Work

Hydrographic transformation of the Persian/Arabian Gulf outflow over rough shelf bathymetry in the Gulf of Oman

Year: 2026

Type: article

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 UAE-Oman margin in the northwestern Arabian Sea, integrating CTD profiles, multibeam bathymetry and ROV imagery. The P/AG outflow forms a thin bottom-attached layer that thickens dramatically 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 bathymetric roughness controls the near-field transformation of the outflow. Because outflow density depends on Gulf warming and evaporation, modest climatic shifts may alter detachment depth, pathway geometry, and intermediate-depth ventilation of the Arabian Sea OMZ.

Source: Ocean science

DOI: 10.5194/os-22-3369-2026

Authors: Ahmed Abdelmaksoud, Aisha H. Al-Suwaidi, Gerd Bruss, Kaveh Samimi-Namin, Mohammed Y. Ali

Institutions: Khalifa University of Science and Technology, Sultan Qaboos University, Naturalis Biodiversity Center, Natural History Museum, University of Oxford

Language: English

Topic: Oceanographic and Atmospheric Processes

Subfield: Oceanography

Field: Earth and Planetary Sciences

Domain: Physical Sciences

SDG: Life below water

Open Access status: gold

Estimated APC paid: $1,412