HR: 0800h
AN: B11A-1005    [Abstracts]
TI: Isotopic Impact of Land Surface Processes on Precipitation: A 15-year Global Simulation using Iso-MATSIRO
AU: * Yoshimura, K
EM: kei@iis.u-tokyo.ac.jp
AF: Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo, 153-8505 Japan
AU: Oki, T
EM: taikan@iis.u-tokyo.ac.jp
AF: Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo, 153-8505 Japan
AU: Kanae, S
EM: kanae@chikyu.ac.jp
AF: Research Institute of Humanity and Nature, 335 Takashima-cho, Kyoto, 602-0878 Japan
AU: Miyazaki, S
EM: miyashin@iis.u-tokyo.ac.jp
AF: Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo, 153-8505 Japan
AB: This study first describes Iso-MATSIRO, a land surface model that includes stable water isotopes and simulates physically reasonable isotopic fluxes and reservoirs at the ground. The model calculates kinetic and equilibrium fractionation of HDO and H_{2}{}¹⁸O between ice, liquid, and vapor phases and separately considers soil surface evaporation, vegetation transpiration, evaporation from the canopy-intercepted reservoir, and snow sublimation. One-dimensional simulations with modeled meteorological forcings showed plausible features in the annual isotopic budget, seasonal variations of δ¹⁸O in soil moisture, diurnal variations of leaf water with some enrichment, and δ-diagram of representative surface reservoirs and fluxes. A subsequent, reanalysis-forced 15-year global offline simulation used Iso-MATSIRO coupled with a simple atmospheric isotope circulation model (ICM, Yoshimura et al., 2003) and the Merlivat_fs modification of sea surface isotopic treatment. Both seasonality and inter-annual variability of simulated precipitation δ¹⁸O were closer to observations than in a previous study, confirming the physical treatments of isotopes in the land surface processes. One-dimensional simulations with observed meteorological forcings and their verification will be presented at the presentation.}
UR: http://hydro.iis.u-tokyo.ac.jp/
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 1041 Stable isotope geochemistry (0454, 4870)
DE: 1818 Evapotranspiration
DE: 1843 Land/atmosphere interactions (1218, 1631, 3322)
DE: 3354 Precipitation (1854)
SC: Biogeosciences [B]
MN: Fall Meeting 2005