Impacts of synoptic atmospheric circulations and topographic conditions of sustained strong surface winds over southern Nunavut
Strong surface winds are an inherent aspect of the eastern Canadian Arctic climate yet few studies have focused on these features. As a result, arctic winds are often poorly predicted by current weather forecasting models. To better predict the arctic weather, we need to understand the role of the A...
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Language: | English |
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McGill University
2007
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Online Access: | http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=18409 |
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ftcanadathes:oai:collectionscanada.gc.ca:QMM.18409 |
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openpolar |
institution |
Open Polar |
collection |
Theses Canada/Thèses Canada (Library and Archives Canada) |
op_collection_id |
ftcanadathes |
language |
English |
topic |
Physics - Atmospheric Science |
spellingShingle |
Physics - Atmospheric Science Nadeau, Daniel Impacts of synoptic atmospheric circulations and topographic conditions of sustained strong surface winds over southern Nunavut |
topic_facet |
Physics - Atmospheric Science |
description |
Strong surface winds are an inherent aspect of the eastern Canadian Arctic climate yet few studies have focused on these features. As a result, arctic winds are often poorly predicted by current weather forecasting models. To better predict the arctic weather, we need to understand the role of the Arctic's unique geographical and meteorological features such as mountains, sea-ice and very stable atmosphericstratification. In this study, we hypothesize that these features have an impact on high wind events in the eastern Canadian Arctic. To test this, we examine the long-term data records of six meteorological stations across southern Nunavut. We also develop a severity index to characterize high wind events, based on duration, maximum gusts and mean wind speed observed. By studying the five most severehigh wind events and the motion of storm systems generating strong winds, we identified how the Arctic's geographical and meteorological features enhanced strong surface winds. High wind events are usually associated with intense cyclones located over Hudson Bay or Labrador Sea, particularly in wintertime. Under this large scale setting, blocking and channeling due to the stable boundary-layer stratificationtypically occur at Clyde River and Iqaluit, enhancing the surface wind speed. Over flatter terrain, high wind events typically occur when the station is situated in a region of strong synoptic pressure gradient between an anticyclone and a cyclone. Malgré leur rôle prépondérant au sein du climat arctique canadien méridional, peu d'études se sont intéressées aux vents violents de surface. Conséquemment, les prévisions météorologiques à leur sujet sont souvent imprécises. Afin d'améliorer les modèles de prévisions météorologiques dans l'Arctique, nous devons mieux doser la contribution des particularités géographiques et météorologiques inhérente à cetterégion, notamment la glace de mer, le relief accidenté et l'importante stabilité atmosphérique. Dans cette étude, nous supposons que ces particularités contribuent à la formation d'événements de vents violents dans l'Arctique canadien méridional. Afin de tester cette hypothèse, nous étudions les données météorologiques de six stations réparties dans le sud du Nunavut. Pour ce faire, nous développons un indice de sévérité basé sur trois paramètres des événements de vents violents: la durée, les rafales maximales observées et la vitesse moyenne du vent. Suite à notre étude, nous observons que les événements de vents violents sont typiquement associés à la présence d'intenses dépressions situées au-dessus de la baie d'Hudson ou de la mer du Labrador, particulièrement en hiver. Sous l'influence de ces systèmes, des phénomènes de blocage et d'effet de canal sont typiquement observés à Clyde Riveret Iqaluit respectivement, modifiant ainsi la vitesse et la direction des vents de surface. Quant auxstations en terrain plat, les événements de vents violents sont davantage provoqués par de forts gradients de pression synoptiques, lorsque la station est située entre un cyclone et un anticyclone. |
author2 |
Ronald Stewart (Internal/Supervisor) |
format |
Thesis |
author |
Nadeau, Daniel |
author_facet |
Nadeau, Daniel |
author_sort |
Nadeau, Daniel |
title |
Impacts of synoptic atmospheric circulations and topographic conditions of sustained strong surface winds over southern Nunavut |
title_short |
Impacts of synoptic atmospheric circulations and topographic conditions of sustained strong surface winds over southern Nunavut |
title_full |
Impacts of synoptic atmospheric circulations and topographic conditions of sustained strong surface winds over southern Nunavut |
title_fullStr |
Impacts of synoptic atmospheric circulations and topographic conditions of sustained strong surface winds over southern Nunavut |
title_full_unstemmed |
Impacts of synoptic atmospheric circulations and topographic conditions of sustained strong surface winds over southern Nunavut |
title_sort |
