1
|
Wendt KA, Nehrbass-Ahles C, Niezgoda K, Noone D, Kalk M, Menviel L, Gottschalk J, Rae JWB, Schmitt J, Fischer H, Stocker TF, Muglia J, Ferreira D, Marcott SA, Brook E, Buizert C. Southern Ocean drives multidecadal atmospheric CO 2 rise during Heinrich Stadials. Proc Natl Acad Sci U S A 2024; 121:e2319652121. [PMID: 38739805 PMCID: PMC11126997 DOI: 10.1073/pnas.2319652121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 03/28/2024] [Indexed: 05/16/2024] Open
Abstract
The last glacial period was punctuated by cold intervals in the North Atlantic region that culminated in extensive iceberg discharge events. These cold intervals, known as Heinrich Stadials, are associated with abrupt climate shifts worldwide. Here, we present CO2 measurements from the West Antarctic Ice Sheet Divide ice core across Heinrich Stadials 2 to 5 at decadal-scale resolution. Our results reveal multi-decadal-scale jumps in atmospheric CO2 concentrations within each Heinrich Stadial. The largest magnitude of change (14.0 ± 0.8 ppm within 55 ± 10 y) occurred during Heinrich Stadial 4. Abrupt rises in atmospheric CO2 are concurrent with jumps in atmospheric CH4 and abrupt changes in the water isotopologs in multiple Antarctic ice cores, the latter of which suggest rapid warming of both Antarctica and Southern Ocean vapor source regions. The synchroneity of these rapid shifts points to wind-driven upwelling of relatively warm, carbon-rich waters in the Southern Ocean, likely linked to a poleward intensification of the Southern Hemisphere westerly winds. Using an isotope-enabled atmospheric circulation model, we show that observed changes in Antarctic water isotopologs can be explained by abrupt and widespread Southern Ocean warming. Our work presents evidence for a multi-decadal- to century-scale response of the Southern Ocean to changes in atmospheric circulation, demonstrating the potential for dynamic changes in Southern Ocean biogeochemistry and circulation on human timescales. Furthermore, it suggests that anthropogenic CO2 uptake in the Southern Ocean may weaken with poleward strengthening westerlies today and into the future.
Collapse
Affiliation(s)
- Kathleen A. Wendt
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR97330
| | - Christoph Nehrbass-Ahles
- Climate and Environmental Physics and Oeschger Center for Climate Change Research, University of Bern, BernCH-3012, Switzerland
- Atmospheric Environmental Science Department, National Physical Laboratory, LondonTW11 0LW, United Kingdom
| | - Kyle Niezgoda
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR97330
| | - David Noone
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR97330
| | - Michael Kalk
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR97330
| | - Laurie Menviel
- Climate Change Research Centre, Australian Centre for Excellence in Antarctic Science, University of New South Wales, SydneyNSW 2052, Australia
| | | | - James W. B. Rae
- School of Earth and Environmental Sciences, University of St Andrews, St AndrewsKY16 9TS, United Kingdom
| | - Jochen Schmitt
- Climate and Environmental Physics and Oeschger Center for Climate Change Research, University of Bern, BernCH-3012, Switzerland
| | - Hubertus Fischer
- Climate and Environmental Physics and Oeschger Center for Climate Change Research, University of Bern, BernCH-3012, Switzerland
| | - Thomas F. Stocker
- Climate and Environmental Physics and Oeschger Center for Climate Change Research, University of Bern, BernCH-3012, Switzerland
| | - Juan Muglia
- Centro Para el Estudio de Sistemas Marinos, El Centro Nacional Patagónico-Conicet, Puerto MadrynU9120ACD, Argentina
| | - David Ferreira
- Meteorology Department, University of Reading, ReadingRG6 6ET, United Kingdom
| | - Shaun A. Marcott
- Department of Geoscience, University of Wisconsin-Madison, Madison, WI53706
| | - Edward Brook
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR97330
| | - Christo Buizert
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR97330
| |
Collapse
|
2
|
Du J, Mix AC, Haley BA, Belanger CL, Sharon. Volcanic trigger of ocean deoxygenation during Cordilleran ice sheet retreat. Nature 2022; 611:74-80. [DOI: 10.1038/s41586-022-05267-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Accepted: 08/23/2022] [Indexed: 11/06/2022]
|
3
|
Edwards GH, Blackburn T, Piccione G, Tulaczyk S, Miller GH, Sikes C. Terrestrial evidence for ocean forcing of Heinrich events and subglacial hydrologic connectivity of the Laurentide Ice Sheet. SCIENCE ADVANCES 2022; 8:eabp9329. [PMID: 36260662 PMCID: PMC9581489 DOI: 10.1126/sciadv.abp9329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 08/31/2022] [Indexed: 06/16/2023]
Abstract
During the last glacial period, the Laurentide Ice Sheet (LIS) underwent episodes of rapid iceberg discharge, recorded in ocean sediments as "Heinrich events" (HEs). Two competing models attempt to describe the stimulus for HEs via either internal ice sheet oscillations or external ocean-climate system forcing. We present a terrestrial record of HEs from the northeastern LIS that strongly supports ocean-climate forcing. Subglacial carbonate precipitates from Baffin Island record episodes of subglacial melting coincident with the three most recent HEs, resulting from acceleration of nearby marine-terminating ice streams. Synchronized ice stream acceleration over Baffin Island and Hudson Strait is inconsistent with internal ice sheet oscillations alone and indicates a shared ocean-climate stimulus to coordinate these different glaciological systems. Isotopic compositions of these precipitates record widespread subglacial groundwater connectivity beneath the LIS. Extensive basal melting and flushing of these aquifers during the last HE may have been a harbinger for terminal deglaciation.
