Education:

• Mar., 2016: PhD in Engineering, Department of Civil Engineering, Graduate School of Engineering, The University of Tokyo
• Mar., 2012: MSc in Engineering, Department of Civil Engineering, Graduate School of Engineering, The University of Tokyo
• Mar., 2009: BSc in Engineering, Department of Civil Engineering and Architecture, School of Engineering, Tohoku University

Appointments:

• Oct., 2023-: Associate Professor (Adjunct), Center for Environmental Remote Sensing, Chiba University
• Oct., 2023-: Associate Professor (Tenure Track), Institute for Advanced Academic Research, Chiba University
• Jun., 2016-: Collaborative Researcher, Institute of Industrial Science, The University of Tokyo
• Mar., 2021-Sep., 2023: Assistant Professor (PI, Tenured), Hirosaki University
• Jun., 2019-Sep., 2023: Visiting Researcher, RIKEN Center for Computational Science
• Jun., 2019-Feb., 2021: Postdoctoral Scholar, Department of Meteorology and Atmospheric Science, Pennsylvania State University
• Apr., 2018-May., 2019: Special Postdoctoral Researcher, RIKEN Center for Computational Science
• Apr,, 2016-Mar., 2018: Postdoctoral Researcher, RIKEN Advanced Institute for Computational Science
• Apr., 2015-Mar., 2016: Research Assistant, Atmosphere and Ocean Research Institute, The University of Tokyo
• Apr., 2013-Mar., 2015: Research Fellow (DC2), Japan Society for Promotion of Science

Achievements:

Publications with reviews

“†” indicates my advisee’s work

Submitted/In revision

1. Kotsuki, S., Shiraishi, K., Okazaki, A., Ensemble data assimilation to diagnose AI-based weather prediction model: A case with ClimaX version 0.3.1. submitted to NPG EGUsphere
2. Cheng, J., Cauquoin, A., Yang, Y., Okazaki, A., and Yoshimura, K., Contrasting Impacts of ENSO Evolution on the Interannual Variation of Precipitation Isotopes over the Tibetan Plateau. submitted to JGR-Atmos
3. Kino, K., Okazaki, A., Bong, H., Yoshimura, K., Challenges in Modeling Synoptic-scale Variability of Water Vapor Isotopes over the Southern Ocean. submitted to HRL
4. ^†Kurosawa, K., Okazaki, A., Kawasaki, F., Kotsuki, K., Bridging Data Assimilation and Control: Ensemble Model Predictive Control for High-Dimensional Nonlinear Systems, submitted to NPG EGUsphere
5. Mitsui, T., Kotsuki, S., Fujiwara, N., Okazaki, A., Tokuda, K., Bottom-up approach for mitigating extreme events under limited intervention options: a case study with Lorenz 96, submitted to NPG EGUsphere
6. Takeshima, A., Shiraishi, K., Okazaki, A., Tsuyuki, T., Kotsuki, S., Bridging Artificial Intelligence and Data Assimilation: The First Data-driven Ensemble Forecasting System ClimaX-LETKF, submitted to GRL
7. Li, Y., Cauquoin, A., Okazaki, A., Yoshimura, K., Improved response of δ¹⁸Osw in the Pacific Ocean to atmosphere-ocean interaction and ENSO using the isotope-enabled Fully Coupled Model MIROC6-iso, submitted to JAMES
8. Okazaki, A., Carrio, D., Dalaiden, Q., Harrison-Lofthouse, J., Kotsuki, S., Yoshimura, K., Observation error estimation in climate proxies with data assimilation and innovation statistics, submitted to CP
9. Kawasaki, F., Okazaki, A., Kurosawa, K., Tsuyuki, T., Kotsuki, S., Model Predictive Control with Foreseeing Horizon Designed for Mitigating Extreme Events of Chaotic Dynamical Systems. in prep.
10. Hamamoto, S., Iizuka, Y., Aizawa, T., Kawakami, K., Matsumoto, M., Matoba, S., Bong, H., Yoshimura, K., Okazaki, A., Uemura, R., Isotope-based Ice Core Age Scale Revealing Multi-Month Climate Variability Over the Past 150 Years in SE-Dome Greenland. in prep.
11. ^†McKinney, M., and Okazaki. A., Intercomparison of the paleoclimate reconstruction products with data assimilation over the last millennium. in prep.

