Sensitivity experiments with an adaptation model of circulation of western tropical Indian Ocean

Abstract

One 18-level adaptation model of circulation with a flat bottom at 900 m depth has been used to study the sensitivity of the solution to different magnitudes of eddy viscosity and diffusivity coefficients. Three numerical experiments conducted showed that the magnitude and directions of current have not changed substantially, although the horizontal exchange coefficients have been increased by one order and vertical eddy diffusivity coefficients have been increased by 10 times. Computed circulation at 10 m depth is controlled by both wind stress and sea surface topography. Circulation at 50 m depth is mainly controlled by thermohaline forcing and sea surface topography. The current speed in the western tropical Indian Ocean is of the order of 75 to 100 cm sec(-1).