Collapse
Affiliation(s)
- Graham H. Edwards
- Department of Earth Sciences, Dartmouth College, Hanover, NH 03755, USA
| | - Terrence Blackburn
- Department of Earth and Planetary Sciences, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Gavin Piccione
- Department of Earth and Planetary Sciences, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Slawek Tulaczyk
- Department of Earth and Planetary Sciences, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Gifford H. Miller
- Institute of Arctic and Alpine Research and the Department of Geological Sciences, University of Colorado, Boulder, CO 80309, USA
| | - Cosmo Sikes
- Department of Geology, University of Maryland, College Park, MD 20742, USA
| |
Collapse
|
4
|
Knudson KP, Ravelo AC, Aiello IW, Knudson CP, Drake MK, Sakamoto T. Causes and timing of recurring subarctic Pacific hypoxia. SCIENCE ADVANCES 2021; 7:eabg2906. [PMID: 34078607 PMCID: PMC11210308 DOI: 10.1126/sciadv.abg2906] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 04/19/2021] [Indexed: 06/12/2023]
Abstract
Several North Pacific studies of the last deglaciation show hypoxia throughout the ocean margins and attribute this phenomenon to the effects of abrupt warming and meltwater inputs. Yet, because of the lack of long records spanning multiple glacial cycles and deglaciation events, it is unclear whether deoxygenation was a regular occurrence of warming events and whether deglaciation and/or other conditions promoted hypoxia throughout time. Here, subarctic Pacific laminated sediments from the past 1.2 million years demonstrate that hypoxic events recurred throughout the Pleistocene as episodes of highly productive phytoplankton growth and were generally associated with interglacial climates, high sea levels, and enhanced nitrate utilization-but not with deglaciations. We suggest that hypoxia was typically stimulated by high productivity from iron fertilization facilitated by redox-remobilized iron from flooded continental shelves.
Collapse
Affiliation(s)
- Karla P Knudson
- Department of Earth and Planetary Sciences, University of California, Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA
| | - Ana Christina Ravelo
- Department of Ocean Sciences, University of California, Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA.
| | - Ivano W Aiello
- Moss Landing Marine Laboratories, Moss Landing, CA 95039, USA
| | - Christina P Knudson
- Department of Mathematics, University of St. Thomas, 2115 Summit Avenue, St. Paul, MN 55105, USA
| | - Michelle K Drake
- Department of Ocean Sciences, University of California, Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA
| | - Tatsuhiko Sakamoto
- Graduate School and Faculty of Bioresources, Mie University, 1577 Kurimamachiya-cho, Tsu, Mie 514-8507, Japan
| |
Collapse
|
5
|
Jaeger JM, Shevenell AE. Steering iceberg armadas. Science 2020; 370:662-663. [DOI: 10.1126/science.abe8461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The Asian-Pacific tropics likely instigated millennial-scale climate changes
Collapse
Affiliation(s)
- John M. Jaeger
- Department of Geological Sciences, University of Florida, Gainesville FL 32611-2120, USA
| | - Amelia E. Shevenell
- College of Marine Science, University of South Florida, St. Petersburg, FL 33701, USA
| |
Collapse
|