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