North Atlantic Deep Water production during the Last Glacial Maximum

• Published in: Nature Communications
• Main Authors: Howe, JNW, Piotrowski, AM, Noble, TL, Mulitza, S, Chiessi, CM, Bayon, G
• Format: Article in Journal/Newspaper
• Language: English
• Published: Nature Publishing Group 2016
• Subjects: Earth Sciences; Oceanography; Chemical Oceanography; North Atlantic Deep Water; North Atlantic
• Online Access: https://doi.org/10.1038/ncomms11765; http://ecite.utas.edu.au/114341

Changes in deep ocean ventilation are commonly invoked as the primary cause of lower glacial atmospheric CO 2 . The water mass structure of the glacial deep Atlantic Ocean and the mechanism by which it may have sequestered carbon remain elusive. Here we present neodymium isotope measurements from cores throughout the Atlantic that reveal glacialinterglacial changes in water mass distributions. These results demonstrate the sustained production of North Atlantic Deep Water under glacial conditions, indicating that southern-sourced waters were not as spatially extensive during the Last Glacial Maximum as previously believed. We demonstrate that the depleted glacial δ 13 C values in the deep Atlantic Ocean cannot be explained solely by water mass source changes. A greater amount of respired carbon, therefore, must have been stored in the abyssal Atlantic during the Last Glacial Maximum. We infer that this was achieved by a sluggish deep overturning cell, comprised of well-mixed northern- and southern-sourced waters.