What Can Thermal Imagery Tell Us About Glacier Melt Below Rock Debris?
Rock debris on the surface of a glacier can dramatically reduce the local melt rate, where the primary factor governing melt reduction is debris layer thickness. Relating surface temperature to debris thickness is a recurring approach in the literature, yet demonstrations of reproducibility have bee...
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Frontiers Media S.A.
2021
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Online Access: | https://doi.org/10.3389/feart.2021.681059 https://doaj.org/article/17bb7591fb7442768ec8dbf42eb6936e |
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ftdoajarticles:oai:doaj.org/article:17bb7591fb7442768ec8dbf42eb6936e 2023-05-15T16:20:35+02:00 What Can Thermal Imagery Tell Us About Glacier Melt Below Rock Debris? Sam Herreid 2021-08-01T00:00:00Z https://doi.org/10.3389/feart.2021.681059 https://doaj.org/article/17bb7591fb7442768ec8dbf42eb6936e EN eng Frontiers Media S.A. https://www.frontiersin.org/articles/10.3389/feart.2021.681059/full https://doaj.org/toc/2296-6463 2296-6463 doi:10.3389/feart.2021.681059 https://doaj.org/article/17bb7591fb7442768ec8dbf42eb6936e Frontiers in Earth Science, Vol 9 (2021) thermal infrared glacier melt modeling ASTER thermal infrared debris covered glaciers cryosphere mountain glaciers Science Q article 2021 ftdoajarticles https://doi.org/10.3389/feart.2021.681059 2022-12-31T13:12:08Z Rock debris on the surface of a glacier can dramatically reduce the local melt rate, where the primary factor governing melt reduction is debris layer thickness. Relating surface temperature to debris thickness is a recurring approach in the literature, yet demonstrations of reproducibility have been limited. Here, I present the results of a field experiment conducted on the Canwell Glacier, Alaska, United States to constrain how thermal data can be used in glaciology. These datasets include, 1) a measured sub-daily “Østrem curve” time-series; 2) a time-series of high resolution thermal images capturing several segments of different debris thicknesses including the measurements from 1); 3) a thermal profile through a 38 cm debris cover; and 4) two Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite thermal images acquired within 2 and 3 min of a field-based thermal camera image. I show that, while clear sky conditions are when space-borne thermal sensors can image a glacier, this is an unfavorable time, limiting the likelihood that different thicknesses of debris will have a unique thermal signature. I then propose an empirical approach to estimate debris thickness and compare it to two recently published methods. I demonstrate that instantaneous calibration is essential in the previously published methods, where model parameters calibrated only 1 h prior to a repeat thermal image return diminished debris thickness estimates, while the method proposed here remains robust through time and does not appear to require re-calibration. I then propose a method that uses a time-series of surface temperature at one location and debris thickness to estimate bare-ice and sub-debris melt. Results show comparable cumulative melt estimates to a recently published method that requires an explicit/external estimate of bare ice melt. Finally, I show that sub-pixel corrections to ASTER thermal imagery can enable a close resemblance to high resolution, field-based thermal imagery. These results offer a ... Article in Journal/Newspaper glacier glaciers Alaska Directory of Open Access Journals: DOAJ Articles Østrem ENVELOPE(8.681,8.681,63.387,63.387) Frontiers in Earth Science 9 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
thermal infrared glacier melt modeling ASTER thermal infrared debris covered glaciers cryosphere mountain glaciers Science Q |
spellingShingle |
thermal infrared glacier melt modeling ASTER thermal infrared debris covered glaciers cryosphere mountain glaciers Science Q Sam Herreid What Can Thermal Imagery Tell Us About Glacier Melt Below Rock Debris? |
topic_facet |
thermal infrared glacier melt modeling ASTER thermal infrared debris covered glaciers cryosphere mountain glaciers Science Q |
description |
Rock debris on the surface of a glacier can dramatically reduce the local melt rate, where the primary factor governing melt reduction is debris layer thickness. Relating surface temperature to debris thickness is a recurring approach in the literature, yet demonstrations of reproducibility have been limited. Here, I present the results of a field experiment conducted on the Canwell Glacier, Alaska, United States to constrain how thermal data can be used in glaciology. These datasets include, 1) a measured sub-daily “Østrem curve” time-series; 2) a time-series of high resolution thermal images capturing several segments of different debris thicknesses including the measurements from 1); 3) a thermal profile through a 38 cm debris cover; and 4) two Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite thermal images acquired within 2 and 3 min of a field-based thermal camera image. I show that, while clear sky conditions are when space-borne thermal sensors can image a glacier, this is an unfavorable time, limiting the likelihood that different thicknesses of debris will have a unique thermal signature. I then propose an empirical approach to estimate debris thickness and compare it to two recently published methods. I demonstrate that instantaneous calibration is essential in the previously published methods, where model parameters calibrated only 1 h prior to a repeat thermal image return diminished debris thickness estimates, while the method proposed here remains robust through time and does not appear to require re-calibration. I then propose a method that uses a time-series of surface temperature at one location and debris thickness to estimate bare-ice and sub-debris melt. Results show comparable cumulative melt estimates to a recently published method that requires an explicit/external estimate of bare ice melt. Finally, I show that sub-pixel corrections to ASTER thermal imagery can enable a close resemblance to high resolution, field-based thermal imagery. These results offer a ... |
format |
Article in Journal/Newspaper |
author |
Sam Herreid |
author_facet |
Sam Herreid |
author_sort |
Sam Herreid |
title |
What Can Thermal Imagery Tell Us About Glacier Melt Below Rock Debris? |
title_short |
What Can Thermal Imagery Tell Us About Glacier Melt Below Rock Debris? |
title_full |
What Can Thermal Imagery Tell Us About Glacier Melt Below Rock Debris? |
title_fullStr |
What Can Thermal Imagery Tell Us About Glacier Melt Below Rock Debris? |
title_full_unstemmed |
What Can Thermal Imagery Tell Us About Glacier Melt Below Rock Debris? |
title_sort |
what can thermal imagery tell us about glacier melt below rock debris? |
publisher |
Frontiers Media S.A. |
publishDate |
2021 |
url |
https://doi.org/10.3389/feart.2021.681059 https://doaj.org/article/17bb7591fb7442768ec8dbf42eb6936e |
long_lat |
ENVELOPE(8.681,8.681,63.387,63.387) |
geographic |
Østrem |
geographic_facet |
Østrem |
genre |
glacier glaciers Alaska |
genre_facet |
glacier glaciers Alaska |
op_source |
Frontiers in Earth Science, Vol 9 (2021) |
op_relation |
https://www.frontiersin.org/articles/10.3389/feart.2021.681059/full https://doaj.org/toc/2296-6463 2296-6463 doi:10.3389/feart.2021.681059 https://doaj.org/article/17bb7591fb7442768ec8dbf42eb6936e |
op_doi |
https://doi.org/10.3389/feart.2021.681059 |
container_title |
Frontiers in Earth Science |
container_volume |
9 |
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1766008513081901056 |