Journal of Geophysical Research-Oceans最新文献

{"title":"Deoxygenation and Its Drivers Analyzed in Steady State for Perpetually Slower and Warmer Oceans","authors":"Benoît Pasquier,&nbsp;Mark Holzer,&nbsp;Matthew A. Chamberlain,&nbsp;Richard J. Matear,&nbsp;Nathaniel L. Bindoff","doi":"10.1029/2024JC021043","DOIUrl":"https://doi.org/10.1029/2024JC021043","url":null,"abstract":"<p>Ocean deoxygenation is an important consequence of climate change that poses an imminent threat to marine life and global food security. However, our understanding of the complex interactions between changes in circulation, solubility, and respiration that drive global-scale deoxygenation is incomplete. Here, we consider idealized biogeochemical steady states in equilibrium with perpetually slower and warmer oceans constructed from climate-model simulations of the 2090s that we hold constant in time. In contrast to simulations of the end-of-century transient state, our idealized states are intensely deoxygenated in the abyss, consistent with perpetually reduced ventilation and throttled Antarctic Bottom Water formation. We disentangle the effects of the deoxygenation drivers on preformed oxygen and true oxygen utilization (TOU) using the novel concept of upstream exposure time, which precisely connects TOU to oxygen utilization rates and preformed oxygen to ventilation. For our idealized steady states, deoxygenation below 2,000 m depth is due to increased TOU, driven dominantly by slower circulations that allow respiration to act roughly 2–3 times longer thereby overwhelming the effects of reduced respiration rates. Above 500 m depth, decreased respiration and slower circulation closely compensate, resulting in little expansion of upper-ocean hypoxia. The bulk of preformed oxygen loss is driven by ventilation shifting equatorward to where warmer surface waters hold less oxygen. Warming-driven declines in solubility account for less than 10% of the total oxygen loss. Although idealized, our analysis suggests that long-term changes in the marine oxygen cycle could be driven dominantly by changes in circulation rather than by thermodynamics or biology.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JC021043","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142152348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Increased Frequency but Decreased Intensity of Marine Heatwaves Around Coral Reef Regions in the Southern South China Sea","authors":"Yushan Lyu,&nbsp;Fuan Xiao,&nbsp;Mengqian Lu,&nbsp;Dongxiao Wang,&nbsp;Qiaoyan Wu,&nbsp;Pin Wang,&nbsp;Yinghai Zeng","doi":"10.1029/2024JC021235","DOIUrl":"https://doi.org/10.1029/2024JC021235","url":null,"abstract":"<p>Marine heatwaves (MHWs) in the South China Sea (SCS) significantly affect both fishery resources and marine ecosystems. The characteristics and causal mechanisms of MHWs occurring in the southern SCS (SSCS) are not yet fully understood. In this study, the properties of MHWs, their long-term trends, and how these compare to those in the coastal shelf region in the northern SCS were explored. It was revealed that the coral reef regions in the SSCS exhibit more frequent but less intense MHWs. Over the past four decades, the average frequency, duration, and total days of MHWs have increased and could be attributed to rising mean sea surface temperature (SST), primarily driven by the horizontal advection, particularly the zonal advection. The associated advections result from the long-term wind stress curl change in the SSCS and strengthened Kuroshio Current, which are due to global warming-induced enhanced vertical density stratification and wind speed acceleration. Furthermore, significant decrease in the MHW intensity around coral reef regions is mainly due to a negative SST–cloud feedback mechanism: during MHW events, enhanced latent heat loss intensifies convection, leading to total cloud formation, which in turn reduces solar radiation and subsequently decreases the MHW intensity. Interestingly, this increase in deep convection and decrease in the MHW intensity appear to coincide with the phase transition of the Interdecadal Pacific Oscillation. Our findings underscore the divergent trends in MHW properties in the SSCS, providing valuable insights into their potential impact on the region’s coral reefs.