Eddy Tracking in the Northwestern Indian Ocean During Southwest Monsoon Regimes

Abstract

The northwestern Indian Ocean exhibits a relatively highly energetic eddy field during the southwest monsoon season between June and September. This study analyzes the seasonal and interannual variability of the eddy characteristics and their trajectories in the northwestern Indian Ocean using altimetric sea surface height observations from 1993 to 2014. Although the highest number of eddies is found in the Arabian Peninsula coastal region, the strongest eddies, characterized by large radii, amplitudes, and eddy kinetic energies are found along the Somali Current. Trajectories of anticyclonic and cyclonic eddies are investigated to provide insight on the generation and propagation of eddies of varying amplitudes. The largest annual eddy in the Somali Current system corresponds to the Great Whirl, for which the year-to-year variability with respect to shape, size, generation, and propagation was examined, as was the development of these characteristics over the Great Whirl's lifetime.