ATOMIC-HYDROGEN AND OZONE CONCENTRATIONS DERIVED FROM SIMULTANEOUS LIDAR AND ROCKET AIRGLOW MEASUREMENTS IN THE EQUATORIAL REGION

Nighttime atomic hydrogen and ozone concentrations are derived from si multaneous measurements of the vertical profiles of upper mesospheric airglow emissions and atmospheric sodium. The airglow profiles were ob tained in a sounding rocket experiment launched from Alcantara (2.5 de grees S, 44.2 degrees W) on May 31, 1992. A lidar operating at the lau nch site was used to measure sodium at the time of the rocket experime nt. A total of 10 airglow photometers, 6 forward looking and 4 side lo oking, observed the OI 557.7 nn, O-2 Herzberg and O-2 atmospheric (0,0 ) bands, sodium D lines, OI 630 nm, OH(8,3) band, and the airglow cont inuum. The simultaneous ground-based sodium lidar and onboard sodium a irglow measurements made it possible to derive the ozone concentration at heights between 85 and 100 km. The hydrogen concentrations were th en calculated from the O-2 atmospheric (0,0), OH(8,3), and the ozone p rofiles. The results suggest that the hydrogen concentration varied fr om 1 x 10(9) cm(-3) at 85 km to 1 x 10(8) cm(-3) at 100 km, values muc h higher than those suggested by recent model atmospheres and by some rocket observations at middle and high latitudes. Although the method of obtaining the concentrations of the minor constituents in the upper atmosphere is an indirect optical technique, this is the first time t hat these concentrations have been measured by rocket in the equatoria l region.