Experimental evidence that microbial activity lowers the albedo of glaciers
Darkening of glacier and ice sheet surfaces is an important positive feedback to increasing global temperatures. Deposition of impurities on glaciers is primarily believed to reduce surface albedo, resulting in greater melt and mass loss. However, no study has yet included the effects of biological...
Published in: | Geochemical Perspectives Letters |
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ftuniaarhuspubl:oai:pure.atira.dk:publications/bf68b8f1-967b-45c3-a481-0054cffa969c 2023-05-15T16:21:14+02:00 Experimental evidence that microbial activity lowers the albedo of glaciers Musilova, Michaela Tranter, Martyn Bamber, Jonathan Takeuchi, Nozomu Anesio, Alexandre 2016-03-11 https://pure.au.dk/portal/da/publications/experimental-evidence-that-microbial-activity-lowers-the-albedo-of-glaciers(bf68b8f1-967b-45c3-a481-0054cffa969c).html https://doi.org/10.7185/geochemlet.1611 eng eng info:eu-repo/semantics/restrictedAccess Musilova , M , Tranter , M , Bamber , J , Takeuchi , N & Anesio , A 2016 , ' Experimental evidence that microbial activity lowers the albedo of glaciers ' , Geochemical Perspectives Letters , vol. 2 , no. 2 , pp. 105-116 . https://doi.org/10.7185/geochemlet.1611 article 2016 ftuniaarhuspubl https://doi.org/10.7185/geochemlet.1611 2022-11-30T23:56:30Z Darkening of glacier and ice sheet surfaces is an important positive feedback to increasing global temperatures. Deposition of impurities on glaciers is primarily believed to reduce surface albedo, resulting in greater melt and mass loss. However, no study has yet included the effects of biological activity in albedo reduction models. Here, we provide the first experimental evidence that microbial activity can significantly decrease glacier surface albedo. Indeed, the addition of nutrients at ice meltwater concentrations to microbe-impurity mixtures resulted in extensive microbial organic carbon fixation and accumulation in Greenland Ice Sheet surface debris. Accumulated organic carbon, over the period of a melt season, darkened the glacial debris in our experiments from 31.1 % to 15.6 % surface reflectivity (used as an analogue for albedo in our calculations), generating a strongly absorbing surface. Our experiments are the first to quantify the microbially-induced potential melt increase for the Greenland Ice Sheet (up to an average of 17.3 ± 2.5 Gt yr -1 at present and up to ~85 Gt yr -1 by 2100, based on our first order calculations). Mass loss from glaciers will conceivably intensify through enhanced microbial activity, resulting from longer melt seasons and fertilisation from anthropogenic sources. Article in Journal/Newspaper glacier Greenland Ice Sheet Aarhus University: Research Greenland Geochemical Perspectives Letters 106 116 |
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Open Polar |
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Aarhus University: Research |
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ftuniaarhuspubl |
language |
English |
description |
Darkening of glacier and ice sheet surfaces is an important positive feedback to increasing global temperatures. Deposition of impurities on glaciers is primarily believed to reduce surface albedo, resulting in greater melt and mass loss. However, no study has yet included the effects of biological activity in albedo reduction models. Here, we provide the first experimental evidence that microbial activity can significantly decrease glacier surface albedo. Indeed, the addition of nutrients at ice meltwater concentrations to microbe-impurity mixtures resulted in extensive microbial organic carbon fixation and accumulation in Greenland Ice Sheet surface debris. Accumulated organic carbon, over the period of a melt season, darkened the glacial debris in our experiments from 31.1 % to 15.6 % surface reflectivity (used as an analogue for albedo in our calculations), generating a strongly absorbing surface. Our experiments are the first to quantify the microbially-induced potential melt increase for the Greenland Ice Sheet (up to an average of 17.3 ± 2.5 Gt yr -1 at present and up to ~85 Gt yr -1 by 2100, based on our first order calculations). Mass loss from glaciers will conceivably intensify through enhanced microbial activity, resulting from longer melt seasons and fertilisation from anthropogenic sources. |
format |
Article in Journal/Newspaper |
author |
Musilova, Michaela Tranter, Martyn Bamber, Jonathan Takeuchi, Nozomu Anesio, Alexandre |
spellingShingle |
Musilova, Michaela Tranter, Martyn Bamber, Jonathan Takeuchi, Nozomu Anesio, Alexandre Experimental evidence that microbial activity lowers the albedo of glaciers |
author_facet |
Musilova, Michaela Tranter, Martyn Bamber, Jonathan Takeuchi, Nozomu Anesio, Alexandre |
author_sort |
Musilova, Michaela |
title |
Experimental evidence that microbial activity lowers the albedo of glaciers |
title_short |
Experimental evidence that microbial activity lowers the albedo of glaciers |
title_full |
Experimental evidence that microbial activity lowers the albedo of glaciers |
title_fullStr |
Experimental evidence that microbial activity lowers the albedo of glaciers |
title_full_unstemmed |
Experimental evidence that microbial activity lowers the albedo of glaciers |
title_sort |
experimental evidence that microbial activity lowers the albedo of glaciers |
publishDate |
2016 |
url |
https://pure.au.dk/portal/da/publications/experimental-evidence-that-microbial-activity-lowers-the-albedo-of-glaciers(bf68b8f1-967b-45c3-a481-0054cffa969c).html https://doi.org/10.7185/geochemlet.1611 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
glacier Greenland Ice Sheet |
genre_facet |
glacier Greenland Ice Sheet |
op_source |
Musilova , M , Tranter , M , Bamber , J , Takeuchi , N & Anesio , A 2016 , ' Experimental evidence that microbial activity lowers the albedo of glaciers ' , Geochemical Perspectives Letters , vol. 2 , no. 2 , pp. 105-116 . https://doi.org/10.7185/geochemlet.1611 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.7185/geochemlet.1611 |
container_title |
Geochemical Perspectives Letters |
container_start_page |
106 |
op_container_end_page |
116 |
_version_ |
1766009245570957312 |