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High‐Energy Surf Zone Currents and Headland Rips at a Geologically Constrained Mesotidal Beach

dc.rights.licenseopenen_US
hal.structure.identifierEnvironnements et Paléoenvironnements OCéaniques [EPOC]
dc.contributor.authorMOURAGUES, Arthur
hal.structure.identifierEnvironnements et Paléoenvironnements OCéaniques [EPOC]
dc.contributor.authorBONNETON, Philippe
hal.structure.identifierEnvironnements et Paléoenvironnements OCéaniques [EPOC]
dc.contributor.authorCASTELLE, Bruno
IDREF: 087596520
hal.structure.identifierEnvironnements et Paléoenvironnements OCéaniques [EPOC]
dc.contributor.authorMARIEU, Vincent
dc.contributor.authorJAK MCCARROLL, R
hal.structure.identifierEnvironnements et Paléoenvironnements OCéaniques [EPOC]
dc.contributor.authorRODRIGUEZ PADILLA, Isaac
dc.contributor.authorSCOTT, Tim
dc.contributor.authorSOUS, Damien
dc.date.accessioned2024-03-27T09:51:09Z
dc.date.available2024-03-27T09:51:09Z
dc.date.issued2020-10
dc.identifier.issn2169-9275en_US
dc.identifier.urihttps://oskar-bordeaux.fr/handle/20.500.12278/189005
dc.description.abstractEnWe analyze Eulerian and Lagrangian measurements of wave-induced circulation collected during a 3-week field experiment at a high-energy mesotidal barred beach with the presence of a 500-m headland and a submerged reef. Small changes in wave and tide conditions were found to largely impact circulation patterns. Three main regimes were identified depending on offshore wave obliquity: (1) Under shore-normal configuration, the flow was dominated by cross-shore motions, except for moderate waves at low tide, with the presence of a quasi-steady circulation cell on the reef. (2) Under shadowed configuration, an onshore-directed current flowing away from the headland and a weak oscillating eddy were present outside and inside the shadow region, respectively. (3) Under deflection configuration, a deflection rip flowing against the headland and extending well beyond the surf zone was present, with activity maximized around low tide for moderate waves. Under 4-m oblique waves, the deflection rip was active regardless of the tide with mean depth-averaged velocities up to 0.7 m/s 800-m offshore in 12-m depth, with energetic low-frequency fluctuations. Our results emphasize the ability of deflection rips to transport materials far offshore, suggesting that such rips can transport sediment beyond the depth of closure. This study indicates that a wide variety of wave-driven circulation patterns can occur and sometimes coexist on beaches with prominent geological settings. Changes in the dominant driving mechanism can occur as a result of small changes in wave and tide conditions, resulting in more spatially and temporally variable circulation than along open sandy beaches. Plain Language Summary Most field experiments about wave-induced circulation patterns have been conducted along open sandy beaches, while experiments in geologically constrained environments are scarce. We performed intensive field measurements at a high-energy beach with the presence of a 500-m headland and a submerged natural reef. Three main circulation patterns were identified depending on the offshore wave obliquity. For shore-normal waves, cross-shore motions dominated the nearshore region, while oblique wave configurations resulted in more complex horizontal circulation. In particular, under intense headland-directed longshore current, the flow was deflected seaward against the headland. This deflection resulted in an intense seaward flowing jet (deflection rip) extending well beyond the surf zone edge, particularly during storm conditions. Such findings highlight the ability of these deflection rips to dominate water and sediment exchanges between the nearshore and the inner shelf region. Our study further outlines the more spatially and temporally variable circulation patterns occurring along geologically constrained beaches compared to open sandy beaches, ranging from small recirculating cells across the reef to a large deflection rip extending hundreds of meters beyond the surf zone.
dc.description.sponsorshipMarier les objectifs de défense côtière avec ceux de la protection du milieu naturel grâce aux dunes sableuses - ANR-17-CE01-0014en_US
dc.language.isoENen_US
dc.title.enHigh‐Energy Surf Zone Currents and Headland Rips at a Geologically Constrained Mesotidal Beach
dc.typeArticle de revueen_US
dc.identifier.doi10.1029/2020jc016259en_US
dc.subject.halPlanète et Univers [physics]en_US
dc.subject.halPlanète et Univers [physics]/Interfaces continentales, environnementen_US
dc.subject.halPlanète et Univers [physics]/Océan, Atmosphèreen_US
bordeaux.journalJournal of Geophysical Research. Oceansen_US
bordeaux.volume125en_US
bordeaux.hal.laboratoriesEPOC : Environnements et Paléoenvironnements Océaniques et Continentaux - UMR 5805en_US
bordeaux.institutionUniversité de Bordeauxen_US
bordeaux.institutionCNRSen_US
bordeaux.teamMETHYSen_US
bordeaux.peerReviewedouien_US
bordeaux.inpressnonen_US
bordeaux.import.sourcehal
hal.identifierhal-03044604
hal.version1
hal.popularnonen_US
hal.audienceInternationaleen_US
hal.exportfalse
workflow.import.sourcehal
dc.rights.ccPas de Licence CCen_US
bordeaux.COinSctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=Journal%20of%20Geophysical%20Research.%20Oceans&rft.date=2020-10&rft.volume=125&rft.eissn=2169-9275&rft.issn=2169-9275&rft.au=MOURAGUES,%20Arthur&BONNETON,%20Philippe&CASTELLE,%20Bruno&MARIEU,%20Vincent&JAK%20MCCARROLL,%20R&rft.genre=article


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