Predissociation linewidths and oscillator strengths for the (2-0) to (13-0) Schumann-Runge bands of O 2

Abstract

Analysis of the absorption spectrum of O 2 in the Schumann-Runge bands ( B 3Σ u −- X 3Σ g −) from the 2-0 to the 13-0 band yields oscillator strengths which are in good agreement with past theoretical calculations. Predissociation linewidths deduced from the data tend to be larger than theoretical predictions for v′ ≤ 5 and are reasonably near theory for v′ > 5. The qualitative dependence of the linewidths on vibrational level is in accord with that expected for a repulsive potential intersecting the B 3Σ state near v′ = 4. For a given band the predissociation linewidth deduced from the spectra tends to increase as the total angular momentum increases. The new linewidths are smaller than some past experimental results, and this will have an impact on future calculations of the photodissociation rates of O 2, NO, and H 2O in the earth's upper atmosphere.