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Travis-Taylor L, Medina-Elizalde M, Karmalkar AV, Polanco-Martinez J, Serrato Marks G, Burns S, Lases-Hernández F, McGee D. Last glacial hydroclimate variability in the Yucatán Peninsula not just driven by ITCZ shifts. Sci Rep 2023; 13:14356. [PMID: 37658086 PMCID: PMC10474098 DOI: 10.1038/s41598-023-40108-6] [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: 07/12/2023] [Accepted: 08/04/2023] [Indexed: 09/03/2023] Open
Abstract
We reconstructed hydroclimate variability in the Yucatán Peninsula (YP) based on stalagmite oxygen and carbon isotope records from a well-studied cave system located in the northeastern YP, a region strongly influenced by Caribbean climate dynamics. The new stalagmite isotopic records span the time interval between 43 and 26.6 ka BP, extending a previously published record from the same cave system covering the interval between 26.5 and 23.2 ka BP. Stalagmite stable isotope records show dominant decadal and multidecadal variability, and weaker variability on millennial timescales. These records suggest significant precipitation declines in the broader Caribbean region during Heinrich events 4 and 3 of ice-rafted discharge into the North Atlantic, in agreement with the antiphase pattern of precipitation variability across the equator suggested by previous studies. On millennial timescales, the stalagmite isotope records do not show the distinctive saw-tooth pattern of climate variability observed in Greenland during Dansgaard-Oeschger (DO) events, but a pattern similar to North Atlantic sea surface temperature (SST) variability. We propose that shifts in the mean position of the Intertropical Convergence Zone (ITCZ), per se, are not the dominant driver of last glacial hydroclimate variability in the YP on millennial timescales but instead that North Atlantic SSTs played a dominant role. Our results support a negative climate feedback mechanism whereby large low latitude precipitation deficits resulting from AMOC slowdown would lead to elevated salinity in the Caribbean and ultimately help reactivate AMOC and Caribbean precipitation. However, because of the unique drivers of future climate in the region, predicted twenty-first century YP precipitation reductions are unlikely to be modulated by this negative feedback mechanism.
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Affiliation(s)
- Leah Travis-Taylor
- Department of Earth, Geographic, and Climate Sciences, UMass Amherst, Amherst, MA, USA.
| | | | | | - Josué Polanco-Martinez
- GECOS-IME, Campus Miguel Unamuno, Edificio FES, Salamanca, and Basque Centre for Climate Change (BC3), University of Salamanca, Leioa, Spain
| | | | - Stephen Burns
- Department of Earth, Geographic, and Climate Sciences, UMass Amherst, Amherst, MA, USA
| | | | - David McGee
- Department of Earth, Atmospheric, and Planetary Sciences, MIT, Cambridge, MA, USA
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Cheng J, Liu Z, He F, Otto-Bliesner BL, Brady EC, Wehrenberg M. Simulated Two-Stage Recovery of Atlantic Meridional Overturning Circulation During the Last Deglaciation. ABRUPT CLIMATE CHANGE: MECHANISMS, PATTERNS, AND IMPACTS 2011. [DOI: 10.1029/2010gm001014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
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Lenton TM, Myerscough RJ, Marsh R, Livina VN, Price AR, Cox SJ. Using GENIE to study a tipping point in the climate system. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2009; 367:871-84. [PMID: 19087945 DOI: 10.1098/rsta.2008.0171] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We have used the Grid ENabled Integrated Earth system modelling framework to study the archetypal example of a tipping point in the climate system; a threshold for the collapse of the Atlantic thermohaline circulation (THC). eScience has been invaluable in this work and we explain how we have made it work for us. Two stable states of the THC have been found to coexist, under the same boundary conditions, in a hierarchy of models. The climate forcing required to collapse the THC and the reversibility or irreversibility of such a collapse depends on uncertain model parameters. Automated methods have been used to assimilate observational data to constrain the pertinent parameters. Anthropogenic climate forcing leads to a robust weakening of the THC and increases the probability of crossing a THC tipping point, but some ensemble members collapse readily, whereas others are extremely resistant. Hence, we test general methods that have been developed to directly diagnose, from time-series data, the proximity of a 'tipping element', such as the THC to a bifurcation point. In a three-dimensional ocean-atmosphere model exhibiting THC hysteresis, despite high variability in the THC driven by the dynamical atmosphere, some early warning of an approaching tipping point appears possible.
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Affiliation(s)
- Timothy M Lenton
- School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK.
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