Spatial and temporal variation of salinity, water density, and temperature of sea's waters in Hormozgan province, Hormoz Strait and the Persian Gulf

Abstract

Horizontal and vertical distribution of water density, salinity and temperature in Hormozgan province along the Persian Gulf, from Sink Harbor to Nayband Bay, during summer and winter in the year 2005 were studied. We used CTD set to test the parameters in waters from surface to one meter above the seabed. A one way ANOVA and Tukey test were applied to the data. Results show that the thermocline layer is formed in the depth 20-60m with a temperature difference of about 12°C and this temperature difference diminishes in winter. Vertical distribution of density and salinity, both for summer and winter seasons are increased, where the scope of changes between surface and bottom layers in summer is more than the winter season. Vertical changes of the three parameters was observed and for salinity along the first transect this was especially significant where we could see a gradual change from surface to about 80 m under water and a drastic change from 80400m. This increase shows the existence of an outgoing water current from the bottom of the Persian Gulf via the Hormoz Strait towards the Sea of Oman. Horizontal distribution of parameters show that seawater temperature increases from east to west in summer and it decreases in the same direction during the winter. In the same direction, density and salinity increases, both in summer and winter seasons. The statistical comparison of average density, salinity and temperature in different depth layers and transect lines showed a significant difference for summer and winter seasons (P<0.05, 95%).