Modelling sea ice as a granular material, with applications to climate variability
A new dynamic service model based on granular material rheology is presented. The service model is coupled to both a mixed-layer ocean model and a 1-layer thermodynamic atmospheric model which allows for an ice-albedo feedback. Land is represented by a 6-meter thick layer with a constant base temper...
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ftcanadathes:oai:collectionscanada.gc.ca:QMM.34472 2023-05-15T13:11:27+02:00 Modelling sea ice as a granular material, with applications to climate variability Tremblay, Louis-Bruno. Mysak, Lawrence A. (advisor) Doctor of Philosophy (Department of Atmospheric and Oceanic Sciences.) 1996 application/pdf http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=34472 en eng McGill University alephsysno: 001566608 proquestno: NQ30406 Theses scanned by UMI/ProQuest. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=34472 All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. Physical Oceanography Paleoecology Physics Atmospheric Science Electronic Thesis or Dissertation 1996 ftcanadathes 2014-02-16T00:44:36Z A new dynamic service model based on granular material rheology is presented. The service model is coupled to both a mixed-layer ocean model and a 1-layer thermodynamic atmospheric model which allows for an ice-albedo feedback. Land is represented by a 6-meter thick layer with a constant base temperature. A 10-year integration including both thermodynamic and dynamic effects and incorporating prescribed climatological wind stress and ocean current data was performed in order for the model to reach a stable periodic seasonal cycle. The commonly observed lead complexes, along which sliding and opening of adjacent ice floes occur in the Arctic sea-ice cover, are well reproduced in this simulation. In particular, shear lines extending from the western Canadian Archipelago toward the central Arctic, often observed in winter satellite images, are present. The ice edge is well positioned both in winter and summer using this thermodynamically coupled ocean-ice-atmosphere model. The results also yield a sea-ice circulation and thickness distribution over the Arctic which are in good agreement with observations. The model also produces an increase in ice formation associated with the dilatation of the ice medium along sliding lines. In this model, incident energy absorbed by the ocean melts ice laterally and warms the mixed layer, causing a smaller ice retreat in the summer. This cures a problem common to many existing thermodynamic-dynamic sea-ice models. The origin and space-time evolution of Beaufort Sea ice anomalies are studied using data and the sea-ice model described above. In particular, the influence of river runoff, atmospheric temperature and wind anomalies in creating anomalous sea ice condition in the Beaufort Sea is studied. The sea-ice model is then used to track the position of an ice anomaly as it is transported by the Beaufort Gyre and the Transpolar Drift Stream out of the Arctic Basin. It can be inferred from driftwood data collected in the Canadian Arctic Archipelago that very different sea-ice drift patterns were present in the Arctic Ocean during the Holocene. In this study, the sea-ice model described above is used to examine the different modes of Arctic sea-ice circulation during this period, and also to infer characteristics of century-to-millennial scale changes in Arctic atmospheric circulation. (Abstract shortened by UMI.) Thesis albedo Arctic Archipelago Arctic Basin Arctic Arctic Ocean Beaufort Sea Canadian Archipelago Canadian Arctic Archipelago Sea ice Theses Canada/Thèses Canada (Library and Archives Canada) Arctic Arctic Ocean Canadian Arctic Archipelago |
institution |
Open Polar |
collection |
Theses Canada/Thèses Canada (Library and Archives Canada) |
op_collection_id |
ftcanadathes |
language |
English |
topic |
Physical Oceanography Paleoecology Physics Atmospheric Science |
spellingShingle |
Physical Oceanography Paleoecology Physics Atmospheric Science Tremblay, Louis-Bruno. Modelling sea ice as a granular material, with applications to climate variability |
topic_facet |
Physical Oceanography Paleoecology Physics Atmospheric Science |
description |
A new dynamic service model based on granular material rheology is presented. The service model is coupled to both a mixed-layer ocean model and a 1-layer thermodynamic atmospheric model which allows for an ice-albedo feedback. Land is represented by a 6-meter thick layer with a constant base temperature. A 10-year integration including both thermodynamic and dynamic effects and incorporating prescribed climatological wind stress and ocean current data was performed in order for the model to reach a stable periodic seasonal cycle. The commonly observed lead complexes, along which sliding and opening of adjacent ice floes occur in the Arctic sea-ice cover, are well reproduced in this simulation. In particular, shear lines extending from the western Canadian Archipelago toward the central Arctic, often observed in winter satellite images, are present. The ice edge is well positioned both in winter and summer using this thermodynamically coupled ocean-ice-atmosphere model. The results also yield a sea-ice circulation and thickness distribution over the Arctic which are in good agreement with observations. The model also produces an increase in ice formation associated with the dilatation of the ice medium along sliding lines. In this model, incident energy absorbed by the ocean melts ice laterally and warms the mixed layer, causing a smaller ice retreat in the summer. This cures a problem common to many existing thermodynamic-dynamic sea-ice models. The origin and space-time evolution of Beaufort Sea ice anomalies are studied using data and the sea-ice model described above. In particular, the influence of river runoff, atmospheric temperature and wind anomalies in creating anomalous sea ice condition in the Beaufort Sea is studied. The sea-ice model is then used to track the position of an ice anomaly as it is transported by the Beaufort Gyre and the Transpolar Drift Stream out of the Arctic Basin. It can be inferred from driftwood data collected in the Canadian Arctic Archipelago that very different sea-ice drift patterns were present in the Arctic Ocean during the Holocene. In this study, the sea-ice model described above is used to examine the different modes of Arctic sea-ice circulation during this period, and also to infer characteristics of century-to-millennial scale changes in Arctic atmospheric circulation. (Abstract shortened by UMI.) |
author2 |
Mysak, Lawrence A. (advisor) |
format |
Thesis |
author |
Tremblay, Louis-Bruno. |
author_facet |
Tremblay, Louis-Bruno. |
author_sort |
Tremblay, Louis-Bruno. |
title |
Modelling sea ice as a granular material, with applications to climate variability |
title_short |
Modelling sea ice as a granular material, with applications to climate variability |
title_full |
Modelling sea ice as a granular material, with applications to climate variability |
title_fullStr |
Modelling sea ice as a granular material, with applications to climate variability |
title_full_unstemmed |
Modelling sea ice as a granular material, with applications to climate variability |
title_sort |
modelling sea ice as a granular material, with applications to climate variability |
publisher |
McGill University |
publishDate |
1996 |
url |
http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=34472 |
op_coverage |
Doctor of Philosophy (Department of Atmospheric and Oceanic Sciences.) |
geographic |
Arctic Arctic Ocean Canadian Arctic Archipelago |
geographic_facet |
Arctic Arctic Ocean Canadian Arctic Archipelago |
genre |
albedo Arctic Archipelago Arctic Basin Arctic Arctic Ocean Beaufort Sea Canadian Archipelago Canadian Arctic Archipelago Sea ice |
genre_facet |
albedo Arctic Archipelago Arctic Basin Arctic Arctic Ocean Beaufort Sea Canadian Archipelago Canadian Arctic Archipelago Sea ice |
op_relation |
alephsysno: 001566608 proquestno: NQ30406 Theses scanned by UMI/ProQuest. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=34472 |
op_rights |
All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
_version_ |
1766247440674979840 |