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142152349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Turbulence Generation via Nonlinear Lee Wave Trailing Edge Instabilities in Kuroshio-Seamount Interactions","authors":"Yu-Yu Yeh,&nbsp;Ming-Huei Chang,&nbsp;Ren-Chieh Lien,&nbsp;Jia-Xuan Chang,&nbsp;Jia-Lin Chen,&nbsp;Sen Jan,&nbsp;Yiing Jang Yang,&nbsp;Anda Vladoiu","doi":"10.1029/2024JC020971","DOIUrl":"https://doi.org/10.1029/2024JC020971","url":null,"abstract":"<p>Physical processes behind flow-topography interactions and turbulent transitions are essential for parameterization in numerical models. We examine how the Kuroshio cascades energy into turbulence upon passing over a seamount, employing a combination of shipboard measurements, tow-yo microstructure profiling, and high-resolution mooring. The seamount, spanning 5 km horizontally with two summits, interacts with the Kuroshio, whose flow speed ranges from 1 to 2 m s⁻¹, modulated by tides. The forward energy cascade process is commenced by forming a train of 2–3 nonlinear lee waves behind the summit with a wavelength of 0.5–1 km and an amplitude of 50–100 m. A train of Kelvin-Helmholtz (KH) billows develops immediately below the lee waves and extends downstream, leading to enhanced turbulence. The turbulent kinetic energy dissipation rate is <i>O</i> (10⁻⁷–10⁻⁴) W kg⁻¹, varying in phase with the upstream flow speed modulated by tides. KH billows occur primarily at the lee wave's trailing edge, where the combined strong downstream shear and low-stratification recirculation trigger the shear instability, <i>Ri</i> &lt; 1/4. The recirculation also creates an overturn susceptible to gravitational instability. This scenario resembles the rotor, commonly found in atmospheric mountain waves but rarely observed in the ocean. A linear stability analysis further suggests that critical levels, where the KH instability extracts energy from the mean flow, are located predominantly at the strong shear layer of the lee wave's upwelling portion, coinciding with the upper boundary of the rotor. These novel observations may provide insights into flow-topography interactions and improve physics-based turbulence parameterization.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JC020971","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142152218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Seasonal, Interannual and Long-Term Variability of Sea Surface Temperature in the NW Iberian Upwelling, 1982–2020","authors":"S. Piedracoba,&nbsp;P. C. Pardo,&nbsp;X. A. Álvarez-Salgado,&nbsp;S. Torres","doi":"10.1029/2024JC021075","DOIUrl":"https://doi.org/10.1029/2024JC021075","url":null,"abstract":"<p>Here the seasonal, inter-annual and long-term variability of satellite-derived sea surface temperature (SST) was analyzed in the NW Iberian margin from 1982 to 2020 to explore spatial differences at high (5-km) resolution. In-situ temperature measurements from five coastal buoys were used to validate the satellite-derived SST data, discarding pixels from areas close to the shoreline. Regional SST increased significantly from 0.07 to 0.25°C per decade, with the lowest rates in shelf waters directly affected by seasonal coastal upwelling. Upwelling filaments also contributed to dampen the temperature increase in the adjacent slope and ocean waters. The spatial variability observed in the amplitude and timing of the seasonal cycle of SST is directly related to hydrography and circulation patterns of the region such as upwelling events during summer and the development of the river's buoyant plume and the warm Iberian Poleward Current during winter.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JC021075","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142130388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Interacting Influences of Diurnal Tides, Winds, and River Discharge on a Large Coastal Plume","authors":"David K. Ralston,&nbsp;W. Rockwell Geyer,&nbsp;Christopher C. Wackerman,&nbsp;Brian Dzwonkowski,&nbsp;David A. Honegger,&nbsp;Merrick C. Haller","doi":"10.1029/2024JC021288","DOIUrl":"https://doi.org/10.1029/2024JC021288","url":null,"abstract":"<p>The dispersal of large river plumes in the coastal ocean depends on multiple factors, and in some cases, can be categorized into distinct dynamical regimes: a tidally dominated near-field, a rotational mid-field, and a coastal current far-field. In this