Global reorganization of atmospheric circulation during Dansgaard-Oeschger cycles

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningfagfællebedømt

  • Jens Fohlmeister
  • Natasha Sekhon
  • Andrea Columbu
  • Vettoretti, Guido
  • Nils Weitzel
  • Kira Rehfeld
  • Cristina Veiga-Pires
  • Maya Ben-Yami
  • Norbert Marwan
  • Niklas Boers

Ice core records from Greenland provide evidence for multiple abrupt cold-warm- cold events recurring at millennial time scales during the last glacial interval. Although climate variations resembling Dansgaard-Oeschger (DO) oscillations have been identified in climate archives across the globe, our understanding of the climate and ecosystem impacts of the Greenland warming events in lower latitudes remains incomplete. Here, we investigate the influence of DO-cold- to- warm transitions on the global atmospheric circulation pattern. We comprehensively analyze δ18O changes during DO transitions in a globally distributed dataset of speleothems and set those in context with simulations of a comprehensive high-resolution climate model featuring internal millennial-scale variations of similar magnitude. Across the globe, speleothem δ18O signals and model results indicate consistent large-scale changes in precipitation amount, moisture source, or seasonality of precipitation associated with the DO transitions, in agreement with northward shifts of the Hadley circulation. Furthermore, we identify a decreasing trend in the amplitude of DO transitions with increasing distances from the North Atlantic region. This provides quantitative observational evidence for previous suggestions of the North Atlantic region being the focal point for these archetypes of past abrupt climate changes.

OriginalsprogEngelsk
Artikelnummere2302283120
TidsskriftProceedings of the National Academy of Sciences of the United States of America
Vol/bind120
Udgave nummer36
Antal sider7
ISSN0027-8424
DOI
StatusUdgivet - 26 jun. 2023

Bibliografisk note

Funding Information:
ACKNOWLEDGMENTS. This is TiPES (Tipping Points in the Earth System) contribution #103; the TiPES project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No. 820970. N.B. acknowledges further funding by the Volkswagen Foundation. M.B.-Y. and N.B. acknowledge additional funding by the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska–Curie grant agreement No. 956170. C.V.-P. acknowledges the financial support of the Portuguese Foundation of Science and Technology to Centre for Marine and Environmental Research through UID/00350/2020 CIMA. N.W. and K.R. acknowledge funding by the Deutsche Forschungsgemeinschaft project no. 395588486 and the German federal ministry of Education and Research through the Palmod project (code 01LP1926C). This study includes data compiled by SISAL, a working group of the Past Global Changes (PAGES) project and is in part inspired by discussions at a SISAL workshop in Xi'an (China) in 2019. PAGES received support from the Swiss Academy of Sciences and the Chinese Academy of Sciences.

Publisher Copyright:
© 2023 the Author(s).

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