Centennial-scale intensifications of the Atlantic Meridional Overturning Circulation during Heinrich Stadial 1
5 affiliations
- 1School of Arts, Sciences and Humanities (EACH), University of São Paulo, São Paulo, Brazil. [email protected]
- 2School of Arts, Sciences and Humanities (EACH), University of São Paulo, São Paulo, Brazil
- 3MARUM-Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany
- 4Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
- 5Center for Nuclear Energy in Agriculture (CENA), University of São Paulo, Piracicaba, Brazil
Abstract
Centennial-scale changes in Atlantic Meridional Overturning Circulation (AMOC) strength might disturb global climate by altering interhemispheric heat transport and CO2 partitioning between the ocean and the atmosphere. Due to the short instrumental record and lack of high-resolution paleo records that so far only resolve millennial-scale changes, centennial-scale changes remain elusive. Here we use radiocarbon ventilation ages from a western equatorial Atlantic sediment core with a remarkably high sedimentation rate to reconstruct AMOC variability during the last deglaciation, with a focus on Heinrich Stadial 1 (HS1; 17.8-14.8 ka). Results from model simulations indicate that ventilation ages serve as a sensitive proxy for AMOC variability under weak overturning conditions (i.e., during HS1) at our study location. Notably, within an overall weakened AMOC condition during HS1, our record shows two centennial-scale AMOC intensifications: one from 16.5 to 15.8 ka and another at ~15.4 ka. These centennial-scale episodes of intensified AMOC briefly revitalized Atlantic interhemispheric heat transport during HS1, resulting in decreased precipitation over northeastern Brazil and short-lived but intense changes in climate elsewhere. These episodes of AMOC intensification likely transported substantial volumes of CO2-rich water from the mid-depth Atlantic to the Southern Ocean, where the CO2 was rapidly outgassed to the atmosphere. Using radiocarbon ages from Atlantic sediments, AMOC variability during Heinrich Stadial 1 is reconstructed, revealing brief intensifications that altered heat transport, reduced rainfall over northeastern Brazil, and likely enhanced atmospheric CO2.
Related
- Cascading impacts of Atlantic meridional overturning circulation weakening and collapse on marine biogeochemistry
- Persistent memory and tail-risk amplification in Atlantic Meridional Overturning Circulation variability: a Volterra integral framework calibrated with CMIP6
- Global stability of the Atlantic overturning circulation: edge state, long transients and boundary crisis under CO2 forcing
- No critical slowing down in the Atlantic Overturning Circulation in historical CMIP6 simulations
- Reversible Atlantic overturning despite continued Greenland ice sheet melt
BibTeX
@article{jena2026centennialscale,
title = {{Centennial-scale intensifications of the Atlantic Meridional Overturning Circulation during Heinrich Stadial 1}},
author = {Partha Sarathi Jena and Cristiano Mazur Chiessi and Ines Beese and Martin Butzin A and Bruna Borba Dias and Marília de Carvalho Campos and Gerrit Lohmann and Stefan Mulitza},
journal = {Nature Communications},
year = {2026},
month = may,
doi = {10.1038/s41467-026-73364-x},
url = {https://doi.org/10.1038/s41467-026-73364-x},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - Centennial-scale intensifications of the Atlantic Meridional Overturning Circulation during Heinrich Stadial 1
AU - Partha Sarathi Jena
AU - Cristiano Mazur Chiessi
AU - Ines Beese
AU - Martin Butzin A
AU - Bruna Borba Dias
AU - Marília de Carvalho Campos
AU - Gerrit Lohmann
AU - Stefan Mulitza
PY - 2026
DA - 2026/05/19
JO - Nature Communications
DO - 10.1038/s41467-026-73364-x
UR - https://doi.org/10.1038/s41467-026-73364-x
AB - Centennial-scale changes in Atlantic Meridional Overturning Circulation (AMOC) strength might disturb global climate by altering interhemispheric heat transport and CO2 partitioning between the ocean and the atmosphere. Due to the short instrumental record and lack of high-resolution paleo records that so far only resolve millennial-scale changes, centennial-scale changes remain elusive. Here we use radiocarbon ventilation ages from a western equatorial Atlantic sediment core with a remarkably high sedimentation rate to reconstruct AMOC variability during the last deglaciation, with a focus on Heinrich Stadial 1 (HS1; 17.8-14.8 ka). Results from model simulations indicate that ventilation ages serve as a sensitive proxy for AMOC variability under weak overturning conditions (i.e., during HS1) at our study location. Notably, within an overall weakened AMOC condition during HS1, our record shows two centennial-scale AMOC intensifications: one from 16.5 to 15.8 ka and another at ~15.4 ka. These centennial-scale episodes of intensified AMOC briefly revitalized Atlantic interhemispheric heat transport during HS1, resulting in decreased precipitation over northeastern Brazil and short-lived but intense changes in climate elsewhere. These episodes of AMOC intensification likely transported substantial volumes of CO2-rich water from the mid-depth Atlantic to the Southern Ocean, where the CO2 was rapidly outgassed to the atmosphere. Using radiocarbon ages from Atlantic sediments, AMOC variability during Heinrich Stadial 1 is reconstructed, revealing brief intensifications that altered heat transport, reduced rainfall over northeastern Brazil, and likely enhanced atmospheric CO2.
SN - 2041-1723
ER -