Joint observations of sodium enhancements and field-aligned ionospheric irregularities

Resonance Lidar observations of neutral sodium and VHF coherent scatter radar observations of field-aligned 3-meter irregularities were obtained during the Coqui II rocket campaign in Puerto Rico. The Lidar, a facility instrument at the Arecibo Observatory (18.3°N, 66.8°W), and the University of Illinois Radar, located near Salinas on the south of the island, both monitored volumes near where the uplegs of the nominal rocket trajectories intersected the E-region. The Observatory's Incoherent Scatter Radar was also used to characterize the plasma layers. Preliminary investigation of the data sets has shown a potential correspondence between VHF backscatter from plasma layers and a new class of characteristic enhancements in the neutral sodium.