Abstract
During winter months continental shelf waters are convectively cooled and shallow coastal regions become colder than deeper offshore waters where the same surface heat flux is distributed over a larger depth. The resulting temperature front adjusts to geostrophic equilibrium producing transient cross-shelf currents which decay with time as the system approaches a steady state. Additional short duration cooling events associated with the passage of local weather systems may be sufficient to re-establish the vertical orientation of the temperature front which will readjust to geostrophic equilibrium once the cooling event has ceased, producing transient cross-shelf circulation associated with the adjustment process. Observations of a temperature front in the entrance of a shallow bay on the southeastern coast of Australia are shown to be consistent with a two-dimensional time dependent numerical model. The model includes stratification and realistic bottom topography and is forced by surface cooling, which produces a temperature front which adjusts to geostrophic equilibrium. Numerical simulation of cooling events is shown to produce transient cross-shelf velocities of order 0.001-0.01 m s-1.
Original language | English |
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Pages (from-to) | 143-157 |
Number of pages | 15 |
Journal | Continental Shelf Research |
Volume | 14 |
Issue number | 2-3 |
DOIs | |
Publication status | Published - 1994 |