SIMULTANEOUS OBSERVATIONS OF TRANSIENT DECREASES OF EARTHS FAR-ULTRAVIOLET DAYGLOW WITH 2 CAMERAS

The Polar spacecraft carries two cameras which are capable of viewing Earth's far-ultraviolet dayglow. One of these two cameras was programm ed into a special operating mode during 12 April and 30 July 1996 in o rder to obtain simultaneous images of transient decreases of dayglow e missions from atomic oxygen at 130.4 nm. During the 76 minutes of usab le imaging the two cameras acquired five sets of frames for which a tr ansient decrease was detected by each camera, and the transient decrea se occurred at the same geographical position in the dayglow. These se ries of observations provide strong evidence for the identification of atmospheric heres as a geophysical phenomenon.