Assessing supraglacial lake depth using ICESat-2, Sentinel-2, TanDEM-X, and in situ sonar measurements over Northeast Greenland
Supraglacial lake development in Greenland consists of intricate hydrological processes, contributing not only to surface mass loss, but also to a lowering of the surface albedo and changes in ice dynamics. While the estimation of lake area has recently improved, the determination of the lake volume...
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ftcopernicus:oai:publications.copernicus.org:egusphere119728 2024-06-23T07:53:13+00:00 Assessing supraglacial lake depth using ICESat-2, Sentinel-2, TanDEM-X, and in situ sonar measurements over Northeast Greenland Lutz, Katrina Bever, Lily Sommer, Christian Humbert, Angelika Scheinert, Mirko Braun, Matthias 2024-05-21 application/pdf https://doi.org/10.5194/egusphere-2024-1244 https://egusphere.copernicus.org/preprints/2024/egusphere-2024-1244/ eng eng doi:10.5194/egusphere-2024-1244 https://egusphere.copernicus.org/preprints/2024/egusphere-2024-1244/ eISSN: Text 2024 ftcopernicus https://doi.org/10.5194/egusphere-2024-1244 2024-06-13T01:24:17Z Supraglacial lake development in Greenland consists of intricate hydrological processes, contributing not only to surface mass loss, but also to a lowering of the surface albedo and changes in ice dynamics. While the estimation of lake area has recently improved, the determination of the lake volume is essential to properly estimate the amount of water contained in and lost from supraglacial lakes throughout the melt seasons. In this study, four supraglacial lake depth estimation methods, including two new regression approaches, are presented and compared to each other. The first empirical equation is based on depth information gathered from ICESat-2 crossings over 19 lakes in Northeast and Southwest Greenland, whereas the second empirical equation uses in situ sonar tracks, providing depth information from four lakes on Zachariæ Isstrøm in Northeast Greenland. The depths from both equations are independently correlated to their corresponding Sentinel-2 reflectance values to create empirical relations. The third method is a standardly used radiative transfer model also based on Sentinel-2 data. Finally, the depths for five lakes in Northeast Greenland were derived from TanDEM-X digital elevation models after lake drainage. All four methods were applied to the five lakes for which digital elevation models were able to be procured, allowing for a direct comparison of the methods. In general, the sonar-based equation aligned best with the estimates from the digital elevation model until its saturation point of 8.6 m. Through the evaluation of the ICESat-2-based equation, a strong influence of lake bed sediment could be seen. The appropriately adapted equation produced slightly deeper depths than the sonar-based equation. The radiative transfer model more strongly overestimated nearly all depths below its saturation point of 16.3 m, when compared to the digital elevation model results. This large overestimation can be primarily attributed to the sensitivity of this method’s parameters. ... Text Greenland Copernicus Publications: E-Journals Four Lakes ENVELOPE(-126.826,-126.826,54.858,54.858) Greenland |
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Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
Supraglacial lake development in Greenland consists of intricate hydrological processes, contributing not only to surface mass loss, but also to a lowering of the surface albedo and changes in ice dynamics. While the estimation of lake area has recently improved, the determination of the lake volume is essential to properly estimate the amount of water contained in and lost from supraglacial lakes throughout the melt seasons. In this study, four supraglacial lake depth estimation methods, including two new regression approaches, are presented and compared to each other. The first empirical equation is based on depth information gathered from ICESat-2 crossings over 19 lakes in Northeast and Southwest Greenland, whereas the second empirical equation uses in situ sonar tracks, providing depth information from four lakes on Zachariæ Isstrøm in Northeast Greenland. The depths from both equations are independently correlated to their corresponding Sentinel-2 reflectance values to create empirical relations. The third method is a standardly used radiative transfer model also based on Sentinel-2 data. Finally, the depths for five lakes in Northeast Greenland were derived from TanDEM-X digital elevation models after lake drainage. All four methods were applied to the five lakes for which digital elevation models were able to be procured, allowing for a direct comparison of the methods. In general, the sonar-based equation aligned best with the estimates from the digital elevation model until its saturation point of 8.6 m. Through the evaluation of the ICESat-2-based equation, a strong influence of lake bed sediment could be seen. The appropriately adapted equation produced slightly deeper depths than the sonar-based equation. The radiative transfer model more strongly overestimated nearly all depths below its saturation point of 16.3 m, when compared to the digital elevation model results. This large overestimation can be primarily attributed to the sensitivity of this method’s parameters. ... |
format |
Text |
author |
Lutz, Katrina Bever, Lily Sommer, Christian Humbert, Angelika Scheinert, Mirko Braun, Matthias |
spellingShingle |
Lutz, Katrina Bever, Lily Sommer, Christian Humbert, Angelika Scheinert, Mirko Braun, Matthias Assessing supraglacial lake depth using ICESat-2, Sentinel-2, TanDEM-X, and in situ sonar measurements over Northeast Greenland |
author_facet |
Lutz, Katrina Bever, Lily Sommer, Christian Humbert, Angelika Scheinert, Mirko Braun, Matthias |
author_sort |
Lutz, Katrina |
title |
Assessing supraglacial lake depth using ICESat-2, Sentinel-2, TanDEM-X, and in situ sonar measurements over Northeast Greenland |
title_short |
Assessing supraglacial lake depth using ICESat-2, Sentinel-2, TanDEM-X, and in situ sonar measurements over Northeast Greenland |
title_full |
Assessing supraglacial lake depth using ICESat-2, Sentinel-2, TanDEM-X, and in situ sonar measurements over Northeast Greenland |
title_fullStr |
Assessing supraglacial lake depth using ICESat-2, Sentinel-2, TanDEM-X, and in situ sonar measurements over Northeast Greenland |
title_full_unstemmed |
Assessing supraglacial lake depth using ICESat-2, Sentinel-2, TanDEM-X, and in situ sonar measurements over Northeast Greenland |
title_sort |
assessing supraglacial lake depth using icesat-2, sentinel-2, tandem-x, and in situ sonar measurements over northeast greenland |
publishDate |
2024 |
url |
https://doi.org/10.5194/egusphere-2024-1244 https://egusphere.copernicus.org/preprints/2024/egusphere-2024-1244/ |
long_lat |
ENVELOPE(-126.826,-126.826,54.858,54.858) |
geographic |
Four Lakes Greenland |
geographic_facet |
Four Lakes Greenland |
genre |
Greenland |
genre_facet |
Greenland |
op_source |
eISSN: |
op_relation |
doi:10.5194/egusphere-2024-1244 https://egusphere.copernicus.org/preprints/2024/egusphere-2024-1244/ |
op_doi |
https://doi.org/10.5194/egusphere-2024-1244 |
_version_ |
1802644785425547264 |