Oceanic sources, sinks, and transport of atmospheric CO2
Figure S1: Contemporary flux estimates of each of the 10 models that participated in the Ocean Inversion Project. (319.5Kb)
Figure S2: Comparison of the contemporary air-sea fluxes estimated by the ocean inversion with the estimates based on three editions of the pCO2 climatology. (274.6Kb)
Table S1: Inverse estimates of the air-sea fluxes of natural, anthropogenic, and river derived CO2 for the 23 regions resolved by the ocean inversion (see Figure 1 in main text). (6.320Kb)
Mikaloff Fletcher, Sara E.
Doney, Scott C.
Follows, Michael J.
Jacobson, Andrew R.
Muller, Simon A.
Sarmiento, Jorge L.
MetadataShow full item record
We synthesize estimates of the contemporary net air-sea CO2 flux on the basis of an inversion of interior ocean carbon observations using a suite of 10 ocean general circulation models (Mikaloff Fletcher et al., 2006, 2007) and compare them to estimates based on a new climatology of the air-sea difference of the partial pressure of CO2 (pCO2) (Takahashi et al., 2008). These two independent flux estimates reveal a consistent description of the regional distribution of annual mean sources and sinks of atmospheric CO2 for the decade of the 1990s and the early 2000s with differences at the regional level of generally less than 0.1 Pg C a−1. This distribution is characterized by outgassing in the tropics, uptake in midlatitudes, and comparatively small fluxes in thehigh latitudes. Both estimates point toward a small (∼ −0.3 Pg C a−1) contemporary CO2 sink in the Southern Ocean (south of 44°S), a result of the near cancellation between a substantial outgassing of natural CO2 and a strong uptake of anthropogenic CO2. A notable exception in the generally good agreement between the two estimates exists within the Southern Ocean: the ocean inversion suggests a relatively uniform uptake, while the pCO2-based estimate suggests strong uptake in the region between 58°S and 44°S, and a source in the region south of 58°S. Globally and for a nominal period between 1995 and 2000, the contemporary net air-sea flux of CO2 is estimated to be −1.7 ± 0.4 Pg C a−1 (inversion) and −1.4 ± 0.7 Pg C a−1 (pCO2-climatology), respectively, consisting of an outgassing flux of river-derived carbon of ∼+0.5 Pg C a−1, and an uptake flux of anthropogenic carbon of −2.2 ± 0.3 Pg C a−1 (inversion) and −1.9 ± 0.7 Pg C a−1 (pCO2-climatology). The two flux estimates also imply a consistent description of the contemporary meridional transport of carbon with southward ocean transport throughout most of the Atlantic basin, and strong equatorward convergence in the Indo-Pacific basins. Both transport estimates suggest a small hemispheric asymmetry with a southward transport of between −0.2 and −0.3 Pg C a−1 across the equator. While the convergence of these two independent estimates is encouraging and suggests that it is now possible to provide relatively tight constraints for the net air-sea CO2 fluxes at the regional basis, both studies are limited by their lack of consideration of long-term changes in the ocean carbon cycle, such as the recent possible stalling in the expected growth of the Southern Ocean carbon sink.
Author Posting. © American Geophysical Union, 2009. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Global Biogeochemical Cycles 23 (2009): GB1005, doi:10.1029/2008GB003349.
Showing items related by title, author, creator and subject.
Allochthonous sources and dynamic cycling of ocean dissolved organic carbon revealed by carbon isotopes Zigah, Prosper; McNichol, Ann P.; Xu, Li; Johnson, Carl G.; Santinelli, Chiara; Karl, David M.; Repeta, Daniel J. (John Wiley & Sons, 2017-03-07)We present concentration and isotopic profiles of total, size, and polarity fractionated dissolved organic carbon (DOC) from Station ALOHA (A Long-term Oligotrophic Habitat Assessment), an oligotrophic site in the North ...
Combined carbonate carbon isotopic and cellular ultrastructural studies of individual benthic foraminifera : method description Martin, Jonathan B.; Bernhard, Joan M.; Curtis, Jason H.; Rathburn, Anthony E. (American Geophysical Union, 2010-06-11)Carbon isotopes of foraminiferal tests provide a widely used proxy for past oceanographic environmental conditions. This proxy can be calibrated using live specimens, which are reliably identified with observations of cell ...
Carbon-nitrogen interactions regulate climate-carbon cycle feedbacks : results from an atmosphere-ocean general circulation model Thornton, Peter E.; Doney, Scott C.; Lindsay, Keith; Moore, J. Keith; Mahowald, Natalie M.; Randerson, James T.; Fung, Inez Y.; Lamarque, J.-F.; Feddema, J. J.; Lee, Y.-H. (Copernicus Publications on behalf of the European Geosciences Union, 2009-10-08)Inclusion of fundamental ecological interactions between carbon and nitrogen cycles in the land component of an atmosphere-ocean general circulation model (AOGCM) leads to decreased carbon uptake associated with CO2 ...