Satellite-Based Analysis of Coastal Upwelling Variability and a Novel Index: Case Studies of the Moroccan Atlantic Coast and the Californian Coast

This study examines the variability of upwelling along eastern boundaries, specifically focusing on two upwelling systems in the northern hemisphere: the Moroccan Atlantic coast and the Californian coast. In this study, we use a specialized archive that is both highly efficient and robust. The archive is specifically designed to tackle the challenge of detecting upwelling phenomena in satellite data. We ensure accurate and reliable results by prioritizing cloud processing in upwelling zones and questionable pixels. The description and analysis of upwelling dynamics from 2000 to 2019 include the interannual and seasonal variability, which are examined using different upwelling indices. Furthermore, this study proposes a novel index to evaluate the agreement between Sea Surface Temperature (SST) and Chlorophyll-a concentration (Chl-a) as indicators of upwelling. This index successfully captures the relationship between biological and physical components at various spatio-temporal scales, indicating its potential for use in other upwelling systems.