L. S. Madani; A. A. Bidokhti; M. Ezam
Volume 2, Issue 1 , March 2012, , Pages 107-114
Abstract
An analytical model for a coastal boundary current was used to investigate heat and salt budget of exchange flows in the Persian Gulf as a marginal sea. Coastal boundary currents exchange heat and freshwater with the mosphere and the offshore waters. As heat and salinity fluxes caused by air-sea interaction ...
Read More
An analytical model for a coastal boundary current was used to investigate heat and salt budget of exchange flows in the Persian Gulf as a marginal sea. Coastal boundary currents exchange heat and freshwater with the mosphere and the offshore waters. As heat and salinity fluxes caused by air-sea interaction and eddy activities, different temperature and salinity associated with boundary currents are adjusted on different length scales. Results obtained from the model show that the temperature and salinity length scales of coastal boundary current are 455 km and 914 km, for summer respectively for summer. In summer the inflow current density initially decreases to a local minimum and then increases, and finally flowing out the basin area with higher density than that of for the inflow. In winter, the estimated temperature and salinity length scales of coastal boundary current are 60 km and 64 km, respectively. In this season, density increases at the beginning with a steep slope and reaches a constant value and, finally the current flows out of the basin area.
A. A. Bidokhti; A. Shekarbaghani
Volume 1, Issue 1 , December 2011, , Pages 13-22
Abstract
Ocean waters often show layered structures especially where exchange flow between two basins occurs. These structures are often attributed to processes such as double.diffusive convection, internal waves, turbulent modulated mixing. In this paper by examining the vertical structures of temperature, salinity ...
Read More
Ocean waters often show layered structures especially where exchange flow between two basins occurs. These structures are often attributed to processes such as double.diffusive convection, internal waves, turbulent modulated mixing. In this paper by examining the vertical structures of temperature, salinity and density, of the middle parts of Caspian Sea it is shown that such layered structure may be due to the normal modes of the internal waves as double diffusive convection (the density ratio is often negative) does not often occur in these waters. Contours of isotherm, isohaline and isopycnal show the existence of rather regular wavy structures, which may indicate that internal waves, which are produced of exchange, flow between two basins; as a result of horizontal density gradients (usually from middle basin to southern basin) may generate these layers. The flow velocity associated with this gravity driven flow is about 0.1 to 0.15 m/s which gives a Froude number of about one. The wave lengths of these wavy structures are about 200 km and hence, the frequencies of them are of order of inertial frequency at these latitudes. The normal modes of these waves appear to have a near steady structure and can fold the inflow front from the Northern
part of the Caspian Sea to the Southern deep basin. The thickness of formed layers is found be about 10-20 m which is
in agreement with the values predicted by the model of
Wong et al. (2001)
and is less likely to be produced by double
diffusive convection as the density ratio is often not appropriate for this process.