High salinity events in the northern Arabian Sea and Sea of Oman

• Published in: Deep-sea research. Part I, Oceanographic research papers Vol. 74; pp. 14 - 24
• Main Authors: Wang, Zhankun, DiMarco, Steven F., Jochens, Ann E., Ingle, Stephanie
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.04.2013; Elsevier; Pergamon Press Inc
• Subjects: Arabian Gulf; Arabian Sea; ARGO floats; Circulation; Cyclone Gonu; Cyclones; Deep mooring; Deep sea; Dissolution; Earth, ocean, space; Exact sciences and technology; External geophysics; High salinity events; Marine; Northern Arabian Sea; Ocean circulation; Oceanography; Persian Gulf outflow; Physics of the oceans; Salinity; Temperature; Temporal distribution; Thermohaline structure and circulation. Turbulence and diffusion; Water mass; Indian Ocean; Persian Gulf; Arabian Sea; Oman; ISW, Arabian Sea, Persian Gulf; ISW, Arabian Sea; ISW, Oman; Cyclone Gonu; Water mass; Deep mooring; ARGO floats; Persian Gulf outflow; High salinity events; Northern Arabian Sea; salinity; Space remote sensing; Altimeter; Current meter; Hydrographic survey; Oceanographic survey; Satellite observation; Drifting float; Measurement in situ; Severe weather; Tropical cyclone; Profiling float; Observation data; Measuring network
• ISSN: 0967-0637; 1879-0119
• DOI: 10.1016/j.dsr.2012.12.004

Moored observations in the northern Arabian Sea (NAS) show substantial velocity, temperature and dissolved oxygen fluctuations, accompanied by episodic high salinity intrusions with maximum values≥37.3 on time scales of 2–10 days after the passage of Cyclone Gonu in 2007. These events are characterized by a rapid increase in temperature, salinity and dissolved oxygen followed by an abrupt decline. The mechanisms behind these high salinity events are investigated using a comprehensive dataset of temperature and salinity profiles from ARGO floats and sea surface height anomaly maps. The spatial and temporal distribution of the Persian/Arabian Gulf outflow to the Sea of Oman is also studied using ARGO profiles. Persian Gulf water (PGW) is mainly measured close to the Strait of Hormuz or along the Oman coast on the continental slope in the Sea of Oman. Both mooring and ARGO data show that high salinity PGW can be advected off the slope and into the interior. More high salinity water is measured in the interior of the Sea of Oman within three months after the Gonu passage in summer 2007, which is caused by the combination effect of the oceanic responses to Cyclone Gonu and a clockwise eddy circulation located at northern Ras al Hadd. At other times, the high salinity water appears more in isolated patches and rare in the interior. This study provides a first look at the high salinity events appearing after Gonu and the properties and dynamics of the PGW in the northern Arabian Sea and Sea of Oman. ► High salinity events are measured in the Sea of Oman and northern Arabian Sea. ► More salinity events occurred in the interior after the passage of Cyclone Gonu. ► The source of the high salinity is the Persian Gulf outflow. ► The events after Gonu are associated with offshore current and mesoscale eddies. ► Observations presented are from both deep moorings and ARGO floats.