HR: 0800h
AN: C21C-1127    [Abstracts]
TI: Winter Synoptic Controls on Precipitation Isotopes in the Canadian Rocky Mountains.
AU: * Sinclair, K
EM: kate.sinclair@ucalgary.ca
AF: University of Calgary, Department of Geography, 2500 University Drive, N.W. Calgary, AB T2N 1N4 Canada
AU: Marshall, S
EM: shawn.marshall@ucalgary.ca
AF: University of Calgary, Department of Geography, 2500 University Drive, N.W. Calgary, AB T2N 1N4 Canada
AB: The variability of synoptic circulation, and associated shifts in vapour transport pathways that bring moisture from Pacific Coast source regions to the Rocky Mountains, is the key control on temperature fluctuations over western Canada. For this reason, precipitation isotope anomalies in the winter snow pack reflect the signatures of major storm systems that bring snow to the region. Ten snow pits were sampled throughout the 2005 winter season on the Haig Glacier, Alberta. Precipitation isotopes (oxygen-18 and deuterium) were analyzed to determine the temporal variability and seasonal evolution of the snow pack. One control snow pit was sampled at the end of winter at the Opabin Glacier (Yoho National Park, British Columbia) to assess the regional transferability of the Haig Glacier isotope profiles. All winter snow pits showed a remarkable degree of correlation both spatially and temporally. Five distinct cold periods, punctuated by six warmer periods were visible in all profiles, with deeper pits recording higher resolution isotope variability. Analysis of the regional synoptic conditions via 500mb pressure charts and flow indices, along with surface weather data and the snow accumulation record from an automatic weather station on the Haig Glacier, enabled the identification and characterization of major storm systems that brought snow to the field site during the sampling period. Each storm left a distinct isotopic signature in the snowpack, illustrating the potential for high resolution snow pit data to be used characterize atmospheric-isotope teleconnections on a regional basis.
DE: 0720 Glaciers
DE: 0736 Snow (1827, 1863)
DE: 3354 Precipitation (1854)
DE: 3364 Synoptic-scale meteorology
SC: Cryosphere [C]
MN: Fall Meeting 2005