HR: 0800h
AN: C21A-1078    [Abstracts]
TI: High resolution modelling of snow accumulation and ablation in alpine regions
AU: * Byrne, J
EM: byrne@uleth.ca
AF: Geography/Environmental Science University of Lethbridge, 4401 University Drive West, Lethbridge, AB T1K3M4 Canada
AU: Kienzle, S
EM: stefan.kienzle@uleth.ca
AF: Geography/Environmental Science University of Lethbridge, 4401 University Drive West, Lethbridge, AB T1K3M4 Canada
AU: Duke, G
EM: guy.duke2@uleth.ca
AF: Geography/Environmental Science University of Lethbridge, 4401 University Drive West, Lethbridge, AB T1K3M4 Canada
AU: Lapp, S
EM: lappsl@uleth.ca
AF: Geography/Environmental Science University of Lethbridge, 4401 University Drive West, Lethbridge, AB T1K3M4 Canada
AU: Taylor, B
EM: Bill.Taylor@ec.gc.ca
AF: Pacific & Yukon Region, Environment Canada, #201, 401 Burrard, Vancouver, BC V6C 3S5 Canada
AU: Neilsen, D
EM: NeilsenD@AGR.GC.CA
AF: Agriculture and Agrifood Canada, Summerland Research Centre, Summerland, BC V0H 1Z0 Canada
AB: This work is to combine downscaled climate change scenarios with several meso-micro scale climatologic assessments of alpine snow accumulation and ablation over winter to evaluate the impacts of forecast climate change on snowpack conditions in the Oldman watershed in southern Alberta and Okanagan watershed in southern British Columbia. The synoptic analysis was used to generate long term precipitation time series scenarios using the Canadian Centre for Climate Modeling and Analysis (CCCma) CGCM1 and CGCM2 coupled general circulation model runs. Forecast changes in wintertime synoptic conditions over western North America provided estimates of changing precipitation regimes for the historical (1961-90) and future time periods (2021-50). Temperature changes as forecast by the GCCM1 and CGCM2 model runs were applied to both study basins. The historic and future climate scenarios were applied to both watersheds with several novel meso and micro scale alpine hydrometeorology models and a range of spatial analysis techniques. Work in the Okanagan basin used empirical analysis to de-trend the historical meteorological data and interpolation routines were applied to develop daily high resolution gridded surfaces of temperature and precipitation. The analysis reveals that temperature will play a dominant role in future SWE accumulations and related water supplies from these alpine watersheds. Midwinter melting and conversion of snow to rain will reduce snow accumulations over winter, resulting in much lower spring runoff volumes in an average year. The overall decline in spring maximum SWE for the future period relative to the historic data was about 30% in the Okanagan and about 40% for the Oldman River basin. However, in warm dry years, SWE declines much more, indicating there could be dramatic water shortages in future. The alpine hydrometeorological models need more development, evaluation and validation. Our estimates of SWE at high elevations are likely subject to high uncertainty given we had few input data points for high elevation in the development phase. However, the modelling techniques show substantial promise for many alpine hydrometeorological and biometeorological applications.
DE: 0736 Snow (1827, 1863)
DE: 0740 Snowmelt
DE: 1620 Climate dynamics (0429, 3309)
DE: 1630 Impacts of global change (1225)
DE: 1840 Hydrometeorology
SC: Cryosphere [C]
MN: Fall Meeting 2005