Geospatial simulations of airborne ice-penetrating radar surveying reveal elevation under-measurement bias for ice-sheet bed topography
© The Author(s), 2020. Published by Cambridge University Press. This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/). Airborne radio-echo sounding (RES) surveys are widely used to measure ice-sheet bed t...
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ftunivhertford:oai:uhra.herts.ac.uk:2299/24388 2023-05-15T13:29:38+02:00 Geospatial simulations of airborne ice-penetrating radar surveying reveal elevation under-measurement bias for ice-sheet bed topography Bartlett, Oliver T. Palmer, Steven J. Schroeder, Dustin M. Mackie, Emma J. Barrows, Timothy T. Graham, Alastair G.C. Department of Psychology, Sport and Geography School of Life and Medical Sciences Agriculture and Environmental Management Research Agriculture, Food and Veterinary Sciences 2021-04-01 12 http://hdl.handle.net/2299/24388 http://www.scopus.com/inward/record.url?scp=85082112730&partnerID=8YFLogxK eng eng Annals of Glaciology School of Life and Medical Sciences Bartlett , O T , Palmer , S J , Schroeder , D M , Mackie , E J , Barrows , T T & Graham , A G C 2021 , ' Geospatial simulations of airborne ice-penetrating radar surveying reveal elevation under-measurement bias for ice-sheet bed topography ' , Annals of Glaciology , vol. 61 , no. 81 , pp. 46-57 . https://doi.org/10.1017/aog.2020.35 0260-3055 PURE: 25060778 PURE UUID: ff7beb31-b411-44c8-a196-c14a5a3bc72b Scopus: 85082112730 ORCID: /0000-0002-0347-7926/work/93471292 http://hdl.handle.net/2299/24388 http://www.scopus.com/inward/record.url?scp=85082112730&partnerID=8YFLogxK Open Glaciological instruments and methods Greenland Ice Sheet radio-echo sounding subglacial topography Earth-Surface Processes 2021 ftunivhertford 2022-01-14T00:01:05Z © The Author(s), 2020. Published by Cambridge University Press. This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/). Airborne radio-echo sounding (RES) surveys are widely used to measure ice-sheet bed topography. Measuring bed topography as accurately and widely as possible is of critical importance to modelling ice dynamics and hence to constraining better future ice response to climate change. Measurement accuracy of RES surveys is influenced both by the geometry of bed topography and the survey design. Here we develop a novel approach for simulating RES surveys over glaciated terrain, to quantify the sensitivity of derived bed elevation to topographic geometry. Furthermore, we investigate how measurement errors influence the quantification of glacial valley geometry. We find a negative bias across RES measurements, where off-nadir return measurement error is typically -1.8 ± 11.6 m. Topographic highlands are under-measured an order of magnitude more than lowlands. Consequently, valley depth and cross-sectional area are largely under-estimated. While overall estimates of ice thickness are likely too high, we find large glacier valley cross-sectional area to be under-estimated by -2.8 ± 18.1%. Therefore, estimates of ice flux through large outlet glaciers are likely too low when this effect is not taken into account. Additionally, bed mismeasurements potentially impact our appreciation of outlet-glacier stability. Peer reviewed Final Published version Other/Unknown Material Annals of Glaciology glacier Greenland Ice Sheet University of Hertfordshire: UH Research Archive Greenland |
institution |
Open Polar |
collection |
University of Hertfordshire: UH Research Archive |
op_collection_id |
ftunivhertford |
language |
English |
topic |
Glaciological instruments and methods Greenland Ice Sheet radio-echo sounding subglacial topography Earth-Surface Processes |
spellingShingle |
Glaciological instruments and methods Greenland Ice Sheet radio-echo sounding subglacial topography Earth-Surface Processes Bartlett, Oliver T. Palmer, Steven J. Schroeder, Dustin M. Mackie, Emma J. Barrows, Timothy T. Graham, Alastair G.C. Geospatial simulations of airborne ice-penetrating radar surveying reveal elevation under-measurement bias for ice-sheet bed topography |
