EGU25-18521, updated on 15 Mar 2025
https://doi.org/10.5194/egusphere-egu25-18521
EGU General Assembly 2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
 Interannual variability of net primary productivity in the Northwest African coastal upwelling system and their relation to Dakar Niños and Niñas.
Rodrigue Anicet Imbol Koungue1, Arthur Prigent2, Joke Lübbecke1, and Peter Brandt1,3
Rodrigue Anicet Imbol Koungue et al.
  • 1GEOMAR Helmholtz Centre for Ocean Research Kiel, FB1 / Physical Oceanography, Kiel, Germany (rimbol@geomar.de)
  • 2Earth System Physics, The Abdus Salam International Centre for Theoretical Physics, Trieste, Italy
  • 3Faculty of Mathematics and Natural Sciences, Kiel University, Kiel, Germany

The Canary upwelling system, located along the Northwest African coast between approximately 10ºN and 35ºN, is among the most productive marine ecosystems globally. It supports rich marine biodiversity and sustains economically significant fisheries. Notably, the coastal regions off Mauritania and Senegal (9ºN–22ºN), comprising the southern part of this system, exhibit pronounced interannual variability in net primary production (NPP). This variability is influenced by extreme warm and cold events, known as Dakar Niños and Niñas, respectively. In this study, we analyze the physical mechanisms driving the interannual variability of NPP from 2003 to 2022, using a combination of satellite observations, reanalysis data, and ocean model outputs. Our results indicate that the interannual variability of NPP is closely linked to changes in sea surface temperature (SST), with the most pronounced effects occurring during February-March-April, i.e. the main upwelling season. A total of six previously undocumented episodes of strong anomalous coastal high and low NPP were identified, nearly all of which are associated with Dakar Niños and Niñas. Our findings suggest that these events are linked to both local and remote forcing mechanisms. The local forcing is associated with variations of the coastal alongshore winds. The remote forcing involves the propagations of coastal trapped waves, triggered by wind fluctuations in the Gulf of Guinea, or by wind-forced equatorial Kelvin waves originating in the western-to-central equatorial Atlantic. Additional remote influences may stem from large-scale climate modes, including the El Niño-Southern Oscillation (ENSO), the North Atlantic Oscillation (NAO), and the Atlantic Meridional Mode (AMM).

How to cite: Imbol Koungue, R. A., Prigent, A., Lübbecke, J., and Brandt, P.:  Interannual variability of net primary productivity in the Northwest African coastal upwelling system and their relation to Dakar Niños and Niñas., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18521, https://doi.org/10.5194/egusphere-egu25-18521, 2025.