[A-AS01] 大気の鉛直運動を基軸とした地球環境学の新展開

[AAS01-04] Clear Air Turbulence Resolved by Numerical Weather Prediction Model Validated by Onboard and Virtual Flight Data

*吉村 僚一¹、伊藤 純至²、Schittenhelm P. A.³、鈴木 健斗⁴、焼野 藍子⁵、大林 茂⁵ (1.名古屋大学 宇宙地球環境研究所、2.東北大学大学院 理学研究科、3.University of Stuttgart, Stuttgart, Germany、4.気象庁、5.東北大学 流体科学研究所)

キーワード：乱気流、Large Eddy Simulation、飛行機、フライトデータ

Turbulence, a sudden shift in air, poses a serious threat to flying airplanes. While most turbulence can be avoided by visually monitoring factors such as clouds or nearby aircraft, Clear Air Turbulence (CAT) remains a challenge due to its invisible nature.

To study CAT generation, high-resolution numerical simulations, offer insights into the intricate processes involved. However, accurately reproducing turbulent eddies in simulations and assessing their danger to aircraft remains uncertain.

In our investigation, we investigate a CAT event affecting aircraft at lower altitudes by enhancing the resolution of a regional weather forecasting model. Through simulations conducted on Fugaku, validated against flight data, we reveal the role of Kelvin-Helmholtz instability waves in generating hazardous turbulence over Tokyo.

Using flight data from encounters with CAT on Dec 30, 2020, we validate simulated results through virtual flight simulations. Our findings suggest that while the 35-m LES captures turbulence shaking aircraft at their natural frequencies, finer grid spacing enhances fidelity to flight data.