Tomoki IWAKIRI

Ph.D.
Postdoctoral Associate, IPRC, University of Hawai‘i at Manoa, USA.
JSPS Research Fellow (PD), Ochanomizu university, Japan

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Climate science
My primary research interest lies in large-scale atmosphere–ocean interactions, with a particular focus on the dynamics of the El Niño-Southern Oscillation.
My research philosophy is to seek simple understanding of the complex climate system.

Personal
Born on January 1995, Japan
Primary email
iwakirit (at) hawaii.edu
Permanent email (transfer to Primary)
iwakiri.tmk (at) gmail.com

ORCID


Publication list


Peer-Reviewed Journal Articles (Lead author)
  1. Iwakiri T., Kug J-S., Jin F-F., Zhao S., An S-I., Kim G-I., Park D. (2025): Abrupt shift of El Niño periodicity under CO2 mitigation. Proc. Natl. Acad. Sci., https://doi.org/10.1073/pnas.2426048122.
    Featured in the PNAS Showcase | More frequent El Niño events due to climate mitigation
  2. Iwakiri T., Imada Y., Takaya Y., Kataoka T., Tatebe H., and Watanabe M. (2023): Triple-dip La Niña in 2020–23: North Pacific atmosphere drives 2nd year La Niña. Geophys. Res. Lett., https://doi.org/10.1029/2023GL105763.
  3. Iwakiri T. and Watanabe M. (2022): Multiyear ENSO dynamics as revealed in observations, climate model simulations, and the linear recharge oscillator. J. Climate, https://doi.org/10.1175/JCLI-D-22-0108.1.
  4. Iwakiri T. and Watanabe M. (2021b): Contribution of Ekman transport to the ENSO periodicity estimated with an extended Wyrtki index. Geophys. Res. Lett., 48, https://doi.org/10.1029/2021GL095193.
  5. Iwakiri T. and Watanabe M. (2021a): Mechanisms linking multi-year La Niña with preceding strong El Niño. Sci. Rep., 11, https://doi.org/10.1038/s41598-021-96056-6.
  6. Iwakiri T. and Watanabe M. (2020): Multiyear La Niña impact on summer temperature over Japan. J. Meteor. Soc. Japan., 98, https://doi.org/10.2151/jmsj.2020-064.
  7. Iwakiri T. and Watanabe M. (2019b): Strengthening of the Indian Ocean dipole with increasing seasonal cycle in the mid-Holocene. Geophys. Res. Lett., 46, https://doi.org/10.1029/2019GL083088.
  8. Iwakiri T. and Watanabe M. (2019a): Mechanisms reducing ENSO amplitude and asymmetry via an enhanced seasonal cycle in the mid-Holocene. J. Climate, https://doi.org/10.1175/JCLI-D-19-0110.1.
Peer-Reviewed Journal Articles (coauthor)
  1. Xu, Z., Kosaka Y., Toda M., Iwakiri T., Huang G., Ji F., Miyamoto A., and Tao W. (2024): Irreversibility of winter precipitation over the Northeastern Pacific and Western North America against CO2 forcing. npj Clim. Atmos. Sci., https://doi.org/10.1038/s41612-024-00864-2.
  2. Hu, S., Watanabe M., Zhang W., Iwakiri T., and Jiang F. (2024): Quantifying the Amplifying Effect of the Winter North Pacific Oscillation on the Subsequent ENSO. Geophys. Res. Lett., https://doi.org/10.1029/2024GL111019.
  3. Watanabe, M., Iwakiri T., Dong Y., and Kang S. M. (2023): Two competing drivers of the recent Walker circulation trend. Geophys. Res. Lett., https://doi.org/10.1029/2023GL105332.
Others
  1. MIROC6 AGCM Document Writing Team (2021), Description of MIROC6 AGCM , CCSR Report No. 65, Division of Climate System Research, Atmosphere and Ocean Research Institute, The University of Tokyo. https://doi.org/10.15083/0002000180.


Career


2025-07 → present  : Postdoctoral Associate, IPRC, University of Hawai‘i, USA (Host: Malte Stuecker)
2024-04 → present  : JSPS*1 Research Fellow (PD), Ochanomizu university, Japan (Host: Tsubasa Kohyama)
2024-05 → 2025-04 : Postdoctoral Researcher, Seoul National University, South Korea (Host: Jong-Seong Kug)
2023-04 → 2024-03 : JSPS Research Fellow (PD), JMA/MRI*2, Japan (Host: Yukiko Imada & Yuhei Takaya)
2023-04 → 2024-03 : Adjunct lecturer for calculus, Ochanomizu university, Japan
2022-04 → 2023-03 : Visiting Researcher, JMA/MRI, Japan
2022-04 → 2023-03 : JSPS Research Fellow (PD), The University of Tokyo (Host: Masahiro Watanabe)
2021-04 → 2022-03 : JSPS Research Fellow (DC2), The University of Tokyo (Host: Masahiro Watanabe)

*1 JSPS : Japan Society for the Promotion of Science (Funding agency for scientists)
*2 JMA/MRI : Japan Meteorological Agency/Meteorological Research Institute


Professional services


2023-08 → present : Associate Editor : Journal of Climate


Education


Mar 2022 - Ph.D. (Science) - The University of Tokyo, Japan

Dissertation: "Mechanisms for multi-year ENSO"
Supervisor: Prof. Masahiro WATANABE

Mar 2019 - M.S. (Science) - The University of Tokyo, Japan

Thesis: "Mechanisms of changes in ENSO and IOD in the mid-Holocene"
Supervisor: Prof. Masahiro WATANABE

Mar 2017 - B.S. (Science) - Nihon University, Japan

Thesis: "Representativeness of wind data from AMeDAS in Kanto region" (In Japanese)
Supervisor: Prof. Hisashi KATO



Award


  • Yamamoto award, Meteorological Society of Japan (MSJ), 2023.
  • Outstanding student presentation award, Japan Geoscience Union (JpGU), 2021 annual meeting.
  • Matsuno award (student presentation award), Meteorological Society of Japan (MSJ), 2019 spring meeting.