Brugger, K.A.; Ruleman, C.A.; Caffee, M.W.; Mason, C.C. Climate during the Last Glacial Maximum in the Northern Sawatch Range, Colorado, USA. Quaternary2019, 2, 36.
Brugger, K.A.; Ruleman, C.A.; Caffee, M.W.; Mason, C.C. Climate during the Last Glacial Maximum in the Northern Sawatch Range, Colorado, USA. Quaternary 2019, 2, 36.
Brugger, K.A.; Ruleman, C.A.; Caffee, M.W.; Mason, C.C. Climate during the Last Glacial Maximum in the Northern Sawatch Range, Colorado, USA. Quaternary2019, 2, 36.
Brugger, K.A.; Ruleman, C.A.; Caffee, M.W.; Mason, C.C. Climate during the Last Glacial Maximum in the Northern Sawatch Range, Colorado, USA. Quaternary 2019, 2, 36.
Abstract
Temperature-index modeling is used to determine the magnitude of temperature depression in the northern Sawatch Range required to maintain steady-state mass balances of six reconstructed glaciers at their extent during the local Last Glacial Maximum (LLGM), dated at ~21 ka. Assuming no significant differences in precipitation compared to modern values, mean annual temperatures in the region were on average 8.8 +0.5/–0.8 °C cooler than they are today. Allowing for modest increases or decreases in precipitation, required temperature depressions only differ by ± 0.2 °C. Temperature depression in the northern Sawatch Range are consistent, although slightly greater, with those determined in other ranges in Colorado using similar approaches. The estimates presented here are, however, substantially less than those suggested by several downscaled simulations of global LGM climate, that might be due to the need for improved calibration of such downscalings, or the models from which they are derived. Our estimates of LGM temperature depression are considerably greater than that previously determined in the study area and those in two other ranges in Colorado derived using different methodologies, the latter being most likely responsible for the discrepancies.
Keywords
Last Glacial Maximum; paleoclimate; temperature-index model; Sawatch Range; Colorado
Subject
Environmental and Earth Sciences, Geophysics and Geology
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
