Title
High-latitude warming initiated the onset of the last deglaciation in the tropics
Document Type
Article
Publication Date
12-11-2019
Publication Title
Science Advances
Department
Department of Earth Sciences
Abstract
Atmospheric greenhouse gas concentrations are thought to have synchronized global temperatures during Pleistocene glacial–interglacial cycles, yet their impact relative to changes in high-latitude insolation and ice-sheet extent remains poorly constrained. Here, we use tropical glacial fluctuations to assess the timing of low-latitude temperature changes relative to global climate forcings. We report 10Be ages of moraines in tropical East Africa and South America and show that glaciers reached their maxima at ~29 to 20 ka, during the global Last Glacial Maximum. Tropical glacial recession was underway by 20 ka, before the rapid CO2 rise at ~18.2 ka. This “early” tropical warming was influenced by rising high-latitude insolation and coincident ice-sheet recession in both polar regions, which lowered the meridional thermal gradient and reduced tropical heat export to the high latitudes.
DOI
10.1126/sciadv.aaw2610
Original Citation
M. S. Jackson, M. A. Kelly, J. M. Russell, A. M. Doughty, J. A. Howley, J. W. Chipman, D. Cavagnaro, B. Nakileza, S. R. H. Zimmerman, High-latitude warming initiated the onset of the last deglaciation in the tropics. Sci. Adv. 5, eaaw2610 (2019).
Dartmouth Digital Commons Citation
Jackson, Margaret S.; Kelly, Meredith A.; Russell, James M.; Doughty, Alice M.; Howley, Jennifer A.; Chipman, Jonathan W.; Cavagnaro, David; Nakileza, Bob; and Zimmerman, Susan R.H., "High-latitude warming initiated the onset of the last deglaciation in the tropics" (2019). Dartmouth Scholarship. 4083.
https://digitalcommons.dartmouth.edu/facoa/4083