Development of a novel numerical model for cloud microphysics resolving cloud simulations

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K14559
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 17020:Atmospheric and hydrospheric sciences-related
• Research Institution: Kobe University (2022-2023); Institute of Physical and Chemical Research (2020-2021)
• Principal Investigator: Matsushima Toshiki 神戸大学, 理学研究科, 特命助教 (00803553)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 雲微物理 / 乱流 / ラージ・エディ・シミュレーション / 超水滴法

Outline of Final Research Achievements

We developed a particle-based cloud model for meter- to submeter-scale-resolution simulations of warm clouds. The time-to-solution of the developed model is shorter than that with a bin method and even comparable to that with a bulk method. In addition to high-level optimizations on the supercomputer 'Fugaku', our model incorporates a novel sampling method using optimal transport to estimate a parameter that controls the interaction between microphysics and turbulence, and a more accurate particle advection scheme to improve the spatial uniformity of the super-droplet number density. Finally, we demonstrated that our model supports numerical experiments with 2 m resolution, which may fill the gap between direct numerical simulations and large-eddy simulations.

Free Research Field

気象学

Academic Significance and Societal Importance of the Research Achievements

本研究課題により、直接数値実験とラージ・エディ・シミュレーションのスケールギャップを繋ぐ数値モデルを開発できた。従来不可能であった精度の数値シミュレーションが可能となることで、今後、微細スケールから気象・気候スケールまでの広いダイナミックレンジにおける、雲と乱流の相互作用の理解に繋がることが期待される。