Changes in the firn structure of the western Greenland Ice Sheet caused by recent warming
Atmospheric warming over the Greenland Ice Sheet during the last 2 decades has increased the amount of surface meltwater production, resulting in the migration of melt and percolation regimes to higher altitudes and an increase in the amount of ice content from refrozen meltwater found in the firn a...
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Language: | English |
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European Geosciences Union
2015
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Online Access: | https://eprints.whiterose.ac.uk/106828/ https://eprints.whiterose.ac.uk/106828/1/tc-9-1203-2015.pdf https://doi.org/10.5194/tc-9-1203-2015 |
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ftleedsuniv:oai:eprints.whiterose.ac.uk:106828 2023-05-15T16:26:18+02:00 Changes in the firn structure of the western Greenland Ice Sheet caused by recent warming de la Pena, S. Howat, I.M. Nienow, P.W. van den Broeke, M.R. Mosley-Thompson, E. Price, S.F. Mair, D. Noel, B. Sole, A.J. 2015-06-11 text https://eprints.whiterose.ac.uk/106828/ https://eprints.whiterose.ac.uk/106828/1/tc-9-1203-2015.pdf https://doi.org/10.5194/tc-9-1203-2015 en eng European Geosciences Union https://eprints.whiterose.ac.uk/106828/1/tc-9-1203-2015.pdf de la Pena, S., Howat, I.M., Nienow, P.W. et al. (6 more authors) (2015) Changes in the firn structure of the western Greenland Ice Sheet caused by recent warming. Cryosphere, 9 (3). pp. 1203-1211. ISSN 1994-0416 cc_by_3 CC-BY Article PeerReviewed 2015 ftleedsuniv https://doi.org/10.5194/tc-9-1203-2015 2023-01-30T21:47:41Z Atmospheric warming over the Greenland Ice Sheet during the last 2 decades has increased the amount of surface meltwater production, resulting in the migration of melt and percolation regimes to higher altitudes and an increase in the amount of ice content from refrozen meltwater found in the firn above the superimposed ice zone. Here we present field and airborne radar observations of buried ice layers within the near-surface (0–20 m) firn in western Greenland, obtained from campaigns between 1998 and 2014. We find a sharp increase in firn-ice content in the form of thick widespread layers in the percolation zone, which decreases the capacity of the firn to store meltwater. The estimated total annual ice content retained in the near-surface firn in areas with positive surface mass balance west of the ice divide in Greenland reached a maximum of 74 ± 25 Gt in 2012, compared to the 1958–1999 average of 13 ± 2 Gt, while the percolation zone area more than doubled between 2003 and 2012. Increased melt and column densification resulted in surface lowering averaging −0.80 ± 0.39 m yr−1 between 1800 and 2800 m in the accumulation zone of western Greenland. Since 2007, modeled annual melt and refreezing rates in the percolation zone at elevations below 2100 m surpass the annual snowfall from the previous year, implying that mass gain in the region is retained after melt in the form of refrozen meltwater. If current melt trends over high elevation regions continue, subsequent changes in firn structure will have implications for the hydrology of the ice sheet and related abrupt seasonal densification could become increasingly significant for altimetry-derived ice sheet mass balance estimates. Article in Journal/Newspaper Greenland Ice Sheet White Rose Research Online (Universities of Leeds, Sheffield & York) Greenland The Cryosphere 9 3 1203 1211 |
institution |
Open Polar |
collection |
White Rose Research Online (Universities of Leeds, Sheffield & York) |
op_collection_id |
ftleedsuniv |
language |
English |
description |
Atmospheric warming over the Greenland Ice Sheet during the last 2 decades has increased the amount of surface meltwater production, resulting in the migration of melt and percolation regimes to higher altitudes and an increase in the amount of ice content from refrozen meltwater found in the firn above the superimposed ice zone. Here we present field and airborne radar observations of buried ice layers within the near-surface (0–20 m) firn in western Greenland, obtained from campaigns between 1998 and 2014. We find a sharp increase in firn-ice content in the form of thick widespread layers in the percolation zone, which decreases the capacity of the firn to store meltwater. The estimated total annual ice content retained in the near-surface firn in areas with positive surface mass balance west of the ice divide in Greenland reached a maximum of 74 ± 25 Gt in 2012, compared to the 1958–1999 average of 13 ± 2 Gt, while the percolation zone area more than doubled between 2003 and 2012. Increased melt and column densification resulted in surface lowering averaging −0.80 ± 0.39 m yr−1 between 1800 and 2800 m in the accumulation zone of western Greenland. Since 2007, modeled annual melt and refreezing rates in the percolation zone at elevations below 2100 m surpass the annual snowfall from the previous year, implying that mass gain in the region is retained after melt in the form of refrozen meltwater. If current melt trends over high elevation regions continue, subsequent changes in firn structure will have implications for the hydrology of the ice sheet and related abrupt seasonal densification could become increasingly significant for altimetry-derived ice sheet mass balance estimates. |
format |
Article in Journal/Newspaper |
author |
de la Pena, S. Howat, I.M. Nienow, P.W. van den Broeke, M.R. Mosley-Thompson, E. Price, S.F. Mair, D. Noel, B. Sole, A.J. |
spellingShingle |
de la Pena, S. Howat, I.M. Nienow, P.W. van den Broeke, M.R. Mosley-Thompson, E. Price, S.F. Mair, D. Noel, B. Sole, A.J. Changes in the firn structure of the western Greenland Ice Sheet caused by recent warming |
author_facet |
de la Pena, S. Howat, I.M. Nienow, P.W. van den Broeke, M.R. Mosley-Thompson, E. Price, S.F. Mair, D. Noel, B. Sole, A.J. |
author_sort |
de la Pena, S. |
title |
Changes in the firn structure of the western Greenland Ice Sheet caused by recent warming |
title_short |
Changes in the firn structure of the western Greenland Ice Sheet caused by recent warming |
title_full |
Changes in the firn structure of the western Greenland Ice Sheet caused by recent warming |
title_fullStr |
Changes in the firn structure of the western Greenland Ice Sheet caused by recent warming |
title_full_unstemmed |
Changes in the firn structure of the western Greenland Ice Sheet caused by recent warming |
title_sort |
changes in the firn structure of the western greenland ice sheet caused by recent warming |
publisher |
European Geosciences Union |
publishDate |
2015 |
url |
https://eprints.whiterose.ac.uk/106828/ https://eprints.whiterose.ac.uk/106828/1/tc-9-1203-2015.pdf https://doi.org/10.5194/tc-9-1203-2015 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Ice Sheet |
genre_facet |
Greenland Ice Sheet |
op_relation |
https://eprints.whiterose.ac.uk/106828/1/tc-9-1203-2015.pdf de la Pena, S., Howat, I.M., Nienow, P.W. et al. (6 more authors) (2015) Changes in the firn structure of the western Greenland Ice Sheet caused by recent warming. Cryosphere, 9 (3). pp. 1203-1211. ISSN 1994-0416 |
op_rights |
cc_by_3 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.5194/tc-9-1203-2015 |
container_title |
The Cryosphere |
container_volume |
9 |
container_issue |
3 |
container_start_page |
1203 |
op_container_end_page |
1211 |
_version_ |
1766015203364831232 |