01-05 December 2025
INCOIS, Hyderabad, India.
| Abstract Submission No. | ABS-06-0252 |
| Title of Abstract | The Role of Advective Ventilation in Intensifying the Arabian Sea Oxygen Minimum Zone. |
| Authors | MOHAMMED MUNZIL P C* |
| Organisation | INCOIS |
| Address | Srambikkal House Malappuram, Kerala, India Pincode: 673641 E-mail: munzil1995@gmail.com |
| Country | India |
| Presentation | Oral |
| Abstract | The Arabian Sea hosts one of the most intense and persistent oxygen minimum zones (OMZs) in the global ocean, with profound implications for regional biogeochemistry and ecosystem functioning. Using multi-decadal (1993⿿2021) biogeochemical model outputs (NEMO v3.6) from the Copernicus Marine Environment Monitoring Service, we examine the evolution of dissolved oxygen variability in the upper 1500 m of the water column. The analysis reveals a sustained decline in oxygen concentrations on annual to decadal scales, with the strongest signal observed in the mesopelagic zone, where the OMZ core exhibits both vertical thickening and lateral expansion towards the south. Latitude⿿depth sections highlight a pronounced reduction in oxygen supply from the south, coinciding with the weakening of large-scale advective ventilation. By investigating the underlying mechanisms, our results suggest that a weakening in lateral ventilation pathways mediated through reduced inflow of oxygen-rich intermediate waters from the south, coupled with intensified stratification, limits the replenishment of subsurface oxygen. This weakened advective supply enhances the residence time of low-oxygen waters, allowing microbial respiration and organic matter remineralization to dominate, thereby accelerating oxygen depletion. Together, these findings emphasize the central role of advective ventilation in modulating oxygen balance in the Arabian Sea and provide new insights into the mechanisms driving OMZ intensification. They also underscore the vulnerability of regional ecosystems to future climate-driven shifts in circulation and ventilation that may further amplify oxygen loss. |
| Are you part of IIOE-2 endorsed project | no |
| Keywords | Arabian Sea, Dissolved Oxygen, Oxyegn Minimum Zone, NEMO |
| For Awards | yes |
| Date Of Birth | 27-02-1995 |
| ECSN Registration Number | IIOE2-ECSN-062 |