Quantifying spatiotemporal variability of glacier algal blooms and the impact on surface albedo in southwestern Greenland
peer reviewed Albedo reduction due to light-absorbing impurities can substantially enhance ice sheet surface melt by increasing surface absorption of solar energy. Glacier algae have been suggested to play a critical role in darkening the ablation zone in southwestern Greenland. It was very recently...
Published in: | The Cryosphere |
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Language: | English |
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2020
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Online Access: | https://orbi.uliege.be/handle/2268/250371 https://orbi.uliege.be/bitstream/2268/250371/1/tc-14-2687-2020.pdf https://doi.org/10.5194/tc-14-2687-2020 |
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ftorbi:oai:orbi.ulg.ac.be:2268/250371 2024-04-21T08:02:26+00:00 Quantifying spatiotemporal variability of glacier algal blooms and the impact on surface albedo in southwestern Greenland Wang, S. Tedesco, M. Alexander, P. Xu, M. Fettweis, Xavier 2020-08-28 https://orbi.uliege.be/handle/2268/250371 https://orbi.uliege.be/bitstream/2268/250371/1/tc-14-2687-2020.pdf https://doi.org/10.5194/tc-14-2687-2020 en eng Copernicus https://tc.copernicus.org/articles/14/2687/2020/ urn:issn:1994-0416 urn:issn:1994-0424 https://orbi.uliege.be/handle/2268/250371 info:hdl:2268/250371 https://orbi.uliege.be/bitstream/2268/250371/1/tc-14-2687-2020.pdf doi:10.5194/tc-14-2687-2020 scopus-id:2-s2.0-85090291282 open access http://purl.org/coar/access_right/c_abf2 info:eu-repo/semantics/openAccess The Cryosphere, 14, 2687–2713 (2020-08-28) Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique journal article http://purl.org/coar/resource_type/c_6501 info:eu-repo/semantics/article peer reviewed 2020 ftorbi https://doi.org/10.5194/tc-14-2687-2020 2024-03-27T14:58:15Z peer reviewed Albedo reduction due to light-absorbing impurities can substantially enhance ice sheet surface melt by increasing surface absorption of solar energy. Glacier algae have been suggested to play a critical role in darkening the ablation zone in southwestern Greenland. It was very recently found that the Sentinel-3 Ocean and Land Colour Instrument (OLCI) band ratio R709 nm∕R673 nm can characterize the spatial patterns of glacier algal blooms. However, Sentinel-3 was launched in 2016, and current data are only available over three melting seasons (2016–2019). Here, we demonstrate the capability of the MEdium Resolution Imaging Spectrometer (MERIS) for mapping glacier algae from space and extend the quantification of glacier algal blooms over southwestern Greenland back to the period 2004–2011. Several band ratio indices (MERIS chlorophyll a indices and the impurity index) were computed and compared with each other. The results indicate that the MERIS two-band ratio index (2BDA) R709 nm∕R665 nm is very effective in capturing the spatial distribution and temporal dynamics of glacier algal growth on bare ice in July and August. We analyzed the interannual (2004–2011) and summer (July–August) trends of algal distribution and found significant seasonal and interannual increases in glacier algae close to the Jakobshavn Isbrae Glacier and along the middle dark zone between the altitudes of 1200 and 1400 m. Using broadband albedo data from the Moderate Resolution Imaging Spectroradiometer (MODIS), we quantified the impact of glacier algal growth on bare ice albedo, finding a significant correlation between algal development and albedo reduction over algae-abundant areas. Our analysis indicates the strong potential for the satellite algal index to be used to reduce bare ice albedo biases in regional climate model simulations. Article in Journal/Newspaper glacier Greenland Ice Sheet Jakobshavn The Cryosphere University of Liège: ORBi (Open Repository and Bibliography) The Cryosphere 14 8 2687 2713 |
institution |
Open Polar |
collection |
University of Liège: ORBi (Open Repository and Bibliography) |
op_collection_id |
ftorbi |
language |
English |
topic |
Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique |
spellingShingle |
Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique Wang, S. Tedesco, M. Alexander, P. Xu, M. Fettweis, Xavier Quantifying spatiotemporal variability of glacier algal blooms and the impact on surface albedo in southwestern Greenland |
topic_facet |
Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique |
description |
peer reviewed Albedo reduction due to light-absorbing impurities can substantially enhance ice sheet surface melt by increasing surface absorption of solar energy. Glacier algae have been suggested to play a critical role in darkening the ablation zone in southwestern Greenland. It was very recently found that the Sentinel-3 Ocean and Land Colour Instrument (OLCI) band ratio R709 nm∕R673 nm can characterize the spatial patterns of glacier algal blooms. However, Sentinel-3 was launched in 2016, and current data are only available over three melting seasons (2016–2019). Here, we demonstrate the capability of the MEdium Resolution Imaging Spectrometer (MERIS) for mapping glacier algae from space and extend the quantification of glacier algal blooms over southwestern Greenland back to the period 2004–2011. Several band ratio indices (MERIS chlorophyll a indices and the impurity index) were computed and compared with each other. The results indicate that the MERIS two-band ratio index (2BDA) R709 nm∕R665 nm is very effective in capturing the spatial distribution and temporal dynamics of glacier algal growth on bare ice in July and August. We analyzed the interannual (2004–2011) and summer (July–August) trends of algal distribution and found significant seasonal and interannual increases in glacier algae close to the Jakobshavn Isbrae Glacier and along the middle dark zone between the altitudes of 1200 and 1400 m. Using broadband albedo data from the Moderate Resolution Imaging Spectroradiometer (MODIS), we quantified the impact of glacier algal growth on bare ice albedo, finding a significant correlation between algal development and albedo reduction over algae-abundant areas. Our analysis indicates the strong potential for the satellite algal index to be used to reduce bare ice albedo biases in regional climate model simulations. |
format |
Article in Journal/Newspaper |
author |
Wang, S. Tedesco, M. Alexander, P. Xu, M. Fettweis, Xavier |
author_facet |
Wang, S. Tedesco, M. Alexander, P. Xu, M. Fettweis, Xavier |
author_sort |
Wang, S. |
title |
Quantifying spatiotemporal variability of glacier algal blooms and the impact on surface albedo in southwestern Greenland |
title_short |
Quantifying spatiotemporal variability of glacier algal blooms and the impact on surface albedo in southwestern Greenland |
title_full |
Quantifying spatiotemporal variability of glacier algal blooms and the impact on surface albedo in southwestern Greenland |
title_fullStr |
Quantifying spatiotemporal variability of glacier algal blooms and the impact on surface albedo in southwestern Greenland |
title_full_unstemmed |
Quantifying spatiotemporal variability of glacier algal blooms and the impact on surface albedo in southwestern Greenland |
title_sort |
quantifying spatiotemporal variability of glacier algal blooms and the impact on surface albedo in southwestern greenland |
publisher |
Copernicus |
publishDate |
2020 |
url |
https://orbi.uliege.be/handle/2268/250371 https://orbi.uliege.be/bitstream/2268/250371/1/tc-14-2687-2020.pdf https://doi.org/10.5194/tc-14-2687-2020 |
genre |
glacier Greenland Ice Sheet Jakobshavn The Cryosphere |
genre_facet |
glacier Greenland Ice Sheet Jakobshavn The Cryosphere |
op_source |
The Cryosphere, 14, 2687–2713 (2020-08-28) |
op_relation |
https://tc.copernicus.org/articles/14/2687/2020/ urn:issn:1994-0416 urn:issn:1994-0424 https://orbi.uliege.be/handle/2268/250371 info:hdl:2268/250371 https://orbi.uliege.be/bitstream/2268/250371/1/tc-14-2687-2020.pdf doi:10.5194/tc-14-2687-2020 scopus-id:2-s2.0-85090291282 |
op_rights |
open access http://purl.org/coar/access_right/c_abf2 info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/tc-14-2687-2020 |
container_title |
The Cryosphere |
container_volume |
14 |
container_issue |
8 |
container_start_page |
2687 |
op_container_end_page |
2713 |
_version_ |
1796942625539883008 |