Geoffrey W. Wake

The temporal evolution of baroclinic basin-scale waves in a rotating circular basin

The temporal evolution of baroclinic basin-scale waves in a rotating circular basin following an initial forcing event is investigated using a laboratory study. Experiments conducted in the circular domain containing a two-layer fluid with a flat bottom and vertical sidewalls demonstrate that the response is essentially linear with frictional effects at the boundaries steadily dissipating wave energy. Experiments conducted in the same configuration but with the addition of simple topographic features, either a radially protruding cape or a bathymetric ridge, exhibit wave/topography interactions that result in the formation of an eddy field and an offshore flow, respectively. The rate of wave decay, as well as the amount of horizontal mixing occurring within the basin, is significantly enhanced by such interactions. The results of this study are then considered in terms of their implications for the baroclinic basin-scale wave energy pathways in large stratified lakes influenced by the Earths rotation.

Near-inertial ocean response to tropical cyclone forcing on the Australian North-West Shelf

The Regional Ocean Modeling System (ROMS) was applied to the Australian North-West Shelf (NWS) to hindcast the ocean response to four intense historical tropical cyclones (TCs). While the four cyclones had very different trajectories across the NWS, all passed within 150 km of a long-term vertical mooring located on the continental shelf in 125 m depth. The observed ocean response at this relatively shallow, Southern Hemisphere shelf site was characterized by the development of a peak in the counter-clockwise (CCW) near-inertial kinetic energy, mixed layer deepening, and subsequent restratification. Strong near-inertial isotherm oscillations were also observed following two of the cyclones. ROMS reproduced these features and also showed that the peak in the near-inertial CCW kinetic energy was observed on the left side of each cyclone trajectory. The time rate of change of near-inertial kinetic energy depended strongly on the storm Rossby number, i.e., defined based on the storm speed, the storm length scale, and the Coriolis frequency. The shallow water depth on the NWS resulted in first, a more rapid decay of near-inertial oscillations than in the deep ocean, and second a generation efficiency (the ratio of near-inertial power to the rate of wind work) of up to 10%, smaller than found for cyclones propagating across deeper water. The total energy put into near-inertial motions is nevertheless large compared to the background tidal energy. The rapid decay of near-inertial motions emphasizes the importance of frictional effects in characterizing the response to cyclone forcing in shallow seas.

Baroclinic geostrophic adjustment in a rotating circular basin

Baroclinic geostrophic adjustment in a rotating circular basin is investigated in a laboratory study. The adjustment process consists of a linear phase before advective and dissipative effects dominate the response for longer time. This work describes in detail the hydrodynamics and energetics of the linear phase of the adjustment process of a two-layer fluid from an initial step height discontinuity in the density interface

Experimental study on resonantly forced interfacial waves in a stratified circular cylindrical basin

\uDelta H

Nonbreaking wave‐induced mixing in upper ocean during tropical cyclones using coupled hurricane‐ocean‐wave modeling

to a final response consisting of both geostrophic and fluctuating components. For a forcing lengthscale

Quantifying Lake Water Quality Evolution: Coupled Geochemistry, Hydrodynamics, and Aquatic Ecology in an Acidic Pit Lake

r_f

Internal tide dynamics in a topographically complex region: Browse Basin, Australian North West Shelf

equal to the basin radius

The temporal evolution of a geostrophic flow in a rotating stratified basin

R_0

Periodic forcing of baroclinic basin-scale waves in a rotating stratified basin

, the geostrophic component takes the form of a basin-scale double gyre while the fluctuating component is composed of baroclinic Kelvin and Poincare waves. The Burger number

Nonbreaking wave-induced mixing in upper ocean during tropical cyclones using coupled hurricane-ocean-wave modeling: WAVE TURBULENCE IN HURRICANE MODELING

S\,{=}\,R/r_f