study, observations and modeling are used to evaluate the factors controlling the variability in the buoyant plume from Mobile Bay. Rather than distinct dynamical regimes, the Mobile Bay plume depends on forcings that act at overlapping temporal and spatial scales: diurnal tides, river discharge events, and winds. Satellite synthetic aperture radar images along with shipboard in-situ sampling and marine radar are used to observe plume fronts in spring 2021. Hydrodynamic model simulations are compared with observations and used to characterize a large coastal plume at consistent tidal phase across a range of forcing conditions. The along-shore position of the plume depends primarily on advection by wind-driven surface currents. The cross-shore extent and plume area depend primarily on the tidal amplitude and river discharge, and secondarily on northerly (seaward) winds. Along-shore winds influence the buoyancy anomaly by altering salinity in the estuary and offshore. Upwelling winds increase the buoyancy anomaly and advect previous plumes away from the mouth. Downwelling winds reduce the buoyancy anomaly by trapping previous plumes near the coast and directing freshwater discharge toward a secondary outlet. Thus, the combined, overlapping influences of the tide, wind, and discharge dominate the variability in freshwater delivery to the shelf at time scales of days and distances of tens of km.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142130389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Long-Term Surface Current Variability Across the Continental Shelf and Slope","authors":"Liliane Paranhos Bitencourt,&nbsp;Charitha B. Pattiaratchi,&nbsp;Simone Cosoli,&nbsp;Yasha Hetzel","doi":"10.1029/2023JC020214","DOIUrl":"https://doi.org/10.1029/2023JC020214","url":null,"abstract":"<p>Continental shelves are amongst the most dynamic and vulnerable regions in the oceans, and understanding their dynamics has implications for the transport of organisms and materials in both coastal and offshore zones. Determining the circulation patterns in systems experiencing high variability is crucial, but challenging as continuous and high-resolution long-term data sets are still scarce. In this paper, we use 9-years (2010–2018) of High-Frequency Radar surface current observations and satellite-derived Sea Surface Temperature to investigate the spatiotemporal variability of surface currents on the offshore, shelf break and inner continental regions along the Wadjemup (Rottnest) Continental Shelf (WCS), South-West Australia. We use the indigenous Noongar calendar that defines six-seasons: Birak (DJ), Bunuru (FM), Djeran (AM), Makuru (JJ), Djilba (AS), and Kambarang (ON); to better represent the seasonal changes in local winds and surface circulation. The surface currents revealed the poleward-flowing Leeuwin Current (LC), the equatorward-flowing Capes Current (CC), their interactions, and eddy features (radii &gt;10 km). The LC was the strongest (weakest) over Djeran/Makuru (Birak/Bunuru), whilst CC and offshore eddies were persistent from Kambarang-Bunuru. Along WCS, CC and offshore eddies locally modulated LC strength and position, whereas the El Niño Southern Oscillation influenced its interannual variability. During El Niño (La Niña) years, LC was weakened (strengthened), whilst CC and offshore eddy activity were strengthened (weakened). Particularly during La Niña years, LC increased its cross-shore migration and had an unseasonal peak in 2011. Our findings contribute to the understanding of the variability of boundary and coastal currents, and their local impacts on coastal circulation.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023JC020214","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142123281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Surface Quasi Geostrophic Reconstruction of Vertical Velocities and Vertical Heat Fluxes in the Southern Ocean: Perspectives for SWOT","authors":"Elisa Carli,&nbsp;Lia Siegelman,&nbsp;Rosemary Morrow,&nbsp;Oscar Vergara","doi":"10.1029/2024JC021216","DOIUrl":"https://doi.org/10.1029/2024JC021216","url":null,"abstract":"<p>Mesoscale currents account for 80% of the ocean's kinetic energy, whereas submesoscale currents capture 50% of the vertical velocity variance. SWOT's first sea surface height (SSH) observations have a spatial resolution an order of magnitude