Subsurface heat channel drove sea surface warming in the high-latitude North Atlantic during the mid-pleistocene transition

• Verfasst von: Amorim Catunda, Maria Carolina [VerfasserIn]
• Verfasst von: Bahr, André [VerfasserIn]
• Verfasst von: Kaboth-Bahr, Stefanie [VerfasserIn]
• Verfasst von: Zhang, Xu [VerfasserIn]
• Verfasst von: Foukal, Nicholas P. [VerfasserIn]
• Verfasst von: Friedrich, Oliver [VerfasserIn]
• Titel: Subsurface heat channel drove sea surface warming in the high-latitude North Atlantic during the mid-pleistocene transition
• Verf.angabe: M. Carolina A. Catunda, André Bahr, Stefanie Kaboth-Bahr, Xu Zhang, Nicholas P. Foukal, and Oliver Friedrich
• E-Jahr: 2021
• Jahr: 1 June 2021
• Umfang: 12 S.
• Fussnoten: Gesehen am 12.08.2021
• Titel Quelle: Enthalten in: Geophysical research letters
• Ort Quelle: Hoboken, NJ : Wiley, 1974
• Jahr Quelle: 2021
• Band/Heft Quelle: 48(2021), 11, Seite 1-12
• ISSN Quelle: 1944-8007
• DOI: doi:10.1029/2020GL091899
• Datenträger: Online-Ressource
• Sprache: eng
• Sach-SW: inter-gyre connectivity
• Sach-SW: Mediterranean outflow
• Sach-SW: mid-Pleistocene transition
• Sach-SW: North Atlantic gyres
• Sach-SW: paleoceanography
• Sach-SW: subsurface heat transport
• K10plus-PPN: 1766555217
• K10plus-PPN:
  Universitätsbibliothek
• Lokale URL UB: Zum Volltext

Abstract

The Mid-Pleistocene Transition (MPT, 1,200-600 ka) marks the rapid expansion of Northern Hemisphere (NH) continental ice sheets and stronger precession pacing of glacial/interglacial cyclicity. Here, we investigate the relationship between thermocline depth in the central North Atlantic, subsurface northward heat transport and the initiation of the 100-kyr cyclicity during the MPT. To reconstruct deep-thermocline temperatures, we generated a Mg/Ca-based temperature record of deep-dwelling (∼800 m) planktonic foraminifera from mid-latitude North Atlantic at Site U1313. This record shows phases of pronounced heat accumulation at subsurface levels during the mid-MPT glacial driven by increased outflow of the Mediterranean Sea. Concurrent warming of the subtropical thermocline and subpolar surface waters indicates enhanced (subsurface) inter-gyre transport of warm water to the subpolar North Atlantic, which provided moisture for ice-sheet growth. Precession-modulated variability in the northward transport of subtropical waters imprinted this orbital cyclicity into NH ice-sheets after Marine Isotope Stage 24.