Physical processes and biological productivity in the upwelling regions of the tropical Atlantic
<p>In this paper, we review observational and modelling results on the upwelling in the tropical Atlantic between 10<span class="inline-formula"><sup>∘</sup></span> N and 20<span class="inline-formula"><sup>∘</sup></span> S. W...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2023-05-01
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| Series: | Ocean Science |
| Online Access: | https://os.copernicus.org/articles/19/581/2023/os-19-581-2023.pdf |
| Summary: | <p>In this paper, we review observational and modelling results on the
upwelling in the tropical Atlantic between 10<span class="inline-formula"><sup>∘</sup></span> N and 20<span class="inline-formula"><sup>∘</sup></span> S. We focus on the physical processes that drive the seasonal variability of
surface cooling and the upward nutrient flux required to explain the seasonality
of biological productivity. We separately consider the equatorial upwelling
system, the coastal upwelling system of the Gulf of Guinea and the tropical
Angolan upwelling system. All three tropical Atlantic upwelling systems have
in common a strong seasonal cycle, with peak biological productivity during
boreal summer. However, the physical processes driving the upwelling vary
between the three systems. For the equatorial regime, we discuss the wind
forcing of upwelling velocity and turbulent mixing, as well as the underlying
dynamics responsible for thermocline movements and current structure. The
coastal upwelling system in the Gulf of Guinea is located along its northern
boundary and is driven by both local and remote forcing. Particular emphasis
is placed on the Guinea Current, its separation from the coast and the shape
of the coastline. For the tropical Angolan upwelling, we show that this
system is not driven by local winds but instead results from the combined
effect of coastally trapped waves, surface heat and freshwater fluxes, and
turbulent mixing. Finally, we review recent changes in the upwelling systems
associated with climate variability and global warming and address possible
responses of upwelling systems in future scenarios.</p> |
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| ISSN: | 1812-0784 1812-0792 |