Observations of atmospheric ozone: 38° to 76° north latitude at altitudes from 8 km to the surface

Ozone data were obtained from 8 km to the surface and at latitudes from 38° to 76° N during January and February 1983. Flight lines covered northeastern U.S., Canada, and Greenland. The results of the latitudinal survey at 5‐ to 8‐km altitude showed O 3 mixing ratios to be ≃ 40 ppbv with little variation in latitude. One region of elevated O 3 was observed and extended from 54° N to 57° N latitude. Ozone reached 150 ppbv at 6.4‐km altitude. This sampling was stratospheric air as the tropopause height was 5.6‐km altitude. Profiles at 76°, 67°, and 53° N showed O 3 to be well mixed from about 5 km to the surface. In some cases, profiles identified a layer of 1 km to 100 m vertical dimension at the surface, in which O 3 destruction had occurred.