摘要：The rate at which a portion of the ocean interior exchanges gases with the atmosphere is generally described in terms of “ventilation”. Ventilation predominantly occurs where dense waters outcrop at high latitudes, pumping radioactive 14C from the atmosphere into the ocean, while simultaneously undoing the work of the ‘biological pump’—releasing the CO2 excess to the atmosphere and replenishing the oxygen shortfall resulting from the decay of organic matter in the ocean interior. As biologically sequestered carbon would be less readily released to the atmosphere if ventilation of the ocean were reduced, some explanations for the low atmospheric pCO2 of the last ice age have invoked a poorly ventilated deep glacial ocean (Toggweiler, 1999; Stephens and Keeling, 2000; Sigman and Boyle, 2000). However, paleoceanographic evidence to support this has been sparse and often ambiguous, particularly in the Pacific Ocean.
