The creation of wavy disturbances (Tollmien–Schlichting waves) by a localized two-dimensional disturbance source vibrating periodically at a fixed frequency in a Blasius boundary layer is discussed. The initial-boundary value problem mathematically models the vibrating ribbon experiment of Schubauer and Skramstad. By considering the ribbon vibration to start at t=0, in the model one gets the transient and the eventual periodic part of the solution. The results of the full simulation are compared with the time-asymptotic solution.

Hubble Space Telescope far-ultraviolet images of Jupiter during the Shoemaker-Levy 9 impacts show the impact regions darkening over the 2 to 3 hours after the impact, becoming darker and more extended than at longer wavelengths, which indicates that ultraviolet-absorbing gases or aerosols are more extended, more absorbing, and at higher altitudes than the absorbers of visible light. Transient auroral emissions were observed near the magnetic conjugate point of the K impact site just after that impact. The global auroral activity was fainter than average during the impacts, and a variable auroral emission feature was observed inside the southern auroral oval preceding the impacts of fragments Q1 and Q2.

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