Calculation of Geostrophic Current in North Atlantic Ocean

In this study, the current in a region of the North Atlantic is determined by calculating the slope of a constant pressure surface relative to a surface of constant geopotential. In the first step, geopotential difference between two constant pressure surfaces at different hydrographic positions is calculated. Then, the slope of the upper pressure surface relative to the lower is estimated; finally the geostrophic current at the upper surface relative to the current at the lower is determined. For computing of current as a function of depth, current of each level related to the reference level is integrated. The results of this study show that maximum current speed is 0.223 m/s, also analyses of calculated data illustrating that up to depth of 1500 m is baroclinic flow and from mentioned depth to the bottom of the sea is barotropic flow. Furthermore, results are demonstrating that flow in vertical axes, in the region of study, can have both baroclinic flowing conditions and barotropic flowing conditions. The comparison of results of this study with field data shows good match.