This proposed program of ground-based optical analyses and modeling of upper atmospheric regions addresses important CEDAR objectives. The areas of investigation are: 1) upper atmosphere dynamics and coupling to the F-region plasma; 2) 630 nm airglow depletions and ionospheric plumes; 3) mesosphere and lower thermosphere dynamics; 4) geocoronal hydrogen dynamics; and 5) enhanced-sensitivity Fabry-Perot interferometer (FPI) development. The Arequipa, peru FPI will be used in simultaneous measurements with the Jicamarca incoherent scatter radar (ISR) for detailed determinations of the height variation of the equatorial thermosphere - F-region plasma coupling. The 1983- 1990 FPI data base will be analyzed to find the response of the upper thermosphere wind and temperatures to changes in solar flux (sa index) and geomagnetic activity (Kp, Ap, AE indicies). A mapping photometer will determine the morphology of 630 nm airglow depletions and their association with ionospheric plumes (measured by the Jicamarca ISR). AT Laurel Ridge, PA, the 150 and 100 nm aperture FPI's (improved by CCD detectors) will determine, respectively, geocoronal hydrogen dynamics (trapped thermal, ballistic and escape components cia the Ha line) and mesopause-lower thermosphere dynamics (via OH and 557.7 nm lines). At Millstone Hill, MA, under the direction of D. P. Sipler, the coordinator FPI and ISR studies of midlatitude thermosphere -ionosphere momentum and energy coupling will continue.
