(Table 3) Air temperatures, and snow and ice characteristics of fresh and brackish water lakes in the Northwest Territories, Canada
The algorithms designed to estimate snow water equivalent (SWE) using passive microwave measurements falter in lake-rich high-latitude environments due to the emission properties of ice covered lakes on low frequency measurements. Microwave emission models have been used to simulate brightness tempe...
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ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.810343 2023-05-15T16:53:58+02:00 (Table 3) Air temperatures, and snow and ice characteristics of fresh and brackish water lakes in the Northwest Territories, Canada Gunn, Grant E Duguay, Claude R Derksen, Chris Lemmetyinen, Juha Toose, Peter MEDIAN LATITUDE: 68.804250 * MEDIAN LONGITUDE: -133.344500 * SOUTH-BOUND LATITUDE: 68.536000 * WEST-BOUND LONGITUDE: -133.800000 * NORTH-BOUND LATITUDE: 69.000000 * EAST-BOUND LONGITUDE: -132.726000 * DATE/TIME START: 2008-04-06T00:00:00 * DATE/TIME END: 2008-04-06T00:00:00 * MINIMUM ELEVATION: 2.0 m * MAXIMUM ELEVATION: 33.0 m 2011-04-17 text/tab-separated-values, 250 data points https://doi.pangaea.de/10.1594/PANGAEA.810343 https://doi.org/10.1594/PANGAEA.810343 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.810343 https://doi.org/10.1594/PANGAEA.810343 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess CC-BY Supplement to: Gunn, Grant E; Duguay, Claude R; Derksen, Chris; Lemmetyinen, Juha; Toose, Peter (2011): Evaluation of the HUT modified snow emission model over lake ice using airborne passive microwave measurements. Remote Sensing of Environment, 115(1), 233-244, https://doi.org/10.1016/j.rse.2010.09.001 DATE/TIME Date/time end Density snow Event label Ice type International Polar Year (2007-2008) IPY Lake_Noel Lake_Sitidgi Lakes_A-B Lakes_Husky Latitude of event Longitude of event Northwest Territories Canada Parsons Lake Sea ice thickness Site Snow/ice sample Snow grain size Snow thickness Snow water equivalent Temperature air Water bodies Dataset 2011 ftpangaea https://doi.org/10.1594/PANGAEA.810343 https://doi.org/10.1016/j.rse.2010.09.001 2023-01-20T09:01:00Z The algorithms designed to estimate snow water equivalent (SWE) using passive microwave measurements falter in lake-rich high-latitude environments due to the emission properties of ice covered lakes on low frequency measurements. Microwave emission models have been used to simulate brightness temperatures (Tbs) for snowpack characteristics in terrestrial environments but cannot be applied to snow on lakes because of the differing subsurface emissivities and scattering matrices present in ice. This paper examines the performance of a modified version of the Helsinki University of Technology (HUT) snow emission model that incorporates microwave emission from lake ice and sub-ice water. Inputs to the HUT model include measurements collected over brackish and freshwater lakes north of Inuvik, Northwest Territories, Canada in April 2008, consisting of snowpack (depth, density, and snow water equivalent) and lake ice (thickness and ice type). Coincident airborne radiometer measurements at a resolution of 80x100 m were used as ground-truth to evaluate the simulations. The results indicate that subsurface media are simulated best when utilizing a modeled effective grain size and a 1 mm RMS surface roughness at the ice/water interface compared to using measured grain size and a flat Fresnel reflective surface as input. Simulations at 37 GHz (vertical polarization) produce the best results compared to airborne Tbs, with a Root Mean Square Error (RMSE) of 6.2 K and 7.9 K, as well as Mean Bias Errors (MBEs) of -8.4 K and -8.8 K for brackish and freshwater sites respectively. Freshwater simulations at 6.9 and 19 GHz H exhibited low RMSE (10.53 and 6.15 K respectively) and MBE (-5.37 and 8.36 K respectively) but did not accurately simulate Tb variability (R= -0.15 and 0.01 respectively). Over brackish water, 6.9 GHz simulations had poor agreement with airborne Tbs, while 19 GHz V exhibited a low RMSE (6.15 K), MBE (-4.52 K) and improved relative agreement to airborne measurements (R = 0.47). Salinity considerations reduced ... Dataset International Polar Year Inuvik IPY Northwest Territories Sea ice PANGAEA - Data Publisher for Earth & Environmental Science Northwest Territories Canada Inuvik ENVELOPE(-133.610,-133.610,68.341,68.341) ENVELOPE(-133.800000,-132.726000,69.000000,68.536000) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
DATE/TIME Date/time end Density snow Event label Ice type International Polar Year (2007-2008) IPY Lake_Noel Lake_Sitidgi Lakes_A-B Lakes_Husky Latitude of event Longitude of event Northwest Territories Canada Parsons Lake Sea ice thickness Site Snow/ice sample Snow grain size Snow thickness Snow water equivalent Temperature air Water bodies |
spellingShingle |
DATE/TIME Date/time end Density snow Event label Ice type International Polar Year (2007-2008) IPY Lake_Noel Lake_Sitidgi Lakes_A-B Lakes_Husky Latitude of event Longitude of event Northwest Territories Canada Parsons Lake Sea ice thickness Site Snow/ice sample Snow grain size Snow thickness Snow water equivalent Temperature air Water bodies Gunn, Grant E Duguay, Claude R Derksen, Chris Lemmetyinen, Juha Toose, Peter (Table 3) Air temperatures, and snow and ice characteristics of fresh and brackish water lakes in the Northwest Territories, Canada |
