Climatological Coastal Jet Collision, Intermediate Water
Formation and the General Circulation of the Red Sea
Gidon Eshel and
Naomi Naik
Journal of Physical Oceanography, Vol. 27(7), pp. 1233-1257, July 1997
Abstract
We present climatologies of a numerical model of the Red Sea, focusing
on the dynamics of winter intermediate water formation. Northward
flowing boundary currents are identified as the major dynamical
elements. At the northern boundary, the eastern current follows the
geometry, eventually turning back to the south. At approximately 26N
and the western wall the two boundary currents collide. At the
collision site, the denser eastern current subducts under the western
boundary current. The subduction forces the western boundary current
eastward into the interior. Convection communicates the surface fluxes
to the downwelled plume and intermediate water forms. The estimated
rate, 0.11 Sv, agrees with previous estimates. We identify basin-scale
sea-surface tilt to the north due to variable thermohaline forcings as
the key dynamical variable. The resultant geostrophic eastward
cross-channel flow interacts with the boundaries, and creates
upwelling and surface topography spatial patterns which drive the
coastal jets. Upwelling-induced vortex stretching dominates the
vorticity balance, and governs the separation of the western boundary
current from the western wall. The process ceases in the summer.