Spatio-temporal variations in rock wall temperature in Norway post the Little Ice Age
International audience Warming-induced permafrost degradation is believed to be responsible for the increasing number of rock-slope instabilities, such as rockfalls or rock avalanches, over the past few decades. Relationship between permafrost degradation and geomorphological activity, is neverthele...
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ftccsdartic:oai:HAL:hal-03866621v1 2024-02-27T08:41:28+00:00 Spatio-temporal variations in rock wall temperature in Norway post the Little Ice Age Czekirda, Justyna Etzelmüller, Bernd Westermann, Sebastian Isaksen, Ketil Magnin, Florence Department of Geosciences Oslo Faculty of Mathematics and Natural Sciences Oslo University of Oslo (UiO)-University of Oslo (UiO) Norwegian Meteorological Institute Oslo (MET) Environnements, Dynamiques et Territoires de Montagne (EDYTEM) Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS) Vienne, Austria 2022-05-23 https://hal.science/hal-03866621 https://doi.org/10.5194/egusphere-egu22-3211 en eng HAL CCSD info:eu-repo/semantics/altIdentifier/doi/10.5194/egusphere-egu22-3211 hal-03866621 https://hal.science/hal-03866621 doi:10.5194/egusphere-egu22-3211 http://creativecommons.org/licenses/by/ EGU General Assembly 2022 https://hal.science/hal-03866621 EGU General Assembly 2022, May 2022, Vienne, Austria. ⟨10.5194/egusphere-egu22-3211⟩ https://www.egu22.eu/ [SDE.ES]Environmental Sciences/Environment and Society [SDE]Environmental Sciences [SDE.MCG]Environmental Sciences/Global Changes info:eu-repo/semantics/conferenceObject Conference papers 2022 ftccsdartic https://doi.org/10.5194/egusphere-egu22-3211 2024-01-28T01:04:30Z International audience Warming-induced permafrost degradation is believed to be responsible for the increasing number of rock-slope instabilities, such as rockfalls or rock avalanches, over the past few decades. Relationship between permafrost degradation and geomorphological activity, is nevertheless, hard to establish because often little is known about the permafrost distribution in steep slopes. In the present study, we assess spatio-temporal changes in rock wall temperature in Norway post the Little Ice Age, using the two-dimensional ground heat flux model CryoGrid 2D. We create transects across the monitored rock walls in the Western Norway, in the high alpine range of Jotunheimen and in the Northern Norway. Our results demonstrate that rock wall temperature at 20 m depth increased by an average of 0.2 °C decade-1 since the 1980s. Therefore, if atmospheric warming rates remain similar, rock wall permafrost currently at -1 °C at 20 m depth could degrade completely at this depth by 2070. Furthermore, we show how rock wall temperature is influenced by: (1) rock wall geometry, (2) rock wall size, (3) magnitude of surface offsets due to the incoming shortwave solar radiation, (4) snow conditions above and below rock walls, (5) blockfield-covered plateaus or glaciers in their vicinity. Multi-dimensional thermal effects are smaller in Norway than in the European Alps due to the dissimilarities in mountain geometry and smaller differences in ground surface temperature between various mountainsides. Rock walls with large surface offsets arising from solar radiation might be warmer than plateaus above or talus slopes below, thus ground heat flux in such rock walls is directed towards colder plateaus or talus slopes. Furthermore, thermal conditions in blockfield-covered plateaus have impact on rock wall temperature and lead to larger warming rates at 20 m depth, whereas large glaciers decrease warming rates at the same depth. Therefore, a potential glaciers retreat would likely increase ground warming rates in the ... Conference Object Ice Northern Norway permafrost Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) Norway |
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Open Polar |
collection |
Archive ouverte HAL (Hyper Article en Ligne, CCSD - Centre pour la Communication Scientifique Directe) |
op_collection_id |
ftccsdartic |
language |
English |
topic |
[SDE.ES]Environmental Sciences/Environment and Society [SDE]Environmental Sciences [SDE.MCG]Environmental Sciences/Global Changes |
spellingShingle |
