Salinity variation in the southeastern Arabian Sea: A revisit

Salinity variability in the southeastern Arabian Sea (SEAS) is discussed utilizing the monthly hydrographic data collected within a 2 degrees x2 degrees grid (8.5 degrees N to 10.5 degrees N) between August 2007 and May 2008. In the climatology, the absolute salinity values were low and fine scale features were absent when compared with the ground truth measurements. Arabian Sea Watermass was present as a subsurface maximum throughout the year between 50 and 100 m depths. Bay of Bengal Watermass occupied the top 10 m in the offshore and 50 m near the coast in January. Between October and January, this water-diluted the surface layers of the coastal regions by similar to 1.5 psu and the offshore regions by similar to 2 psu. A noticeable observation during August and September was the presence of a low salinity plume (<34.5 psu) that extended upto a depth" of.10m and sandwiched between saline waters on both side. The curling of currents around a cyclonic gyre that formed in the SEAS during the southwest monsoon brings fresh water from the equator and near coastal regions into the offshore, thereby created the loW salinity plume. Replacement of southward currents west of 75 degrees E in September by the eddy circulation diluted the surface layers in those regions.