Increased mixed layer salinity during the monsoon intraseasonal Oscillation in the Northern Bay of Bengal

Abstract The northern Bay of Bengal (BoB) exhibits low mixed layer salinity accompanied by strong intraseasonal variability, primarily driven by the Indian Summer Monsoon and monsoon intraseasonal oscillation (MISO). Notably, the northern BoB shows concurrent increases in mixed layer salinity and MISO-induced precipitation at intraseasonal timescales. This contrasts with the central BoB where precipitation typically reduces salinity in mixed layer. Diagnostic studies reveal that horizontal advec