Continuing to use transportable, broad pass-band, Fabry-Perot spectrometers, the investigator determines composition, temperature, winds and fluxes in planetary thermospheres and exosphere, particularly emphasizing those regions in earth's atmosphere. Expanding upon results obtained from previous research, he is conducting five related projects: (1) measuring infrared neutral, metastable helium to determine neutral temperature, neutral helium density, and neutral winds near the earth's exobase; (2) measuring infrared OI 8446 angstrom emission to establish a new technique for determining thermospheric at5omic oxygen density in conjunction with adapted photoelectron models; (3) establishing a new ground-based technique to determine the abundance of nitric oxide in the lower thermosphere using infrared emission measurements; (4) measuring the altitude profile of atomic hydrogen density from 350-10,000 kilometers, the effective hydrogen temperature, and the hydrogen escape flux; and (5) searching for supra-thermal sodium atoms and sulfur atoms in Mercury's atmosphere.
