Simulating the thermal regime and ice mass balance in blocky terrain in mountain environments
Ground temperatures in coarse, blocky deposits such as in mountain blockfields and rock glaciers have long been observed to be lower in comparison with other (sub)surface material. One of the reasons for this negative temperature anomaly is the lower soil moisture content in blocky terrain, which de...
Main Author: | |
---|---|
Format: | Master Thesis |
Language: | English |
Published: |
2022
|
Subjects: | |
Online Access: | http://hdl.handle.net/10852/95119 http://urn.nb.no/URN:NBN:no-97646 |
id |
ftoslouniv:oai:www.duo.uio.no:10852/95119 |
---|---|
record_format |
openpolar |
spelling |
ftoslouniv:oai:www.duo.uio.no:10852/95119 2023-05-15T16:21:59+02:00 Simulating the thermal regime and ice mass balance in blocky terrain in mountain environments Renette, Cas 2022-08-19T22:00:24Z http://hdl.handle.net/10852/95119 http://urn.nb.no/URN:NBN:no-97646 eng eng http://urn.nb.no/URN:NBN:no-97646 Renette, Cas. Simulating the thermal regime and ice mass balance in blocky terrain in mountain environments. Master thesis, University of Oslo, 2022 http://hdl.handle.net/10852/95119 URN:NBN:no-97646 Fulltext https://www.duo.uio.no/bitstream/handle/10852/95119/1/CasRenette_MastersThesis.pdf Utsatt tilgjengeliggjøring: Kun forskere og studenter kan få innsyn i dokumentet. Tilgangskode/Access code B embargoedaccess mountain permafrost ground ice thermal anomaly CryoGrid blocky material permafrost model Master thesis Masteroppgave 2022 ftoslouniv 2022-08-24T22:35:23Z Ground temperatures in coarse, blocky deposits such as in mountain blockfields and rock glaciers have long been observed to be lower in comparison with other (sub)surface material. One of the reasons for this negative temperature anomaly is the lower soil moisture content in blocky terrain, which decreases the duration of the zero curtain in autumn and can introduce a zero curtain in spring. Many permafrost modelling studies did not include varying water and ice contents. In this thesis, the CryoGrid community model is used to simulate the effect of drainage in blocky terrain on the ground thermal regime and ground ice at two Norwegian mountain permafrost sites and at three ancillary sites in the global permafrost extent. Three idealized stratigraphies are used to investigate thermal anomalies under different amounts of snowfall. The stratigraphies are labeled blocks only, blocks with sediment and sediment only and are either drained or undrained of water, resulting six ‘scenarios’. The model setup features a surface energy balance, heat conduction and advection, a bucket water scheme with a lateral drainage component and (an adaptation of) the CROCUS snow scheme. The results show markedly lower ground temperatures in the blocks only, drained scenario compared to all five other scenarios. A sensitivity analysis to snowfall results in a thermal anomaly is up to 1.5 °C at the sites in Norway for scenarios with relatively high snowfall amounts and up to 3.5 °C at a continental site in northern Siberia. The effect almost vanishes when no persistent ground ice is present. Stable permafrost conditions are simulated at the location of a rock glacier in northern Norway with a mean annual ground surface temperature (MAGST) of 2.0-2.5 °C in the blocks only, drained scenario. Other scenarios under the same climate forcing feature positive ground temperatures. At the location of a blockfield in southern Norway, it is shown that stable permafrost can be present in the blocks only, drained scenario even under an extremely ... Master Thesis glacier Ice Northern Norway permafrost Siberia Universitet i Oslo: Digitale utgivelser ved UiO (DUO) Norway |
institution |
Open Polar |
collection |
Universitet i Oslo: Digitale utgivelser ved UiO (DUO) |
op_collection_id |
ftoslouniv |
language |
English |
topic |
mountain permafrost ground ice thermal anomaly CryoGrid blocky material permafrost model |
spellingShingle |
mountain permafrost ground ice thermal anomaly CryoGrid blocky material permafrost model Renette, Cas Simulating the thermal regime and ice mass balance in blocky terrain in mountain environments |
topic_facet |
mountain permafrost ground ice thermal anomaly CryoGrid blocky material permafrost model |
description |
Ground temperatures in coarse, blocky deposits such as in mountain blockfields and rock glaciers have long been observed to be lower in comparison with other (sub)surface material. One of the reasons for this negative temperature anomaly is the lower soil moisture content in blocky terrain, which decreases the duration of the zero curtain in autumn and can introduce a zero curtain in spring. Many permafrost modelling studies did not include varying water and ice contents. In this thesis, the CryoGrid community model is used to simulate the effect of drainage in blocky terrain on the ground thermal regime and ground ice at two Norwegian mountain permafrost sites and at three ancillary sites in the global permafrost extent. Three idealized stratigraphies are used to investigate thermal anomalies under different amounts of snowfall. The stratigraphies are labeled blocks only, blocks with sediment and sediment only and are either drained or undrained of water, resulting six ‘scenarios’. The model setup features a surface energy balance, heat conduction and advection, a bucket water scheme with a lateral drainage component and (an adaptation of) the CROCUS snow scheme. The results show markedly lower ground temperatures in the blocks only, drained scenario compared to all five other scenarios. A sensitivity analysis to snowfall results in a thermal anomaly is up to 1.5 °C at the sites in Norway for scenarios with relatively high snowfall amounts and up to 3.5 °C at a continental site in northern Siberia. The effect almost vanishes when no persistent ground ice is present. Stable permafrost conditions are simulated at the location of a rock glacier in northern Norway with a mean annual ground surface temperature (MAGST) of 2.0-2.5 °C in the blocks only, drained scenario. Other scenarios under the same climate forcing feature positive ground temperatures. At the location of a blockfield in southern Norway, it is shown that stable permafrost can be present in the blocks only, drained scenario even under an extremely ... |
format |
Master Thesis |
author |
Renette, Cas |
author_facet |
Renette, Cas |
author_sort |
Renette, Cas |
title |
Simulating the thermal regime and ice mass balance in blocky terrain in mountain environments |
title_short |
Simulating the thermal regime and ice mass balance in blocky terrain in mountain environments |
title_full |
Simulating the thermal regime and ice mass balance in blocky terrain in mountain environments |
title_fullStr |
Simulating the thermal regime and ice mass balance in blocky terrain in mountain environments |
title_full_unstemmed |
Simulating the thermal regime and ice mass balance in blocky terrain in mountain environments |
title_sort |
simulating the thermal regime and ice mass balance in blocky terrain in mountain environments |
publishDate |
2022 |
url |
http://hdl.handle.net/10852/95119 http://urn.nb.no/URN:NBN:no-97646 |
geographic |
Norway |
geographic_facet |
Norway |
genre |
glacier Ice Northern Norway permafrost Siberia |
genre_facet |
glacier Ice Northern Norway permafrost Siberia |
op_relation |
http://urn.nb.no/URN:NBN:no-97646 Renette, Cas. Simulating the thermal regime and ice mass balance in blocky terrain in mountain environments. Master thesis, University of Oslo, 2022 http://hdl.handle.net/10852/95119 URN:NBN:no-97646 Fulltext https://www.duo.uio.no/bitstream/handle/10852/95119/1/CasRenette_MastersThesis.pdf |
op_rights |
Utsatt tilgjengeliggjøring: Kun forskere og studenter kan få innsyn i dokumentet. Tilgangskode/Access code B embargoedaccess |
_version_ |
1766009959017873408 |