[SDE.ES]Environmental Sciences/Environment and Society [SDE]Environmental Sciences [SDE.MCG]Environmental Sciences/Global Changes Czekirda, Justyna Etzelmüller, Bernd Westermann, Sebastian Isaksen, Ketil Magnin, Florence Spatio-temporal variations in rock wall temperature in Norway post the Little Ice Age |
topic_facet |
[SDE.ES]Environmental Sciences/Environment and Society [SDE]Environmental Sciences [SDE.MCG]Environmental Sciences/Global Changes |
description |
International audience Warming-induced permafrost degradation is believed to be responsible for the increasing number of rock-slope instabilities, such as rockfalls or rock avalanches, over the past few decades. Relationship between permafrost degradation and geomorphological activity, is nevertheless, hard to establish because often little is known about the permafrost distribution in steep slopes. In the present study, we assess spatio-temporal changes in rock wall temperature in Norway post the Little Ice Age, using the two-dimensional ground heat flux model CryoGrid 2D. We create transects across the monitored rock walls in the Western Norway, in the high alpine range of Jotunheimen and in the Northern Norway. Our results demonstrate that rock wall temperature at 20 m depth increased by an average of 0.2 °C decade-1 since the 1980s. Therefore, if atmospheric warming rates remain similar, rock wall permafrost currently at -1 °C at 20 m depth could degrade completely at this depth by 2070. Furthermore, we show how rock wall temperature is influenced by: (1) rock wall geometry, (2) rock wall size, (3) magnitude of surface offsets due to the incoming shortwave solar radiation, (4) snow conditions above and below rock walls, (5) blockfield-covered plateaus or glaciers in their vicinity. Multi-dimensional thermal effects are smaller in Norway than in the European Alps due to the dissimilarities in mountain geometry and smaller differences in ground surface temperature between various mountainsides. Rock walls with large surface offsets arising from solar radiation might be warmer than plateaus above or talus slopes below, thus ground heat flux in such rock walls is directed towards colder plateaus or talus slopes. Furthermore, thermal conditions in blockfield-covered plateaus have impact on rock wall temperature and lead to larger warming rates at 20 m depth, whereas large glaciers decrease warming rates at the same depth. Therefore, a potential glaciers retreat would likely increase ground warming rates in the ... |
author2 |
Department of Geosciences Oslo Faculty of Mathematics and Natural Sciences Oslo University of Oslo (UiO)-University of Oslo (UiO) Norwegian Meteorological Institute Oslo (MET) Environnements, Dynamiques et Territoires de Montagne (EDYTEM) Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS) |
format |
Conference Object |
author |
Czekirda, Justyna Etzelmüller, Bernd Westermann, Sebastian Isaksen, Ketil Magnin, Florence |
author_facet |
Czekirda, Justyna Etzelmüller, Bernd Westermann, Sebastian Isaksen, Ketil Magnin, Florence |
author_sort |
Czekirda, Justyna |
title |
Spatio-temporal variations in rock wall temperature in Norway post the Little Ice Age |
title_short |
Spatio-temporal variations in rock wall temperature in Norway post the Little Ice Age |
title_full |
Spatio-temporal variations in rock wall temperature in Norway post the Little Ice Age |
title_fullStr |
Spatio-temporal variations in rock wall temperature in Norway post the Little Ice Age |
title_full_unstemmed |
Spatio-temporal variations in rock wall temperature in Norway post the Little Ice Age |
title_sort |
spatio-temporal variations in rock wall temperature in norway post the little ice age |
publisher |
HAL CCSD |
publishDate |
2022 |
url |
https://hal.science/hal-03866621 https://doi.org/10.5194/egusphere-egu22-3211 |
op_coverage |
Vienne, Austria |
geographic |
Norway |
geographic_facet |
Norway |
genre |
Ice Northern Norway permafrost |
genre_facet |
Ice Northern Norway permafrost |
op_source |
EGU General Assembly 2022 https://hal.science/hal-03866621 EGU General Assembly 2022, May 2022, Vienne, Austria. ⟨10.5194/egusphere-egu22-3211⟩ https://www.egu22.eu/ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/egusphere-egu22-3211 hal-03866621 https://hal.science/hal-03866621 doi:10.5194/egusphere-egu22-3211 |
op_rights |
http://creativecommons.org/licenses/by/ |
op_doi |
https://doi.org/10.5194/egusphere-egu22-3211 |
_version_ |
1792048745952575488 |