Small-scale variability of the current in the Strait of Bonifacio

Abstract

International audienceCurrent dynamics in the Strait of Bonifacio (south Corsica) were investigated at a small scale during the STELLAMARE1 multidisciplinary cruise in summer 2012, using in situ measurements and modeling data. The Strait of Bonifacio is a particularly sensitive marine area in which specific conservation measures have been taken to preserve the natural environment and wild species. Good knowledge of the hydrodynamics in this area is essential to optimize the Marine Protected Area’s management rules. Therefore, we used a high-resolution model (400 m) based on the MARS3D code to investigate the main flux exchanges and to formulate certain hypotheses about the formation of possible eddy structures. The aim of the present paper is first to synthetize the results obtained by combining Acoustic Doppler Current Profiler data, hydrological parameters, Lagrangian drifter data, and satellite observations such as MODIS OC5 chlorophyll a data or Metop-A AVHRR Sea Surface Temperature (SST) data. These elements are then used to validate the presence of the mesoscale eddies simulated by the model and their recurrence outside the cruise period. To complete the analysis, the response of the 3D hydrodynamical model was evaluated under two opposing wind systems and certain biases were detected. Strong velocities up to 1 m s−1 were recorded in the east part due to the Venturi effect; a complementary system of vortices governed by Coriolis effect and west wind was observed in the west part, and horizontal stratification in the central part has been identified under typical wind condition

Evaluation of <em>Homarus gammarus</em> (Crustacea: Decapoda: Nephropidae) catches and potential in a Mediterranean small-scale fishery

“…The spatial approach identified an area of high abundance in the south, precisely in the Strait of Bonifacio. In the south of the island, potentially suitable habitats for adults coupled with (i) a considerable larval pool from the Bonifacio Strait Natural Reserve (Santoni et al 2008), (ii) favourable early life history traits such as short pelagic larval duration (Bennet et al 1993, Goñi and Latrouite 2005, Øresland and Ulmestrand 2013 and (iii) advantageous hydrological features such as eddies (Gérigny et al 2015) could explain the high abundance of the European lobster. For H. gammarus, larval self-recruitment mechanisms have already been discussed (Schmalenbach andBuchholz 2010, Øresland andUlmestrand 2013).…”

Climate change signal in the ocean circulation of the Tyrrhenian Sea

“…10A). The strongest wind speeds occur to the east side of Sardinia and Bonifacio straits, due to wind funneling (see e.g., Gérigny et al, 2015). These areas of enhanced wind speed coincide with those where the main dynamical structures are found (see Figs.…”

Coastal sea level rise at Senetosa (Corsica) during the Jason altimetry missions

“…Abrupt changes were considered spurious and removed (Birol el al., 2017). This strategy has proved to be very efficient in recovering a significant amount of valid altimeter measurements that were otherwise flagged in the standard GDR products (Jebri et al, 2016). In a second step, all corrections were recomputed at the 20 Hz high rate using only the valid data through interpolation/extrapolation methods.…”