Journal of Geophysical Research: Earth Surface最新文献

{"title":"Impacts of Exotic Saltmarsh Vegetation Removal and Native Saltmarsh Vegetation Restoration on Bed Level Change and Surficial Sediment Distribution in an Estuary Wetland","authors":"Yiming Wu,&nbsp;Zeng Zhou,&nbsp;Chuning Dong,&nbsp;Hang Zheng,&nbsp;Wenbo Lin,&nbsp;Jujuan Gao,&nbsp;Pingping Guo,&nbsp;Yuxian Gu,&nbsp;Tongchao Le,&nbsp;Karin R. Bryan","doi":"10.1029/2024JF008119","DOIUrl":"10.1029/2024JF008119","url":null,"abstract":"<p>The invasion of exotic saltmarsh species precipitates the degradation of native estuarine wetlands. In response, saltmarsh restoration projects, which concentrate on removing exotic saltmarsh species and replanting native ones, have been widely adopted to protect wetland biodiversity and restore ecosystem services. However, the morphological and sedimentary responses of wetlands during the restoration process remain unclear. This study investigates the impacts of saltmarsh restoration on bed level changes and surficial sediment distribution in the Shanyutan Wetland, Southeast China. A biomorphodynamic model is developed that integrates a remote-sensing-informed vegetation module with hydrodynamics and sediment transport processes. This model is used to explore the drivers of these morphodynamic changes and to understand the underlying mechanisms. Model results indicate that the removal of exotic saltmarshes induces erosion along saltmarsh edges and within zones near tidal channels, accompanied by a reduction in mud content. Meanwhile, the interior saltmarsh areas experience a modest increase in mud accumulation. The influence of this removal extends beyond the initial removed site, leading to sand deposition seawards of the salt marsh. Replanting native species contributes to an average increase in bed elevation, though it shows limited efficacy in enhancing mud content. These findings suggest that while wetland elevation may recover from the initial erosion induced by vegetation removal to reach a pre-removal state within 1–3 years, restoring sediment distribution by native saltmarsh replanting remains challenging. Overall, this research deepens our understanding of morphodynamic responses during estuarine wetland restoration and offers critical insights for landscape reconstruction in wetland management.</p>","PeriodicalId":15887,"journal":{"name":"Journal of Geophysical Research: Earth Surface","volume":"130 7","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144514774","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":"Numerical Simulation of Sound-Side Barrier-Island Inundation and Breaching During Hurricane Dorian (2019)","authors":"John C. Warner,&nbsp;Christopher R. Sherwood,&nbsp;Christie A. Hegermiller,&nbsp;Zafer Defne,&nbsp;Joe Zambon,&nbsp;Ruoying He,&nbsp;George Xue,&nbsp;Daoyang Bao,&nbsp;Dongxiao Yin,&nbsp;Melissa Moulton","doi":"10.1029/2025JF008309","DOIUrl":"10.1029/2025JF008309","url":null,"abstract":"<p>Hurricane-induced morphological changes and associated community hazards along sandy, barrier-island coastlines have been studied primarily from the perspective of ocean-side attack by storm-driven ocean surge and large waves. Thus, our understanding of long-term barrier island morphological change focuses on beach erosion, overwash, and inlet formation. In contrast, outwash events with inundation from the sound side, such as one that occurred in Cape Lookout National Seashore, North Carolina, USA during Hurricane Dorian (September 2019), are understudied. Studying such events can improve understanding of barrier island response and stability for a broader range of conditions. Here, we model the hydrodynamics and morphological evolution of a barrier island using a coupled wave-current-sediment transport modeling system. Wind-driven surge in Pamlico Sound led to overtopping from the sound side, which eroded outwash channels and transported sediment seaward into the nearshore. Simulations reproduce the channel features observed with aerial imagery and provide information not available from the remote-sensing observations, including channel depths (&gt;2 m) and the fate of the eroded sand. We found that &gt;99% of the eroded sand was deposited in the nearshore, within 1,000 m of the shoreline in depths &lt;10 m, suggesting that the deposited sediment remains available for littoral transport and beach recovery. Simulations with combinations of coarse or fine sediment and vegetated or unvegetated landcover indicate that channel position did not vary with grain size or vegetation, while volume of erosion and channel morphology were more responsive to variations in grain size and less responsive to presence of vegetation.