCIENCES

Ocean Modelling

Pub Date : 2024-10-16 DOI: 10.1016/j.ocemod.2024.102455

Harikrishnan Sreeshylam , Zhilong Liu , Brian Dzwonkowski , John Lehrter

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.

准确估算水体温度对物理和生物地球化学过程建模至关重要。太阳辐射衰减是上层海洋热动力学的一个关键过程。在浅湍流沿岸系统中，时空变化的光学特性给常用的衰减参数化方案带来了挑战。本研究采用六种不同的衰减方法（包括三种基本方法），对莫比尔湾（一个浅浊流河口）的 ROMS 模式的温度依赖性进行了研究：基于水体类型-9 的传统方法 PS77；与原位 PAR 衰减和盐度有关的新方法 SAL；以及表面受困辐照度方法 ST。此外，还对这些基本方法进行了地表大气热通量校正（QC）测试。模拟结果与各种来源的观测数据进行了验证，以确定年度和天气尺度上的最佳方法。虽然所有模拟都显示出有效的年周期温度表现，但月度分析显示出一定的季节性，冬季月份的表现通常好于夏季月份。由于地表热通量主要驱动浅层系统的温度变化，因此 QC 的影响明显提高了年尺度和同步尺度的温度性能。总体性能最好的是包含 QC 的 ST 方法。相反，不含 QC 的 PS77 性能最差。采用 QC 的 SAL 模型比采用 QC 的 PS77 有明显改善，但与采用 QC 的 ST 模型相比，其性能相当但较弱。这项研究还表明，在长期区域气候模拟中忽略次季节验证可能会给分析与次季节温度相关的事件带来不确定性。

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引用次数: 0

Total water level prediction at continental scale: Coastal ocean 大陆尺度的总水位预测：沿岸海洋

IF 3.1 3区地球科学 Q2 METEOROLOGY & ATMOSPHERIC SCIENCES

Ocean Modelling

Pub Date : 2024-10-11 DOI: 10.1016/j.ocemod.2024.102451

Linlin Cui , Fei Ye , Y. Joseph Zhang , Haocheng Yu , Zhengui Wang , Saeed Moghimi , Gregory Seroka , Jack Riley , Shachak Pe'eri , Soroosh Mani , Edward Myers , Kyungmin Park , Liujuan Tang , Zizang Yang , Yan-Ming Wang

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.

我们以美国东海岸/墨西哥湾沿岸海洋为例，展示了大陆尺度总水位（TWL）模拟的最新进展。大陆尺度建模与小尺度建模的主要区别在于前者需要更精确的垂直基准。利用基于大地水准面的基准（xGEOID20b）、卫星测高产品和最先进的三维非结构网格模型，我们显著提高了近海和近海 TWL 的精度。NOAA 所有站点的平均均方根误差为 14 厘米。我们发现，非潮汐信号对边界附近大尺度海流系统的表示非常敏感，而扩大域范围以适应该系统则可改善这些信号。

引用次数: 0

Variation of suspended-sediment caused by tidal asymmetry and wave effects 潮汐不对称和波浪效应引起的悬浮沉积物变化

IF 3.1 3区地球科学 Q2 METEOROLOGY & ATMOSPHERIC SCIENCES

Ocean Modelling

Pub Date : 2024-10-10 DOI: 10.1016/j.ocemod.2024.102454

Jianbin Xie , Xingru Feng , Guandong Gao

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.

悬浮泥沙在海岸地形演变和生态环境变化中起着重要作用。为了清楚地了解其内在机理，我们利用 SCHISM 的波-流-沉积物模型研究了悬浮沉积物动力学对潮流和波-流相互作用的响应。研究结果表明，研究区域的潮汐具有明显的不对称性，悬浮泥沙浓度（SSC）在一个潮汐周期内发生了显著变化。我们还对波浪-海流相互作用进行了分解，以确定波浪模型和水动力模型中各物理机制的贡献。关于波-流相互作用对 SSC 的各种影响的重要性，应考虑波引起的底剪应力和波引起的辐射应力。水平空间平流的重要性与波浪诱导的底剪应力和波浪诱导的辐射应力相当，且大于其他类型的波能平流。该研究成功地解释了影响海南岛西南部 SSC 变化的所有机制，有助于海岸管理，并可为其他沿海地区提供参考。

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引用次数: 0

A dynamically adaptive Langmuir turbulence parameterization scheme for variable wind wave conditions: Model application 针对多变风浪条件的动态自适应朗缪尔湍流参数化方案：模型应用

IF 3.1 3区地球科学 Q2 METEOROLOGY & ATMOSPHERIC SCIENCES

Ocean Modelling

Pub Date : 2024-10-09 DOI: 10.1016/j.ocemod.2024.102453

Fangrui Xiu , Zengan Deng

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.

