The Western Alboran Gyre helps ventilate the Western Mediterranean Deep Water through Gibraltar

Variable properties of the Mediterranean outflow and the variability of the Western Alboran Gyre are analyzed by means of 5-year long time series of near bottom potential temperature at Espartel sill in the Strait of Gibraltar and altimetry data in the Alboran Sea. Geostrophic velocity at the southern edge of the gyre and potential temperature at Espartel sill are significantly correlated (correlation coefficient 0.67), suggesting that the intensification of the Alboran Gyre favors the ventilation of Western Mediterranean Deep Water. The analysis of historical temperature profiles shows that Western Mediterranean Deep Water in the Alboran Sea can be suctioned from a layer between 500 and 700 m depth for typical changes of the gyre intensification.

► We examine a long time series of potential temperature near the bottom in the Strait of Gibraltar.
► We examine the variability of the Western Alboran Gyre looking at geostrophic velocities.
► The Western Alboran Gyre helps ventilate Western Mediterranean Deep Water trough Gibraltar.
► A numerical experiment clarifies the whole circulation.