Reconstructing Deglacial Circulation Changes in the Northern North Atlantic and Nordic Seas: Δ14C, δ13C, Temperature and δ18OSW Evidence

• Main Author: Thornalley, DJR
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2015
• Subjects: ice core; Nordic Seas; North Atlantic
• Online Access: https://discovery.ucl.ac.uk/id/eprint/1474082/1/Thornalley%202015%20-%20Reconstructing%20deglacial%20circulation%20change%20NATL%20Nordic%20Nova%20Acta.pdf; https://discovery.ucl.ac.uk/id/eprint/1474082/

Ice-core records have revealed that atmospheric CO2 has varied during glacial-interglacial by ~90 ppm, with rapid increases in atmospheric CO2 occurring during deglaciations. It is widely accepted that changes in the amount of carbon stored in the deep ocean play a leading role in explaining these cycles, primarily because of the size of the deep ocean carbon reservoir (~60 times that of the atmosphere) and the millennial timescales on which it interacts with the atmosphere (Sigman et al. 2010). To gain an understanding of how changes in deep ocean carbon storage may have controlled past variations in atmospheric CO2, we ideally require robust and detailed proxy records of the properties and ventilation pathways of the deep ocean across glacial-interglacial transitions. The deep ocean is ventilated in the high latitudes, where dense isopycnals outcrop at the sea surface. Therefore to help understand deep ocean-atmosphere exchange we require reconstructions of past hydrographic changes at these high latitude ventilation sites. Furthermore, constraints on the timing and phasing of deglacial changes in these regions enable us to evaluate hypotheses regarding the underlying mechanisms of the glacial termination.