Glacier algae accelerate melt rates on the south-western Greenland Ice Sheet
Melting of the Greenland Ice Sheet (GrIS) is the largest single contributor to eustatic sea level and is amplified by the growth of pigmented algae on the ice surface, which increases solar radiation absorption. This biological albedo-reducing effect and its impact upon sea level rise has not previo...
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Copernicus Publications
2020
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Online Access: | https://eprints.whiterose.ac.uk/156247/ https://eprints.whiterose.ac.uk/156247/1/tc-14-309-2020.pdf https://eprints.whiterose.ac.uk/156247/7/tc-14-309-2020-supplement.pdf |
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ftleedsuniv:oai:eprints.whiterose.ac.uk:156247 2023-05-15T16:21:30+02:00 Glacier algae accelerate melt rates on the south-western Greenland Ice Sheet Cook, J.M. Tedstone, A.J. Williamson, C. McCutcheon, J. Hodson, A.J. Dayal, A. Skiles, M. Hofer, S. Bryant, R. McAree, O. McGonigle, A. Ryan, J. Anesio, A.M. Irvine-Fynn, T.D.L. Hubbard, A. Hanna, E. Flanner, M. Mayanna, S. Benning, L.G. van As, D. Yallop, M. McQuaid, J.B. Gribbin, T. Tranter, M. 2020-01-29 text https://eprints.whiterose.ac.uk/156247/ https://eprints.whiterose.ac.uk/156247/1/tc-14-309-2020.pdf https://eprints.whiterose.ac.uk/156247/7/tc-14-309-2020-supplement.pdf en eng Copernicus Publications https://eprints.whiterose.ac.uk/156247/1/tc-14-309-2020.pdf https://eprints.whiterose.ac.uk/156247/7/tc-14-309-2020-supplement.pdf Cook, J.M., Tedstone, A.J., Williamson, C. et al. (21 more authors) (2020) Glacier algae accelerate melt rates on the south-western Greenland Ice Sheet. The Cryosphere, 14 (1). pp. 309-330. ISSN 1994-0416 cc_by_4 CC-BY Article PeerReviewed 2020 ftleedsuniv 2023-01-30T22:26:25Z Melting of the Greenland Ice Sheet (GrIS) is the largest single contributor to eustatic sea level and is amplified by the growth of pigmented algae on the ice surface, which increases solar radiation absorption. This biological albedo-reducing effect and its impact upon sea level rise has not previously been quantified. Here, we combine field spectroscopy with a radiative-transfer model, supervised classification of unmanned aerial vehicle (UAV) and satellite remote-sensing data, and runoff modelling to calculate biologically driven ice surface ablation. We demonstrate that algal growth led to an additional 4.4–6.0 Gt of runoff from bare ice in the south-western sector of the GrIS in summer 2017, representing 10 %–13 % of the total. In localized patches with high biomass accumulation, algae accelerated melting by up to 26.15±3.77 % (standard error, SE). The year 2017 was a high-albedo year, so we also extended our analysis to the particularly low-albedo 2016 melt season. The runoff from the south-western bare-ice zone attributed to algae was much higher in 2016 at 8.8–12.2 Gt, although the proportion of the total runoff contributed by algae was similar at 9 %–13 %. Across a 10 000 km2 area around our field site, algae covered similar proportions of the exposed bare ice zone in both years (57.99 % in 2016 and 58.89 % in 2017), but more of the algal ice was classed as “high biomass” in 2016 (8.35 %) than 2017 (2.54 %). This interannual comparison demonstrates a positive feedback where more widespread, higher-biomass algal blooms are expected to form in high-melt years where the winter snowpack retreats further and earlier, providing a larger area for bloom development and also enhancing the provision of nutrients and liquid water liberated from melting ice. Our analysis confirms the importance of this biological albedo feedback and that its omission from predictive models leads to the systematic underestimation of Greenland's future sea level contribution, especially because both the bare-ice zones available for ... Article in Journal/Newspaper glacier Greenland Ice Sheet The Cryosphere White Rose Research Online (Universities of Leeds, Sheffield & York) Greenland |
institution |
Open Polar |
collection |
White Rose Research Online (Universities of Leeds, Sheffield & York) |
op_collection_id |
ftleedsuniv |
language |
English |
description |
