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...
Published in: | The Cryosphere |
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Language: | English |
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European Geosciences Union (EGU)
2020
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Online Access: | https://hdl.handle.net/10037/17320 https://doi.org/10.5194/tc-14-309-2020 |
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ftunivtroemsoe:oai:munin.uit.no:10037/17320 2023-05-15T16:21:31+02:00 Glacier algae accelerate melt rates on the south-western Greenland Ice Sheet Cook, Joseph M. Tedstone, Andrew J. Williamson, Christopher McCutcheon, Jenine Hodson, Andrew J. Dayal, Archana Skiles, McKenzie Hofer, Stefan Bryant, Robert McAree, Owen McGonigle, Andrew Ryan, Jonathan Anesio, Alexandre M. Irvine-Fynn, Tristram D.L. Hubbard, Alun Lloyd Hanna, Edward Flanner, Mark Mayanna, Sathish Benning, Liane G. van As, Dirk Yallop, Marian McQuaid, James B. Gribbin, Thomas Tranter, Martyn 2020-01-29 https://hdl.handle.net/10037/17320 https://doi.org/10.5194/tc-14-309-2020 eng eng European Geosciences Union (EGU) The Cryosphere Cook JM, Tedstone AJ, Williamson CJ, McCutcheon, Hodson, Dayal, Skiles, Hofer S, Bryant, McAree, McGonigle, Ryan J, Anesio, Irvine-Fynn TD, Hubbard AL, Hanna E, Flanner MG, Mayanna, Benning, van As D, Yallop M, McQuaid JB, Gribbin, Tranter M. Glacier algae accelerate melt rates on the south-western Greenland Ice Sheet. The Cryosphere. 2019;14:309-338 FRIDAID 1790410 doi:10.5194/tc-14-309-2020 1994-0416 1994-0424 https://hdl.handle.net/10037/17320 openAccess Copyright 2020 The Author(s) VDP::Mathematics and natural science: 400::Geosciences: 450 VDP::Matematikk og Naturvitenskap: 400::Geofag: 450 Journal article Tidsskriftartikkel Peer reviewed publishedVersion 2020 ftunivtroemsoe https://doi.org/10.5194/tc-14-309-2020 2021-06-25T17:57:13Z 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 algal colonization and the length of the biological growth season are set to expand in the future. Article in Journal/Newspaper glacier Greenland Ice Sheet The Cryosphere University of Tromsø: Munin Open Research Archive Greenland The Cryosphere 14 1 309 330 |
institution |
Open Polar |
collection |
University of Tromsø: Munin Open Research Archive |
op_collection_id |
ftunivtroemsoe |
language |
English |
topic |
VDP::Mathematics and natural science: 400::Geosciences: 450 VDP::Matematikk og Naturvitenskap: 400::Geofag: 450 |
spellingShingle |
VDP::Mathematics and natural science: 400::Geosciences: 450 VDP::Matematikk og Naturvitenskap: 400::Geofag: 450 Cook, Joseph M. Tedstone, Andrew J. Williamson, Christopher McCutcheon, Jenine Hodson, Andrew J. Dayal, Archana Skiles, McKenzie Hofer, Stefan Bryant, Robert McAree, Owen McGonigle, Andrew Ryan, Jonathan Anesio, Alexandre M. Irvine-Fynn, Tristram D.L. Hubbard, Alun Lloyd Hanna, Edward Flanner, Mark Mayanna, Sathish Benning, Liane G. van As, Dirk Yallop, Marian McQuaid, James B. Gribbin, Thomas Tranter, Martyn Glacier algae accelerate melt rates on the south-western Greenland Ice Sheet |
topic_facet |
VDP::Mathematics and natural science: 400::Geosciences: 450 VDP::Matematikk og Naturvitenskap: 400::Geofag: 450 |
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 algal colonization and the length of the biological growth season are set to expand in the future. |
format |
Article in Journal/Newspaper |
author |
Cook, Joseph M. Tedstone, Andrew J. Williamson, Christopher McCutcheon, Jenine Hodson, Andrew J. Dayal, Archana Skiles, McKenzie Hofer, Stefan Bryant, Robert McAree, Owen McGonigle, Andrew Ryan, Jonathan Anesio, Alexandre M. Irvine-Fynn, Tristram D.L. Hubbard, Alun Lloyd Hanna, Edward Flanner, Mark Mayanna, Sathish Benning, Liane G. van As, Dirk Yallop, Marian McQuaid, James B. Gribbin, Thomas Tranter, Martyn |
author_facet |
Cook, Joseph M. Tedstone, Andrew J. Williamson, Christopher McCutcheon, Jenine Hodson, Andrew J. Dayal, Archana Skiles, McKenzie Hofer, Stefan Bryant, Robert McAree, Owen McGonigle, Andrew Ryan, Jonathan Anesio, Alexandre M. Irvine-Fynn, Tristram D.L. Hubbard, Alun Lloyd Hanna, Edward Flanner, Mark Mayanna, Sathish Benning, Liane G. van As, Dirk Yallop, Marian McQuaid, James B. Gribbin, Thomas Tranter, Martyn |
author_sort |
Cook, Joseph 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 |
European Geosciences Union (EGU) |
publishDate |
2020 |
url |
https://hdl.handle.net/10037/17320 https://doi.org/10.5194/tc-14-309-2020 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
glacier Greenland Ice Sheet The Cryosphere |
genre_facet |
glacier Greenland Ice Sheet The Cryosphere |
op_relation |
The Cryosphere Cook JM, Tedstone AJ, Williamson CJ, McCutcheon, Hodson, Dayal, Skiles, Hofer S, Bryant, McAree, McGonigle, Ryan J, Anesio, Irvine-Fynn TD, Hubbard AL, Hanna E, Flanner MG, Mayanna, Benning, van As D, Yallop M, McQuaid JB, Gribbin, Tranter M. Glacier algae accelerate melt rates on the south-western Greenland Ice Sheet. The Cryosphere. 2019;14:309-338 FRIDAID 1790410 doi:10.5194/tc-14-309-2020 1994-0416 1994-0424 https://hdl.handle.net/10037/17320 |
op_rights |
openAccess Copyright 2020 The Author(s) |
op_doi |
https://doi.org/10.5194/tc-14-309-2020 |
container_title |
The Cryosphere |
container_volume |
14 |
container_issue |
1 |
container_start_page |
309 |
op_container_end_page |
330 |
_version_ |
1766009524301332480 |