Notes

Outline

OUTLINE Anthropogenic Transient Historic Future Response to Perturbations Southern Ocean  Low latitudes Mitigation Fertilization Deep injection Biological Response to Warming Other?

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Predicting the Ocean Carbon Sink Ocean models and observations agree on historical uptake, but differ on regional details. Predictions diverge with time. Impact of future biological and ocean circulation changes is speculative (we do not yet understand the ice age behavior)

Box vs. GCM

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Iron Fertilization

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Model Scenarios of Patch Fertilization Assume: Iron addition results in stripping out of nutrients Simulations: Location of fertilization: Eastern Equatorial Pacific at 2.2°S, 110°W Area of fertilization: One model grid cell (4°x4° = 200,000 km2) Length of time: one month (September) Cases considered: CASE 1 - Iron added & lost (probably most realistic) with (a) shallow regeneration of organic matter & (b) bottom regeneration of organic matter. CASE 2 - Iron & macronutrients added & retained (upper limit) with (a) shallow regeneration of organic matter & (b) bottom regeneration of organic matter.

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Deep Injection

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Global Warming Response

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Global Mean Response of Model Physics to Global Warming (2040-2060)

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CONCLUSIONS Anthropogenic Transient Historic - MAINLY PHYSICS A better sense of range of model behavior Data show many models are wrong Model improvement is urgent Future - PHYSICS & BIOLOGY Wide range in physical response Biological contribution highly speculative

CONCLUSIONS Response to Perturbations Two new ice age hypotheses (THE ONGOING SAGA) Southern Ocean HYPOTHESIS: reduced AABW influence Fertilization out/air-sea equilibration in Real ocean more like box  models (high sensitivity) than GCMs (low sensitivity)  Low latitudes HYPOTHESIS: SAMW-SiO2/CaCO3 iron fertilization scenario fertilization in Real ocean more like GCMs (high sensitivity) than box models (low sensitivity)

CONCLUSIONS Mitigation - Need for a “truth squad” Fertilization Deep injection Biological Response to Warming - The big unknown Other? - eddies, variability (seasonal & interannual), margins