</p>","PeriodicalId":15887,"journal":{"name":"Journal of Geophysical Research: Earth Surface","volume":"130 6","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025JF008309","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144331803","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":"Impact of Interfacial Friction at the Ice-Bed Boundary on Glacier Sliding","authors":"J. P. Roldán-Blasco,&nbsp;F. Gimbert,&nbsp;O. Gagliardini,&nbsp;A. Gilbert","doi":"10.1029/2022JF007028","DOIUrl":"10.1029/2022JF007028","url":null,"abstract":"<p>Current theories for describing glacier sliding over hard beds assume that basal drag is entirely due to normal forces acting on meter-scale bed roughness and neglect tangential friction at the ice-bed interface. However, this interfacial friction is likely to account for a significant proportion of basal drag in the presence of basal debris or cold ice, and may render current sliding theories inaccurate. The aim of the study is to evaluate if current sliding laws still apply in the presence of interfacial friction. We propose a simplified analytical model of glacier sliding controlled by both ice creep around bed irregularities, as proposed by Weertman (1957, https://doi.org/10.3189/s0022143000024709), and interfacial friction at the ice-bed boundary determined by Coulomb dependency. We show that reduced sliding speed from additional interfacial friction is mitigated by increased ice deformation near the bed, which occurs as a result of additional basal deviatoric stresses reducing the effective viscosity. We further generalize these results using a numerical model of glacier sliding over a sinusoidal bed, capable of simulating cavity formation and basal sliding with several formulations of interfacial friction. We find that the additional friction generally does not modify the form of previously proposed friction laws but significantly increases the maximum resistive shear stress of the bed. These results suggest that friction laws that are commonly used in ice-sheet models and whose parameters are empirically optimized, could be still used in circumstances where interfacial friction is non-negligible.</p>","PeriodicalId":15887,"journal":{"name":"Journal of Geophysical Research: Earth Surface","volume":"130 6","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2022JF007028","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144309173","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":"Direct Interception of Particles by a Vegetation Stem With Varying Adhesive Forces","authors":"Mahdi Khademishamami,&nbsp;Lawrence Sanford,&nbsp;William Nardin,&nbsp;Elizabeth North","doi":"10.1029/2024JF007915","DOIUrl":"10.1029/2024JF007915","url":null,"abstract":"<p>The direct interception of particles by vegetation stems has been reported in field studies of saltmarsh platforms as a major cause for removing suspended particles and pollutants. Laboratory observations and numerical models reported in the literature have computed the attachment efficiency under the assumption that particles stick and do not move when they collide with the surface of the collector (i.e., perfect attachment). This study was aimed at lifting this assumption using a Discrete Element Model (DEM) with varying adhesive contact forces coupled with Computational Fluid Dynamics (CFD). The CFD-DEM model considers the stickiness of the collector through a surface energy parameter. Model predictions showed good agreement with laboratory observations. The final configuration of particles on the collector's surface and the attachment efficiency changed when the collector's surface energy was varied. In some cases, the attachment efficiency was twice that under the perfect attachment assumption, indicating that modeling studies with perfect attachment may underestimate suspended particle removal. As biofilms are considered the main cause of the adhesiveness of stems, our study shows that any biofilm formation that could create a surface energy as low as 0.01 <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mtext>mJ</mtext>\u0000 <mo>/</mo>\u0000 <msup>\u0000 <mi>m</mi>\u0000 <mn>2</mn>\u0000 </msup>\u0000 </mrow>\u0000 <annotation> $text{mJ}/{mathrm{m}}^{2}$</annotation>\u0000 </semantics></math> could lead to attachment of particles on a single saltmarsh stem.</p>","PeriodicalId":15887,"journal":{"name":"Journal of Geophysical Research: Earth Surface","volume":"130 6","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JF007915","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144300293","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":"Are Equilibrium Shoreline Models Just Convolutions?","authors":"Sean Vitousek,&nbsp;Daniel Buscombe,&nbsp;Eduardo Gomez-de la Peña,&nbsp;Kit Calcraft,&nbsp;Mark Lundine,&nbsp;Kristen D. Splinter,&nbsp;Giovanni Coco,&nbsp;Patrick L. Barnard","doi":"10.1029/2025JF008452","DOIUrl":"10.1029/2025JF008452","url":null,"abstract":"<p>Yes. Equilibrium shoreline models, which simulate wave-driven cross-shore erosion and accretion, are mathematically equivalent to a discrete convolution (i.e., a weighted, moving average) of a time series of wave-forcing conditions with a parameterized memory-decay kernel function. The direct equivalence between equilibrium shoreline models and convolutions reveals key theoretical aspects of equilibrium behavior. Convolutions (representing quasi-low-pass filter operations) provide an intuitive theoretical description of shoreline erosion and accretion behavior in response to waves: that is, shoreline position often mirrors the weighted moving average of wave time series. Model-convolution equivalence also provides a conceptual basis to interpret, evaluate, and construct data-driven Machine-Learning/Deep-Learning (ML/DL) models that use convolutions to extract features from data and then apply them for prediction (e.g., Convolutional Neural Networks (CNNs)). Finally, our findings provide a methodological pathway (based on Fourier transforms) for future understanding of wave-driven shoreline change, which can be used to interpret the coherence between the frequency spectrum of the processes of waves and shoreline change and construct more computationally efficient and effective shoreline-modeling approaches.