Tentative observation of stratospheric N₂O₅

Abstract

Models of stratospheric chemistry have long predicted the existence of N 2 O 5 in the stratosphere (1). A previously measured upper limit suggested that the lower stratosphere contained less than 1/10 of the N 2 O 5 predicted (2). This serious discrepancy had eroded faith in predictions of changes in stratospheric composition due to man's activities. These new observations of atmospheric emission at N 2 O 5 wavelengths suggest a mixing ratio of 1.1 ± 0.5 × 10 −9 between 30 and 40 km. This value is fully consistent with model predictions.