Rotational temperatures and intensities of OH(6-2) and OH(8-3) bands in the night airglow

Abstract

Clearly resolved spectra of P 1(4), P 2(4), P 1(3), P 2(3), P 1(2) and P 2(2) lines, Q and R branches of the OH(6-2) band in the night airglow have been obtained together with those of P 1(4), P 2(4), P 1(3), P 2(3) and P 1(2) lines of the OH(8-3) band. A tilting-filter photometer which is equipped with a cooled RCA-C31034A photomultiplier and narrow bandpass filters is used. Rotational temperatures are derived from the ratios between P 1 lines, giving an average of 228 ±23 K for the OH(6-2) band and of 231 ± 29 K for the OH(8-3) band for the winter 1977–1978. The correlation between the rotational temperature and intensity is investigated for a time interval of 2 h during the night and for a temperature range of 20 K. It is found that the correlations obtained for intervals between 2000 and 0200 LT are significant and that the correlation calculated from the remainder is insignificant. It is also found that the correlations obtained for the temperature range up to 20 K are not significant. It is shown that the correlation coefficients calculated from the temperature and intensity variations for all the data from the OH (6-2) and (8-3) bands exceed the level of significance, according to Students t-test (5%), which also indicated that the temperature variations during a single night are partially correlated with intensity changes when the spectra are taken every 30 min during the night.