Stratospheric ozone and hydroxyl radical measurements by balloon-borne lidar

A balloon-borne lidar system for the measurement of ozone and hydroxyl radical in the stratosphere has been constructed and flown by Goddard Space Flight Center. On this flight ozone concentration at altitudes between 20 and 37 km were determined with vertical resolution of ∼0.5 km. In addition, horizontally resolved ozone measurements with 0.15-km resolution were obtained over a 2-km range. The temporal variation of the hydroxyl radical concentration was measured in the 34–37-km altitude region, ranging from 40 parts/trillion shortly after noon to ∼5 parts/trillion 2 h after sunset. Improvements in the system are proposed to increase the sensitivity of the instrument below the parts/trillion level, permitting hydroxyl determinations in the 20–30-km altitude range.