S.U.P. Jinadasa, Gayan Pathirana
Abstract: Intrusion of Arabian Sea (AS) waters into the Bay of Bengal (BoB) during August 2015 is examined using Conductivity Temperature Depth (CTD) observations made during R/V Roger Revelle research cruise (4-15 August 2015). Consistent with earlier studies Southwest Monsoon Current (SMC) flows eastward around Sri Lanka (SL) serving as an open ocean link connecting AS and BoB during summer monsoon. We have noted that SMC is strong during early August with a speed of 0.8 1.2 m/s and reduces up to 0.6 0.7 m/s at the end of the month. CTD observations in southern BoB clearly indicates the presence of AS waters (ASW) at a depth of 80 110m (34.8 35.2 psu) and provide evidence for the intrusion of ASW into the BoB during summer. Further, our analysis indicates the presence of our salinity extreme layers in the upper 250 m with a thickness around 10 20 m east of SL and points out the importance of subsurface mixing associated with Temperature-Salinity properties of the water column.
Keywords: Arabian Sea, Bay of Bengal, Summer Monsoon Current, Water Exchange