Quantifying supraglacial debris thickness at local to regional scales
Supraglacial debris thickness is a key control on the surface energy balance of debris-covered glaciers, which are common in temperate mountain ranges around the world. As such, it is an important input variable to the sorts of models that are used to understand and predict glacier change, which are...
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ftnerc:oai:nora.nerc.ac.uk:524151 2023-05-15T18:02:42+02:00 Quantifying supraglacial debris thickness at local to regional scales McCarthy, Michael James 2018-12 text http://nora.nerc.ac.uk/id/eprint/524151/ https://nora.nerc.ac.uk/id/eprint/524151/1/michael_mccarthy_thesis_2018.pdf en eng https://nora.nerc.ac.uk/id/eprint/524151/1/michael_mccarthy_thesis_2018.pdf McCarthy, Michael James orcid:0000-0001-8099-0531 . 2018 Quantifying supraglacial debris thickness at local to regional scales. Scott Polar Research Institute and British Antarctic Survey, PhD Thesis, 220pp. Publication - Thesis NonPeerReviewed 2018 ftnerc 2023-02-04T19:48:43Z Supraglacial debris thickness is a key control on the surface energy balance of debris-covered glaciers, which are common in temperate mountain ranges around the world. As such, it is an important input variable to the sorts of models that are used to understand and predict glacier change, which are essential for determining future water supply in glacierised regions and glacier contributions to sealevel rise. However, to quantify supraglacial debris thickness is difficult: making direct measurements is laborious and existing remote sensing approaches have not been thoroughly validated, so there is a general paucity of supraglacial debris thickness data. This thesis investigates methods of quantifying supraglacial debris thickness at local to regional scales. First, it makes in-situ field measurements of debris thickness at the local scale on glaciers in the Himalaya and the European Alps by manual excavation and by ground-penetrating radar (GPR). Second, it uses some of these field measurements to test and develop thermal remote sensing approaches to quantifying supraglacial debris thickness at the glacier scale. Third, it uses a dynamic energy-balance model in an inverse approach to quantify debris thickness on the glaciers of three watersheds in High Mountain Asia from thermal satellite imagery and high-resolution meteorological reanalysis data. At the local scale, GPR is found to be useful for measuring supraglacial debris thickness accurately and precisely, at least in the range 0.16-4.9 m. Debris thickness is highly variable over horizontal distances of < 10 m on individual glaciers due to gravitational reworking, which necessarily implies higher sub-debris ice melt rates than if debris thickness was spatially invariable. At the glacier scale, thermal remote sensing approaches can reproduce field measurements, and remote sensing estimates of supraglacial debris thickness can be used successfully to model sub-debris melting. If welldistributed field measurements are available, supraglacial debris ... Text Polar Research Natural Environment Research Council: NERC Open Research Archive |
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Natural Environment Research Council: NERC Open Research Archive |
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Supraglacial debris thickness is a key control on the surface energy balance of debris-covered glaciers, which are common in temperate mountain ranges around the world. As such, it is an important input variable to the sorts of models that are used to understand and predict glacier change, which are essential for determining future water supply in glacierised regions and glacier contributions to sealevel rise. However, to quantify supraglacial debris thickness is difficult: making direct measurements is laborious and existing remote sensing approaches have not been thoroughly validated, so there is a general paucity of supraglacial debris thickness data. This thesis investigates methods of quantifying supraglacial debris thickness at local to regional scales. First, it makes in-situ field measurements of debris thickness at the local scale on glaciers in the Himalaya and the European Alps by manual excavation and by ground-penetrating radar (GPR). Second, it uses some of these field measurements to test and develop thermal remote sensing approaches to quantifying supraglacial debris thickness at the glacier scale. Third, it uses a dynamic energy-balance model in an inverse approach to quantify debris thickness on the glaciers of three watersheds in High Mountain Asia from thermal satellite imagery and high-resolution meteorological reanalysis data. At the local scale, GPR is found to be useful for measuring supraglacial debris thickness accurately and precisely, at least in the range 0.16-4.9 m. Debris thickness is highly variable over horizontal distances of < 10 m on individual glaciers due to gravitational reworking, which necessarily implies higher sub-debris ice melt rates than if debris thickness was spatially invariable. At the glacier scale, thermal remote sensing approaches can reproduce field measurements, and remote sensing estimates of supraglacial debris thickness can be used successfully to model sub-debris melting. If welldistributed field measurements are available, supraglacial debris ... |
format |
Text |
author |
McCarthy, Michael James |
spellingShingle |
McCarthy, Michael James Quantifying supraglacial debris thickness at local to regional scales |
author_facet |
McCarthy, Michael James |
author_sort |
McCarthy, Michael James |
title |
Quantifying supraglacial debris thickness at local to regional scales |
title_short |
Quantifying supraglacial debris thickness at local to regional scales |
title_full |
Quantifying supraglacial debris thickness at local to regional scales |
title_fullStr |
Quantifying supraglacial debris thickness at local to regional scales |
title_full_unstemmed |
Quantifying supraglacial debris thickness at local to regional scales |
title_sort |
quantifying supraglacial debris thickness at local to regional scales |
publishDate |
2018 |
url |
http://nora.nerc.ac.uk/id/eprint/524151/ https://nora.nerc.ac.uk/id/eprint/524151/1/michael_mccarthy_thesis_2018.pdf |
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Polar Research |
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Polar Research |
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https://nora.nerc.ac.uk/id/eprint/524151/1/michael_mccarthy_thesis_2018.pdf McCarthy, Michael James orcid:0000-0001-8099-0531 . 2018 Quantifying supraglacial debris thickness at local to regional scales. Scott Polar Research Institute and British Antarctic Survey, PhD Thesis, 220pp. |
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