Temporal Variability of Surface Reflectance Supersedes Spatial Resolution in Defining Greenland’s Bare-Ice Albedo
Ice surface albedo is a primary modulator of melt and runoff, yet our understanding of how reflectance varies over time across the Greenland Ice Sheet remains poor. This is due to a disconnect between point or transect scale albedo sampling and the coarser spatial, spectral and/or temporal resolutio...
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fthsvestlandet:oai:hvlopen.brage.unit.no:11250/2977963 2024-03-03T08:45:03+00:00 Temporal Variability of Surface Reflectance Supersedes Spatial Resolution in Defining Greenland’s Bare-Ice Albedo Irvine-Fynn, Tristram D. L. Bunting, Peter S. Cook, Joseph M. Hubbard, Alun Barrand, Nicholas E. Hanna, Edward Hardy, Andy J. Hodson, Andrew J. Holt, Tom O. Huss, Matthias McQuaid, James B. Nilsson, Johan Naegeli, Kathrin Roberts, Osian Ryan, Jonathan C. Tedstone, Andrew J. Tranter, Martyn Williamson, Christopher J. 2022 application/pdf https://hdl.handle.net/11250/2977963 https://doi.org/10.3390/rs14010062 eng eng MDPI Norges forskningsråd: 223259 Irvine-Fynn, T. D. L., Bunting, P., Cook, J. M., Hubbard, A., Barrand, N. E., Hanna, E., . . . Williamson, C. J. (2021). Temporal Variability of Surface Reflectance Supersedes Spatial Resolution in Defining Greenland’s Bare-Ice Albedo. Remote Sensing, 14(1): 62. urn:issn:2072-4292 https://hdl.handle.net/11250/2977963 https://doi.org/10.3390/rs14010062 cristin:1975168 Navngivelse 4.0 Internasjonal http://creativecommons.org/licenses/by/4.0/deed.no © 2021 by the authors. 14 Remote Sensing 1 62 Peer reviewed Journal article 2022 fthsvestlandet https://doi.org/10.3390/rs14010062 2024-02-02T12:40:30Z Ice surface albedo is a primary modulator of melt and runoff, yet our understanding of how reflectance varies over time across the Greenland Ice Sheet remains poor. This is due to a disconnect between point or transect scale albedo sampling and the coarser spatial, spectral and/or temporal resolutions of available satellite products. Here, we present time-series of bare-ice surface reflectance data that span a range of length scales, from the 500 m for Moderate Resolution Imaging Spectrometer’s MOD10A1 product, to 10 m for Sentinel-2 imagery, 0.1 m spot measurements from ground-based field spectrometry, and 2.5 cm from uncrewed aerial drone imagery. Our results reveal broad similarities in seasonal patterns in bare-ice reflectance, but further analysis identifies short-term dynamics in reflectance distribution that are unique to each dataset. Using these distributions, we demonstrate that areal mean reflectance is the primary control on local ablation rates, and that the spatial distribution of specific ice types and impurities is secondary. Given the rapid changes in mean reflectance observed in the datasets presented, we propose that albedo parameterizations can be improved by (i) quantitative assessment of the representativeness of time-averaged reflectance data products, and, (ii) using temporally-resolved functions to describe the variability in impurity distribution at daily time-scales. We conclude that the regional melt model performance may not be optimally improved by increased spatial resolution and the incorporation of sub-pixel heterogeneity, but instead, should focus on the temporal dynamics of bare-ice albedo. publishedVersion Article in Journal/Newspaper Greenland Ice Sheet Høgskulen på Vestlandet: HVL Open Greenland Remote Sensing 14 1 62 |
institution |
Open Polar |
collection |
Høgskulen på Vestlandet: HVL Open |
op_collection_id |
fthsvestlandet |
language |
English |
description |
