The Advection of Submesoscale Thermal Features in the Alboran Sea Gyre

Abstract NOAA-7 infrared and Nimbus-7 multi-spectral visible imagery of the Alboran Sea collected as part of the “Donde Va?” experiment during the period 6–20 October, show the advection of submesoscale cold-water features about the Alboran Sea Gyre. Continuous monitoring of thew cold-water features using satellite imagery is possible because of the twice-daily (every 12 h) spacing of the NOAA-7 coverage of the area. After registration to a Mercator projection and atmospheric correction, analysis of the displacement of the cold-water features in successive images shows their apparent origin to be just east of Gibraltar, their movement at average speeds of 0.4 m s−1 around the Gyre and their apparent re-entrainment into the incoming Atlantic water east of Gibraltar. The Nimbus-7 CZCS imagery supplements the analysis by adding details of the movement and the theory on where the cold-water features originate. During the 15-day period, nine cold-water features were thermally distinct enough to be tracked for ...