Observations of nearshore crescentic sandbars van Enckevort, I en_US Ruessink, B en_US Coco, G en_US Suzuki, Kazuo en_US Turner, Ian en_US Plant, N en_US Holman, Robert en_US 2021-11-25T14:35:49Z 2021-11-25T14:35:49Z 2004 en_US
dc.description.abstract The temporal and spatial variability of crescentic sandbars is analyzed with hourly long-term (months) video observations collected at four barred sites and are qualitatively compared to the temporal and spatial variability predicted by hypotheses underpinning existing approaches and models for crescentic bar formation (edge-wave template model, linear stability analysis, and nonlinear models). The observations, coming from the single barred beaches at Duck (North Carolina, USA) and Miyazaki (Kyushu, Japan), and from the double-barred beaches at the northern Gold Coast (Queensland, Australia) and Noordwijk (Netherlands), show that crescentic sandbar wavelength and amplitude variations over space and time are very common. For instance, at any moment in time, the wavelength of the smallest and longest crescentic bar can differ by a factor of 2. Temporal changes in wavelength and amplitude result from merging and splitting of individual crescents, causing the `final` configuration of a crescentic sandbar system to be very different from the initial configuration. The Gold Coast data indicate that these intrinsically nonlinear interactions are an attempt of the crescentic bar system to self-organize into a more uniform pattern, as splitting is usually confined to the longest crescentic bar observed, whereas merging usually combines the smallest crescentic bars into a longer bar. The observed spatial and temporal crescentic bar behavior contrasts qualitatively with behavior predicted from the edge-wave template model and implies that the predictive skill of linear stability models is limited. Nonlinear models are potentially better suited for a comparison against these field observations; several suggestions to improve these models, and hence to facilitate a data-model comparison, are made. en_US
dc.identifier.issn 0148-0227 en_US
dc.language English
dc.language.iso EN en_US
dc.rights CC BY-NC-ND 3.0 en_US
dc.rights.uri en_US
dc.source Legacy MARC en_US
dc.subject.other nearshore crescentic sandbars en_US
dc.title Observations of nearshore crescentic sandbars en_US
dc.type Journal Article en
dcterms.accessRights metadata only access
dspace.entity.type Publication en_US
unsw.relation.faculty Engineering
unsw.relation.ispartofissue C6 en_US
unsw.relation.ispartofjournal JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS en_US
unsw.relation.ispartofpagefrompageto 1-17 en_US
unsw.relation.ispartofvolume 109 en_US
unsw.relation.originalPublicationAffiliation van Enckevort, I en_US
unsw.relation.originalPublicationAffiliation Ruessink, B en_US
unsw.relation.originalPublicationAffiliation Coco, G en_US
unsw.relation.originalPublicationAffiliation Suzuki, Kazuo en_US
unsw.relation.originalPublicationAffiliation Turner, Ian, Civil & Environmental Engineering, Faculty of Engineering, UNSW en_US
unsw.relation.originalPublicationAffiliation Plant, N en_US
unsw.relation.originalPublicationAffiliation Holman, Robert en_US School of Civil and Environmental Engineering *
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