Melting of the Greenland Ice Sheet (GrIS) is the largest single contributor to eustatic sea level and is amplified by the growth of pigmented algae on the ice surface, which increases solar radiation absorption. This biological albedo-reducing effect and its impact upon sea level rise has not previously been quantified. Here, we combine field spectroscopy with a radiative-transfer model, supervised classification of unmanned aerial vehicle (UAV) and satellite remote-sensing data, and runoff modelling to calculate biologically driven ice surface ablation. We demonstrate that algal growth led to an additional 4.4–6.0 Gt of runoff from bare ice in the south-western sector of the GrIS in summer 2017, representing 10 %–13 % of the total. In localized patches with high biomass accumulation, algae accelerated melting by up to 26.15±3.77 % (standard error, SE). The year 2017 was a high-albedo year, so we also extended our analysis to the particularly low-albedo 2016 melt season. The runoff from the south-western bare-ice zone attributed to algae was much higher in 2016 at 8.8–12.2 Gt, although the proportion of the total runoff contributed by algae was similar at 9 %–13 %. Across a 10 000 km2 area around our field site, algae covered similar proportions of the exposed bare ice zone in both years (57.99 % in 2016 and 58.89 % in 2017), but more of the algal ice was classed as “high biomass” in 2016 (8.35 %) than 2017 (2.54 %). This interannual comparison demonstrates a positive feedback where more widespread, higher-biomass algal blooms are expected to form in high-melt years where the winter snowpack retreats further and earlier, providing a larger area for bloom development and also enhancing the provision of nutrients and liquid water liberated from melting ice. Our analysis confirms the importance of this biological albedo feedback and that its omission from predictive models leads to the systematic underestimation of Greenland's future sea level contribution, especially because both the bare-ice zones available for ... |
format |
Article in Journal/Newspaper |
author |
Cook, J.M. Tedstone, A.J. Williamson, C. McCutcheon, J. Hodson, A.J. Dayal, A. Skiles, M. Hofer, S. Bryant, R. McAree, O. McGonigle, A. Ryan, J. Anesio, A.M. Irvine-Fynn, T.D.L. Hubbard, A. Hanna, E. Flanner, M. Mayanna, S. Benning, L.G. van As, D. Yallop, M. McQuaid, J.B. Gribbin, T. Tranter, M. |
spellingShingle |
Cook, J.M. Tedstone, A.J. Williamson, C. McCutcheon, J. Hodson, A.J. Dayal, A. Skiles, M. Hofer, S. Bryant, R. McAree, O. McGonigle, A. Ryan, J. Anesio, A.M. Irvine-Fynn, T.D.L. Hubbard, A. Hanna, E. Flanner, M. Mayanna, S. Benning, L.G. van As, D. Yallop, M. McQuaid, J.B. Gribbin, T. Tranter, M. Glacier algae accelerate melt rates on the south-western Greenland Ice Sheet |
author_facet |
Cook, J.M. Tedstone, A.J. Williamson, C. McCutcheon, J. Hodson, A.J. Dayal, A. Skiles, M. Hofer, S. Bryant, R. McAree, O. McGonigle, A. Ryan, J. Anesio, A.M. Irvine-Fynn, T.D.L. Hubbard, A. Hanna, E. Flanner, M. Mayanna, S. Benning, L.G. van As, D. Yallop, M. McQuaid, J.B. Gribbin, T. Tranter, M. |
author_sort |
Cook, J.M. |
title |
Glacier algae accelerate melt rates on the south-western Greenland Ice Sheet |
title_short |
Glacier algae accelerate melt rates on the south-western Greenland Ice Sheet |
title_full |
Glacier algae accelerate melt rates on the south-western Greenland Ice Sheet |
title_fullStr |
Glacier algae accelerate melt rates on the south-western Greenland Ice Sheet |
title_full_unstemmed |
Glacier algae accelerate melt rates on the south-western Greenland Ice Sheet |
title_sort |
glacier algae accelerate melt rates on the south-western greenland ice sheet |
publisher |
Copernicus Publications |
publishDate |
2020 |
url |
https://eprints.whiterose.ac.uk/156247/ https://eprints.whiterose.ac.uk/156247/1/tc-14-309-2020.pdf https://eprints.whiterose.ac.uk/156247/7/tc-14-309-2020-supplement.pdf |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
glacier Greenland Ice Sheet The Cryosphere |
genre_facet |
glacier Greenland Ice Sheet The Cryosphere |
op_relation |
https://eprints.whiterose.ac.uk/156247/1/tc-14-309-2020.pdf https://eprints.whiterose.ac.uk/156247/7/tc-14-309-2020-supplement.pdf Cook, J.M., Tedstone, A.J., Williamson, C. et al. (21 more authors) (2020) Glacier algae accelerate melt rates on the south-western Greenland Ice Sheet. The Cryosphere, 14 (1). pp. 309-330. ISSN 1994-0416 |
op_rights |
cc_by_4 |
op_rightsnorm |
CC-BY |
_version_ |
1766009506797453312 |