Assessing the Ability of Zonal δ18O Contrast in Benthic Foraminifera to Reconstruct Deglacial Evolution of Atlantic Meridional Overturning Circulation
Year: 2019
Type: article
Abstract: δ18O in foraminifera (δ18Oc) is a useful proxy for density, and the strength of the Atlantic Meridional Overturning Circulation (AMOC) can be reconstructed by the zonal density contrast in the Atlantic. However, whether the deglacial zonal δ18Oc contrast can represent the AMOC change is still unclear. δ18Oc contrast across the Florida Straits has been hypothesized as a proxy for the AMOC evolution during the last deglaciation, but the strength of Florida Current could also be influenced by wind forcing. Here we examine the ability of the zonal δ18Oc contrast to reconstruct AMOC in a deglacial model simulation. The model simulation suggests that the deglacial variation of the Florida Current strength is dominated by AMOC, with the wind effect on the variation of the Florida Current being negligible. Furthermore, the δ18Oc contrast across the western boundary along the entire Atlantic and the basin‐wide δ18Oc contrast in the North Atlantic in the upper ocean can also be used to reconstruct AMOC. However, using basin‐wide δ18Oc contrast to reconstruct AMOC in the South Atlantic is not possible at all water depths. In the subtropical South Atlantic, the basin‐wide δ18Oc contrast is decoupled from the density contrast between 400 to 600 m through the deglaciation because of the deglacial change of the Antarctic Intermediate Water. Therefore, δ18Oc is a useful proxy to reconstruct past density and in turn past AMOC, but caution has to be used when using the basin‐wide δ18Oc contrast to reconstruct the basin‐wide density contrast in the South Atlantic.
DOI: 10.1029/2019pa003564
Institutions: Qingdao National Laboratory for Marine Science and Technology, Ocean University of China, The Ohio State University, Georgia Institute of Technology, Institute of Arctic and Alpine Research, University of Colorado Boulder, Los Alamos National Laboratory, NSF National Center for Atmospheric Research, NSF NCAR Climate and Global Dynamics Laboratory
Language: English
Subfield: Atmospheric Science
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: bronze
Awards: 近21000年来地球气候-同位素协同演变的模拟研究, NEW; TITLE: COLLABORATIVE PROJECT: DEVELOPMENT OF AN ISOTOPE-ENABLED CESM FOR TESTING ABRUPT CLIMATE CHANGES; PI: BETTE OTTO-BLIESNER, Collaborative Research: Carbon Isotope and geotracer-enabled simulation of the Transient Climate Evolution of the Deglacial Ocean (C-iTRACE-O), Collaborative Research: P2C2--isotope-enabled TRAnsient Climate Evolution of the last 21,000 years (iTRACE21)----Understanding Deglacial Climate/Isotope Changes Using iCESM, G6195818568, Collaborative Research: P2C2--isotope-enabled TRAnsient Climate Evolution of the last 21,000 years (iTRACE21)----Understanding Deglacial Climate/Isotope Changes Using iCESM, G7044180687, G8796606907
OpenAlex ID: W2941921391