Publication Date:
2012-02-17
Description:
We assess the role of riverine inputs of N, Si, Fe, organic and inorganic C in the tropical Atlantic Ocean using a global ocean biogeochemistry model. We use two sensitivity tests to investigate the role of the western (South American Rivers) and eastern (African Rivers) riverine nutrient inputs on the tropical Atlantic Ocean biogeochemistry (between 20° S–20° N and 70° W–20°). Increased nutrient availability from river inputs in this area (compared to an extreme scenario with no river nutrients) leads to an increase in 14 % (0.7 Pg C a−1) in open ocean primary production (PP), and 21 % (0.2 Pg C a−1) in coastal ocean PP. We estimate very modest increases in open and coastal ocean export production and sea-air CO2 fluxes. Results suggest that in the tropical Atlantic Ocean, the large riverine nutrient inputs on the western side have a larger impact on primary production and sea-air CO2 exchanges. On the other hand, African river inputs, although smaller than South American inputs, have larger impact on the coastal and open tropical Atlantic Ocean export production. This is probably due to a combination of nutrient trapping in upwelling areas off the Congo River outflow, and differences in delivered nutrient ratios leading to alleviation in limitation conditions mainly for diatoms.
Print ISSN:
1810-6277
Electronic ISSN:
1810-6285
Topics:
Biology
,
Geosciences
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