Preprint Article Version 1 This version is not peer-reviewed

Exchange Flow Variability between Hypersaline Shark Bay and the Ocean

Version 1 : Received: 20 March 2018 / Approved: 20 March 2018 / Online: 20 March 2018 (08:44:49 CET)

A peer-reviewed article of this Preprint also exists.

Hetzel, Y.; Pattiaratchi, C.; Mihanović, H. Exchange Flow Variability between Hypersaline Shark Bay and the Ocean. J. Mar. Sci. Eng. 2018, 6, 65. Hetzel, Y.; Pattiaratchi, C.; Mihanović, H. Exchange Flow Variability between Hypersaline Shark Bay and the Ocean. J. Mar. Sci. Eng. 2018, 6, 65.

Journal reference: J. Mar. Sci. Eng. 2018, 6, 65
DOI: 10.3390/jmse6020065

Abstract

In Shark Bay, a large hypersaline bay in Western Australia, longitudinal density gradients force gravitational circulation that is important for Bay-ocean exchange. Observations of vertical stratification and velocity are presented, confirming a steady near-bed dense water outflow from Shark Bay’s northern Geographe Channel that persisted through all stages of the tide. Outflow velocities were 2–3 times stronger than the outflows recorded previously in Naturaliste Channel (in the west) and were more resistant to breakdown by tidal mixing. Estimates of turbulent kinetic energy production derived from ADCP data using the variance method showed a more complex structure in Geographe Channel, due to shear associated with the stratified conditions, with peak levels of turbulence occurring during reversal of tidal flows. For both channels the main source of turbulence was tidal flow along the seabed, with the bottom current speed cubed, |Ub3|, providing a reasonable proxy for tidal mixing and prediction of dense water outflows from Shark Bay the majority of the time. Orientation and deeper water of Geographe Channel along the main axis of the longitudinal density gradient provided an explanation for the predominant outflow from the Bay’s northern entrance. These density-driven currents could potentially influence recruitment of commercially fished scallops and prawns through dispersal and flushing of larvae.

Subject Areas

Hypersaline Bay; circulation; turbulent mixing; exchange flow; Australia; Shark Bay

Readers' Comments and Ratings (0)

Leave a public comment
Send a private comment to the author(s)
Rate this article
Views 0
Downloads 0
Comments 0
Metrics 0
Leave a public comment

×
Alerts
Notify me about updates to this article or when a peer-reviewed version is published.