Open AccessField Observations of Multimode Raindrop Oscillations by High-Speed Imaging
Author(s) -
Firat Yener Testik,
Ana P. Barros,
Larry F. Bliven
Publication year - 2006
Publication title -
journal of the atmospheric sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.853
H-Index - 173
eISSN - 1520-0469
pISSN - 0022-4928
DOI - 10.1175/jas3773.1
Subject(s) - oscillation (cell signaling) , physics , multi mode optical fiber , mode (computer interface) , falling (accident) , terminal velocity , optics , field (mathematics) , drop (telecommunication) , mechanics , computer science , optical fiber , telecommunications , genetics , mathematics , pure mathematics , biology , operating system , medicine , environmental health
Periodic oscillations of raindrops falling at terminal velocity in natural rain are visualized for the first time by high-speed imaging. These images show the existence of an oscillation mode with the same frequency as the fundamental harmonic, but with shape different than that predicted by linear theory. These oscillations cause a lateral drift with a speed of approximately 20%–30% of the drop terminal velocity and without a preferred direction. These experimental observations serve as an insightful illustration of the potential benefit of applying high-speed imaging technology to investigate the dynamical microstructure of rainfall at the raindrop scale.