Ventilation of the Bay of Bengal oxygen minimum  zone by the Southwest Monsoon Current

Sheehan, Peter M. F.; Webber, Benjamin G. M.; Sanchez-Franks, Alejandra; Queste, Bastien Y.

doi:https://doi.org/10.5194/os-21-1575-2025

Articles | Volume 21, issue 4

https://doi.org/10.5194/os-21-1575-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

Special issue:

Advances in ocean science from underwater gliders

https://doi.org/10.5194/os-21-1575-2025

© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 21, issue 4

Research article

|

29 Jul 2025

Research article |

| 29 Jul 2025

Ventilation of the Bay of Bengal oxygen minimum zone by the Southwest Monsoon Current

Peter M. F. Sheehan, Benjamin G. M. Webber, Alejandra Sanchez-Franks, and Bastien Y. Queste

Data sets

Ocean glider data from five Seagliders deployed in the Bay of Bengal during the BoBBLE (Bay of Bengal Boundary Layer Experiment) project in July 2016 Benjamin G. M. Webber et al. https://doi.org/10.5285/996bf53d-5448-297a-e053-6c86abc0b996

Global Ocean Physics Reanalysis Mercator Ocean International https://doi.org/10.48670/moi-00021

Global Ocean Gridded L 4 Sea Surface Heights And Derived Variables Reprocessed 1993 Ongoing CLS https://doi.org/10.48670/moi-00148

Index of /data/oceans/woa/WOA23/DATA NOAA https://www.ncei.noaa.gov/data/oceans/woa/WOA23/DATA/

Short summary

Using measurements and computer models, we identify a large flux of oxygen within the Southwest Monsoon Current, which flows north into the Bay of Bengal between June and September each year. Oxygen levels in the bay are very low, but they are not quite low enough for key nutrient cycles to be as dramatically altered as in other low-oxygen regions. We suggest that the flux which we identify contributes to keeping oxygen levels in the bay above the threshold below which dramatic changes would occur.