Ice Age Storage of Respired Carbon in the Deep Pacific

The partitioning of carbon between the atmosphere, oceans, biosphere, and shallow lithosphere is one of the most fundamental controls on Earth’s climate system. Reconstructions of past changes to the concentration of dissolved carbon and oxygen in the abyssal ocean are thus of interest to paleoceanographers because of their potential to help characterize changes in the climate system and improve our understanding of the mechanisms and feedbacks driving change. Direct approaches to constraining deep ocean carbon storage have proven challenging due to inherited air-sea δ13C signatures, terrestrial biosphere variations, changes in preformed CO32-, and the input of hydrothermal 14C-dead carbon. To better describe and model past and future changes in ocean carbon storage, paleoceanographers have developed and refined new proxies to quantify the biogeochemical reciprocal of deep ocean respired carbon storage, oxygen availability. Here, Allison presents recently published orbital-resolution bottom water oxygen reconstructions from new proxies, and dust flux and productivity reconstructions from nearby sites. This talk discusses the significance of these records for finding and quantifying the glacial CO2 reservoir, and identifying regions of carbon entry into the deep ocean.

Abstract: TBD About this Series: The Chemical Oceanography, Geology, Geochemistry, and Geobiology Seminar [COG3] is a student-run seminar series. Topics include chemical oceanography, geology, geochemistry, and geobiology. Contact cog3_seminar_organizers@mit.edu for more information and Zoom password.