Airglow. This image
by Doug Zubenel taken in Nebraska nicely shows the airglow's sometimes
banded and patchy structure. They change imperceptably
over minutes or tens of minutes and arise as slowly moving gravity
waves at the
airglow's height of 90-100 km modulate the tenuous gas density
and temperature. Measurements of airglow
intensity and spectra give insight on the mesosphere -
lower thermosphere region.
Imaged in Cherry County, Nebraska, 2300 CDT July 23,2000. The field
measures 41°X27°. 50mm lens at f/2.8, 15 minute guided exposure on
Fuji NHG II 800.
Image ©Doug Zubenel, shown with permission.