Application of a wind-driven barotropic model to simulate the seasonal circulation of the northern Arabian Sea

A two dimensional numerical barotropic model based on the depth-integrated equations is presented here. Sensitivity of the model is analyzed by using wind stresses of different months. Real wind data and actual bathymetry are used as an input to obtain the circulation patterns of the northern Arabian Sea during specific seasons. However, the model is also tested with constant depth for comparison. A number of numerical simulations are performed to study the combined effects of wind stress, bathymetry and basin geometry. Since the goal of this study is to simulate the circulation of the northern Arabian sea in accordance with the observed wind stress, therefore, wind stresses of different months like July (the peak os SW monsoon), October (the transition period from SW to NE monsoon), January (the peack of NE monsoon) and April (the transition period from NE to SW monsoon) are used to examine the circulation patterns. The results obtained are satisfactory in that they resemble known patterns.

A three dimensional model of Caspian Sea circulation

Observations of Caspian Sea during August - September 1995 are used to develop a three dimensional numerical for calculating temperature and current. This period was chosen because of extensive set of observational data including surface temperature observations. Data from the meteorological buoy network on Caspian Sea are combined with routine observation at first order synoptic station around the lake to obtain hourly values of wind stress and pressure fields. Initial temperature distribution as a function of depth and horizontal coordinates are derived from ship cruises. The model has variable grid resolution and horizontal smoothing which filters out small scale vertical motion. The hydrodynamic model of Caspian Sea has 6 vertical levels and a uniform horizontal grid size of 50 km The model is driven with surface fluxes of heat and momentum derived from observed meteorological. The model was able to reproduce all of the basic feature of the thermal structure in Caspian sea and: larger scale circulation patterns tend to be cyclone, with cyclone circulation with each sub basin. Result has agreement with observations.