The Bay of Bengal is a tropical sea in the northern Indian Ocean that is surrounded by land on three sides. It is shaped by major rivers, heavy rainfall, seasonal changes in temperature and salt levels, and strong winds that drive ocean currents. These conditions also create rotating water features called “eddies,” which mix the ocean and help regulate its temperature and salinity.

In this study, we used a high‑resolution computer model to better understand how tides affect surface currents and eddies in the Bay of Bengal. We found that when tidal forces are included, the southwestern part of the bay shows much stronger cyclonic and anticyclonic circulation compared to the northwest. Eddies become most active in the spring and peak in June and July, driven by strong winds and the East India Coastal Current. In the eastern Bay of Bengal, smaller eddies are often linked to coastal waves that travel along shorelines.

Our findings show that tides play a key role in shaping the bay’s currents and eddies. This knowledge is important for understanding tropical cyclones, the carbon cycle, and how the ocean supports life and regulates climate.