Published/In print

1. Accepted Otsuka, T., Okazaki, A., Masaki, O., Kotsuki, S., Convex Optimization of Initial Perturbations toward Quantitative Weather Control, SOLA, 2025. arXiv
2. Ishidoya, S., Sugawara, S., Okazaki. A., First detection of variations in present day’s delta-18O of atmospheric O2 and its application to evaluate changes in oxygen, carbon, and water cycles., Atmos. Chem. Phys., 25, 1965–1987, https://doi.org/10.5194/acp-25-1965-2025, 2025. ACP Press
3. Cauquoin, A., Gusyev, M., Bong, H., Okazaki, A., Yoshimura, K., Modeling tritium release to the atmosphere during the Fukushima Daiichi Nuclear Power Plant accident and application to estimating post-accident water system transit times. Environ. Sci. Pollut. Res., https://doi.org/10.1007/s11356-025-35919-1, 2025. ESPR
4. Inuki, K., Kaneko, R., Okazaki, A., Kotsuki, S., Reconstructing Rankine Vortices from Doppler wind data using deep-learning-based generative models, JJJSCE, 82, 16, 24-16185, https://doi.org/10.2208/jscejj.24-16185, 2025. (in Japanese) JJJSCE
5. Morita, M., Kajita, H., Okazaki, A., Ueda, N., Umeda, K., Yamaoka, K., Uchida, E., Kawahata, H., Evaluation of Bicarbonate Flux through Groundwater and River Water at the Western Foothill of Mt. Chokai, Geochemical Journal, 58, 6, 267-275, 2024. GJ
6. Ketsuka, R., Muto, Y., Okazaki, A., Kotsuki, S., Optimizing investment policies for flood disaster in a mathematical model with reinforcement learning, Artificial Intelligence and Data Science, 5, 3, 186-193, https://doi.org/10.11532/jsceiii.5.3_186, 2024. (in Japanese) JSCEIII
7. Kino, K., Cauquoin, A., Okazaki. A., Oki, T. and Yoshimura, K., Heavy Water Isotope Precipitation in Inland East Antarctica Accompanied by Strong Southern Westerly Winds during the Last Glacial Maximum, Geophys. Res. Let., 2024. GRL
8. Cauquoin, A., Fourre, E., Landais, A., Okazaki, A., Yoshimura, K., Modeling natural tritium in precipitation and its dependence on decadal variations of solar activity using the atmospheric general circulation model MIROC5-iso, JGR-Atmos, 2024. JGR-A
9. Bong, H., Cauquoin, A., Okazaki, A., Chang, E.-C., Werner, M., Wei, Z., Yeo, N., and Yoshimura, K., Process-based inter-comparison of water isotope-enabled models and reanalysis nudging effects, JGR-Atmos, 129, e2023JD038719, 2024. JGR-A
10. Li. Y., Cauquoin, A., Okazaki. A., and Yoshimura, K., Development of the isotope version of the fully coupled climate model MIROC6-iso, JJSCE,12, 2, 23-16035, 2024. JJSCE
11. Shoji, S., Okazaki, A., Yoshimura, K., Impact of proxies and prior estimates on data assimilation using isotope ratios for the climate reconstruction of the last millennium, Earth and Space Science, 9, e2020EA001618, 2022. ESS
12. Zhang, Y., Sieron, S. B., Lu, Y., Chen, X., Nystrom, R. G., Minamide, M., Chan, M.-Y., Hartman, C. M., Yao, Z., Ruppert J. H., Okazaki, A., Greybush, S. J., Clothiaux, E. E., Zhang, F., Ensemble-Based Assimilation of Satellite All-Sky Microwave Radiances Improves Intensity and Rainfall Predictions for Hurricane Harvey (2017). Geophysical Research Letters, 48, e2021GL096410, 2021. GRL
13. Kino, K., Okazaki, A., Cauquoin, A., Yoshimura, K., Contribution of the Southern Annular Mode on variations in water isotopes of daily precipitation at Dome Fuji, East Antarctica, JGR-Atmos, 126, e2021JD035397, 2021. JGR-A
