HR: 11:35h
AN: A12B-06    [Abstracts]
TI: On the Robustness of Air-Sea Flux Estimates of Carbon Dioxide from Ocean Inversions
AU: * Mikaloff Fletcher, S E
EM: fletcher@igpp.ucla.edu
AF: Department of Atmospheric and Oceanic Sciences, The University of California, 5839 Slichter Hall, Los Angeles, CA 90095 United States
AU: Gruber, N P
EM: ngruber@igpp.ucal.edu
AF: Department of Atmospheric and Oceanic Sciences, The University of California, 5839 Slichter Hall, Los Angeles, CA 90095 United States
AU: Jacobson, A
EM: andyj@splash.princeton.edu
AF: Department of Atmospheric and Oceanic Sciences, Princeton, PO Box CN710, Princeton, NJ 08544-0710 United States
AU: Doney, S
EM: sdoney@whoi.edu
AF: Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, 360 Woods Hole Road, Woods Hole, MA 02543-1543 United States
AU: Dutkiewicz, S
EM: stephd@ocean.mit.edu
AF: Department of Earth, Atmosphere, and Planetary Sciences, Massachussets Institute of Technology, 54-1412, 77 Massachusetts Avenue, Cambridge, MA 02139 United States
AU: Follows, M
EM: mick@ocean.mit.edu
AF: Department of Earth, Atmosphere, and Planetary Sciences, Massachussets Institute of Technology, 54-1412, 77 Massachusetts Avenue, Cambridge, MA 02139 United States
AU: Lindsay, K
EM: klindsay@ucar.edu
AF: Climate and Global Dynamics, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307 United States
AU: Menemenlis, D
EM: menemenlis@jpl.nasa.gov
AF: Jet Propulsion Laboratory, MS 300-323, 4800 Oak Grove Dr, Pasedena, CA 91109 United States
AU: Mouchet, A
EM: A.Mouchet@ulg.ac.be
AF: Astrophysics and Geophysics Institute, University of Liege, All{\'e}e du 6 Ao{\^u}t, 17 Bƒt. B5c, Liege, B 4000 Belgium
AB: Inverse methods analogous to those used for atmospheric inversions have been adapted to estimate regional air-sea fluxes of carbon dioxide using ocean interior observations of dissolved inorganic carbon and related tracers and an Ocean General Circulation Model (OGCM). We estimate seperately the preindustrial component and the component due to the anthropogenic perturbation of atmospheric carbon dioxide. Previous sensitivity studies have shown that model circulation is one of the most important sources of error in the ocean inversion. We present estimates of preindustrial and anthropogenic air-sea carbon dioxide exchange using a suite of nine different OGCM's in order to quantify the robustness of our results and explore the role of different representations of ocean circulation in the inversion. Most of the large scale features of the inverse estimates are robust across all models. The preindustrial inverse estimates generally follow the expected pattern of uptake at high latitudes and out gassing in the tropics; however, all of the models call for out gassing in the Southern Ocean between 44S and 58 S. The greatest anthropogenic carbon uptake occurs at mid- to high- latitudes, with a large anthropogenic carbon sink in the Southern Ocean, while the bulk of the anthropogenic carbon storage occurs at mid-latitudes. Preliminary results also suggest interesting, robust differences between these inverse estimates and estimates from forward model simulations. Both the preindustrial and anthropogenic carbon dioxide flux estimates are most robust at mid and high northern latitudes, except for the high latitude North Atlantic. The carbon dioxide flux estimates are most uncertain in the Southern Ocean, where the inverse estimates are strongly dependent on the rates of deep water ventilation in the OGCM. The preindustrial inverse estimates for the Indian Ocean are also sensitive to the choice of OGCM, and the anthropogenic estimates have significant uncertainties in the tropical Pacific. Over large spatial scales, inverse estimates based on different OGCM's are in better agreement than estimates based on forward simulations of the same models, but this is not necessarily true for smaller model regions.
UR: http://quercus.igpp.ucla.edu/OceanInversion
DE: 4806 Carbon cycling
DE: 4842 Modeling
DE: 1615 Biogeochemical processes (4805)
DE: 0312 Air/sea constituent fluxes (3339, 4504)
DE: 0322 Constituent sources and sinks
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting