EXAMINATION OF THE OXYGEN RED LINE SIGNATURE OF A POLAR-CAP IONIZATION PATCH AS SEEN FROM THE DYNAMICS EXPLORER 2 SATELLITE

Ground-based observations of polar cap ionization patches have been ma de for many years. Optical measurements indicate that, enhancements oc curring in the 630.0-nm emission line are correlated with these ioniza tion patches. The present study examines data from the Fabry-Perot int erferometer (FPI) on the Dynamics Explorer 2 spacecraft to determine i f patches can be observed optically from sl,ace. Since the FPI scanned the forward horizon, it was able to observe the vertical profile of a irglow emissions associated with patches, thus giving information abou t the vertical structure. FPI measurements have been correlated with d ata from several in situ instruments on tile spacecraft. These in situ measurements include electron density, atomic oxygen density, electro n temperature, neutral temperature, and electron energy flux. Three po lar cal, patches have been detected both by the FPI and the in situ in struments. The red line emission patches are enhancements in the 630.0 -nm red line in a specific altitude region which create an irregular a ltitude profile. The red line emission region associated with polar ca p ionization patches varies from patch to patch and occurs in the alti tude range from below 300 km to 400 km.