A modeling study of circulation and effect of mesoscale eddies on sound speed profiles in the Persian Gulf by ROMS model

Abstract Seasonal variability of circulation and meso scale eddies in the Persian Gulf are investigated by using results from an (~3 km) Regional Ocean Modeling System (ROMS) with particular reference to the year 2009 in 16 sigma level. Circulation in the Persian Gulf is mainly due to three factors of wind stress, density (thermohaline flow) and tidal current. The main current in the Persian Gulf, which is cyclonic, is caused by a density difference. Also, oscillations in the wind stress force cause a variable flow in the Strait of Hormuz .Cyclonic circulation in the center of Persian Gulf will be stronger from April to July, so the model during August the highest clarity is observed in the formation of meso scale eddies. In this research, we selected 4 stations in various situations in Persian Gulf. We investigated the effect of eddies formation on salinity and temperature and specially the sound speed. As the method of sound wave propagation in underwater environment is very important to performance of acoustic system. So, The effect of the presence and absence of eddy on the sound velocity graphs was compared. The result is that, the presence of eddies decreases the sound speed propagation and the transmission loss .