Show simple item record  

dc.contributor.authorO’Callaghan, J.M.
dc.contributor.authorPattiaratchi, C.B.
dc.contributor.authorHamilton, David P.
dc.date.accessioned2010-09-27T03:45:18Z
dc.date.available2010-09-27T03:45:18Z
dc.date.issued2010
dc.identifier.citationO’ Callaghan, J.M., Pattiaratchi, C.B. & Hamilton, D.P. (2010). The role of intratidal oscillations in sediment resuspension in a diurnal, partially mixed estuary. Journal of Geophysical Research, 115, C07018.en_NZ
dc.identifier.urihttp://hdl.handle.net/10289/4608
dc.description.abstractUsing detailed observations of the mean and turbulent properties of flow, salinity and turbidity that spanned 2001/02, we examined the physical mechanisms underpinning sediment resuspension in the low-energy Swan River estuary, Western Australia. In this diurnal tidally-dominated estuary, the presence of intratidal oscillations, a tidal inequality lasting 2 to 3 hours on the flood tide, generated by interactions of the four main diurnal and semidiurnal astronomical constituents, K₁, O₁, M₂, and S₂, played a major role in modifying vertical stratification and mixing. These intratidal oscillations are controlled by phase differences between the tropic and synodic months rather than being temporally-fixed by bed friction, as occurs in semidiurnal estuaries. Intratidal oscillations are largest, at around 0.1 m, near to the Austral solstice when the lunar and solar declination are in-phase. Despite the seemingly small change in water level, shear-induced interfacial mixing caused destratification of the water column with the top-to-bottom salinity (ΔS) difference of 3.5 present early in the flood tide eroded to less than 0.3 by the end of the intratidal oscillation. High turbidity peaks, of 250 nephelometric turbidity units, coincided with these intratidal oscillations and could not be explained by bed friction since shear stress from mean flow did not exceed threshold criteria. High Reynolds stresses of ∼1 Nm⁻² did, however, exceed τcr and together with negative Reynolds fluxes indicate a net downward transport of material. Destratification of the water column induced by shear instabilities resulted in large overturns capable of moving in situ material towards the bed during intratidal oscillations and these turbidities were ∼10 times greater than those from bed-generated resuspension observed later during the flood tide.en_NZ
dc.format.mimetypeapplication/pdf
dc.language.isoen
dc.publisherAmerican Geophysical Unionen_NZ
dc.relation.urihttp://www.agu.org/pubs/crossref/2010/2009JC005760.shtmlen_NZ
dc.rightsThis article has been published in the Journal of Geophysical Research. Copyright 2010 by the American Geophysical Union.
dc.subjectdiurnal tidesen_NZ
dc.subjectstratificationen_NZ
dc.titleThe role of intratidal oscillations in sediment resuspension in a diurnal, partially mixed estuaryen_NZ
dc.typeJournal Articleen_NZ
dc.identifier.doi10.1029/2009JC005760en_NZ
dc.relation.isPartOfJournal of Geophysical Research (Oceans)en_NZ
pubs.begin-page1en_NZ
pubs.elements-id35336
pubs.end-page17en_NZ
pubs.issue7en_NZ
pubs.volume115en_NZ
uow.identifier.article-noARTN C07018en_NZ


Files in this item

This item appears in the following Collection(s)

Show simple item record