Sea-air CO₂ flux estimated from SOCAT surface-ocean CO₂ partial pressure data and atmospheric CO₂ mixing ratio data

Christian Rödenbeck (1) , Ralph F. Keeling (2) , Dorothee C. E. Bakker (3) , Nicolas Metzl (4) , Are Olsen (5, 6, 7) , Christopher L. Sabine (7) , M. Heimann (8)

1 MPI-BGC - Max-Planck-Institut für Biogeochemie
2 SIO - UC San Diego - Scripps Institution of Oceanography
3 School of Environmental Sciences [Norwich]
4 PHYBIOCAR - Couplage physique-biogéochimie-carbone
5 IMR - Institute of Marine Research [Bergen]
6 BCCR - Bjerknes Centre for Climate Research
7 PMEL - NOAA Pacific Marine Environmental Laboratory [Seattle]
8 MPI-BGC - Max Planck Institute for Biogeochemistry

Surface-ocean CO₂ partial pressure data have been assimilated into a simple diagnostic model of surface-ocean biogeochemistry to estimate the spatio-temporal CO₂ partial pressure field and ultimately the sea-air CO₂ fluxes. Results compare well with the widely used monthly climatology by Takahashi et al. (2009) but also contain some short-term and interannual variations. Fitting the same model to atmospheric CO₂ data yields less robust but consistent estimates, confirming that using the partial pressure based estimates as ocean prior in atmospheric CO₂ inversions may improve land CO₂ flux estimates. Estimated seasonality of ocean-internal carbon sources and sinks is discussed in the light of observed nutrient variations.

Domaines: Géophysique [physics.geo-ph]; Géophysique [physics.geo-ph]; Milieux et Changements globaux

Christian Rödenbeck, Ralph F. Keeling, Dorothee C. E. Bakker, Nicolas Metzl, Are Olsen, et al.. Sea-air CO₂ flux estimated from SOCAT surface-ocean CO₂ partial pressure data and atmospheric CO₂ mixing ratio data. Ocean Science Discussions, 2012, 9, pp.2273-2326. ⟨10.5194/OSD-9-2273-2012⟩. ⟨hal-00784582⟩