1.Particle-Based Cloud Modeling using the Super-Droplet Method
The super-droplet method (SDM) is a particle-based numerical algorithm that enables accurate simulation of cloud microphysics with lower computational demand (Shima et al., 2009). We are developing a highly accurate cloud model using the SDM, which will contribute to reducing the uncertainties of numerical weather prediction and climate simulation.  We are also interested in applying the methodology to other research areas, such as volcanic fumes, star formation, and spray combustion.

Precipitation from a shallow maritime cumulus (2D simulation). Click the figure to see the movie.

VR movie of a cumulus congestus, created by our collaborator Dr. Toshiki Matsushima (R-CCS).

2.Synchronization Phenomena
Self-sustained oscillators can generate macroscopic rhythms as a collective through their mutual interaction. This is referred to as synchronization phenomenon or rhythmic phenomenon. Various things are known to synchronize, ranging from mechanical ones such as metronomes, to biological ones such as heart cells, circadian rhythms, crowd clapping, firefly flashingh, and croaking of frogs.


3.Micro-Macro Interlocked Simulation
物理法則には階層性があり,  ミクロな領域とマクロな領域が現象の中に共存することがあります.  この特徴を利用し, 注目する現象のマクロの振舞いを効率良く, かつ, 精密に数値計算しようというのが, 連結階層シミュレーションと言う方法論の発想です.

2 つの位相特異点の引力的相互作用の連結階層シミュレーション. (a) は原理計算の結果. (b) と(c) は連結階層シミュレーションの結果で, (b) に表示された領域のうち, (c) の赤い領域に対応する領域がミクロ領域です.

4.Data Assimilation of Complex Systems
データ同化とは, 不確かさを伴うシミュレーションと観測を融合し, そこからより確かな情報を抽出する統計学的枠組みです. 社会・産業・環境に関する複雑な現象のシミュレーションにデータ同化を応用する研究を行っています.


Master's Thesis
・Two-dimensional idealized simulation of orographic snow clouds in Hokuriku using the super-droplet method
・Numerical analysis of the wall adhesion and flow characteristics of micro droplets in oil mist separator
・Improvement of ice crystal growth model and the assessment of its impact to cumulonimbus simulation
・Numerical study of the impact of aerosol regeneration process on orographic clouds and precipitation using the super-droplet method