Coastal circulation off Ratnagiri, west coast of India during monsoon seasons: a numerical model study

Abstract

Present study is the coastal circulation modelling off Ratnagiri under the influence of winds and tides. A two-dimensional hydrodynamic model MIKE 21HD has been used to simulate tides and currents, and model results are in a good agreement with the measurements. In July, representing the southwest monsoon, wind is relatively strong, onshore current component is more pronounced; but, tidal variations are masked to a great extent by the wind driven circulation. Relatively stronger winds of the order of 8 m/s, persisted for a longer period, and that contributed to the southward flowing coastal current which is more consistent in its direction and magnitude. Meridional current has a prominent southward direction with a maximum alongshore speed of ~0.41 m/s. Zonal current is too weak to have a considerable impact on the circulation pattern. Prominent circulation is southward, irrespective of the seasons.