Title Topographic control of snow distribution in an alpine watershed of Western Canada inferred from spatially- filtered MODIS snow products
Author Tong, J.; Déry, S.J.; Jackson, P.L.
Author Affil Tong, J., University of Northern British Columbia, Natural Resources and Environmental Studies, Prince George, BC, Canada
Source Hydrology and Earth System Sciences (HESS), 13(3), p.319-326, . Publisher: Copernicus GmbH on behalf of the European Geosciences Union, Katlenburg-Lindau, Germany. ISSN: 1027-5606
Publication Date 2009
Notes In English. Published in Hydrology and Earth System Sciences Discussions: 26 August 2008, http://www.hydrol-earth-syst-sci- discuss.net/5/2347/2008/hessd-5-2347-20 08.html; accessed in July, 2009,. 28 refs. GeoRef Acc. No: 307835
Index Terms ablation; clouds (meteorology); glaciers; glacier ablation; remote sensing; snow; statistical analysis; thickness; topography; water balance; Canada--British Columbia--Fraser River; Canada--British Columbia--Quesnel Lake; British Columbia; Canada; clouds; correlation coefficient; elevation; energy balance; Fraser River; geomorphologic controls; MODIS; Quesnel Lake; Quesnel River basin; seasonal variations; spatial distribution; spatial frequency filters; temporal distribution; Western Canada
Abstract A spatial filter (SF) is used to reduce cloud coverage in Moderate Resolution Imaging Spectroradiometer (MODIS) 8-day maximum snow cover extent products (MOD10A2) from 2000- 2007, which are obtained from MODIS daily snow cover extent products (MOD10A1), 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 new product developed using the SF method 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)/dz) during the snowmelt season is 8% (100 m)-1. The average ablation 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 season, snowmelt season, and entire year, respectively. The SF decreases the standard deviations of SCDs compared to MOD10A2 with a maximum difference near 0.6 day, 0.9 day, and 1.0 day for the snow onset season, snowmelt season, and entire year, respectively.
URL http://hdl.handle.net/10.5194/hess-13-319-2009
Publication Type journal article
Record ID 65004849