</p>","PeriodicalId":15887,"journal":{"name":"Journal of Geophysical Research: Earth Surface","volume":"130 6","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025JF008452","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144308978","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":"Experimental Measurements of Sediment Pickup Probability at Low Transport Stage","authors":"Chengxiao Lu,&nbsp;Nian-Sheng Cheng","doi":"10.1029/2024JF008222","DOIUrl":"10.1029/2024JF008222","url":null,"abstract":"<p>The concept of pickup probability is integral to the study of bed load sediment transport, dating back to Einstein's pioneering work. Despite its significance, there have been few efforts to experimentally measure the pickup probability. The scarcity of experimental data is largely due to difficulties associated with precisely pinpointing the timing of individual grain movements. This study introduces an innovative experimental method for measuring the pickup probability for the case of low sediment transport rates. First, the laser scanning technology was employed to monitor the temporal variations in bed surface elevation, enabling the detection of all instances of grain entrainment and deposition. Subsequently, the grains being entrained were identified and separated from the recorded events by establishing a criterion that defines the minimum bed-level change required for a grain to be fully entrained. This criterion allowed for a reasonable distinction between grains that were in motion and those that remained in place. The pickup probability was finally evaluated by assessing the proportion of the channel width that was occupied by grains being entrained at any given moment. The results obtained from this method were found to be in agreement with the findings from previous research.</p>","PeriodicalId":15887,"journal":{"name":"Journal of Geophysical Research: Earth Surface","volume":"130 6","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144300294","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":"Method Dependence in Thermal Conductivity and Aerodynamic Roughness Length Estimates on a Debris-Covered Glacier","authors":"Vicente Melo-Velasco,&nbsp;Evan Miles,&nbsp;Michael McCarthy,&nbsp;Thomas E. Shaw,&nbsp;Catriona Fyffe,&nbsp;Adrià Fontrodona-Bach,&nbsp;Francesca Pellicciotti","doi":"10.1029/2025JF008360","DOIUrl":"10.1029/2025JF008360","url":null,"abstract":"&lt;p&gt;Rock debris partially covers glaciers worldwide, with varying extents and distributions, and controls sub-debris melt rates by modifying energy transfer from the atmosphere to the ice. Two key physical properties controlling this energy exchange are thermal conductivity &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;(&lt;/mo&gt;\u0000 &lt;mi&gt;k&lt;/mi&gt;\u0000 &lt;mo&gt;)&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $(k)$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; and aerodynamic roughness length &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mfenced&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;z&lt;/mi&gt;\u0000 &lt;mn&gt;0&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mfenced&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $left({z}_{0}right)$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;. Accurate representation of these properties in energy-balance models is critical for understanding climate-glacier interactions and predicting the behavior of debris-covered glaciers. However, &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;k&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $k$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; and &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;z&lt;/mi&gt;\u0000 &lt;mn&gt;0&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${z}_{0}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; have been derived at very few sites from limited local measurements, using different approaches, and most model applications rely on values reported from these few sites and studies. We derive &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;k&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $k$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; and &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;z&lt;/mi&gt;\u0000 &lt;mn&gt;0&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${z}_{0}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; using established and modified approaches from data at three locations on Pirámide Glacier in the central Chilean Andes. By comparing methods and evaluating melt simulated with an energy-balance model, we reveal substantial differences between approaches. These lead to discrepancies between ice melt from energy-balance simulations and observed data, and highlight the impact of method choice on calculated ice melt. Optimizing &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;k&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 ","PeriodicalId":15887,"journal":{"name":"Journal of Geophysical Research: Earth Surface","volume":"130 6","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025JF008360","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144292719","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":"Quantifying Soil Resistance to Sheet and Lateral Erosion Across Different Habitats on a Managed Sandy Back-Barrier Island","authors":"Beatriz Marin-Diaz,&nbsp;Valérie C. Reijers,&nbsp;Linda Meijer,&nbsp;Daphne van der Wal,&nbsp;Han Olff,&nbsp;Tjeerd J. Bouma,&nbsp;Laura