Measured and simulated snow irradiance profiles as well as snow specific surface area and density data measured at shrub and shrub-free sites in the Tasiapik Valley in Umiujaq, Northern Québec
Abstract
This dataset was collected during an autumn campaign in 2015 in Umiujaq, Northern Quebec. The dataset includes vertical profiles of 1) snow specific surface area (SSA), 2) snow density, and 3) measured and simulated spectral irradiance. All data, except the simulated spectral irradiance, were measured at seven sites which were all located in the Tasiapik valley near the village of Umiujaq. Four of the seven sites were covered by shrubs and three were without shrubs. Snow SSA was acquired with the DUFISSS instrument detailed in Gallet et al. (2009), https://doi.org/10.5194/tc-3-167-2009. Snow density profiles were measured with a 100 cm^3 box cutter. Measured spectral irradiance was taken with the SOLEXS instrument which has been described in detail by Picard et al. (2016) https://doi.org/10.5194/tc-10-2655-2016. Simulated spectral irradiance was calculated as a function of measured snow SSA, snow density and a selection of different impurity concentrations and types (i.e. BC and mineral dust) using the model SnowMCML (Picard et al., 2016). More details on method and data analysis can be found in the publication «On the influence of erect shrubs on the irradiance profile in snow» by Belke-Brea et al. (2021) https://doi.org/10.5194/bg-18-5851-2021.
Additional notes:
1) Snow SSA and density: profiles were measured with a resolution of 1 to 3 cm. Where data was missing for a given depth, we performed linear interpolation between measured density data points, in order to synchronize the SSA and density profiles.
2) Several corrections have been applied to the measured irradiance profiles including a) the subtraction of the dark current, b) a depth correction, c) a normalization of the photosensor current to correct for small fluctuations during the measurements. Moreover, irradiance profiles were normalized with the incoming radiation at the surface.
Additional notes:
1) Snow SSA and density: profiles were measured with a resolution of 1 to 3 cm. Where data was missing for a given depth, we performed linear interpolation between measured density data points, in order to synchronize the SSA and density profiles.
2) Several corrections have been applied to the measured irradiance profiles including a) the subtraction of the dark current, b) a depth correction, c) a normalization of the photosensor current to correct for small fluctuations during the measurements. Moreover, irradiance profiles were normalized with the incoming radiation at the surface.
Data citation
Belke-Brea M., Domine F.,Picard G., Arnaud L. 2022. Measured and simulated snow irradiance profiles as well as snow specific surface area and density data measured at shrub and shrub-free sites in the Tasiapik Valley in Umiujaq, Northern Québec, v. 1.0. Nordicana D96, doi: 10.5885/45753CE-F2A3EB5488B442E3.
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Key references
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Belke-Brea, M., F. Domine, G. Picard, M. Barrere, and L. Arnaud (2021), On the influence of erect shrubs on the irradiance profile in snow, Biogeosciences, 18(21), 5851-5869.
DOI: 10.5194/bg-18-5851-2021
Version history
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Version 1.0 (2015–2015)Updated February 9, 2022
You can request an older version by contacting nordicana@cen.ulaval.ca
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