Glacier outflow dissolved organic matter as a window into seasonally changing carbon sources: Leverett Glacier, Greenland
The Greenland Ice Sheet is losing mass at a remarkable rate as a result of climatic warming. This mass loss coincides with the export of dissolved organic matter (DOM) in glacial meltwaters. However, little is known about how the source and composition of exported DOM changes over the melt season, w...
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Online Access: | http://nora.nerc.ac.uk/id/eprint/528718/ https://nora.nerc.ac.uk/id/eprint/528718/1/2019JG005161.pdf https://doi.org/10.1029/2019JG005161 |
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ftnerc:oai:nora.nerc.ac.uk:528718 2023-05-15T16:21:04+02:00 Glacier outflow dissolved organic matter as a window into seasonally changing carbon sources: Leverett Glacier, Greenland Kellerman, A. M. Hawkings, J. R. Wadham, J. L. Kohler, T. J. Stibal, M. Grater, E. Marshall, M. Hatton, J. E. Beaton, A. Spencer, R. G. M. 2020-04-23 text http://nora.nerc.ac.uk/id/eprint/528718/ https://nora.nerc.ac.uk/id/eprint/528718/1/2019JG005161.pdf https://doi.org/10.1029/2019JG005161 en eng https://nora.nerc.ac.uk/id/eprint/528718/1/2019JG005161.pdf Kellerman, A. M.; Hawkings, J. R.; Wadham, J. L.; Kohler, T. J.; Stibal, M.; Grater, E.; Marshall, M.; Hatton, J. E.; Beaton, A.; Spencer, R. G. M. 2020 Glacier outflow dissolved organic matter as a window into seasonally changing carbon sources: Leverett Glacier, Greenland. Journal of Geophysical Research: Biogeosciences, 125 (4), e2019JG005161. https://doi.org/10.1029/2019JG005161 <https://doi.org/10.1029/2019JG005161> Publication - Article PeerReviewed 2020 ftnerc https://doi.org/10.1029/2019JG005161 2023-02-04T19:51:14Z The Greenland Ice Sheet is losing mass at a remarkable rate as a result of climatic warming. This mass loss coincides with the export of dissolved organic matter (DOM) in glacial meltwaters. However, little is known about how the source and composition of exported DOM changes over the melt season, which is key for understanding its fate in downstream ecosystems. Over the 2015 ablation season, we sampled the outflow of Leverett Glacier, a large land‐terminating glacier of the Greenland Ice Sheet. Dissolved organic carbon (DOC) concentrations and DOM fluorescence were analyzed to assess the evolution of DOM sources over the course of the melt season. DOC concentrations and red‐shifted fluorescence were highly associated (R2 > 0.95) and suggest terrestrial inputs from overridden soils dominated DOM early season inputs before progressive dilution with increasing discharge. During the outburst period, supraglacial drainage events disrupted the subglacial drainage system and introduced dominant protein‐like fluorescence signatures not observed in basal flow. These results suggest that subglacial hydrology and changing water sources influence exported DOC concentration and DOM composition, and these sources were differentiated using fluorescence characteristics. Red‐shifted fluorescence components were robust proxies for DOC concentration. Finally, the majority of DOM flux, which occurs during the outburst and postoutburst periods, was characterized by protein‐like fluorescence from supraglacial and potentially subglacial microbial sources. As protein‐like fluorescence is linked to the bioavailability of DOM, the observed changes likely reflect seasonal variations in the impact of glacial inputs on secondary production in downstream ecosystems due to shifting hydrologic regimes. Article in Journal/Newspaper glacier Greenland Ice Sheet Leverett Glacier Natural Environment Research Council: NERC Open Research Archive Greenland Leverett Glacier ENVELOPE(-147.583,-147.583,-85.633,-85.633) Journal of Geophysical Research: Biogeosciences 125 4 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
description |