14. Okazaki, A., Miyoshi, T., Yoshimura, K., Greybush, S. J., and Zhang, F., Revisiting online and offline data assimilation comparison for paleoclimate reconstruction: an idealized OSSE study, 126, e2020JD034214, JGR-Atmos, 2021. JGR-A
15. Taylor, J., Okazaki, A., Honda, T., Kotsuji, S., Yamaji, M., Kubota, T., Oki, R., Iguchi, T. and Miyoshi, T., Oversampling Reflectivity Observations from a Geostationary Precipitation Radar Satellite: Impact on Typhoon Forecasts within an OSSE Framework, JAMES, 2021. JAMES Press Media
16. Shoji, S., Okazaki, A., Yoshimura, K., Comparative study towards millennium reanalysis by data assimilation using isotope ratios of proxies, JJSCE, 65, I_121-126, 2020. JJSCE
17. Kotsuki, S., Pensoneault, A., Okazaki, A., Miyoshi, T. Weight structure of the Local Ensemble Transform Kalman Filter: A case with an intermediate atmospheric general circulation model. Q. J. R. Meteorol. Soc., 146, 3399–3415, 2020. QJRMS
18. Okazaki, A., Honda, T., Kotsuki, S., Yamaji, M., Kubota, T., Oki, R., Iguchi, T., and Miyoshi, T., Simulating precipitation radar observations from a geostationary satellite, Atmos. Meas. Tech., 12, 3985-3996, 2019. AMT
19. Okazaki, A., and Yoshimura, K., Global evaluation of proxy models for stable water isotopes with realistic atmospheric forcing, JGR-Atmos, 124, 8972– 8993, 2019. JGR-A
20. Shoji, S., Okazaki, A., and Yoshimura, K., Study on spatiotemporal characteristic of observation impact in proxy data assimilation, JJSCE, 74 (5), I_49-I_54, 2018. JJSCE
21. Hydro 2k Consortium, Comparing proxy and model estimates of hydroclimate variability and change over the Common Era, Clim. Past., 13, 1851-1900, 2017. CP
22. Okazaki, A., and K. Yoshimura, Development and evaluation of a system of proxy data assimilation for paleoclimate reconstruction, Clim. Past, 13, 379-393, 2017. CP
23. Wei, Z., K. Yoshimura, A. Okazaki, K. Ono, W. Kim, M. Yokoi, C.-T. Lai, Understanding the variability of water isotopologues in near-surface atmospheric moisture over a humid subtropical rice paddy in Tsukuba, Japan, J. Hydrology, 533, 91-102, 2016. J. Hydrology
24. Wei, Z., K. Yoshimura, A. Okazaki, W. Kim, Z. Liu, M. Yokoi, Partitioning of evapotranspiration using high frequency water vapor isotopic measurement over a paddy field, Water Resour. Res., 51(5), 3716-3729, 2015. WRR
25. Okazaki, A., Y. Satoh, G. Tremoy, F. Vimeux, R. Scheepmaker, and K. Yoshimura, Interannual variation of vapor isotope in West Africa and its relation to ENSO, Atmos. Chem. Phys., 15, 3193-3204, 2015. ACP
26. Wei, Z., A. Okazaki, H. Maeda, Y. Satoh, M. Kiguchi, K. Noda, M. Koike, W. Kim, Z. Liu, and K. Yoshimura, Investigating vegetation-atmosphere water exchange by using high frequency spectroscopy vapor isotope observations, Journal of Japan Society of Civil Engineers, Ser. B1, 70, 181-186, 2014. JJSCE
27. Okazaki, A., P. J.-F. Yeh, K. Yoshimura, M. Watanabe, M. Kimoto, and T. Oki, Changes in Flood Risk under Global Warming Estimated Using MIROC5 and the Discharge Probability Index, J. Meteor Soc. Japan, 90(4), 509-524, 2012. JMSJ
28. Ozawa, T., Fujibayashi, M., Okazaki, A., Chiba, N., Nomura, M., Nakano, K., Nishimura, O., マルタニシ(Cipangopaludina cheinensis laeta)における触角異常の実態調査, Japanese Journal of Water Treatment Biology, 28 (69), 2008.

