Influence of Rossby waves on primary production from a coupled physical-biogeochemical model in the North Atlantic Ocean

Rossby waves appear to have a clear signature on surface chlorophyll concentrations which can be explained by a combination of vertical and horizontal mechanisms. In this study, we investigate the role of the different physical processes in the north Atlantic to explain the surface chlorophyll signa...

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Bibliographic Details
Main Authors: G. Charria, I. Dadou, P. Cipollini, M. Drévillon, V. Garçon
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2008
Subjects:
geo
Online Access:http://www.ocean-sci.net/4/199/2008/os-4-199-2008.pdf
https://doaj.org/article/66a704e03c0f4751b1c90086837c6bda
Description
Summary:Rossby waves appear to have a clear signature on surface chlorophyll concentrations which can be explained by a combination of vertical and horizontal mechanisms. In this study, we investigate the role of the different physical processes in the north Atlantic to explain the surface chlorophyll signatures and the consequences on primary production, using a 3-D coupled physical/biogeochemical model for the year 1998. The analysis at 20 given latitudes, mainly located in the subtropical gyre, where Rossby waves are strongly correlated with a surface chlorophyll signature, shows the important contribution of horizontal advection and of vertical advection and diffusion of inorganic dissolved nitrogen. The main control mechanism differs according to the biogeochemical background conditions of the area. The surface chlorophyll anomalies, induced by these physical mechanisms, have an impact on primary production. We estimate that Rossby waves induce, locally in space and time, increases (generally associated with the chlorophyll wave crest) and decreases (generally associated with the chlorophyll wave trough) in primary production, ~±20% of the estimated background primary production. This symmetrical situation suggests a net weak effect of Rossby waves on primary production.