The Greenland spatial fingerprint of Dansgaard-Oeschger events in observations and models

• 成果类型: Article
• 署名作者: Buizert, Christo; Sowers, Todd A.; Niezgoda, Kyle; Blunier, Thomas; Gkinis, Vasileios; Harlan, Margaret; He, Chengfei; Jones, Tyler R.; Kjaer, Helle A.; Liisberg, Jesper B.; Menking, James A.; Morris, Valerie; Noone, David; Rasmussen, Sune Olander; Sime, Louise C.; Steffensen, Jurgen P.; Svensson, Anders; Vaughng, Bruce H.; Vinther, Bo M.; White, James W. C.
• 署名单位: Oregon State University; Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park; Rice University; University of Copenhagen; Niels Bohr Institute; University of Tasmania; University of Miami; University of Colorado System; University of Colorado Boulder; Commonwealth Scientific & Industrial Research Organisation (CSIRO); CSIRO Environment; University of Tasmania; University of Auckland; UK Research & Innovation (UKRI); Natural Environment Research Council (NERC); NERC British Antarctic Survey; University of North Carolina; University of North Carolina Chapel Hill
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-10425
• DOI: 10.1073/pnas.2402637121
• 发表日期: 2024-10-29
• 关键词: glacial-interglacial changes; marine isotope stage-3; stable water isotopes; abrupt climate-change; earth system model; sea-ice; temperature reconstruction; deuterium excess; nordic seas; record

摘要

Pleistocene Ice Ages display abrupt Dansgaard-Oeschger (DO) climate oscillations that provide prime examples of Earth System tipping points-abrupt transition that may result in irreversible change. Greenland ice cores provide key records of DO climate variability, but gas- calibrated estimates of the temperature change magnitudes have been limited to central and northwest Greenland. Here, we present ice- core delta 15 N-N records from south (Dye 3) and coastal east Greenland (Renland) to calibrate the local water isotope thermometer and provide a Greenland- wide spatial characterization of DO event magnitude. We combine these data with existing records of delta 18 O, deuterium excess, and accumulation rates to create a multiproxy fingerprint of the DO impact on Greenland. Isotope- enabled climate models have skill in simulating the observational multiproxy DO event impact, and we use a series of idealized simulations with such models to identify regions of the North Atlantic that are critical in explaining DO variability. Our experiments imply that wintertime sea ice variation in the subpolar gyre, rather than the commonly invoked Nordic Seas, is both a sufficient and a necessary condition to explain the observed DO impacts in Greenland, whatever the distal cause. Moisture- tagging experiments support the idea that Greenland DO isotope signals may be explained almost entirely via changes in the vapor source distribution and that site temperature is not a main control on delta 18 O during DO transitions, contrary to the traditional interpretation. Our results provide a comprehensive, multiproxy, data- model synthesis of abrupt DO climate variability in Greenland.