Water currents


Anim 1 : Recovery of current meters (in the middle of the frame) and nephelometers (on the side of the frame) deployed in shallow estuarine waters with swift tidal currents.
Anim 2 : Visualisation of the complex bathymetry around Rattray Island, a 1500m wide island in 20-30m depth in the Great Barrier Reef, Australia.
Anim 3 : Visualisation of the observed circulation in the lee of Rattray Island. The thick arrows are observations from 26 moored current meters. The thin arrows are linearly interpolated from the data. Colour is added as a function of speed from blue (low speed) to red (high speed).
Figure 4 : Aerial photograph of Rattray Island showing an eddy formed in the lee of the island.
Anim 4 : Visualisation of the predicted circulation in the lee of Rattray Island. The colours denote upwelling and downwelling zones as a way to show the three-dimensional flow structure in the eddy.
Anim 5 : Visualisation of the predicted vorticity around Rattray Island, computed by a vortex-tracking model hence the vortices are individually discretised, over 2 tidal cycles. Adapted from Furukawa and Wolanski(1998). Note the formation of vortex sheets formed by the alignment of individual vortices, the rolling of vortex sheets into large-scale eddies, and the interaction between large-scale eddies that apparently mimics the behaviour of strange attractors in chaos theory. Eddies at successive tides show much variability, another indication of chaos. The data were kindly provided by K. Furukawa.
Anim 6 : Visualisation of the predicted tidal circulation through the central region of the Great Barrier Reef. The study area is about 260km long.
Anim 7 : Visualisation of the predicted plume of passive tracers in the central region of the Great Barrier Reef, the plume far from the reefs remains coherent and the plume in the matrix of the reefs breaks down in patches.
Anim 8 : Visualisation of the currents in the Fly River estuary under spring tides, mean river discharge of 6,000 m3s-1 and no wind.


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