topic_facet |
DATE/TIME Date/time end Density snow Event label Ice type International Polar Year (2007-2008) IPY Lake_Noel Lake_Sitidgi Lakes_A-B Lakes_Husky Latitude of event Longitude of event Northwest Territories Canada Parsons Lake Sea ice thickness Site Snow/ice sample Snow grain size Snow thickness Snow water equivalent Temperature air Water bodies |
description |
The algorithms designed to estimate snow water equivalent (SWE) using passive microwave measurements falter in lake-rich high-latitude environments due to the emission properties of ice covered lakes on low frequency measurements. Microwave emission models have been used to simulate brightness temperatures (Tbs) for snowpack characteristics in terrestrial environments but cannot be applied to snow on lakes because of the differing subsurface emissivities and scattering matrices present in ice. This paper examines the performance of a modified version of the Helsinki University of Technology (HUT) snow emission model that incorporates microwave emission from lake ice and sub-ice water. Inputs to the HUT model include measurements collected over brackish and freshwater lakes north of Inuvik, Northwest Territories, Canada in April 2008, consisting of snowpack (depth, density, and snow water equivalent) and lake ice (thickness and ice type). Coincident airborne radiometer measurements at a resolution of 80x100 m were used as ground-truth to evaluate the simulations. The results indicate that subsurface media are simulated best when utilizing a modeled effective grain size and a 1 mm RMS surface roughness at the ice/water interface compared to using measured grain size and a flat Fresnel reflective surface as input. Simulations at 37 GHz (vertical polarization) produce the best results compared to airborne Tbs, with a Root Mean Square Error (RMSE) of 6.2 K and 7.9 K, as well as Mean Bias Errors (MBEs) of -8.4 K and -8.8 K for brackish and freshwater sites respectively. Freshwater simulations at 6.9 and 19 GHz H exhibited low RMSE (10.53 and 6.15 K respectively) and MBE (-5.37 and 8.36 K respectively) but did not accurately simulate Tb variability (R= -0.15 and 0.01 respectively). Over brackish water, 6.9 GHz simulations had poor agreement with airborne Tbs, while 19 GHz V exhibited a low RMSE (6.15 K), MBE (-4.52 K) and improved relative agreement to airborne measurements (R = 0.47). Salinity considerations reduced ... |
format |
Dataset |
author |
Gunn, Grant E Duguay, Claude R Derksen, Chris Lemmetyinen, Juha Toose, Peter |
author_facet |
Gunn, Grant E Duguay, Claude R Derksen, Chris Lemmetyinen, Juha Toose, Peter |
author_sort |
Gunn, Grant E |
title |
(Table 3) Air temperatures, and snow and ice characteristics of fresh and brackish water lakes in the Northwest Territories, Canada |
title_short |
(Table 3) Air temperatures, and snow and ice characteristics of fresh and brackish water lakes in the Northwest Territories, Canada |
title_full |
(Table 3) Air temperatures, and snow and ice characteristics of fresh and brackish water lakes in the Northwest Territories, Canada |
title_fullStr |
(Table 3) Air temperatures, and snow and ice characteristics of fresh and brackish water lakes in the Northwest Territories, Canada |
title_full_unstemmed |
(Table 3) Air temperatures, and snow and ice characteristics of fresh and brackish water lakes in the Northwest Territories, Canada |
title_sort |
(table 3) air temperatures, and snow and ice characteristics of fresh and brackish water lakes in the northwest territories, canada |
publisher |
PANGAEA |
publishDate |
2011 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.810343 https://doi.org/10.1594/PANGAEA.810343 |
op_coverage |
MEDIAN LATITUDE: 68.804250 * MEDIAN LONGITUDE: -133.344500 * SOUTH-BOUND LATITUDE: 68.536000 * WEST-BOUND LONGITUDE: -133.800000 * NORTH-BOUND LATITUDE: 69.000000 * EAST-BOUND LONGITUDE: -132.726000 * DATE/TIME START: 2008-04-06T00:00:00 * DATE/TIME END: 2008-04-06T00:00:00 * MINIMUM ELEVATION: 2.0 m * MAXIMUM ELEVATION: 33.0 m |
long_lat |
ENVELOPE(-133.610,-133.610,68.341,68.341) ENVELOPE(-133.800000,-132.726000,69.000000,68.536000) |
geographic |
Northwest Territories Canada Inuvik |
geographic_facet |
Northwest Territories Canada Inuvik |
genre |
International Polar Year Inuvik IPY Northwest Territories Sea ice |
genre_facet |
International Polar Year Inuvik IPY Northwest Territories Sea ice |
op_source |
Supplement to: Gunn, Grant E; Duguay, Claude R; Derksen, Chris; Lemmetyinen, Juha; Toose, Peter (2011): Evaluation of the HUT modified snow emission model over lake ice using airborne passive microwave measurements. Remote Sensing of Environment, 115(1), 233-244, https://doi.org/10.1016/j.rse.2010.09.001 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.810343 https://doi.org/10.1594/PANGAEA.810343 |
op_rights |
CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1594/PANGAEA.810343 https://doi.org/10.1016/j.rse.2010.09.001 |
_version_ |
1766044580026777600 |