Quantifying spatiotemporal variability of glacier algal blooms and the impact on surface albedo in southwestern Greenland
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 th...
Published in: | The Cryosphere |
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Language: | English |
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Copernicus Publications
2020
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00052923 2023-05-15T16:20:56+02:00 Quantifying spatiotemporal variability of glacier algal blooms and the impact on surface albedo in southwestern Greenland Wang, Shujie Tedesco, Marco Alexander, Patrick Xu, Min Fettweis, Xavier 2020-08 electronic https://doi.org/10.5194/tc-14-2687-2020 https://noa.gwlb.de/receive/cop_mods_00052923 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00052576/tc-14-2687-2020.pdf https://tc.copernicus.org/articles/14/2687/2020/tc-14-2687-2020.pdf eng eng Copernicus Publications The Cryosphere -- ˜Theœ Cryosphere -- http://www.bibliothek.uni-regensburg.de/ezeit/?2393169 -- http://www.the-cryosphere.net/ -- 1994-0424 https://doi.org/10.5194/tc-14-2687-2020 https://noa.gwlb.de/receive/cop_mods_00052923 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00052576/tc-14-2687-2020.pdf https://tc.copernicus.org/articles/14/2687/2020/tc-14-2687-2020.pdf https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess CC-BY article Verlagsveröffentlichung article Text doc-type:article 2020 ftnonlinearchiv https://doi.org/10.5194/tc-14-2687-2020 2022-02-08T22:35:45Z 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 Niedersächsisches Online-Archiv NOA Greenland The Sentinel ENVELOPE(73.317,73.317,-52.983,-52.983) The Cryosphere 14 8 2687 2713 |
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Open Polar |
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Niedersächsisches Online-Archiv NOA |
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ftnonlinearchiv |
language |
English |
topic |
article Verlagsveröffentlichung |
spellingShingle |
article Verlagsveröffentlichung Wang, Shujie Tedesco, Marco Alexander, Patrick Xu, Min Fettweis, Xavier Quantifying spatiotemporal variability of glacier algal blooms and the impact on surface albedo in southwestern Greenland |
topic_facet |
article Verlagsveröffentlichung |
description |
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, Shujie Tedesco, Marco Alexander, Patrick Xu, Min Fettweis, Xavier |
author_facet |
Wang, Shujie Tedesco, Marco Alexander, Patrick Xu, Min Fettweis, Xavier |
author_sort |
Wang, Shujie |
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 Publications |
publishDate |
2020 |
url |
https://doi.org/10.5194/tc-14-2687-2020 https://noa.gwlb.de/receive/cop_mods_00052923 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00052576/tc-14-2687-2020.pdf https://tc.copernicus.org/articles/14/2687/2020/tc-14-2687-2020.pdf |
long_lat |
ENVELOPE(73.317,73.317,-52.983,-52.983) |
geographic |
Greenland The Sentinel |
geographic_facet |
Greenland The Sentinel |
genre |
glacier Greenland Ice Sheet Jakobshavn The Cryosphere |
genre_facet |
glacier Greenland Ice Sheet Jakobshavn The Cryosphere |
op_relation |
The Cryosphere -- ˜Theœ Cryosphere -- http://www.bibliothek.uni-regensburg.de/ezeit/?2393169 -- http://www.the-cryosphere.net/ -- 1994-0424 https://doi.org/10.5194/tc-14-2687-2020 https://noa.gwlb.de/receive/cop_mods_00052923 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00052576/tc-14-2687-2020.pdf https://tc.copernicus.org/articles/14/2687/2020/tc-14-2687-2020.pdf |
op_rights |
https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY |
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_ |
1766008957991649280 |