Hydrographic transformation of the Persian/Arabian Gulf outflow over rough shelf bathymetry in the Gulf of Oman
- 1Khalifa University of Science and Technology (Abu Dhabi, United Arab Emirates)
Abstract
Hypersaline overflows from marginal seas contribute to global ocean circulation and climate variability. The Persian/Arabian Gulf (P/AG) contributes dense, saline, oxygenated deep outflow into the Arabian Sea's Oxygen Minimum Zone (OMZ). Here, we present high-resolution hydrographic mapping of the United Arab Emirates-Oman margin in the northwestern Arabian Sea, integrating conductivity-temperature-depth profiles, multibeam bathymetry and remotely-operated vehicle imagery. The P/AG outflow forms a thin (10–30 m) bottom-attached layer that, on crossing an abrupt bathymetric step, undergoes a hydraulic transition and thickens to 200 m over the rough, irregular seafloor of the unstable shelf, where dilution and loss of bottom contact occur. Near-bottom salinity, oxygen, and pH decrease systematically downstream in association with enhanced mixing. Distinct benthic assemblages coincide with attached versus detached flow sectors, consistent with differing near-bed hydrodynamic regimes. These observations indicate that the bathymetric step/hydraulic transition is responsible for the near-field plume transformation followed by the lower effect of bathymetric roughness. Because outflow density depends on Gulf warming and evaporation, modest climatic shifts may alter outflow dynamics, its detachment depth, pathway geometry, and intermediate-depth ventilation of the Arabian Sea OMZ.
Versions
Related
- Satellite-derived bathymetry of Arabian Gulf ports under leakage-free validation: a multi-site benchmark of empirical, machine-learning and deep-learning models against 285,000 multibeam soundings, with an outlook for UAE waters
- Integrative taxonomy reveals a new species, Anadara adiastola sp. nov. (Bivalvia, Arcidae) from the northern Arabian/Persian Gulf, north-western Indian Ocean.
- Current dynamics, drivers, and vertical thermal structure around Sir Bu Nair Island (Arabian/Persian Gulf)
- A drifting GPS buoy for retrieving effective riverbed bathymetry
- Calibration Is Not Enough: TAP-Bathy v1.0, a Three-Axis Protocol for Evaluating Spatial Uncertainty in Bathymetry
BibTeX
@article{abdelmaksoud2026hydrographic,
title = {{Hydrographic transformation of the Persian/Arabian Gulf outflow over rough shelf bathymetry in the Gulf of Oman}},
author = {Ahmed Abdelmaksoud and Aisha H. Al-Suwaidi and Gerd Bruss and Kaveh Samimi-Namin and Mohammed Y. Ali},
journal = {Ocean Science},
year = {2026},
month = oct,
doi = {10.5194/os-22-3369-2026},
url = {https://os.copernicus.org/articles/22/3369/2026/},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Hydrographic transformation of the Persian/Arabian Gulf outflow over rough shelf bathymetry in the Gulf of Oman
AU - Ahmed Abdelmaksoud
AU - Aisha H. Al-Suwaidi
AU - Gerd Bruss
AU - Kaveh Samimi-Namin
AU - Mohammed Y. Ali
PY - 2026
DA - 2026/10/22
JO - Ocean Science
DO - 10.5194/os-22-3369-2026
UR - https://os.copernicus.org/articles/22/3369/2026/
AB - Hypersaline overflows from marginal seas contribute to global ocean circulation and climate variability. The Persian/Arabian Gulf (P/AG) contributes dense, saline, oxygenated deep outflow into the Arabian Sea's Oxygen Minimum Zone (OMZ). Here, we present high-resolution hydrographic mapping of the United Arab Emirates-Oman margin in the northwestern Arabian Sea, integrating conductivity-temperature-depth profiles, multibeam bathymetry and remotely-operated vehicle imagery. The P/AG outflow forms a thin (10–30 m) bottom-attached layer that, on crossing an abrupt bathymetric step, undergoes a hydraulic transition and thickens to 200 m over the rough, irregular seafloor of the unstable shelf, where dilution and loss of bottom contact occur. Near-bottom salinity, oxygen, and pH decrease systematically downstream in association with enhanced mixing. Distinct benthic assemblages coincide with attached versus detached flow sectors, consistent with differing near-bed hydrodynamic regimes. These observations indicate that the bathymetric step/hydraulic transition is responsible for the near-field plume transformation followed by the lower effect of bathymetric roughness. Because outflow density depends on Gulf warming and evaporation, modest climatic shifts may alter outflow dynamics, its detachment depth, pathway geometry, and intermediate-depth ventilation of the Arabian Sea OMZ.
SN - 1812-0792
ER -