topic_facet |
Glaciological instruments and methods Greenland Ice Sheet radio-echo sounding subglacial topography Earth-Surface Processes |
description |
© The Author(s), 2020. Published by Cambridge University Press. This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/). Airborne radio-echo sounding (RES) surveys are widely used to measure ice-sheet bed topography. Measuring bed topography as accurately and widely as possible is of critical importance to modelling ice dynamics and hence to constraining better future ice response to climate change. Measurement accuracy of RES surveys is influenced both by the geometry of bed topography and the survey design. Here we develop a novel approach for simulating RES surveys over glaciated terrain, to quantify the sensitivity of derived bed elevation to topographic geometry. Furthermore, we investigate how measurement errors influence the quantification of glacial valley geometry. We find a negative bias across RES measurements, where off-nadir return measurement error is typically -1.8 ± 11.6 m. Topographic highlands are under-measured an order of magnitude more than lowlands. Consequently, valley depth and cross-sectional area are largely under-estimated. While overall estimates of ice thickness are likely too high, we find large glacier valley cross-sectional area to be under-estimated by -2.8 ± 18.1%. Therefore, estimates of ice flux through large outlet glaciers are likely too low when this effect is not taken into account. Additionally, bed mismeasurements potentially impact our appreciation of outlet-glacier stability. Peer reviewed Final Published version |
author2 |
Department of Psychology, Sport and Geography School of Life and Medical Sciences Agriculture and Environmental Management Research Agriculture, Food and Veterinary Sciences |
author |
Bartlett, Oliver T. Palmer, Steven J. Schroeder, Dustin M. Mackie, Emma J. Barrows, Timothy T. Graham, Alastair G.C. |
author_facet |
Bartlett, Oliver T. Palmer, Steven J. Schroeder, Dustin M. Mackie, Emma J. Barrows, Timothy T. Graham, Alastair G.C. |
author_sort |
Bartlett, Oliver T. |
title |
Geospatial simulations of airborne ice-penetrating radar surveying reveal elevation under-measurement bias for ice-sheet bed topography |
title_short |
Geospatial simulations of airborne ice-penetrating radar surveying reveal elevation under-measurement bias for ice-sheet bed topography |
title_full |
Geospatial simulations of airborne ice-penetrating radar surveying reveal elevation under-measurement bias for ice-sheet bed topography |
title_fullStr |
Geospatial simulations of airborne ice-penetrating radar surveying reveal elevation under-measurement bias for ice-sheet bed topography |
title_full_unstemmed |
Geospatial simulations of airborne ice-penetrating radar surveying reveal elevation under-measurement bias for ice-sheet bed topography |
title_sort |
geospatial simulations of airborne ice-penetrating radar surveying reveal elevation under-measurement bias for ice-sheet bed topography |
publishDate |
2021 |
url |
http://hdl.handle.net/2299/24388 http://www.scopus.com/inward/record.url?scp=85082112730&partnerID=8YFLogxK |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Annals of Glaciology glacier Greenland Ice Sheet |
genre_facet |
Annals of Glaciology glacier Greenland Ice Sheet |
op_relation |
Annals of Glaciology School of Life and Medical Sciences Bartlett , O T , Palmer , S J , Schroeder , D M , Mackie , E J , Barrows , T T & Graham , A G C 2021 , ' Geospatial simulations of airborne ice-penetrating radar surveying reveal elevation under-measurement bias for ice-sheet bed topography ' , Annals of Glaciology , vol. 61 , no. 81 , pp. 46-57 . https://doi.org/10.1017/aog.2020.35 0260-3055 PURE: 25060778 PURE UUID: ff7beb31-b411-44c8-a196-c14a5a3bc72b Scopus: 85082112730 ORCID: /0000-0002-0347-7926/work/93471292 http://hdl.handle.net/2299/24388 http://www.scopus.com/inward/record.url?scp=85082112730&partnerID=8YFLogxK |
op_rights |
Open |
_version_ |
1766001622486351872 |