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Chief Scientist Laboratories Mathematical Climatology Laboratory

Chief Scientist: Hirofumi Tomita (D.Eng.)

Research Summary

Hirofumi  Tomita(D.Eng.)

We aim to understand important processes for climate system and uncertainty in future climate prediction from the viewpoint of mathematical science. Our study will focus on the evaluation of convergence of solution by using LES instead of current turbulence scheme (RANS), the construction of theory for moist LES including phase transition of water, the sophistication of physical processes (e.g., micro-physics) and development of fast algorithm for these schemes, and the proposal of appropriate parameterization to low resolution models.

Main Research Fields

  • Mathematical & Physical Sciences

Related Research Fields

  • Complex Systems


  • Understanding of self-organization and hierarchical structure of cloud related to atmospheric turbulence
  • Exploration of climatological multi equilibrium solution under ideal condition
  • Development of new downscaling simulation method for regional climate projection

Selected Publications

  • 1. Yuta Kawai and Hirofumi Tomita:
    "Numerical Accuracy Necessary for Large-Eddy Simulation of Planetary Boundary Layer Turbulence using Discontinuous Galerkin Method"
    Monthly Weather Review, Early Online Release on 13 Mar 2023, (2023).
    doi: 10.1175/MWR-D-22-0245.1
  • 2. Yanase, T., S. Nishizawa, H. Miura, and H. Tomita:
    "Characteristic form and distance in high-level hierarchical structure of self-aggregated clouds in radiative-convective equilibrium"
    Geophysical Research Letters, Vol. 49, Issue 18, e2022GL100000 (2022).
  • 3. Yanase, T., S. Nishizawa, H. Miura, T. Takemi, and H. Tomita:
    "Low-level circulation and its coupling with free-tropospheric variability as a mechanism of spontaneous aggregation of moist convection"
    Journal of the Atmospheric Sciences, Vol. 79, Issue 12, p.3429-3451 (2022).
  • 4. Sueki, K., S. Nishizawa, T. Yamaura, and H. Tomita:
    "Precision and convergence speed of the ensemble Kalman filter-based parameter estimation: setting parameter uncertainty for reliable and efficient estimation"
    Progress in Earth and Planetary Science 9, Article number: 47 (2022).
  • 5. Yanase, T., S. Nishizawa, H. Miura, T. Takemi, and H. Tomita:
    "New critical length for the onset of self-aggregation of moist convection"
    Geophysical Research Letters, 47, e2020GL088763 (2020).
  • 6. Adachi, S. A. and H. Tomita:
    "Methodology of the constraint condition in dynamical downscaling for regional climate evaluation: A review"
    J. Geophys. Res., 125 (11), e2019JD032166 (2020).
  • 7. Sueki, K., T. Yamaura, H. Yashiro, S. Nishizawa, R. Yoshida, Y. Kajikawa, and H. Tomita:
    "Convergence of convective updraft ensembles with respect to the grid spacing of atmospheric models"
    Geophysical Research Letters, 46, 14817-14825 (2019).
  • 8. Adachi, S. A., S. Nishizawa, K. Ando, T. Yamaura, R. Yoshida, H. Yashiro, Y. Kajikawa, and H. Tomita:
    "An evaluation method for uncertainties in regional climate projections"
    Atmospheric Science Letters, Volume20, Issue1, e877 (2019).

Annual research report

Related Links

Lab Members

Principal investigator

Hirofumi Tomita
Chief Scientist

Core members

Sachiho Adachi
Research Scientist
Tomoro Yanase
Special Postdoctoral Researcher

Contact Information

RIKEN Center for Computational Science
7-1-26, Minatojima-minami-machi,
Chuo-ku, Kobe, Hyogo,
650-0047, Japan
Email: htomita [at] riken.jp