L. Govers","doi":"10.1029/2024JF007950","DOIUrl":"10.1029/2024JF007950","url":null,"abstract":"<p>Back-barrier islands are understudied, dynamic, soft-sediment coastal landscapes located in fetch-limited environments. They are of key ecological importance; however, they are threatened by global change impacts including increasing storm surges and sea level rise. This study aimed to investigate the soil erosion resistance to hydraulic forces of different habitats across a sandy back-barrier island with characteristic sandy subsoils that has been managed &gt;100 years to prevent its complete erosion and submergence. We quantified sheet and lateral soil erosion resistance in flumes, investigated their correlations with sediment and belowground vegetation characteristics, and discussed how these characteristics may relate to the island's past management and development. Soil cores were collected from the barrier dune ridge, back-barrier marshes and unvegetated sandflats and were exposed laterally to waves (lateral erosion) and horizontally to water flow (sheet erosion). Resistance to sheet and lateral erosion was not correlated. Resistance to lateral erosion depended on the thickness of the cohesive topsoil layer accreted by the marsh vegetation on top of a sandy subsoil. For instance, marsh soils with thin cohesive topsoils were resistant to sheet erosion (&lt;0.5 cm erosion in 3 hr) but not to lateral erosion (collapsed within the first 10 min), which could make them vulnerable to wave attacks if they get laterally exposed during island erosion. Topsoil thickness was related to marsh elevation and age. In turn, the development of the cohesive layer may be related to the past management of the island, as soft engineering measures such as beach nourishments can create sheltered conditions for marsh development.</p>","PeriodicalId":15887,"journal":{"name":"Journal of Geophysical Research: Earth Surface","volume":"130 6","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JF007950","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144292633","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":"New Catalog of Thwaites Glacier Subglacial Lakes and Their Activity Revealed by CryoSat-2 Altimetry","authors":"Byeong-Hoon Kim,&nbsp;Choon-Ki Lee,&nbsp;Ki-Weon Seo,&nbsp;Won Sang Lee,&nbsp;Jeong-Won Park","doi":"10.1029/2023JF007602","DOIUrl":"10.1029/2023JF007602","url":null,"abstract":"<p>Previously, the existence of seven active subglacial lakes was reported beneath Thwaites Glacier, one of West Antarctica's largest glaciers, predicted to significantly impact future sea level rise. In this study, we re-evaluate the CryoSat-2 satellite radar altimeter data from 2010 to 2022 and identify 27 subglacial lakes that were active during 2013–2014 and 2016–2018, including those previously observed. Our new observations reveal three lakes located downstream of the lakes identified previously that appear to drain 3 months prior to the drainage of upstream lakes in 2013. Despite being over 100 km apart, the observed lakes (from the farthest upstream to downstream) exhibited synchronized behaviors. The timing of lake activities shows a complex activity propagation pattern, featuring both upward and downward transmission, contrasting with the simpler, one-directional flows observed in previous studies. While lake activities correlate with abrupt changes in ice speed near the grounding line, their impacts are limited, regardless of the total amount of drained water.</p>","PeriodicalId":15887,"journal":{"name":"Journal of Geophysical Research: Earth Surface","volume":"130 6","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144281518","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":"Barchans Interacting With Dune-Size Obstacles: Details of the Fluid Flow and Motion of Grains","authors":"N. C. Lima,&nbsp;W. R. Assis,&nbsp;D. S. Borges,&nbsp;E. M. Franklin","doi":"10.1029/2025JF008504","DOIUrl":"10.1029/2025JF008504","url":null,"abstract":"<p>We investigate details of the interaction of subaqueous barchans with dune-size obstacles by carrying out numerical simulations where the fluid is solved at the grain scale and the motions of individual grains are computed at all time steps. With the outputs, we analyze the disturbances of the fluid flow, the trajectories of grains, and the resultant force on each grain, the latter being unfeasible from experiments and field measurements. We show that in some cases particles pass over the obstacle, while in others they completely circumvent it (without touching it), or are even blocked. For the circumvention and blocking cases, which we call bypass and trapped, respectively, we show the existence of a strong vortex between the lee face of the dune and the obstacle. This vortex results from the interactions of recirculation regions and horseshoe vortices, and has enough strength to deviate the main flow and carry grains around the obstacle in those cases. Our results shed light on the reasons for passing over, circumventing, and blocking, and contribute to our understanding of dunes in the presence of large obstacles such as hills, crater rims, and human constructions.</p>","PeriodicalId":15887,"journal":{"name":"Journal of Geophysical Research: Earth Surface","volume":"130 6","pages":""},"PeriodicalIF":3.8,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025JF008504","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144264488","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}