TRENDS OF AIRGLOW IMAGER OBSERVATIONS NEAR ADELAIDE, AUSTRALIA

From April, 1995 to January, 1996 a nightglow imager and an airglow ph otometer were colocated near Adelaide, Australia. The data obtained on more than 50 clear nights revealed seasonal changes in the airglow in tensities and temperatures as well as in the gravity wave activity. Th ese temperature data are the first seasonal results from the mid-latit ude southern hemisphere mesopause region. The OH Meinel band was obser ved to have a rotational temperature that was warmer than the O-2 Atmo spheric band in the winter. There were also summer solstice maxima and winter solstice minima in the O-2 Atmospheric band and OI(557.7) airg low intensities. The gravity wave activity, seen in the 50 to 80 km ho rizontal wavelength waves, was generally greatest in the OH Meinel lay er and showed a semiannual variation with a strong summer solstice max imum. The relationship between gravity wave activity and airglow inten sities disagrees somewhat with models. Compared to previous studies, t he data suggest that there may be a difference in the seasonal variabi lity of short and long period gravity waves.