HR: 0800h
AN: C51B-1044    [Abstracts]
TI: ISOSTORM: A High-Resolution Volunteer Network To Characterize the Isotopic Composition of Event-Based Precipitation Across North America
AU: * Blair, D
EM: d.blair@uwinnipeg.ca
AF: Department of Geography, University of Winnipeg, 515 Portage Avenue, Winnipeg, MB R3B2E9 Canada
AU: Buhay, W M
EM: b.buhay@uwinnipeg.ca
AF: Department of Geography, University of Winnipeg, 515 Portage Avenue, Winnipeg, MB R3B2E9 Canada
AU: Gibson, J
EM: john.gibson@ec.gc.ca
AF: National Water Research Institute atW-CIRC, University of Victoria, PO Box 1700 STN CSC, Victoria, BC V8W2Y2 Canada
AB: The oxygen and hydrogen isotopic composition of precipitation in the mid and high latitudes is very much related to the temperature of the air within which the precipitation forms. Consequently, time-averaged isotopic compositions correlate strongly with concurrent mean atmospheric temperatures. Substantial deviations from the expected temperature-isotope relationship are largely determined by the length of the averaging period and by the trajectory and history of the precipitating air mass (continental effects and orographic rainout). Consequently, detailed attribution of the deviations is difficult, especially when using the standard monthly precipitation samples, including those used by the Global Network for Isotopes in Precipitation (GNIP). We propose to establish a dense network of volunteers associated with automated weather stations at universities, colleges or schools across North America to collect daily, synchronized samples of precipitation for isotopic analysis. With the onset of a significant synoptic-scale storm (e.g., a large Colorado Low), the volunteers would be asked to collect daily samples for a week, or so, perhaps several times per year. Spatial and temporal analysis of the isotopic signatures in the precipitation will produce valuable insight into the effects of the atmospheric circulation on isotopic compositions, which in turn will provide better isotope-based palaeoclimate reconstructions (from tree-rings, for example).
DE: 3364 Synoptic-scale meteorology
DE: 3309 Climatology (1620)
DE: 1833 Hydroclimatology
SC: Cryosphere [C]
MN: 2004 AGU Fall Meeting