ClimaTea Lecture: "Oceanic outgassing of CO2 during the last deglaciation: Is radiocarbon evidence consistent with a deep Pacific source?"

Speaker: Dr. David Lund (University of Connecticut - Avery Point)

Abstract: 

The deep Pacific Ocean is the largest reservoir of readily exchangeable carbon on Earth.  Reconstructions of deep Pacific ventilation rate are therefore key to understanding the ocean's role in glacial-interglacial CO2 cycles.  High resolution radiocarbon data spanning 5 to 25 kyr BP will be presented and different ventilation age methods will be discussed.  Both projection age and transit time distribution results suggest that ventilation ages increased during the last deglaciation, implying the deep Pacific was an unlikely source of carbon to the atmosphere.  The ventilation age signal was likely driven by a shift in the initial 14C content of water entering the Pacific basin, perhaps related to weakening of the Atlantic Meridional Overturning Circulation.

Please see attached papers (2) as primers for Dr. Lund's talk.