Kei Yoshimura / Associate Professor / Division of Environmental Studies
Department of Natural Environmental Studies / / Isotope meteorology, hydrology

Career Summary
2000: BEng, Faculty of Civil Engineering (University of Tokyo)
2002: MSc in Engineering, Department of Civil Engineering, Graduate School of Engineering (University of Tokyo)
2002-2004: Technical Research Fellow, Japan Science and Technology Agency
2004-2008: Research Associate, Institute of Industrial Science, University of Tokyo
2006: PhD, Graduate School of Engineering (University of Tokyo)
2006-2008: Visiting Scholar, Scripps Institution of Oceanography, UCSD
2008-2010: Assistant Project Scientist, Scripps Institution of Oceanography, UCSD
2010: Associate Professor, Institute of Industrial Science, University of Tokyo
2010: Associate Professor, Atmosphere and Ocean Research Institute, University of Tokyo
Educational Activities
Graduate school: advanced hydrology
Undergraduate course: global hydrologic cycle and society
Research Activities
Study on processes of Earth hydrological cycle with stable water isotopes (2001-present):
Stable oxygen and hydrogen isotopes in water (H218O and HDO) have been used not only as proxy information for paleoclimate reconstruction, but also as natural tracers for hydrologic cycles since the 1960s. Because their concentrations (a.k.a. "isotope ratio") are sensitive to phase changes of water during circulation, geographic and temporal variations of isotopic ratios emerge in vapor and precipitation. Therefore, by using isotopic information in precipitation and vapor, I have been studying atmospheric vapor cycling processes in various scales, such as large-scale transport and in-cloud processes. In particular, by incorporating the isotopes into global and regional climate models, I have intensively studied the relation between atmospheric processes and isotopic information in water vapor and precipitation.

Water isotopes and hydrologic cycle
1) Yoshimura, K., M. Kanamitsu, and M. Dettinger, Regional downscaling for stable water isotopes: A case study of an atmospheric river event, J. Geophys. Res., 115, doi:10.1029/2010JD014032, 2010.
2) Schneider, M., K. Yoshimura, F. Hase, and T. Blumenstock, The ground-based FTIR network's potential for investigating the atmospheric water cycle, Atmos. Chem. Phys., 10, 3427-3442, 2010.
3) Frankenberg, C., K. Yoshimura, T. Warneke, I. Aben, A. Butz, N. Deutscher, D. Griffith, F. Hase, J. Notholt, M. Schneider, H. Schrijver, and T. Rockmann: Dynamic processes governing lower-tropospheric HDO/H2O ratios as observed from space and ground, Science, 325, 1374-1377, 2009.
4) Yoshimura, K. and M. Kanamitsu, Specification of external forcing for regional model integrations, Mon. Wea. Rev., 137, 1409-1421, 2009.
5) Yoshimura, K., M. Kanamitsu, D. Noone, and T. Oki, Historical isotope simulation using Reanalysis atmospheric data, J. Geophys. Res, 113, D19108, doi:1029.10/2008JD010074, 2008.
6) Fudeyasu, H., K. Ichiyanagi, A. Sugimoto, K. Yoshimura, A. Ueta, M. D. Yamanaka, and K. Ozawa, Isotope ratios of precipitation and water vapor observed in Typhoon Shanshan, J. Geophys. Res., 113, D12113, doi:10.1029/2007JD009313, 2008.
7) Yoshimura, K., T. Oki, N. Ohte, and S. Kanae, A quantitative analysis of short-term 18O variability with a Rayleigh-type isotope circulation model. J. Geophys. Res., 108(D20), 4647, doi:10.1029/2003JD003477, 2003.

Other Activities
Japan Society of Hydrology and Water Resources Engineering
Meteorological Society of Japan
American Geophysical Union
Future Plan
My current research is focused on various interdisciplinary areas, including global and regional meteorology, land surface and atmospheric hydrology, and paleoclimatology, all of which are bridged by natural isotopic tracers. The main thrust of my work is toward better understanding of the Earthfs climate system. This is explored both by utilizing additional information obtained from isotopic records and by developing models that simulate the observed processes.
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