No abstract

Abstract. OH(6–2) Q1/P1 and R1/P1 airglow emission intensity ratios, for rotational states up to j' = 4.5, are measured to be lower than implied by transition probabilities published by various authors including Mies, Langhoff et al. and Turnbull and Lowe. Experimentally determined relative values of j' transitions yield OH(6–2) rotational temperatures 2 K lower than Langhoff et al., 7 K lower than Mies and 13 K lower than Turnbull and Lowe.Key words: Atmospheric composition and structure (airglow and aurora; pressure, density and temperature)

Abstract. The OH(6±2) band was monitored during 1990 at Davis, Antarctica 68X6 S, 78.0 E using a CzernyTurner scanning spectrometer. Spectra obtained with a 0.15-nm bandwidth and wavelength steps of 0.005 nm have been recorded in an attempt to isolate auroral features. This has enabled detailed study of weak features in the region k837X5À 855X5 nm. These weak features can contribute to the apparent intensity of Pbranch lines and to the background. Their presence is allowed for in our calculation of rotational temperature, but the P 1 3 line is excluded because of signi®cant contamination. An average temperature of 221 AE 2 K is obtained from a selected data set of 104 spectra. The mid-winter average temperature, for the months of May, June and July, is 224 AE 2 K, which is consistent with the 1986 CIRA model values for mid-winter at this height and latitude, but this result is dependent on the choice of transition probabilities. Preliminary assessments of seasonal and diurnal variations in rotational temperature and intensity are presented.

The OH(6±2) band was monitored during 1990 at Davis, Antarctica 68X6 S, 78.0 E using a Czerny-Turner scanning spectrometer. Spectra obtained with a 0.15-nm bandwidth and wavelength steps of 0.005 nm have been recorded in an attempt to isolate auroral features. This has enabled detailed study of weak features in the region k837X5À 855X5 nm. These weak features can contribute to the apparent intensity of Pbranch lines and to the background. Their presence is allowed for in our calculation of rotational temperature, but the P 1 3 line is excluded because of signi®cant contamination. An average temperature of 221 AE 2 K is obtained from a selected data set of 104 spectra. The midwinter average temperature, for the months of May, June and July, is 224 AE 2 K, which is consistent with the 1986 CIRA model values for midwinter at this height and latitude, but this result is dependent on the choice of transition probabilities. Preliminary assessments of seasonal and diurnal variations in rotational temperature and intensity are presented.