Περίληψη:
The three-dimensional circulation of the Red Sea is studied using a set
of Miami Isopycnic Coordinate Ocean Model (MICOM) simulations. The model
performance is tested against the few available observations in the
basin and shows generally good agreement with the main observed features
of the circulation. The main findings of this analysis include an
intensification of the along-axis flow toward the coasts, with a
transition from western intensified boundary flow in the south to
eastern intensified flow in the north, and a series of strong seasonal
or permanent eddy-like features. Model experiments conducted with
different forcing fields (wind-stress forcing only, surface buoyancy
forcing only, or both forcings combined) showed that the circulation
produced by the buoyancy forcing is stronger overall and dominates the
wind-driven part of the circulation. The main circulation pattern is
related to the seasonal buoyancy flux ( mostly due to the evaporation),
which causes the density to increase northward in the basin and produces
a northward surface pressure gradient associated with the downward
sloping of the sea surface. The response of the eastern boundary to the
associated mean cross-basin geostrophic current depends on the
stratification and beta-effect. In the northern part of the basin this
results in an eastward intensification of the northward surface flow
associated with the presence of Kelvin waves while in the south the
traditional westward intensification due to Rossby waves takes place.
The most prominent gyre circulation pattern occurs in the north where a
permanent cyclonic gyre is present that is involved in the formation of
Red Sea Outflow Water (RSOW). Beneath the surface boundary currents are
similarly intensified southward undercurrents that carry the RSOW to the
sill to flow out of the basin into the Indian Ocean.
