Spatial and temporal seasonal trends in coastal upwelling off Northwest Africa, 1981-2012

摘要: Seasonal coastal upwelling was analyzed along the NW African coastline (11-35°N) from 1981 to 2012. Upwelling magnitudes are calculated by wind speed indices, sea-surface temperature indices and inferred meteorological station, height vertical water column transport data. A permanent annual regime is documented across 21-35°N a seasonal 12-19°N, in accordance with climatology of previous studies. regions were split into three zones: (1) Mauritania-Senegalese zone (12-19°N), (2) strong (21-26°N) (3) weak (26-35°N). We find compelling evidence our various for Bakun intensification hypothesis due significant summer increase, resulting an increase upwelling-favorable speeds north 20°N downwelling-favorable winds south 20°N. The North Atlantic Oscillation plays leading role modifying interannual variability during other seasons (autumn-spring), its influence dominating winter. East pattern shows correlation spring, while El NiA±o Southern Multi-decadal teleconnections not found. disagreement between observationally-based products reanalysis-derived data explored. modification Africa presented, which accounts latitudinal divide regimes. © 2014 Authors.