Presentation (selected only)

1. Okazaki, A., Tanoue, M., Kino, K., Cauquoin, A., Yoshimura, K., Estimation of Parameters in an Isotope-Enabled GCM with Data Assimilation and Satellite-Based Observations, JpGU Meeting 2024, 26-31 May 2024, Chiba, Japan. (Invited)
2. Okazaki, A., Ultra-High Spatiotemporal Resolution Reconstruction of the Climate around Japan with Large Ensemble of Climate Simulations and Old Documents, JpGU Meeting 2024, 26-31 May 2024, Chiba, Japan. (Invited)
3. Okazaki, A., Kotsuki, S., Carrio, D., Yoshimura, K., Climate reconstruction with observation errors estimated by innovation statistics, JpGU Meeting 2023, Chiba, Japan, 21-26 May 2023. (Invited poster)
4. Okazaki, A., Observation Error Estimation for Climate Proxies with Innovation Statistics, DA Seminar, RIKEN R-CCS, Kobe, Japan, 14 Nov. 2022. (Invited)
5. Okazaki, A. and Yoshimura, K., Paleoclimate Reconstruction with Isotope-Enabled GCM and Proxy System Models, IsoNet 2022, Virtual Seminar, 6 Oct. 2022.(Invited)
6. 岡崎淳史、データ同化とイノベーション統計を用いた古気候復元と気候プロキシに含まれる誤差の推定、日本地球化学第69回年会、高知、7-9 Sep 2022. (Invited)
7. Okazaki, A. and Yoshimura, K., Evaluation of proxy system models for stable water isotopes and introduction of their application to paleoclimate studies, JpGU2021, 4 Jun. 2021. (Invited)
8. Okazaki, A., Honda, T., Kotsuki, S., Miyoshi, T., Precipitation radar data assimilation with an ensemble Kalman filter: an observing system simulation experiment for a typhoon case, ADAPT seminar, PSU, PA, US, Mar 29 2019. (Invited)
9. 2018 May, Okazaki, A., Miyoshi, T., Yoshimura, K., Zhang, F., Toward online data assimilation for the millennium reanalysis, A-CC29, JpGU 2018, Makuhari, Chiba, Japan, May 20-24 2018. (Invited)
10. 2017 May, Atsushi Okazaki, Development and evaluation of isotopic proxy data assimilation system, First workshop of the PAGES working group on Paleoclimate Reanalyses, Data Assimilation and Proxy System modelling (DAPS), Louvain-la-Neuve, Belgium, 29 May-1 Jun 2017. (Invited)
11. 2017 May, Yoshimura, K., Okazaki, A., and Neluwala, P., Challenges for millennium reanalysis, JpGU-AGU Joint Meeting 2017, Makuhari, Japan, 20-25 May, 2017. (Invited)
12. 2016 Oct., Okazaki, A., Basics of data assimilation and its application to paleoclimate, Kongju National University, Gongju, Korea, 17-21 Oct., 2016. (Invited)

Full list is available at HERE

Grants:

