kohfeld dust ocean co2

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Dust impact on marine biota and atmospheric CO2 in glacial periods L. Bopp1, 2, K. E. Kohfeld 2, C. Le Quéré2, O. Aumont3 1 LSCE, Saclay, France 2 MPI-Biogeochemistry, Jena, Germany 3 LODC, Paris, France With Contributions from: MAGIC Project Green Ocean Project Paleoceanographic Data Community (Bopp et al., submitted, Paleoceanography)

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Glacial Dust and Atmospheric CO2? Petit et al., 1999; 2001

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Impact of Glacial Dust on Modern Ocean Total Atm CO2 drawdown = 15 ppm

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Forcing during the Last Glacial Maximum • Circulation Changes (Simulation OPA O. Marti) • Increased Sea -Ice in Winter (Crosta et al. 98) • Cooling of SST, from CLIMAP (1981)

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Glacial Paleoproduction Indicators Compared to Today

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Glacial – Modern Difference, Ocean Carbon Export Total Atmospheric CO2 Drawdown = 30 ppm gC/m2/y

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Summary Paleo-Data Comparison: Basic Patterns Correct

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DATA DEVELOPMENT: More Data in BLUE regions! (Semi) Quantification of fluxes Different Proxies Ocean Biota Types Geochemical Tracers Future Work: Conserve Patterns, but change amplitudes MODEL DEVELOPMENT: Incorporate new processes N-fixation Sediment diagenesis Coastal / Physical Ocean