The Influence of Snow Cover Variability and Tundra Lakes on Passive Microwave Remote Sensing of Late Winter Snow Water Equivalent in the Hudson Bay Lowlands

Current North American operational satellite passive microwave snow water equivalent (SWE) retrieval algorithms consistently underestimate SWE levels for tundra environments when compared to four years of regional snow surveys conducted in the Northwest Territories and northern Manitoba, Canada. Alm...

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Main Author: Toose, Peter
Format: Master Thesis
Language:English
Published: University of Waterloo 2007
Subjects:
Online Access:http://hdl.handle.net/10012/3282
id ftunivwaterloo:oai:uwspace.uwaterloo.ca:10012/3282
record_format openpolar
spelling ftunivwaterloo:oai:uwspace.uwaterloo.ca:10012/3282 2023-05-15T15:55:07+02:00 The Influence of Snow Cover Variability and Tundra Lakes on Passive Microwave Remote Sensing of Late Winter Snow Water Equivalent in the Hudson Bay Lowlands Toose, Peter 2007-09 http://hdl.handle.net/10012/3282 en eng University of Waterloo http://hdl.handle.net/10012/3282 snow water equivalent passive microwave tundra lake ice Geography Master Thesis 2007 ftunivwaterloo 2022-06-18T22:58:06Z Current North American operational satellite passive microwave snow water equivalent (SWE) retrieval algorithms consistently underestimate SWE levels for tundra environments when compared to four years of regional snow surveys conducted in the Northwest Territories and northern Manitoba, Canada. Almost all contemporary SWE algorithms are based on the brightness temperature difference between the 37GHz and 19GHz frequencies found onboard both past and present spaceborne sensors. This underestimation is likely a result of the distribution and deposition of the tundra snow, coupled with the influence of tundra lakes on brightness temperatures at the 19GHz frequency. To better our understanding concerning the underestimation of passive microwave SWE retrievals on the tundra, Environment Canada collected in situ measurements of SWE, snow depth, and density at 87 sites within a 25km by 25km study domain located near Churchill, Manitoba in March 2006. Coincident multi-scale passive microwave airborne (70m & 500m resolution) and spaceborne (regridded to 12.5km & 25km resolution depending on frequency) data were measured at 6.9GHz, 19GHz, 37GHz and 89 GHz frequencies during the same time period. The snow survey data highlighted small-scale localized patterns of snow distribution and deposition on the tundra that likely influences current SWE underestimation. Snow from the open tundra plains is re-distributed by wind into small-scale vegetated features and micro-topographic depressions such as narrow creekbeds, lake edge willows, small stands of coniferous trees and polygonal wedge depressions. The very large amounts of snow deposited in these spatially-constrained features has little influence on the microwave emission measured by large-scale passive microwave spaceborne sensors and is therefore unaccounted for in current methods of satellite SWE estimation. The analysis of the passive microwave airborne data revealed that brightness temperatures at the 19GHz were much lower over some tundra lakes, effectively ... Master Thesis Churchill Hudson Bay Northwest Territories Tundra University of Waterloo, Canada: Institutional Repository Northwest Territories Hudson Bay Canada Hudson
institution Open Polar
collection University of Waterloo, Canada: Institutional Repository
op_collection_id ftunivwaterloo
language English
topic snow water equivalent
passive microwave
tundra
lake ice
Geography
spellingShingle snow water equivalent
passive microwave
tundra
lake ice
Geography
Toose, Peter
The Influence of Snow Cover Variability and Tundra Lakes on Passive Microwave Remote Sensing of Late Winter Snow Water Equivalent in the Hudson Bay Lowlands
topic_facet snow water equivalent
passive microwave
tundra
lake ice
Geography
description Current North American operational satellite passive microwave snow water equivalent (SWE) retrieval algorithms consistently underestimate SWE levels for tundra environments when compared to four years of regional snow surveys conducted in the Northwest Territories and northern Manitoba, Canada. Almost all contemporary SWE algorithms are based on the brightness temperature difference between the 37GHz and 19GHz frequencies found onboard both past and present spaceborne sensors. This underestimation is likely a result of the distribution and deposition of the tundra snow, coupled with the influence of tundra lakes on brightness temperatures at the 19GHz frequency. To better our understanding concerning the underestimation of passive microwave SWE retrievals on the tundra, Environment Canada collected in situ measurements of SWE, snow depth, and density at 87 sites within a 25km by 25km study domain located near Churchill, Manitoba in March 2006. Coincident multi-scale passive microwave airborne (70m & 500m resolution) and spaceborne (regridded to 12.5km & 25km resolution depending on frequency) data were measured at 6.9GHz, 19GHz, 37GHz and 89 GHz frequencies during the same time period. The snow survey data highlighted small-scale localized patterns of snow distribution and deposition on the tundra that likely influences current SWE underestimation. Snow from the open tundra plains is re-distributed by wind into small-scale vegetated features and micro-topographic depressions such as narrow creekbeds, lake edge willows, small stands of coniferous trees and polygonal wedge depressions. The very large amounts of snow deposited in these spatially-constrained features has little influence on the microwave emission measured by large-scale passive microwave spaceborne sensors and is therefore unaccounted for in current methods of satellite SWE estimation. The analysis of the passive microwave airborne data revealed that brightness temperatures at the 19GHz were much lower over some tundra lakes, effectively ...
format Master Thesis
author Toose, Peter
author_facet Toose, Peter
author_sort Toose, Peter
title The Influence of Snow Cover Variability and Tundra Lakes on Passive Microwave Remote Sensing of Late Winter Snow Water Equivalent in the Hudson Bay Lowlands
title_short The Influence of Snow Cover Variability and Tundra Lakes on Passive Microwave Remote Sensing of Late Winter Snow Water Equivalent in the Hudson Bay Lowlands
title_full The Influence of Snow Cover Variability and Tundra Lakes on Passive Microwave Remote Sensing of Late Winter Snow Water Equivalent in the Hudson Bay Lowlands
title_fullStr The Influence of Snow Cover Variability and Tundra Lakes on Passive Microwave Remote Sensing of Late Winter Snow Water Equivalent in the Hudson Bay Lowlands
title_full_unstemmed The Influence of Snow Cover Variability and Tundra Lakes on Passive Microwave Remote Sensing of Late Winter Snow Water Equivalent in the Hudson Bay Lowlands
title_sort influence of snow cover variability and tundra lakes on passive microwave remote sensing of late winter snow water equivalent in the hudson bay lowlands
publisher University of Waterloo
publishDate 2007
url http://hdl.handle.net/10012/3282
geographic Northwest Territories
Hudson Bay
Canada
Hudson
geographic_facet Northwest Territories
Hudson Bay
Canada
Hudson
genre Churchill
Hudson Bay
Northwest Territories
Tundra
genre_facet Churchill
Hudson Bay
Northwest Territories
Tundra
op_relation http://hdl.handle.net/10012/3282
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