Low Latitude Andean Glaciers: Climate Drivers of Past, Present, and Future Changes /

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Bibliographic Details
Author / Creator:Malone, Andrew Grady Oros, author.
Ann Arbor : ProQuest Dissertations & Theses, 2017
Description:1 electronic resource (148 pages)
Format: E-Resource Dissertations
Local Note:School code: 0330
URL for this record:http://pi.lib.uchicago.edu/1001/cat/bib/11715090
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Other authors / contributors:University of Chicago. degree granting institution.
Notes:Advisors: Douglas R. MacAyeal Committee members: Dorian S. Abbot; Edwin Kite; Raymond T. Pierrehumbert.
This item is not available from ProQuest Dissertations & Theses.
Dissertation Abstracts International, Volume: 78-12(E), Section: B.
Summary:Tropical Andean glaciers are an essential component of the alpine Earth system providing vital water resources for life in their vicinity. Glaciers are also archives of past climate change and barometers of present climate change, and tropical glaciers can provide a much needed additional low-latitude terrestrial paleoclimate proxy. Despite their societal and scientific importance, the study of tropical glaciers is nascent. This dissertation provides new perspectives on the climate components most important for tropical glacier change, illustrates that records of past tropical glacier changes can be used as a quantitive paleoclimate proxy, and provides a framework for a more rigorous interpretation of tropical glacier advances and retreats as a climate proxy.
A regional-scale surface energy and mass balance model is developed and implemented to quantify tropical glacier response to different types of climate change. The mass balance evolution from thermal year (July - June) 1980 - 2009 CE is simulated, and the dominant input climate variables are determined. The dominant climate drivers of glacier change at tropical Andean glaciers vary, depending on the regional climate setting and in particular the amount of annual precipitation. For both wet inner tropical glaciers and wet outer tropical glaciers, interannual temperature variability is the dominant climate forcing mechanism for equilibrium line altitude (ELA) or mass balance variability. For dry tropical glaciers, precipitation variability is the dominant variable for mass balance and ELA variability. For tropical glaciers, all-wave radiation (i.e. net shortwave and longwave radiation) is the dominant source of available melt energy, and at wet tropical glaciers, which is the classification type of the majority of Andean glaciers, temperature is able to modulate the all-wave radiation from year-to-year. By dictating the phase of precipitation, temperature determines the surface albedo and absorbed shortwave radiation at the lowest extents of the glacier, and this relationship is so strong that it can define the glacier-wide mass balance. Thus, for wet tropical glaciers, observations of mass balance or length changes primarily reflect temperature change.