The Greenland Ice Sheet is losing mass at a remarkable rate as a result of climatic warming. This mass loss coincides with the export of dissolved organic matter (DOM) in glacial meltwaters. However, little is known about how the source and composition of exported DOM changes over the melt season, which is key for understanding its fate in downstream ecosystems. Over the 2015 ablation season, we sampled the outflow of Leverett Glacier, a large land‐terminating glacier of the Greenland Ice Sheet. Dissolved organic carbon (DOC) concentrations and DOM fluorescence were analyzed to assess the evolution of DOM sources over the course of the melt season. DOC concentrations and red‐shifted fluorescence were highly associated (R2 > 0.95) and suggest terrestrial inputs from overridden soils dominated DOM early season inputs before progressive dilution with increasing discharge. During the outburst period, supraglacial drainage events disrupted the subglacial drainage system and introduced dominant protein‐like fluorescence signatures not observed in basal flow. These results suggest that subglacial hydrology and changing water sources influence exported DOC concentration and DOM composition, and these sources were differentiated using fluorescence characteristics. Red‐shifted fluorescence components were robust proxies for DOC concentration. Finally, the majority of DOM flux, which occurs during the outburst and postoutburst periods, was characterized by protein‐like fluorescence from supraglacial and potentially subglacial microbial sources. As protein‐like fluorescence is linked to the bioavailability of DOM, the observed changes likely reflect seasonal variations in the impact of glacial inputs on secondary production in downstream ecosystems due to shifting hydrologic regimes. |
format |
Article in Journal/Newspaper |
author |
Kellerman, A. M. Hawkings, J. R. Wadham, J. L. Kohler, T. J. Stibal, M. Grater, E. Marshall, M. Hatton, J. E. Beaton, A. Spencer, R. G. M. |
spellingShingle |
Kellerman, A. M. Hawkings, J. R. Wadham, J. L. Kohler, T. J. Stibal, M. Grater, E. Marshall, M. Hatton, J. E. Beaton, A. Spencer, R. G. M. Glacier outflow dissolved organic matter as a window into seasonally changing carbon sources: Leverett Glacier, Greenland |
author_facet |
Kellerman, A. M. Hawkings, J. R. Wadham, J. L. Kohler, T. J. Stibal, M. Grater, E. Marshall, M. Hatton, J. E. Beaton, A. Spencer, R. G. M. |
author_sort |
Kellerman, A. M. |
title |
Glacier outflow dissolved organic matter as a window into seasonally changing carbon sources: Leverett Glacier, Greenland |
title_short |
Glacier outflow dissolved organic matter as a window into seasonally changing carbon sources: Leverett Glacier, Greenland |
title_full |
Glacier outflow dissolved organic matter as a window into seasonally changing carbon sources: Leverett Glacier, Greenland |
title_fullStr |
Glacier outflow dissolved organic matter as a window into seasonally changing carbon sources: Leverett Glacier, Greenland |
title_full_unstemmed |
Glacier outflow dissolved organic matter as a window into seasonally changing carbon sources: Leverett Glacier, Greenland |
title_sort |
glacier outflow dissolved organic matter as a window into seasonally changing carbon sources: leverett glacier, greenland |
publishDate |
2020 |
url |
http://nora.nerc.ac.uk/id/eprint/528718/ https://nora.nerc.ac.uk/id/eprint/528718/1/2019JG005161.pdf https://doi.org/10.1029/2019JG005161 |
long_lat |
ENVELOPE(-147.583,-147.583,-85.633,-85.633) |
geographic |
Greenland Leverett Glacier |
geographic_facet |
Greenland Leverett Glacier |
genre |
glacier Greenland Ice Sheet Leverett Glacier |
genre_facet |
glacier Greenland Ice Sheet Leverett Glacier |
op_relation |
https://nora.nerc.ac.uk/id/eprint/528718/1/2019JG005161.pdf Kellerman, A. M.; Hawkings, J. R.; Wadham, J. L.; Kohler, T. J.; Stibal, M.; Grater, E.; Marshall, M.; Hatton, J. E.; Beaton, A.; Spencer, R. G. M. 2020 Glacier outflow dissolved organic matter as a window into seasonally changing carbon sources: Leverett Glacier, Greenland. Journal of Geophysical Research: Biogeosciences, 125 (4), e2019JG005161. https://doi.org/10.1029/2019JG005161 <https://doi.org/10.1029/2019JG005161> |
op_doi |
https://doi.org/10.1029/2019JG005161 |
container_title |
Journal of Geophysical Research: Biogeosciences |
container_volume |
125 |
container_issue |
4 |
_version_ |
1766009082879148032 |