Abstract
The connection between abrupt high-latitude warming during the last glacial period—Dansgaard–Oeschger (DO) events—and rapid climate changes at lower latitudes has revealed inter-hemispheric teleconnections in the ocean–atmosphere system. Links between DO events and climate variability in mid-latitude, mid-continent settings remain, however, poorly understood, especially in North America where climate archives with sufficient time resolution are scarce. Here we examine a speleothem that grew from ~70–50 thousand years ago (ka) in Wisconsin (United States) and combine fluorescent imaging of its growth banding with an annual-resolution oxygen isotope (δ18O) record. Eight large (2.0–3.0‰) negative δ18O excursions, each with an onset in <10 annual growth bands, occur between 61–55 ka, when DO events 17–14 are recorded in the ice core of the North Greenland Ice Core Project. Although the age model does not allow these δ18O excursions to be matched to specific DO events, their magnitude and rapid onset support a credible link. Isotope-enabled climate simulations suggest that abrupt DO warming would increase the δ18O of annual precipitation in the study area and corroborate that warming of >10 °C in <10 years is thus required to produce the observed negative δ18O excursions. Our findings of expansive abrupt DO warming in central North America has implications for environmental, climate and ice sheet dynamics.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 257-261 |
| Number of pages | 5 |
| Journal | Nature Geoscience |
| Volume | 16 |
| Issue number | 3 |
| DOIs | |
| State | Published - Mar 2023 |
| Externally published | Yes |
Bibliographical note
Funding Information:This work was supported by the US National Science Foundation (NSF) (grant P2C2-1805629 to S.A.M. and I.J.O.); the WiscSIMS Laboratory, which is supported by NSF (grants EAR-1355590, EAR-1658823); the University of Wisconsin–Madison Office of the Vice Chancellor for Research and Graduate Education with funding from the Wisconsin Alumni Research Foundation (F.H.) and the Isotope Laboratory at the University of Minnesota (R.L.E.). This research used resources of the Oak Ridge Leadership Computing Facility at the Oak Ridge National Laboratory, which is supported by the Office of Science of the US Department of Energy under contract number DE-AC05-00OR22725 (F.H.). We thank J. Klimczak and A. Wescott for their permission to collect stalagmite samples at Cave of the Mounds, R. Slaughter for sample collection help, D. Rogers for sample preparation, L. Rodenkirch for CLFM help at the University of Wisconsin–Madison Optical Imaging Core and associated colleagues for prior U–Th analyses at the University of Minnesota. Stalagmite CM-5 is curated at the University of Wisconsin–Madison Geology Museum.
Funding Information:
This work was supported by the US National Science Foundation (NSF) (grant P2C2-1805629 to S.A.M. and I.J.O.); the WiscSIMS Laboratory, which is supported by NSF (grants EAR-1355590, EAR-1658823); the University of Wisconsin–Madison Office of the Vice Chancellor for Research and Graduate Education with funding from the Wisconsin Alumni Research Foundation (F.H.) and the Isotope Laboratory at the University of Minnesota (R.L.E.). This research used resources of the Oak Ridge Leadership Computing Facility at the Oak Ridge National Laboratory, which is supported by the Office of Science of the US Department of Energy under contract number DE-AC05-00OR22725 (F.H.). We thank J. Klimczak and A. Wescott for their permission to collect stalagmite samples at Cave of the Mounds, R. Slaughter for sample collection help, D. Rogers for sample preparation, L. Rodenkirch for CLFM help at the University of Wisconsin–Madison Optical Imaging Core and associated colleagues for prior U–Th analyses at the University of Minnesota. Stalagmite CM-5 is curated at the University of Wisconsin–Madison Geology Museum.
Publisher Copyright:
© 2023, The Author(s), under exclusive licence to Springer Nature Limited.