Injection of Oxygenated Persian Gulf Water Into the Southern Bay of Bengal
Peter M. Sheehan, Benjamin G. M. Webber, Alejandra Sanchez‐Franks, Adrian J. Matthews, Karen J. Heywood, P. N. Vinayachandran
Abstract
Abstract Persian Gulf Water (PGW) is an oxygenated, high‐salinity water mass that has recently been detected in the Bay of Bengal (BoB). However, little is known about the transport pathways of PGW into the BoB. Ocean glider observations presented here demonstrate the presence of PGW in the southwestern BoB. Output from an ocean reanalysis product shows that this PGW signal is associated with a northward‐flowing filament of high‐salinity water. Particle tracking experiments reveal two pathways: one in the eastern Arabian Sea that takes a minimum of 2 years and another in the western Arabian Sea that takes a minimum of 3 years. The western pathway connects to the BoB via equatorial currents. The greatest influx of PGW occurs between 82° and 87°E during the southwest monsoon. We propose that injection of PGW to the BoB oxygen minimum zone (OMZ) contributes to keeping oxygen concentrations in the BoB above the level at which denitrification occurs.