Monsoon-driven seasonal hypoxia along the northern coast of Oman

Frontiers in Marine Science

Marine Science

Ann E. Jochens¹  Leila Belabbassi¹  Marion Stoessel¹  Matthew K. Howard¹  Steven F. DiMarco²  Piers Chapman²  Stephanie Ingle³  Hilal al-Shaqsi⁴  Lubna al-Kharusi⁴  Zhankun Wang⁵ 

[1] Department of Oceanography, Texas A&M University, College Station, TX, United States;Department of Oceanography, Texas A&M University, College Station, TX, United States;Geochemical and Environmental Research Group, Texas A&M University, College Station, TX, United States;Fugro, Houston, TX, United States;Marine Science and Fisheries Centre, Ministry of Agriculture and Fisheries Wealth, Muscat, Oman;National Centers for Environmental Information, National Oceanic and Atmospheric Administration (NOAA), Silver Spring, MD, United States;

关键词: hypoxia;    dissolved oxygen;    monsoonal winds;    upwelling and downwelling;    Sea of Oman;    cabled mooring array;   

DOI  :  10.3389/fmars.2023.1248005

 received in 2023-06-26, accepted in 2023-09-01,  发布年份 2023

来源: Frontiers

【 摘 要 】

Dissolved oxygen and current observations from a cabled ocean observatory in the Sea of Oman show that the annual recurrence of coastal hypoxia, defined as dissolved oxygen concentrations ≤63 μM, is associated with the seasonal cycle of local monsoon winds. The observations represent the first long-term (5+ years) continuous moored observations off the northern Omani coast. During the summer/fall southwest (SW) monsoon season (Jun-Nov), winds in the Sea of Oman generate ocean currents that result in coastal upwelling of subsurface waters with low dissolved oxygen concentrations. The source of the poorly oxygenated water is the oxygen minimum zone (OMZ) in the Arabian Sea, a layer approximately 1000-m thick within the 100 to 1200 m depth range, where dissolved oxygen values approach anoxia. During the winter monsoon season (Dec-Feb), the Sea of Oman winds are from the northwest, forcing strong and persistent southeast currents. These winds generate oceanic downwelling conditions along the coastal ocean that ventilate waters at depth. Possible impacts of the monsoon-driven seasonal hypoxia on local fisheries and implications due to climate change are also discussed in this study.

【 授权许可】

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Copyright © 2023 DiMarco, Wang, Chapman, al-Kharusi, Belabbassi, al-Shaqsi, Stoessel, Ingle, Jochens and Howard