Centers & Labs

RIKEN Center for Computational Science

Computational Climate Science Research Team

Team Leader: Hirofumi Tomita (D.Eng.)
Hirofumi  Tomita(D.Eng.)

In climate simulations, combinations of numerical methods in models lead to large uncertainties of results. The necessary issues are to identify which part does cause the uncertainties and to estimate the inevitable uncertainties. To make such issues be easily resolved, our team develops the common library for computational climate science with high efficiency on high performance computers. The library systematizes various schemes, providing with model itself and analysis tools. At the same time, we will carry out pioneering works of large-scale climate computing. To do them, we are constructing the numerical schemes and reconsidering their theories by more principle than that in conventional models.

Main Research Field

Environmental science

Related Research Fields

Interdisciplinary science and engineering / Engineering


  • high performance computing
  • climate modeling

Selected Publications

  1. Yoshida, R., Nishizawa, S., Yashiro, H., Adachi, S. A., Sato, Y., Yamaura, T., and Tomita, H.:
    “CONeP: A cost-effective online nesting procedure for regional atmospheric models”
    Parallel Computing, Volume 65, Pages 21–31 (2017).
  2. Adachi, S. A., Kimura, F., Takahashi, H. G., Hara, M., Ma, X., and Tomita, H.:
    “Impact of high-resolution sea surface temperature and urban data on estimations of surface air temperature in a regional climate”
    Journal of Geophysical Research Atmospheres, Volume 121, Issue 18, Pages 10,486–10,504 (2016).
  3. Yashiro, H., Terasaki, K., Miyoshi, T., and Tomita, H.:
    “Performance evaluation of a throughput-aware framework for ensemble data assimilation: the case of NICAM-LETKF”
    Geoscientific Model Development, Volume 9, issue 7, Page 2293-2300 (2016).
  4. Nishizawa, S., Odaka, M., Takahashi, Y. O., Sugiyama, K., Nakajima, K., Ishiwatari, M., Takehiro, S., Yashiro, H., Sato, Y., Tomita, H., and Hayashi, Y.-Y.:
    “Martian dust devil statistics from high-resolution large-eddy simulations”
    Geophysical Research Letters, Volume 43, Issue 9, Pages 4180–4188 (2016).
  5. Kajikawa, Y., Miyamoto, Y., Yoshida, R., Yamaura, T., Yashiro, H., and Tomita, H.:
    “Resolution dependence of deep convections in a global simulation from over 10-kilometer to sub-kilometer grid spacing”
    Progress in Earth and Planetary Science, 3:16 (2016).
  6. Nishizawa, S., Yashiro, H., Sato, Y., Miyamoto, Y., and Tomita, H.:
    “Influence of grid aspect ratio on planetary boundary layer turbulence in large-eddy simulations”
    Geosci. Model Dev., 8, 3393-3419 (2015).
  7. Sato, Y., Nishizawa, S., Yashiro, H., Miyamoto, Y., Kajikawa, Y., and Tomita, H.:
    “Impacts of cloud microphysics on trade wind cumulus: which cloud microphysics processes contribute to the diversity in a large eddy simulation?”
    Prog. Earth Planet. Sci., 2, 23 (2015).
  8. Sato, Y., Miyamoto, Y., Nishizawa, S., Yashiro, H., Kajikawa, Y., Yoshida, R., Yamaura, T., and Tomita, H.:
    “Horizontal Distance of Each Cumulus and Cloud Broadening Distance Determine Cloud Cover”
    SOLA, 11, 75-79 (2015).
  9. Miyamoto Y., Yoshida, R., Yamaura, T., Yashiro, H., Tomita, H., and Kajikawa, Y.:
    “Does convection vary in different cloudy disturbances?”
    Atmos. Sci. Lett., 16, 3, 305-309 (2015).
  10. Miyamoto, Y., Kajikawa, Y., Yoshida, R., Yamaura, T., Yashiro, H., and Tomita, H.:
    “Deep moist atmospheric convection in a sub-kilometer global simulation”
    Geophys. Res. Lett., pp.4922–4926 (2013).

Lab Members

Principal Investigator

Hirofumi Tomita
Team Leader

Core Members

Yoshiyuki Kajikawa
Senior Scientist
Seiya Nishizawa
Research Scientist
Hisashi Yashiro
Research Scientist
Sachiho Adachi
Research Scientist
Tsuyoshi Yamaura
Research Scientist
Kenta Sueki
Postdoctoral Researcher
Toshiki Matsushima
Postdoctoral Researcher
Hiroaki Miura
Visiting Scientist
Hiroshi Taniguchi
Visiting Scientist
Yoshiaki Miyamoto
Visiting Scientist
Yousuke Sato
Visiting Scientist
Shin-ichiro Shima
Visiting Scientist
Ryuji Yoshida
Visiting Scientist