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www.hydrol-earth-syst-sci-discuss.net/5/2347/2008/
doi:10.5194/hessd-5-2347-2008
© Author(s) 2008. This work is distributed
under the Creative Commons Attribution 3.0 License.
Topographic control of snow distribution in an alpine watershed of western Canada inferred from spatially-filtered MODIS snow products
Environmental Science and Engineering Program, University of Northern British Columbia, Prince George, BC, V2N 4Z9, Canada
Abstract. A spatial filter (SF) is used to reduce cloud coverage in MODIS 8-day maximum snow cover extent products (MOD10A2) from 2000–2007 to assess the topographic control on snow cover fraction (SCF) and snow cover duration (SCD) in the Quesnel River Basin (QRB) of British Columbia, Canada. Results show that the SF reduces cloud coverage and improves by 2% the accuracy of snow mapping in the QRB. The SF shows larger SCF and longer SCD than MOD10A2, with higher altitudes experiencing longer snow cover and perennial snow above 2500 m. The gradient of SCF with elevation (d(SCF)/d(elevation)) during the snowmelt season is 8% (100 m)−1. The average melt rates of SCF are similar for different 100 m elevation bands at about 5.5% (8 days)−1 for altitudes <1500 m with decreasing values with elevation to near 0% (8 days)−1 for altitudes >2500 m. Different combinations of slopes and aspects also affect the SCF with a maximum difference of 20.9% at a given time. Correlation coefficients between SCD and elevation attain 0.96 (p<0.001). Mean gradients of SCD with elevation are 3.8, 4.3, and 11.6 days (100 m)−1 for the snow onset, snowmelt, and entire year, respectively. The SF decreases the standard deviations of SCDs compared to MOD10A2 with a maximum difference near 0.63 days, 0.89 days, and 1.04 days for the snow onset, snowmelt and entire year, respectively.
Discussion Paper (PDF, 1011 KB) Interactive Discussion (Closed, 6 Comments) Final Revised Paper (HESS)
Citation: Tong, J., Déry, S. J., and Jackson, P. L.: Topographic control of snow distribution in an alpine watershed of western Canada inferred from spatially-filtered MODIS snow products, Hydrol. Earth Syst. Sci. Discuss., 5, 2347-2371, doi:10.5194/hessd-5-2347-2008, 2008. Bibtex EndNote Reference Manager XML
