title: North Atlantic Deep Water Production during the Last Glacial Maximum.
abstract: Changes in deep ocean ventilation are commonly invoked as the primary cause of lower glacial atmospheric CO2. 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 glacial-interglacial 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.
authors.affiliation: Department of Earth Sciences, University of Cambridge, Cambridge CB2 3EQ, UK.
authors.forename: Jacob N W
authors.initials: JN
authors.lastname: Howe
authors.affiliation: Department of Earth Sciences, University of Cambridge, Cambridge CB2 3EQ, UK.
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Piotrowski
authors.affiliation: Department of Earth Sciences, University of Cambridge, Cambridge CB2 3EQ, UK.|Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, Hobart, Tasmania 7001, Australia.
authors.forename: Taryn L
authors.initials: TL
authors.lastname: Noble
authors.affiliation: MARUM-Center for Marine Environmental Sciences, University of Bremen, Leobener Strasse, D-28359 Bremen, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Mulitza
authors.affiliation: School of Arts, Sciences and Humanities, University of São Paulo, Av. Arlindo Bettio 1000, CEP03828-000 São Paulo SP, Brazil.
authors.forename: Cristiano M
authors.initials: CM
authors.lastname: Chiessi
authors.affiliation: Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Unité de Recherche Géosciences Marines, F-29280 Plouzané, France.
authors.forename: Germain
authors.initials: G
authors.lastname: Bayon