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What drives the seasonality of air-sea CO2 fluxes in the ice-free zone of the Southern Ocean: A 1D coupled physical-biogeochemical model approach


Pasquer, B and Metzl, N and Goosse, H and Lancelot, C, What drives the seasonality of air-sea CO2 fluxes in the ice-free zone of the Southern Ocean: A 1D coupled physical-biogeochemical model approach, Marine Chemistry, 177 pp. 554-565. ISSN 0304-4203 (2015) [Refereed Article]

Copyright Statement

Copyright 2015 Elsevier B.V.

DOI: doi:10.1016/j.marchem.2015.08.008


The complex biogeochemical SWAMCO-3 model has been used to assess the response of the ice-free Southern Ocean to the physical and biological mechanisms governing air-sea CO2 exchanges. For this application, the model explicitly details the dynamics of three Phytoplankton Functional Types (PFTs) of importance for C, N, P, Si, Fe cycling and air-sea CO2 exchange in this area. These are the diatoms, the pico-nanophytoplankton and the coccolithophores whose growth regulation by light, temperature and nutrients has been obtained from a literature review of phenomenological observations available for these PFTs. The performance of the SWAMCO-3 model coupled to a vertical one-dimensional physical model was first assessed at the location of the JGOFS time-series station KERFIX. The model was able to reproduce a mean seasonal cycle based on years where a maximum of chemical and biological observations are available at this location (1993-1994, 1994-1995, 1998-1999 and 2000-2001). Ocean fCO2 in equilibrium with the atmosphere are simulated both in Austral winter associated with surface layer replenishment in DIC due to deep vertical mixing and in late summer as a consequence of the warming effect on the carbonate system. A clear under-saturation is found in spring/summer. Analysis of the modelled seasonal biogeochemical and physical features shows that thermodynamical conditions are driving the air-sea exchange of CO2 in the region, while the biological activity under the control of light and iron availability, is responsible for the predicted relatively modest annual carbon sink (-0.9 mol C m-2 y-1).

Item Details

Item Type:Refereed Article
Keywords:biogeochemical modelling, Southern Ocean, air–seas CO2 fluxes, seasonality
Research Division:Earth Sciences
Research Group:Atmospheric sciences
Research Field:Atmospheric dynamics
Objective Division:Environmental Management
Objective Group:Air quality, atmosphere and weather
Objective Field:Atmospheric processes and dynamics
UTAS Author:Pasquer, B (Dr Benedicte Pasquer)
ID Code:110754
Year Published:2015
Web of Science® Times Cited:4
Deposited By:Integrated Marine Observing System
Deposited On:2016-08-11
Last Modified:2017-11-06

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