greater than traditional nadir-looking altimeters and capture mesoscale and submesoscale features. This enables the derivation of submesoscale vertical velocities, crucial for the vertical transport of heat, carbon and nutrients between the ocean interior and the surface. This work focuses on a mesoscale energetic region south of Tasmania using a coupled ocean-atmosphere simulation at km-scale resolution and preliminary SWOT SSH observations. Vertical velocities (<i>w</i>), temperature anomalies and vertical heat fluxes (VHF) from the surface down to 1,000 m are reconstructed using effective surface Quasi-Geostrophic (sQG) theory. An independent method for reconstructing temperature anomalies, mimicking an operational gridded product, is also developed. Results show that sQG reconstructs 90% of the modeled <i>w</i> and VHF rms at scales down to 30 km just below the mixed layer and 50%–70% of the rms for scales larger than 70 km at greater depth, with a spatial correlation of <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>∼</mo>\u0000 </mrow>\u0000 <annotation> ${sim} $</annotation>\u0000 </semantics></math> 0.6. The reconstruction is spectrally coherent <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>(</mo>\u0000 <mrow>\u0000 <mo>&gt;</mo>\u0000 <mn>0.65</mn>\u0000 </mrow>\u0000 <mo>)</mo>\u0000 </mrow>\u0000 <annotation> $( &gt; 0.65)$</annotation>\u0000 </semantics></math> for scales larger than 30–40 km at the surface, slightly degrading (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>∼</mo>\u0000 </mrow>\u0000 <annotation> ${sim} $</annotation>\u0000 </semantics></math> 0.55) at depth. Two temperature anomaly data sets yield similar results, indicating the dominance of <i>w</i> on VHF. The RMS of sQG <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>w</mi>\u0000 </mrow>\u0000 <annotation> $w$</annotation>\u0000 </semantics></math> and VHF derived from SWOT are twice as large as those derived from conventional altimetry, highlighting the potential of SWOT for reconstructing energetic meso and submesoscale dynamics in the ocean interior.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JC021216","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142123265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Large Porewater-Derived Carbon Outwelling Across Mangrove Seascapes Revealed by Radium Isotopes","authors":"Alex Cabral,&nbsp;Gloria M. S. Reithmaier,&nbsp;Yvonne Y. Y. Yau,&nbsp;Luiz C. Cotovicz Jr.,&nbsp;João Barreira,&nbsp;Bárbara Viana,&nbsp;Juliana Hayden,&nbsp;Steven Bouillon,&nbsp;Nilva Brandini,&nbsp;Vanessa Hatje,&nbsp;Carlos E. de Rezende,&nbsp;Alessandra L. Fonseca,&nbsp;Isaac R. Santos","doi":"10.1029/2024JC021319","DOIUrl":"https://doi.org/10.1029/2024JC021319","url":null,"abstract":"<p>Mangrove-dominated coastlines have high carbon sequestration capacity, but it remains unclear whether tidally outwelled carbon is transformed within the coastal ocean or exported offshore. Here, we used radium isotopes (²²⁴Ra and ²²³Ra) to investigate carbon outwelling in two mangrove seascapes in Brazil across multiple spatial scales. We sampled porewaters to define the source composition, mangrove creek waters to resolve tidal cycles, and cross-shelf transects to trace outwelling in coastal seascapes. Radium isotopes were positively correlated with dissolved inorganic (DIC), organic (DOC) and particulate organic (POC) carbon across the seascapes. DIC was the primary form of carbon (mean ± SD), representing 85% of the total carbon pool as bicarbonate (75 ± 11%), carbonate (6 ± 5%), and CO₂ (4 ± 9%). DOC and POC accounted for 10 ± 6% and 5 ± 6% of total carbon, respectively. Although mangrove waters emitted CO₂ to the atmosphere (38–143 mmol m⁻² d⁻¹), both bays and continental shelves were a CO₂ sink (−2.5 to −0.5 mmol m⁻² d⁻¹) associated to chlorophyll-a enrichments (<i>r</i>² = 0.86). Total carbon outwelled from mangroves were 3–4 times higher than soil carbon burial at both mangrove sites. Bicarbonate export (27–72 mmol m⁻² d⁻¹) to the continental shelf was the major fate of carbon outwelling, more than doubling the perceived capacity of mangrove soil to sequester carbon. Hence, disregarding outwelling as a blue carbon sink mechanism would lead to underestimated assessments of how mangroves capture CO₂ and help to mitigate climate change.