impacts of synoptic atmospheric circulations and topographic conditions of sustained strong surface winds over southern nunavut |
publisher |
McGill University |
publishDate |
2007 |
url |
http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=18409 |
op_coverage |
Master of Science (Department of Atmospheric and Oceanic Sciences) |
long_lat |
ENVELOPE(-78.666,-78.666,58.417,58.417) ENVELOPE(-74.999,-74.999,58.500,58.500) ENVELOPE(-70.451,-70.451,69.854,69.854) ENVELOPE(-55.998,-55.998,55.000,55.000) |
geographic |
Arctic Baie d'Hudson Baie-d'Hudson Clyde River Hudson Hudson Bay Mer du Labrador Nunavut |
geographic_facet |
Arctic Baie d'Hudson Baie-d'Hudson Clyde River Hudson Hudson Bay Mer du Labrador Nunavut |
genre |
Arctic Arctique* Baie d'Hudson Clyde River Hudson Bay Iqaluit Labrador Sea Nunavut Sea ice |
genre_facet |
Arctic Arctique* Baie d'Hudson Clyde River Hudson Bay Iqaluit Labrador Sea Nunavut Sea ice |
op_relation |
Electronically-submitted theses. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=18409 |
op_rights |
All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
_version_ |
1766330331867119616 |
spelling |
ftcanadathes:oai:collectionscanada.gc.ca:QMM.18409 2023-05-15T14:58:15+02:00 Impacts of synoptic atmospheric circulations and topographic conditions of sustained strong surface winds over southern Nunavut Nadeau, Daniel Ronald Stewart (Internal/Supervisor) Master of Science (Department of Atmospheric and Oceanic Sciences) 2007 application/pdf http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=18409 en eng McGill University Electronically-submitted theses. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=18409 All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. Physics - Atmospheric Science Electronic Thesis or Dissertation 2007 ftcanadathes 2014-02-16T00:46:58Z Strong surface winds are an inherent aspect of the eastern Canadian Arctic climate yet few studies have focused on these features. As a result, arctic winds are often poorly predicted by current weather forecasting models. To better predict the arctic weather, we need to understand the role of the Arctic's unique geographical and meteorological features such as mountains, sea-ice and very stable atmosphericstratification. In this study, we hypothesize that these features have an impact on high wind events in the eastern Canadian Arctic. To test this, we examine the long-term data records of six meteorological stations across southern Nunavut. We also develop a severity index to characterize high wind events, based on duration, maximum gusts and mean wind speed observed. By studying the five most severehigh wind events and the motion of storm systems generating strong winds, we identified how the Arctic's geographical and meteorological features enhanced strong surface winds. High wind events are usually associated with intense cyclones located over Hudson Bay or Labrador Sea, particularly in wintertime. Under this large scale setting, blocking and channeling due to the stable boundary-layer stratificationtypically occur at Clyde River and Iqaluit, enhancing the surface wind speed. Over flatter terrain, high wind events typically occur when the station is situated in a region of strong synoptic pressure gradient between an anticyclone and a cyclone. Malgré leur rôle prépondérant au sein du climat arctique canadien méridional, peu d'études se sont intéressées aux vents violents de surface. Conséquemment, les prévisions météorologiques à leur sujet sont souvent imprécises. Afin d'améliorer les modèles de prévisions météorologiques dans l'Arctique, nous devons mieux doser la contribution des particularités géographiques et météorologiques inhérente à cetterégion, notamment la glace de mer, le relief accidenté et l'importante stabilité atmosphérique. Dans cette étude, nous supposons que ces particularités contribuent à la formation d'événements de vents violents dans l'Arctique canadien méridional. Afin de tester cette hypothèse, nous étudions les données météorologiques de six stations réparties dans le sud du Nunavut. Pour ce faire, nous développons un indice de sévérité basé sur trois paramètres des événements de vents violents: la durée, les rafales maximales observées et la vitesse moyenne du vent. Suite à notre étude, nous observons que les événements de vents violents sont typiquement associés à la présence d'intenses dépressions situées au-dessus de la baie d'Hudson ou de la mer du Labrador, particulièrement en hiver. Sous l'influence de ces systèmes, des phénomènes de blocage et d'effet de canal sont typiquement observés à Clyde Riveret Iqaluit respectivement, modifiant ainsi la vitesse et la direction des vents de surface. Quant auxstations en terrain plat, les événements de vents violents sont davantage provoqués par de forts gradients de pression synoptiques, lorsque la station est située entre un cyclone et un anticyclone. Thesis Arctic Arctique* Baie d'Hudson Clyde River Hudson Bay Iqaluit Labrador Sea Nunavut Sea ice Theses Canada/Thèses Canada (Library and Archives Canada) Arctic Baie d'Hudson ENVELOPE(-78.666,-78.666,58.417,58.417) Baie-d'Hudson ENVELOPE(-74.999,-74.999,58.500,58.500) Clyde River ENVELOPE(-70.451,-70.451,69.854,69.854) Hudson Hudson Bay Mer du Labrador ENVELOPE(-55.998,-55.998,55.000,55.000) Nunavut |