Abstract
Heinrich Stadials significantly affected tropical precipitation through changes in the interhemispheric temperature gradient as a result of abrupt cooling in the North Atlantic. Here, we focus on changes in South American monsoon precipitation during Heinrich Stadials using a suite of speleothem records covering the last 85 ky B.P. from eastern South America. We document the response of South American monsoon precipitation to episodes of extensive iceberg discharge, which is distinct from the response to the cooling episodes that precede the main phase of ice-rafted detritus deposition. Our results demonstrate that iceberg discharge in the western subtropical North Atlantic led to an abrupt increase in monsoon precipitation over eastern South America. Our findings of an enhanced Southern Hemisphere monsoon, coeval with the iceberg discharge into the North Atlantic, are consistent with the observed abrupt increase in atmospheric methane concentrations during Heinrich Stadials.
Original language | English (US) |
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Pages (from-to) | 3788-3793 |
Number of pages | 6 |
Journal | Proceedings of the National Academy of Sciences of the United States of America |
Volume | 115 |
Issue number | 15 |
DOIs | |
State | Published - 2018 |
Bibliographical note
Funding Information:ACKNOWLEDGMENTS. We thank L. Mancine, O. Antunes, and A. Barros for their support during the stable isotope data acquisition at the University of São Paulo. We are grateful to Instituto Brasileiro do Meio Ambiente/Instituto Chico Mendes de Conservação da Biodiversidade (IBAMA/ICMBio) for permission to collect stalagmite samples. This work was supported by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Grants 2012/01187-4 and 2016/ 00299-4 (to I.K.), PhD Fellowship 2011/12087-4 (to N.M.S.), and FAPESP/NSF Research Program on Biodiversity Characterization, Conservation, Restoration and Sustainable (BIOTA) and Dimensions of Biodiversity Grants 2012/ 50260-6 and 2013/50297 (to F.W.C.) and NSFC 41731174 (to H.Z.). The work also benefited from support of the Interdisciplinary Climate Investigation Center (INCLINE) research group at the University of São Paulo and NSF Award AGS-1303828 (to M.V.).
Funding Information:
We thank L. Mancine, O. Antunes, and A. Barros for their support during the stable isotope data acquisition at the University of São Paulo. We are grateful to Instituto Brasileiro do Meio Ambiente/Instituto Chico Mendes de Conservação da Biodiversidade (IBAMA/ICMBio) for permission to collect stalagmite samples. This work was supported by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Grants 2012/01187-4 and 2016/ 00299-4 (to I.K.), PhD Fellowship 2011/12087-4 (to N.M.S.), and FAPESP/NSF Research Program on Biodiversity Characterization, Conservation, Restoration and Sustainable (BIOTA) and Dimensions of Biodiversity Grants 2012/ 50260-6 and 2013/50297 (to F.W.C.) and NSFC 41731174 (to H.Z.). The work also benefited from support of the Interdisciplinary Climate Investigation Center (INCLINE) research group at the University of São Paulo and NSF Award AGS-1303828 (to M.V.).
Publisher Copyright:
© 2018 National Academy of Sciences. All Rights Reserved.
Keywords
- Heinrich Stadial
- Ice-rafted detritus
- South American monsoon
- Speleothem