Low Frequency Sound Waves and the Upper Atmosphere

Waves in Pluto’s Upper Atmosphere

Observations of the 2007 March 18 occultation of the star P445.3 (2UCAC 25823784; R = 15.3) by Pluto were obtained at high time resolution at five sites across the western United States and reduced to produce light curves for each station using standard aperture photometry. Global models of Pluto’s upper atmosphere are fitted simultaneously to all resulting light curves. The results of these mo...

Nonlinear internal waves in the upper atmosphere

This paper considers the large-scale dynamics generated in the upper atmosphere by the destabilization of a linear internal gravity wave and its eventual restabilization through nonlinear processes into a coherent pattern. The assumption of a strongly dissipative medium is relevant to wave propagation in the thermosphere range above 100 km. A parametric instability analysis is carried out invol...

Physical Simulation of Baroclinic Waves and Vortices in the Atmosphere

High-frequency Waves Detected in the Solar Atmosphere

A spectrum of weakly guided waves in the solar atmosphere at frequencies as high as 100 mHz (10 s period) has been detected with high-cadence solar image sequences from the Transition Region and Coronal Explorer (TRACE) spacecraft. The waves are visible in the TRACE 1600 far-UV passband and were detected as faint Å ridges in an energy spectrum produced by Fourier transformation of subfields of ...

Entropic " Sound " in the Atmosphere

It is shown that small, local disturbances of entropy in the atmosphere may give rise to " sound " waves propagating with the wind velocity.