气候变化领域集成服务门户(CCPortal): Energy Transfers and Reflection of Infragravity Waves at a Dissipative Beach Under Storm Waves

CCPortal

DOI	10.1029/2019JC015714
	Energy Transfers and Reflection of Infragravity Waves at a Dissipative Beach Under Storm Waves
	Bertin X.; Martins K.; de Bakker A.; Chataigner T.; Guérin T.; Coulombier T.; de Viron O.
发表日期	2020
ISSN	21699275
卷号	125 期号:5
英文摘要	This study presents unpublished field observations of infragravity waves, collected at the dissipative beach of Saint-Trojan (Oléron Island, France) during the storm Kurt (3 February 2017), characterized by incident short waves of significant heights reaching 9.5 m and peak periods reaching 22 s. Data analysis reveals the development of exceptionally large infragravity waves, with significant heights reaching 1.85 m close to shore. Field observations are complemented by numerical modeling with XBeach, which well reproduces the development of such infragravity waves. Model results reveal that infragravity waves were generated mainly through the bound wave mechanism, enhanced by the development of a phase lag with the shortwave energy envelope. Spectral analysis of the free surface elevation shows the generation of superharmonic and subharmonic infragravity waves, the latter dominating the free surface elevation variance close to shore. Modeling results suggest that subharmonic infragravity waves result, at least partly, from infragravity-wave merging, promoted by the combination of free and bound infragravity waves propagating across a several kilometer-wide surf zone. Due to the steeper slope of the upper part of the beach profile, observed and modeled reflection coefficients under moderate-energy show a strong tidal modulation, with a weak reflection at low tide (R2<0.2) and a full reflection at high tide (R2∼1.0). Under storm waves, the observed reflection coefficients remain unusually high for a dissipative beach (R2∼0.5−1.0), which is explained by the development of subharmonic infragravity waves with frequencies around 0.005 Hz, too long to suffer a substantial dissipation. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	bound wave; dissipative beach; infragravity waves; merging; numerical model; reflection
语种	英语
来源期刊	Journal of Geophysical Research: Oceans
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/186899
作者单位	UMR 7266 LIENSs CNRS-La Rochelle Université, La Rochelle, France; Now at UMR 5805 EPOC, CNRS-University of Bordeaux, Bordeaux, France; Now at Unit of Marine and Coastal Systems, Deltares, Delft, Netherlands; Now at Laboratoire Saint Venant, Sorbonne University, Paris, France; Now at SAS Benoit Waeles - Consultant Génie Côtier, Brest, France
推荐引用方式 GB/T 7714	Bertin X.,Martins K.,de Bakker A.,et al. Energy Transfers and Reflection of Infragravity Waves at a Dissipative Beach Under Storm Waves[J],2020,125(5).
APA	Bertin X..,Martins K..,de Bakker A..,Chataigner T..,Guérin T..,...&de Viron O..(2020).Energy Transfers and Reflection of Infragravity Waves at a Dissipative Beach Under Storm Waves.Journal of Geophysical Research: Oceans,125(5).
MLA	Bertin X.,et al."Energy Transfers and Reflection of Infragravity Waves at a Dissipative Beach Under Storm Waves".Journal of Geophysical Research: Oceans 125.5(2020).