Ice surface albedo is a primary modulator of melt and runoff, yet our understanding of how reflectance varies over time across the Greenland Ice Sheet remains poor. This is due to a disconnect between point or transect scale albedo sampling and the coarser spatial, spectral and/or temporal resolutions of available satellite products. Here, we present time-series of bare-ice surface reflectance data that span a range of length scales, from the 500 m for Moderate Resolution Imaging Spectrometer’s MOD10A1 product, to 10 m for Sentinel-2 imagery, 0.1 m spot measurements from ground-based field spectrometry, and 2.5 cm from uncrewed aerial drone imagery. Our results reveal broad similarities in seasonal patterns in bare-ice reflectance, but further analysis identifies short-term dynamics in reflectance distribution that are unique to each dataset. Using these distributions, we demonstrate that areal mean reflectance is the primary control on local ablation rates, and that the spatial distribution of specific ice types and impurities is secondary. Given the rapid changes in mean reflectance observed in the datasets presented, we propose that albedo parameterizations can be improved by (i) quantitative assessment of the representativeness of time-averaged reflectance data products, and, (ii) using temporally-resolved functions to describe the variability in impurity distribution at daily time-scales. We conclude that the regional melt model performance may not be optimally improved by increased spatial resolution and the incorporation of sub-pixel heterogeneity, but instead, should focus on the temporal dynamics of bare-ice albedo. publishedVersion |
format |
Article in Journal/Newspaper |
author |
Irvine-Fynn, Tristram D. L. Bunting, Peter S. Cook, Joseph M. Hubbard, Alun Barrand, Nicholas E. Hanna, Edward Hardy, Andy J. Hodson, Andrew J. Holt, Tom O. Huss, Matthias McQuaid, James B. Nilsson, Johan Naegeli, Kathrin Roberts, Osian Ryan, Jonathan C. Tedstone, Andrew J. Tranter, Martyn Williamson, Christopher J. |
spellingShingle |
Irvine-Fynn, Tristram D. L. Bunting, Peter S. Cook, Joseph M. Hubbard, Alun Barrand, Nicholas E. Hanna, Edward Hardy, Andy J. Hodson, Andrew J. Holt, Tom O. Huss, Matthias McQuaid, James B. Nilsson, Johan Naegeli, Kathrin Roberts, Osian Ryan, Jonathan C. Tedstone, Andrew J. Tranter, Martyn Williamson, Christopher J. Temporal Variability of Surface Reflectance Supersedes Spatial Resolution in Defining Greenland’s Bare-Ice Albedo |
author_facet |
Irvine-Fynn, Tristram D. L. Bunting, Peter S. Cook, Joseph M. Hubbard, Alun Barrand, Nicholas E. Hanna, Edward Hardy, Andy J. Hodson, Andrew J. Holt, Tom O. Huss, Matthias McQuaid, James B. Nilsson, Johan Naegeli, Kathrin Roberts, Osian Ryan, Jonathan C. Tedstone, Andrew J. Tranter, Martyn Williamson, Christopher J. |
author_sort |
Irvine-Fynn, Tristram D. L. |
title |
Temporal Variability of Surface Reflectance Supersedes Spatial Resolution in Defining Greenland’s Bare-Ice Albedo |
title_short |
Temporal Variability of Surface Reflectance Supersedes Spatial Resolution in Defining Greenland’s Bare-Ice Albedo |
title_full |
Temporal Variability of Surface Reflectance Supersedes Spatial Resolution in Defining Greenland’s Bare-Ice Albedo |
title_fullStr |
Temporal Variability of Surface Reflectance Supersedes Spatial Resolution in Defining Greenland’s Bare-Ice Albedo |
title_full_unstemmed |
Temporal Variability of Surface Reflectance Supersedes Spatial Resolution in Defining Greenland’s Bare-Ice Albedo |
title_sort |
temporal variability of surface reflectance supersedes spatial resolution in defining greenland’s bare-ice albedo |
publisher |
MDPI |
publishDate |
2022 |
url |
https://hdl.handle.net/11250/2977963 https://doi.org/10.3390/rs14010062 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Ice Sheet |
genre_facet |
Greenland Ice Sheet |
op_source |
14 Remote Sensing 1 62 |
op_relation |
Norges forskningsråd: 223259 Irvine-Fynn, T. D. L., Bunting, P., Cook, J. M., Hubbard, A., Barrand, N. E., Hanna, E., . . . Williamson, C. J. (2021). Temporal Variability of Surface Reflectance Supersedes Spatial Resolution in Defining Greenland’s Bare-Ice Albedo. Remote Sensing, 14(1): 62. urn:issn:2072-4292 https://hdl.handle.net/11250/2977963 https://doi.org/10.3390/rs14010062 cristin:1975168 |
op_rights |
Navngivelse 4.0 Internasjonal http://creativecommons.org/licenses/by/4.0/deed.no © 2021 by the authors. |
op_doi |
https://doi.org/10.3390/rs14010062 |
container_title |
Remote Sensing |
container_volume |
14 |
container_issue |
1 |
container_start_page |
62 |
_version_ |
1792500566471999488 |