Meltwater Retention and Refreezing Processes in Glacier Snow and Firn
Glacier mass losses from all the regions of the world are a strong indication of global warming. The sum of glacier and ice sheet contributions is the dominant source of global sea level rise over the past two decades, and mass loss from the Greenland Ice Sheet is increasing due to significant incre...
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| Other Authors: | , , , , , |
| Format: | Doctoral or Postdoctoral Thesis |
| Language: | English |
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Arts
2020
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| Subjects: | |
| Online Access: | http://hdl.handle.net/1880/114297 https://doi.org/10.11575/PRISM/39512 |
| Summary: | Glacier mass losses from all the regions of the world are a strong indication of global warming. The sum of glacier and ice sheet contributions is the dominant source of global sea level rise over the past two decades, and mass loss from the Greenland Ice Sheet is increasing due to significant increases in surface melt and runoff. A fraction of summer meltwater is retained as liquid water or refrozen ice as meltwater percolates into cold (sub-zero) underlying snow and firn, which helps to reduce the summer runoff. However, there are challenges to quantifying both infiltration and refreezing of meltwater in heterogeneous snow and firn and to understanding the spatial variability of these processes. In this study, I introduce a new method to continuously monitor meltwater infiltration and refreezing in snow and firn, applying Time Domain Reflectometry (TDR) measurements of dielectric permittivity as an indirect measure of snow/firn liquid water content. To my knowledge, this is the first application of TDR to studies of ice sheet hydrology. I developed and conducted field experiments on Haig Glacier in the Canadian Rocky Mountains and at DYE-2, Greenland, including in situ measurements of the evolution of subsurface temperature and liquid water content through a summer melt season. My studies aim to advance understanding of meltwater infiltration and refreezing processes in supraglacial snow and firn. In addition, my field data can help the modelling community to build more accurate models of firn hydrology in the percolation zone of glaciers and ice sheets, in support of glacier mass balance modelling. |
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