SEASONAL VARIABILITY OF THE OCEAN MIXED LAYER DEPTH INMOROCCAN UPWELLING AREAS DERIVED FROM IN SITU PROFILES.

Abstract

The determination of the ocean mixed layer depth (MLD), in relationship with the upwelling phenomenon, is important to a wide variety of oceanic investigations including ocean productivity, air-sea exchange processes, and long-term climate change. The MLD can be estimated using different methods including the threshold value criteria or the gradient method. The aim of this study was to create scripts combining both approaches using an optimal threshold value 0.5 °C of the temperature relative to the surface and a maximum gradient of each parameter temperature and density determined depending on its profile in water column. Moreover, we used surface distributions of Temperature, salinity, oxygen and Fluorescence in sea surface to detect the upwelling activity. The CTD data was collected along the Atlantic coast of Morocco during the winter season of 2011/2012 and the summer season of 2012. Our results revealed high seasonal variability of the MLD. The MLD is generally much deeper in winter as compared to summer all over the Atlantic coast of Morocco following the spatial and temporal variability of the upwelling phenomenon. Copy Right, IJAR, 2017,. All rights reserved.