Intensity profiles of the 6300-A and 5577-A O I lines in the night airglow

Abstract

Altitude profiles of the 5577-A and 6300-A O I nightglow radiations have been observed with rocket photometers to an altitude of 258 km. Five hours after sunset, the 6300-A red line exhibited an intensity maximum at approximately 245 km. The 5577-A green line also exhibited a second intensity maximum at this same altitude in addition to the lower peak at 97 km. The high-altitude green line intensity was about ⅓ that of the red line intensity at the same altitude and about 1/10 that of the 5577-A layer at 97 km. The dissociative recombination reaction of O2+ is the only mechanism required to explain the observed profiles. Upper limits for the specific dissociative recombination coefficients of O(¹S) ≈ 1.1 × 10−8 cm³ sec−1 and O(¹D) ≈ 3.5 × 10−8 cm³ sec−1 have been derived from these nightglow observations. An upper limit of ≈ 1 × 10−11 cm³ sec−1 is obtained for the collisional deactivation coefficient of O(¹D) with the assumption that molecular nitrogen is the principal deactivating species in the upper atmosphere.