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JC021319","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142100531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Interannual Variability of the Heat Budget in the Tropical Pacific Ocean and Its Link to the Overturning Circulation","authors":"Oleg A. Saenko,&nbsp;Neil F. Tandon","doi":"10.1029/2024JC020981","DOIUrl":"https://doi.org/10.1029/2024JC020981","url":null,"abstract":"<p>Using a suite of coupled climate models and an extensive set of ocean heat budget diagnostics, we address the relative roles of heat convergence and surface heat flux in driving the annual rate of ocean heat content (OHC) change in the tropical Pacific and its interannual variability. The net heat convergence is further separated into convergences associated with the large-scale ocean circulation, (parameterized) mesoscale effects and small-scale mixing. It is found that the heat convergence due to the large-scale ocean circulation provides the dominant contribution to the annual OHC tendency. Interannual variations of heat convergence are larger in the tropical Pacific than in the tropical Atlantic. These heat convergence variations are linked to interannual variations of the Pacific meridional overturning circulation (PMOC), driven by the associated variations in the northward Ekman transport (EkT). Northward variations of the tropical PMOC and EkT are typically associated with heat divergence and negative annual OHC tendency in the central and eastern near-equatorial Pacific along with heat convergence and positive annual OHC tendency in the western and northwestern tropical Pacific. In the Niño3.4 region, interannual variations of the near-surface OHC tendency negatively (positively) correlate with interannual PMOC variations at zero lag (1 year lag, when PMOC leads OHC).</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142100532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing the Optimal Tsunami Inundation Modeling Strategy for Large Earthquakes in Subduction Zones","authors":"A. Scala,&nbsp;S. Lorito,&nbsp;C. Escalante Sánchez,&nbsp;F. Romano,&nbsp;G. Festa,&nbsp;A. Abbate,&nbsp;H. B. Bayraktar,&nbsp;M. J. Castro,&nbsp;J. Macías,&nbsp;J. M. Gonzalez-Vida","doi":"10.1029/2024JC020941","DOIUrl":"https://doi.org/10.1029/2024JC020941","url":null,"abstract":"<p>Tsunamis are rare events involving several complex physical phenomena. Due to this complexity and the relative scarcity of observations, tsunami research makes extensive use of numerical simulations. For seismogenic tsunamis, the source is often modeled as an instantaneous sea-floor displacement (IS), while the tsunami propagation and inundation is computed through a shallow water approximation (SW). Here, we investigate what is the best tsunami inundation modeling strategy for different realistic earthquake source size and duration. We use 1D earthquake-tsunami coupled simulations of large <i>M</i> &gt; 8 earthquakes in Tohoku-like subduction zone to test for which conditions the IS and/or the SW approximations can simulate with enough accuracy the tsunami evolution. We use as a reference a time-dependent (TD), multi-layer, non-hydrostatic (NH) 1D model. Source duration, and size, are based on 1D dynamic rupture simulations with realistic stress drop and rigidity. We show that slow ruptures, generating slip in the shallow part of subduction zones (e.g., tsunami earthquakes), and very large events, with an along-dip extent comparable with the trench-coast distance (as occurs for megathrust events) require a TD-NH modeling, especially for regions with steep coastal bathymetry. Conversely, deeper, higher stress-drop events can be modeled through an IS-SW approximation. We finally show that: (a) steeper bathymetries generate larger runups and, (b) a resonant mechanism emerges with runup amplifications associated with larger source size on flatter bathymetries. These results, obtained with 1D modeling, can serve as a guide for the appropriate 2/3D simulation approach for applications ranging from fundamental tsunami science to computational-intensive hazard assessments.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":null,"pages":null},"PeriodicalIF":3.3,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JC020941","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142099990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}