Mapping the vertical heterogeneity of Greenland's firn from 2011–2019 using airborne radar and laser altimetry
The firn layer on the Greenland Ice Sheet (GrIS) plays a crucial role in buffering surface meltwater runoff, which is constrained by the available firn pore space and impermeable ice layers that limit deeper meltwater percolation. Understanding these firn properties is essential for predicting curre...
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Online Access: | https://doi.org/10.5194/tc-18-2455-2024 https://tc.copernicus.org/articles/18/2455/2024/ |
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ftcopernicus:oai:publications.copernicus.org:tc115423 2024-09-09T19:43:07+00:00 Mapping the vertical heterogeneity of Greenland's firn from 2011–2019 using airborne radar and laser altimetry Rutishauser, Anja Scanlan, Kirk M. Vandecrux, Baptiste Karlsson, Nanna B. Jullien, Nicolas Ahlstrøm, Andreas P. Fausto, Robert S. How, Penelope 2024-05-17 application/pdf https://doi.org/10.5194/tc-18-2455-2024 https://tc.copernicus.org/articles/18/2455/2024/ eng eng doi:10.5194/tc-18-2455-2024 https://tc.copernicus.org/articles/18/2455/2024/ eISSN: 1994-0424 Text 2024 ftcopernicus https://doi.org/10.5194/tc-18-2455-2024 2024-08-28T05:24:15Z The firn layer on the Greenland Ice Sheet (GrIS) plays a crucial role in buffering surface meltwater runoff, which is constrained by the available firn pore space and impermeable ice layers that limit deeper meltwater percolation. Understanding these firn properties is essential for predicting current and future meltwater runoff and its contribution to global sea-level rise. While very-high-frequency (VHF) radars have been extensively used for surveying the GrIS, their lower bandwidth restricts direct firn stratigraphy extraction. In this study, we use concurrent VHF airborne radar and laser altimetry data collected as part of Operation IceBridge over the 2011–2019 period to investigate our hypothesis that vertical heterogeneities in firn (i.e. ice layers) cause vertical offsets in the radar surface reflection ( d z ). Our results, corroborated by modelling and firn core analyses, show that a d z larger than 1 m is strongly related to the vertical heterogeneity of a firn profile and effectively delineates between vertically homogeneous and vertically heterogeneous firn profiles over a depth range of ∼ 4 m. Temporal variations in d z align with climatic events and reveal an expansion of heterogeneous firn between 2011–2013 covering an area of ∼ 350 815 km 2 , followed by firn replenishment over the years 2014–2019 spanning an area of ∼ 667 725 km 2 . Our approach reveals the firn evolution of key regions on the Greenland Ice Sheet, providing valuable insights for detecting potential alterations in meltwater runoff patterns. Text Greenland Ice Sheet Copernicus Publications: E-Journals Greenland The Cryosphere 18 5 2455 2472 |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
language |
English |
description |
The firn layer on the Greenland Ice Sheet (GrIS) plays a crucial role in buffering surface meltwater runoff, which is constrained by the available firn pore space and impermeable ice layers that limit deeper meltwater percolation. Understanding these firn properties is essential for predicting current and future meltwater runoff and its contribution to global sea-level rise. While very-high-frequency (VHF) radars have been extensively used for surveying the GrIS, their lower bandwidth restricts direct firn stratigraphy extraction. In this study, we use concurrent VHF airborne radar and laser altimetry data collected as part of Operation IceBridge over the 2011–2019 period to investigate our hypothesis that vertical heterogeneities in firn (i.e. ice layers) cause vertical offsets in the radar surface reflection ( d z ). Our results, corroborated by modelling and firn core analyses, show that a d z larger than 1 m is strongly related to the vertical heterogeneity of a firn profile and effectively delineates between vertically homogeneous and vertically heterogeneous firn profiles over a depth range of ∼ 4 m. Temporal variations in d z align with climatic events and reveal an expansion of heterogeneous firn between 2011–2013 covering an area of ∼ 350 815 km 2 , followed by firn replenishment over the years 2014–2019 spanning an area of ∼ 667 725 km 2 . Our approach reveals the firn evolution of key regions on the Greenland Ice Sheet, providing valuable insights for detecting potential alterations in meltwater runoff patterns. |
format |
Text |
author |
Rutishauser, Anja Scanlan, Kirk M. Vandecrux, Baptiste Karlsson, Nanna B. Jullien, Nicolas Ahlstrøm, Andreas P. Fausto, Robert S. How, Penelope |
spellingShingle |
Rutishauser, Anja Scanlan, Kirk M. Vandecrux, Baptiste Karlsson, Nanna B. Jullien, Nicolas Ahlstrøm, Andreas P. Fausto, Robert S. How, Penelope Mapping the vertical heterogeneity of Greenland's firn from 2011–2019 using airborne radar and laser altimetry |
author_facet |
Rutishauser, Anja Scanlan, Kirk M. Vandecrux, Baptiste Karlsson, Nanna B. Jullien, Nicolas Ahlstrøm, Andreas P. Fausto, Robert S. How, Penelope |
author_sort |
Rutishauser, Anja |
title |
Mapping the vertical heterogeneity of Greenland's firn from 2011–2019 using airborne radar and laser altimetry |
title_short |
Mapping the vertical heterogeneity of Greenland's firn from 2011–2019 using airborne radar and laser altimetry |
title_full |
Mapping the vertical heterogeneity of Greenland's firn from 2011–2019 using airborne radar and laser altimetry |
title_fullStr |
Mapping the vertical heterogeneity of Greenland's firn from 2011–2019 using airborne radar and laser altimetry |
title_full_unstemmed |
Mapping the vertical heterogeneity of Greenland's firn from 2011–2019 using airborne radar and laser altimetry |
title_sort |
mapping the vertical heterogeneity of greenland's firn from 2011–2019 using airborne radar and laser altimetry |
publishDate |
2024 |
url |
https://doi.org/10.5194/tc-18-2455-2024 https://tc.copernicus.org/articles/18/2455/2024/ |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Ice Sheet |
genre_facet |
Greenland Ice Sheet |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-18-2455-2024 https://tc.copernicus.org/articles/18/2455/2024/ |
op_doi |
https://doi.org/10.5194/tc-18-2455-2024 |
container_title |
The Cryosphere |
container_volume |
18 |
container_issue |
5 |
container_start_page |
2455 |
op_container_end_page |
2472 |
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1809912463354757120 |