HR: 1340h
AN: B33D-1581    [Abstracts]
TI: The isotopic composition of water vapor in an irrigated urban area
AU: * Bijoor, N
EM: nbijoor@uci.edu
AF: Department of Earth System Science, University of California- Irvine, Irvine, CA 92697,
AU: Pataki, D
EM: dpataki@uci.edu
AF: Department of Earth System Science, University of California- Irvine, Irvine, CA 92697,
AB: The isotopic composition of water vapor in urban areas has rarely been measured, but has the potential to provide information about urban water cycle processes. We measured the isotope values of water vapor at two heights above an urban wetland, 20 m above an urban campus, and 30 m from the ocean. Diurnal isotope values at the beach and marsh showed a 5.8 per mil difference in d2H and 1 per mil difference in d18O, indicating the influence of local processes at each location. Isotope profiles show differences between the top and bottom of the marsh, supporting the idea of a local marsh isotopic signature. The Keeling plot approach and the mass- balance approach were used to partition evapotranspiration from the marsh. Both methods suggest that marsh water loss is dominated by transpiration. The data suggest that stable isotopes of water vapor can be a powerful tool to partition sources of evaporation and transpiration.
DE: 0495 Water/energy interactions (1878)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting