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Joshua King
Environment Canada
GeologySea iceBackscatterSnowRadar
23Publications
7H-index
167Citations
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Publications 33
Newest
#1Joshua KingH-Index: 7
Last. Justin M. Beckers (U of A: University of Alberta)H-Index: 3
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Abstract. Local-scale variations in snow density and layering on Arctic sea ice were characterized using a combination of traditional snow pit and SnowMicroPen (SMP) measurements. In total, 14 sites were evaluated within the Canadian Arctic Archipelago and Arctic Ocean on both first (FYI) and multi-year (MYI) sea ice. Sites contained multiple snow pits with coincident SMP profiles as well as unidirectional SMP transects. An existing SMP density model was recalibrated using manual density cutter ...
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#1Aaron Thompson (UW: University of Waterloo)H-Index: 1
#2Richard Kelly (UW: University of Waterloo)H-Index: 12
Last. Joshua KingH-Index: 7
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AbstractRadar scatterometer observations at 17.2 GHz and 9.6 GHz were made of the snow cover in mid-latitude agricultural fields, using the University of Waterloo scatterometer, to determine the se...
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#1Nick Rutter (Northumbria University)H-Index: 14
#2Melody SandellsH-Index: 5
Last. Matthew Sturm (UAF: University of Alaska Fairbanks)H-Index: 14
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Abstract. Spatial variability in snowpack properties negatively impacts our capacity to make direct measurements of snow water equivalent (SWE) using satellites. A comprehensive data set of snow microstructure (94 profiles at 36 sites) and snow layer thickness (9000 vertical profiles across 9 trenches) collected over two winters at Trail Valley Creek, NWT, Canada, were applied in synthetic radiative transfer experiments. This allowed robust assessment of the impact of first guess information of ...
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#1Chris DerksenH-Index: 33
#2Juha Lemmetyinen (Finnish Meteorological Institute)H-Index: 20
Last. Paul Siqueira (UMass: University of Massachusetts Amherst)H-Index: 17
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Current satellite observing systems lack the capability to derive terrestrial snow water equivalent (SWE, the amount of liquid water stored in solid form by snow) at the spatial resolution, synoptic sensitivity, global coverage, and accuracy required for operational environmental monitoring, services, and prediction. The required combination of revisit time, spatial coverage, measurement resolution, and sensitivity to the mass of snow on the ground necessitates a new spaceborne observing concept...
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#2Robert RickerH-Index: 10
Last. Christian HaasH-Index: 37
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The snow layer on sea ice has high importance for polar climate as it affects heat, radiation, and fresh-water budgets. Additionally, snow loading is a critical parameter for the sea-ice freeboard-to-thickness conversion for satellite radar and laser altimeters. Despite its importance, there is a lack of snow observations spanning different spatial and temporal scales, thus introducing a significant source of uncertainty to altimetric sea-ice thickness retrievals. The ultra-wideband microwave ra...
Last. Chris DerksenH-Index: 33
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#1Joshua KingH-Index: 7
#2Chris DerksenH-Index: 33
Last. Matthew Sturm (UAF: University of Alaska Fairbanks)H-Index: 14
view all 11 authors...
Abstract Recent advancement in the understanding of snow-microwave interactions has helped to isolate the considerable potential for radar-based retrieval of snow water equivalent (SWE). There are however, few datasets available to address spatial uncertainties, such as the influence of snow microstructure, at scales relevant to space-borne application. In this study we introduce measurements from SnowSAR, an airborne, dual-frequency (9.6 and 17.2 GHz) synthetic aperture radar (SAR), to evaluate...
5 CitationsSource
#1Jiyue Zhu (UM: University of Michigan)H-Index: 2
#2Shurun Tan (UM: University of Michigan)H-Index: 9
Last. Leung Tsang (UM: University of Michigan)H-Index: 53
view all 6 authors...
In this paper, we develop a radar snow water equivalent (SWE) retrieval algorithm based on a parameterized forward model of bicontinuous dense media radiative transfer (Bic-DMRT). The algorithm is based on retrieving the absorption loss of the snowpack which is directly proportional to the SWE. In the algorithm, Bic-DMRT is first applied to generate a lookup table (LUT) of snowpack backscattering at X- and Ku-band. Regression training is applied to the LUT to transform the dual-frequency backsca...
2 CitationsSource
#1Grant E. Gunn (MSU: Michigan State University)H-Index: 6
#2Claude R. Duguay (UW: University of Waterloo)H-Index: 30
Last. Peter TooseH-Index: 11
view all 5 authors...
A winter time series of ground-based (X- and Ku-bands) scatterometer and spaceborne synthetic aperture radar (SAR) (C-band) fully polarimetric observations coincident with in situ snow and ice measurements are used to identify the dominant scattering mechanism in bubbled freshwater lake ice in the Hudson Bay Lowlands near Churchill, Manitoba. Scatterometer observations identify two physical sources of backscatter from the ice cover: the snow–ice and ice–water interfaces. Backscatter time series ...
4 CitationsSource
#1Juha LemmetyinenH-Index: 20
#2Chris DerksenH-Index: 33
Last. Jouni PulliainenH-Index: 36
view all 10 authors...
Current methods for retrieving SWE (snow water equivalent) from space rely on passive microwave sensors. Observations are limited by poor spatial resolution, ambiguities related to separation of snow microstructural properties from the total snow mass, and signal saturation when snow is deep (~>80 cm). The use of SAR (Synthetic Aperture Radar) at suitable frequencies has been suggested as a potential observation method to overcome the coarse resolution of passive microwave sensors. Nevertheless,...
7 CitationsSource
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