Variability of the ocean mixed layer depth and the upwelling activity in the Cape Bojador, Morocco

This study examines the seasonality of the patterns of the ocean mixed layer depth (MLD) with the coastal upwelling system, using a model data from marine Copernicus with a resolution of 0.083° × 0.083°. For that, we examined wind forcing, ocean circulation, sea surface temperature, sea surface salinity, sea surface chlorophyll-a, and mixed layer depth seasonality from 2007 to 2017 in the Cape Bojador south of the Moroccan Atlantic coast. We observed that in the fall season the wind speed was low, and the maximum wind speed is in the summer season. Furthermore, we found that coastal areas are related to a generally shallower MLD all the year in the Cape. We also proved that the source of the upwelling is between 25 and 26°N. However, we observed that the sea surface chlorophyll concentration in the same region is minimum, while in the region between 24.5 and 22°N, the CHL-a is maximum. We suggested that the biological richness in Cape Bojador, due to the activity of upwelling, derives to the south because of the northward ocean filament. Despite the different physical and biological parameters used to detect upwelling activity, we found that upwelling detection based on sea surface temperature is the best method to describe the upwelling activity in this region.