The role of salinity on the dynamics of the Arabian Sea mini warm pool

• Published in: Journal of Geophysical Research: Oceans Vol. 117; no. C9
• Main Authors: Nyadjro, Ebenezer S., Subrahmanyam, Bulusu, Murty, V. S. N., Shriver, Jay F.
• Format: Journal Article
• Language: English
• Published: Washington, DC Blackwell Publishing Ltd 01-09-2012; American Geophysical Union
• Subjects: Arabian Sea; Argo; Earth sciences; Earth, ocean, space; Exact sciences and technology; HYCOM; Marine; salinity; SMOS; warm pool; Indian Ocean; Asia; Europe; Southern Europe; Italy; Marches Italy; Arabian Sea; India; ISW, Arabian Sea; ISW, India; ocean currents; salinity; Sea surface; salt; Barrier layer; stratification; coordinates; Sea surface temperature; variability; chemically precipitated rocks; evaporites; in situ; Ocean model; Drifting float; sedimentary rocks; dynamics; Coastal current; Measuring network; heat flux; Vortex; monsoons; heat transfer; collapse
• ISSN: 0148-0227; 2169-9275; 2156-2202; 2169-9291
• DOI: 10.1029/2012JC007978

Warmer (>28°C) sea surface temperature (SST) occurs in the South Eastern Arabian Sea (SEAS, 5°N–13°N, 65°E–76°E) during March–April, and is known as the Arabian Sea Mini Warm Pool (ASMWP). In this study, we address the role of salinity and the upper layer heat and salt budgets in the formation and collapse of this ASMWP. An assessment of Level 3 sea surface salinity (SSS) data from the Soil Moisture and Ocean Salinity (SMOS) satellite mission for the year 2010 shows that SMOS is able to capture the SSS variability in the SEAS. Analysis of temperature, salinity and currents from the Hybrid Coordinate Ocean Model during 2003–06, and, in situ temperature and salinity data from Argo floats during 2003–06 for the SEAS revealed that low salinity waters cap the top 60 m of the SEAS in January–February. This minimum salinity was concurrent with the formation of a barrier layer and with the time when the SEAS gained little net heat flux and the equatorward flowing East India Coastal Current (EICC) fed low saline waters into the SEAS. Subsequently, the net heat flux increased to a peak value under the increased salinity stratification, leading to the formation of the ASMWP in March–April. The ASMWP collapsed by May due to increase in SSS and the associated weakening of the salinity stratification. The monsoon onset vortex in May 2004 could be related to the minimum SSS that occurred in February 2004, followed by higher SST and heat content of the ASMWP in April 2004.
Key Points
Detection of fresh water plumes using SMOS salinity
Dynamics of Arabian Sea warm pool using HYCOM
Connection of Arabian Sea warm pool and monsoon vortex