• 2024-2025, JSPS Grant-in-Aid for Transformative Research Areas (A)(Publicly Offered Research), Ultra-high spatiotemporal resolution climate reconstruction: Toward development of historical meteorology, 24H00920, PI, 7,200,000JPY.
• 2024-2025, JST MIRAI Program, Impact assessment of SAMRAI satellite observations on tropical cyclone forecastings, Co-PI (PM: Naoya Tomii@JAXA), 5,200,000JPY.
• 2023-2026, JST Moonshot Goal 8, Artificial generation of upstream maritime heavy rains to govern intense-rain-induced disasters over land, JPMJMS2389-4-1, PI (PM: S. Kotsuki@Chiba Univ.), 91,500,000JPY.
• 2023-2024, MLIT Kasensabo-Gijutsu, Basin-scale impact-based risk assessment of the climate change, PI, 4,000,000JPY.
• 2023, JAXA contract resesarch (PI), 500,000JPY.
• 2022-2026, JSPS Grant-in-Aid for Scientific Research (S) , Generation of Millennium Atmospheric Reanalysis Product, 22H04938, Co-PI, 37,700,000JPY.
• 2022-2024, JST Moonshot Goal 8, Quantifying Weather Controllability and Mitigatable Flood Damage Based on Ensemble Weather Forecast, JPMJMS2284, PI (PM: S. Kotsuki@Chiba Univ.), 23,400,000JPY.
• 2022-2024, JSPS Grant-in-Aid for Early-Career Scientists, Development of Stable Water Isotopes Dataset for Atmospheric Science by Fusing Model Simulations and Observations, 22K14095, PI, 4,680,000JPY.
• 2022-2024, JAXA 3rd Research Announcement on the Earth Observations: EO-RA3, Advances and applications of satellite data assimilation of clouds, precipitation, and the ocean, CI (PI: Takemasa Miyoshi@RIKEN R-CCS).
• 2022-2023, JSPS Grant-in-Aid for Transformative Research Areas (A)(Publicly Offered Research), High-resolution Climate Reconstruction Toward Expansion of Historical Socio-Hydrology in Japan, 22H05228, PI, 3,770,000JPY.
• 2021-2024, JSPS Grant-in-Aid for Scientific Research (A), Exploring Real-time Rainfall and Flood Predictions in Fugaku Era with the State-of-the-art Data Science, 21H04571, Co-PI (PI: Shunji Kotsuki@Chiba Univ.), 4,420,000 JPY.
• 2021, Start-Up Grant for Young Scientists, Hirosaki University, PI, 930,000 JPY.
• 2021, Interdisciplinary Collaborative Research Grant for Young Scientists, Hirosaki University, Co-PI PI: Tomoya Takano@Hirosaki Univ.), 750,000 JPY.
• 2018-2020, Grant-in-Aid for RIKEN Special Postdoctoral Researcher, PI, 3,000,000 JPY
• 2017-2021, JSPS Grant-in-Aid for Young Scientists (B), Development of a data assimilation method toward high-accuracy paleoclimate reconstruction, 17K14397, PI, 3,120,000 JPY.
• 2013-2014, Grant-in-Aid for JSPS Fellows, 13J09182, PI, 2,000,000 JPY.

Computer Resources

• 2024: Fugaku, General Access, Development and Demonstration of Model Predictive Control Method for Weather Control, hp240169, 2,518,125 NH.
• 2023: Fugaku, Fugaku Trial for General Access, Application of SCALE-LETKF for studies on weather control, hp230317 and hp230476, 61,200 NH.
• 2022-: Wisteria, Cooperative Research Activities of Collaborative Use of Computing Facility of the Atmosphere and Ocean Research Institute, the University of Tokyo, Study on paleoclimate reconstruction with data assimilation, 16,000 NH.

Awards & Honors:

• Oct 2022, Hirosaki University Outstanding Young Thesis Award
• Apr 2018, Selected for RIKEN Special Postdoctoral Researcher (SPDR)
• Apr 2013, Selected for JSPS Research Fellow (DC2)

External Services:

Paper reviewer

Atmosphere (2) Atmospheric Chemistry and Physics (1) Climate Dynamics (2) Earth and Space Science (1) Geochemical Journal (1) Geophysical Research Letters (1) Geoscience Data Journal (1) Geoscientific Model Development (1) Journal of Advances in Modeling Earth Systems (1) Journal of Climate (1) Journal of Geophysical Research: Atmosphere (1) Journal of Geophysical Research: Biogeosciences (1) Journal of the Meteorological Society of Japan (2) Nature (2) Nature Communications (1) Nonlinear Processes in Geophysics (1) PEPS (1) Quarterly Journal of the Royal Meteorological Society (1) Tellus-A (1)

Editorial board

• Nov. 2024 -: Journal of Japan Society of Hydrology and Water Resources
• Nov. 2018 - Oct. 2022: Journal of Japan Society of Hydrology and Water Resources