Tropical mountain ice core : A Goldilocks indicator for global temperature change

 Tropical mountain ice core : A Goldilocks indicator for global temperature change   Zhengyu Liu^1,2,3, , Yuntao Bao¹, Lonnie G. Thompson^3,4, Ellen Mosley-Thompson^1,3,  Tabor Clay⁵, Guang J. Zhang⁶, Mi Yan², Marcus Lofverstrom⁷, Isabel Montanez⁸,  Jessica Oster⁹  1.      Department of Geography, The Ohio State University, Columbus, OH 2.      School of Geography Science, Nanjing Normal University, Nanjing, China. 3.      Byrd Polar and Climate Research Center, The Ohio State University, Columbus, OH 4.      School of Earth Sciences, The Ohio State University, Columbus, OH 5.      Department of Earth Sciences, University of Connecticut, Storrs, CT 6.      Scripps Institute of Oceanography, University of California San Diego, San Diego, CA

• Department of Geosciences, University of Arizona, Tucson, AZ
• Department of Earth and Planetary Sciences, University of California–Davis, Davis, CA
• Department of Earth and Environmental Sciences, Vanderbilt University, Nashville, TN

 

Very high tropical alpine ice coresprovide a distinct paleoclimate record for climate changes in the middle and upper troposphere. However, the climatic interpretation of a key proxy, the stable water oxygen isotopic ratio in ice cores (), remains an outstanding problem. Here, combining proxy records with climate models, modern satellite measurements and radiative-convective equilibrium theory, we show that the tropical  is an indicator of the temperature of the middle and upper troposphere, with a glacial cooling of -7.35+-1.1oC (66% CI). Moreover, it severs as a “Goldilocks-type” indicator of global mean surface temperature change, providing the first estimate of glacial stage cooling that is independent of marine proxies as -5.9+-1.2oC. Combined with all estimations available gives the maximum likelihood estimate of glacial cooling as -5.85+10.51oC .