A Study of Chlorophyll Variation under the Influence of the Western Boundary Current System of Atlantic and Pacific Ocean Sectors of the Southern Ocean

The south western part of the Atlantic and Pacific sector plays a unique role in terms of ocean currents and variation in Chla. The Atlantic part of the study region contains the confluence region of two current system named Brazil current and Malvinas current. And the western part of the Pacific region is one of the thrive place for coral. This study represents the connection of the Chl-a variation along with the seasonal and inters annual variation of the respective current systems. The Chl-a in the Brazil Malvinas Confluence area is boosted by the nutrient-rich coastal water of the Brazil Current. During the summer, Chl-a reached a peak of 1.6 mg m -3 (log10 scale) and then fell to 2.5 mg m -3 (log10 scale) during the winter in this region. In La Nia, the dominance of the nutrient rich Malvinas current favors the enhancement of Chl, whereas wind plays an important role in mixing and enhancement of Chl-a in the positive phase of SAM. The East Australian Current (EAC) of the Pacific region is strongest in the summer and gradually weakens in the winter. More dominant EAC means the lesser intrusion of Tasmania Sea water in this region.Frontal eddies resulted from the mixing of these two water masses, which is one of the reasons for Chl-a in the offshore area.In La Nia, the strength of the EAC decreased and hence the influence of nutrient rich polar water increases, which leads to a higher Chl-a of 2.5 mg m -3 (in log10 scale) in the shelf region and 0.8 mg m -3 (in log10 scale).