朗缪尔环流和湍流（LT）在海洋上层混合层中至关重要，对海气动量、热量和质量交换有重大影响。制定适当的 LT 参数化方案对海洋建模至关重要。本研究采用大涡模拟（LES）和物理信息神经网络（PINN），通过动态调整由风浪决定的关键参数 E6，优化 KC04 Langmuir 湍流方案。不同风浪状态下的 LES 模拟显示了 PINN 所推导的 E6 值。在 OCSPapa 站进行的 GOTM 模拟结果表明，优化方案在模拟垂直涡扩散率和温度方面优于原始 KC04 方案，温度的均方根误差（RMSE）年减幅为 6.24%，秋季的均方根误差减幅为 8.23%。此外，优化后的方案还增加了混合层厚度，达到 4.9 米。

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引用次数: 0

Improving the accuracy of global ECMWF wave height forecasts with machine learning 利用机器学习提高 ECMWF 全球波高预报的准确性

IF 3.1 3区地球科学 Q2 METEOROLOGY & ATMOSPHERIC SCIENCES

Ocean Modelling

Pub Date : 2024-10-09 DOI: 10.1016/j.ocemod.2024.102450

Shuyi Zhou , Jiuke Wang , Yuhan Cao , Brandon J. Bethel , Wenhong Xie , Guangjun Xu , Wenjin Sun , Yang Yu , Hongchun Zhang , Changming Dong

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.

显著波高（SWH）是海上活动最关键的参数之一。然而，即使是广泛使用的欧洲中期天气预报中心综合预报系统（ECMWF-IFS）提供的 SWH 数据也存在误差和不确定性。本研究采用光梯度提升机（LightGBM）推断 ECMWF-IFS SWH 全球预报偏差。结果表明，在全球范围内，LightGBM 可将均方根误差降低 10-20%。尤其值得注意的是，在夏末西太平洋观测到的预报精度有所提高。此外，2019 年超强台风 "勒基马 "期间的修正预报结果表明，即使在四个台风同时出现的情况下，模型也能有效提高台风诱发风浪的预报精度。本研究证实了 LightGBM 在推断单步 SWH 预报偏差方面的可行性，并提出了一种用于增强全球海浪预报的经济有效的模式。

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引用次数: 0

Contribution of high-mode near-inertial waves to enhanced typhoon-induced sea surface temperature cooling in the South China Sea 高模近惯性波对台风诱发的南海海面温度冷却增强的贡献

IF 3.1 3区地球科学 Q2 METEOROLOGY & ATMOSPHERIC SCIENCES

Ocean Modelling

Pub Date : 2024-10-08 DOI: 10.1016/j.ocemod.2024.102452

Shukui Cheng , Anzhou Cao , Jinbao Song , Xinyu Guo

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.

海面温度冷却（SSTC）是海洋对台风反应的一个重要指标，也是台风演变的一个因素。了解不同台风诱发 SSTC 的复杂机制非常重要。基于数值模拟，我们研究了台风 "鲇鱼"（2010 年）、"玲花"（2015 年）和 "莎莉嘉"（2011 年）诱发的 SSTC。作为最强（最弱）的台风，鲇鱼（莎莉嘉）诱发的 SSTC 最大（最小），这与强台风通常比弱台风诱发更大 SSTC 的传统认识一致。然而，中等强度台风 "莲花 "诱发的 SSTC 几乎与 "鲇鱼 "相当，而 "莲花 "的风能输入却比 "鲇鱼 "小一个数量级。对 "玲花 "和 "鲇鱼 "引起的近惯性波（NIWs）进行的比较表明，前者含有较大比例的高模式，对垂直切变有很大的影响。因此，"林法 "期间的垂直混合系数达到了 "鲇鱼 "期间的三分之一。由于 SSTC 主要受垂直混合的影响，而垂直混合又以混合层深度的垂直扩散为主，因此，Linfa 期间相对较强的垂直混合系数和较大的温度梯度最终导致 SSTC 几乎与 Megi 期间诱发的 SSTC 相当。本研究的结果加深了人们对台风诱发的 SSTC 的理解。

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引用次数: 0