noun
clear-air turbulence
Technical meteorological term for sudden, invisible turbulence in cloudless skies, often encountered by aircraft.
晴天乱気流はレーダーで探知しにくいため、パイロットにとって危険です。
Clear-air turbulence is dangerous for pilots because it is difficult to detect by radar.
飛行機
The aircraft encountered clear-air turbulence and shook violently.