Water masses and mixing processes off Northwest Africa

Abstract

The environment of the Canary Islands is defined by its oceanographic characteristics. Canary Current (CC) is the main water stream flowing through them. This current is an Eastern Boundary Current (EBC) near to northwest African upwelling system. This research analyses mesoscale structures related to this current and water mixing processes associated with they, using data obtained in BIOCAN98, a cruise performed in September 1998. This work completes the results of other works done with the same data, such as Bode et al. (2001), Hernández-Guerra et al. (2001) and González- Dávila et al. (2006), which have been taken as a reference for this study. Multiparametric methods has been applied for the study of water masses distribution and their mixing percentages in the study region. The mixing processes has been studied below the Mixed Layer Depth (MLD), which has been obtained using the method of Holte and Talley (2009). Parameters as Turner angle (Tu), turbulent diffusion coefficients and the density ratio, have been calculated showing variable values of the turbulent diffusion coefficients in the region. Also, an intrathermocline eddy associated with the upwelling filament has been detected, similar to recently identify by Sangrà et al. (2015) in Cabe Ghir Filament.