Abstract

The Halogen Occultation Experiment (HALOE) was launched September 12, 1991, by the Space Shuttle Discovery into a 57°, 585-km, near-circular orbit onboard the Upper Atmosphere Research Satellite (UARS). The experiment was allowed to outgass for about 1 month before science observations began on October 11, 1991. The experiment approach is solar occultation. The instrument technique uses the principle of gas-filter radiometry in four channels to measure vertical profiles of HCℓ, HF, CH₄, and NO, and broadband radiometry in four other channels to measure NO₂, H₂O, O₃, and CO₂. The latter channel is used for pressure registration and temperature versus pressure sounding of the atmosphere. Methane measurements extend to about 70 km, H₂O and temperature to 80 km, O₃ to 90 km, HCℓ and HF to ≈ 60 km, NO₂ to ≈ 55 km, and NO to 120 km altitude. Results from this experiment have provided the first pressure versus latitude cross sections of HCℓ, HF, and NO, including continuous measurements of NO from the upper troposphere, in some cases, to the lower thermosphere. The data set will be used to pursue a number of scientific investigations, including stratospheric photochemistry and dynamics studies, evaluation of the impact of natural versus anthropogenic chlorine sources on total chlorine, the effect of volcanic aerosols on the chemistry, and study of Antarctic processes which occur during the ozone hole development and recovery phases.

© 1993 Optical Society of America