A model study of Abrahamsenbreen, a surging glacier in northern Spitsbergen
The climate sensitivity of Abrahamsenbreen, a 20 km long surge-type glacier in northern Spitsbergen, is studied with a simple glacier model. A scheme to describe the surges is included, which makes it possible to account for the effect of surges on the total mass budget of the glacier. A climate rec...
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ftcopernicus:oai:publications.copernicus.org:tc27281 2023-05-15T16:39:27+02:00 A model study of Abrahamsenbreen, a surging glacier in northern Spitsbergen Oerlemans, J. van Pelt, W. J. J. 2018-09-27 application/pdf https://doi.org/10.5194/tc-9-767-2015 https://tc.copernicus.org/articles/9/767/2015/ eng eng doi:10.5194/tc-9-767-2015 https://tc.copernicus.org/articles/9/767/2015/ eISSN: 1994-0424 Text 2018 ftcopernicus https://doi.org/10.5194/tc-9-767-2015 2020-07-20T16:24:39Z The climate sensitivity of Abrahamsenbreen, a 20 km long surge-type glacier in northern Spitsbergen, is studied with a simple glacier model. A scheme to describe the surges is included, which makes it possible to account for the effect of surges on the total mass budget of the glacier. A climate reconstruction back to AD 1300, based on ice-core data from Lomonosovfonna and climate records from Longyearbyen, is used to drive the model. The model is calibrated by requesting that it produce the correct Little Ice Age maximum glacier length and simulate the observed magnitude of the 1978 surge. Abrahamsenbreen is strongly out of balance with the current climate. If climatic conditions remain as they were for the period 1989–2010, the glacier will ultimately shrink to a length of about 4 km (but this will take hundreds of years). For a climate change scenario involving a 2 m year −1 rise of the equilibrium line from now onwards, we predict that in the year 2100 Abrahamsenbreen will be about 12 km long. The main effect of a surge is to lower the mean surface elevation and thereby to increase the ablation area, causing a negative perturbation of the mass budget. We found that the occurrence of surges leads to a faster retreat of the glacier in a warming climate. Because of the very small bed slope, Abrahamsenbreen is sensitive to small perturbations in the equilibrium-line altitude. If the equilibrium line were lowered by only 160 m, the glacier would steadily grow into Woodfjorddalen until, after 2000 years, it would reach Woodfjord and calving would slow down the advance. The bed topography of Abrahamsenbreen is not known and was therefore inferred from the slope and length of the glacier. The value of the plasticity parameter needed to do this was varied by +20 and −20%. After recalibration the same climate change experiments were performed, showing that a thinner glacier (higher bedrock in this case) in a warming climate retreats somewhat faster. Text ice core Longyearbyen Woodfjord* Spitsbergen Copernicus Publications: E-Journals Lomonosovfonna ENVELOPE(17.663,17.663,78.774,78.774) Longyearbyen Woodfjorddalen ENVELOPE(14.000,14.000,79.167,79.167) The Cryosphere 9 2 767 779 |
institution |
Open Polar |
collection |
Copernicus Publications: E-Journals |
op_collection_id |
ftcopernicus |
language |
English |
description |
The climate sensitivity of Abrahamsenbreen, a 20 km long surge-type glacier in northern Spitsbergen, is studied with a simple glacier model. A scheme to describe the surges is included, which makes it possible to account for the effect of surges on the total mass budget of the glacier. A climate reconstruction back to AD 1300, based on ice-core data from Lomonosovfonna and climate records from Longyearbyen, is used to drive the model. The model is calibrated by requesting that it produce the correct Little Ice Age maximum glacier length and simulate the observed magnitude of the 1978 surge. Abrahamsenbreen is strongly out of balance with the current climate. If climatic conditions remain as they were for the period 1989–2010, the glacier will ultimately shrink to a length of about 4 km (but this will take hundreds of years). For a climate change scenario involving a 2 m year −1 rise of the equilibrium line from now onwards, we predict that in the year 2100 Abrahamsenbreen will be about 12 km long. The main effect of a surge is to lower the mean surface elevation and thereby to increase the ablation area, causing a negative perturbation of the mass budget. We found that the occurrence of surges leads to a faster retreat of the glacier in a warming climate. Because of the very small bed slope, Abrahamsenbreen is sensitive to small perturbations in the equilibrium-line altitude. If the equilibrium line were lowered by only 160 m, the glacier would steadily grow into Woodfjorddalen until, after 2000 years, it would reach Woodfjord and calving would slow down the advance. The bed topography of Abrahamsenbreen is not known and was therefore inferred from the slope and length of the glacier. The value of the plasticity parameter needed to do this was varied by +20 and −20%. After recalibration the same climate change experiments were performed, showing that a thinner glacier (higher bedrock in this case) in a warming climate retreats somewhat faster. |
format |
Text |
author |
Oerlemans, J. van Pelt, W. J. J. |
spellingShingle |
Oerlemans, J. van Pelt, W. J. J. A model study of Abrahamsenbreen, a surging glacier in northern Spitsbergen |
author_facet |
Oerlemans, J. van Pelt, W. J. J. |
author_sort |
Oerlemans, J. |
title |
A model study of Abrahamsenbreen, a surging glacier in northern Spitsbergen |
title_short |
A model study of Abrahamsenbreen, a surging glacier in northern Spitsbergen |
title_full |
A model study of Abrahamsenbreen, a surging glacier in northern Spitsbergen |
title_fullStr |
A model study of Abrahamsenbreen, a surging glacier in northern Spitsbergen |
title_full_unstemmed |
A model study of Abrahamsenbreen, a surging glacier in northern Spitsbergen |
title_sort |
model study of abrahamsenbreen, a surging glacier in northern spitsbergen |
publishDate |
2018 |
url |
https://doi.org/10.5194/tc-9-767-2015 https://tc.copernicus.org/articles/9/767/2015/ |
long_lat |
ENVELOPE(17.663,17.663,78.774,78.774) ENVELOPE(14.000,14.000,79.167,79.167) |
geographic |
Lomonosovfonna Longyearbyen Woodfjorddalen |
geographic_facet |
Lomonosovfonna Longyearbyen Woodfjorddalen |
genre |
ice core Longyearbyen Woodfjord* Spitsbergen |
genre_facet |
ice core Longyearbyen Woodfjord* Spitsbergen |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-9-767-2015 https://tc.copernicus.org/articles/9/767/2015/ |
op_doi |
https://doi.org/10.5194/tc-9-767-2015 |
container_title |
The Cryosphere |
container_volume |
9 |
container_issue |
2 |
container_start_page |
767 |
op_container_end_page |
779 |
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1766029801501491200 |