DOPPLER DETECTION OF HYDROXYL COLUMN ABUNDANCE IN THE MIDDLE ATMOSPHERE - 2 - MEASUREMENT FOR 3 YEARS AND COMPARISON WITH A 1D MODEL

The hydroxyl column abundance in the middle atmosphere is measured for 3 years in Tokyo by ground-based uv absorption spectroscopy utilizing the Doppler shift of the solar spectrum due to the solar rotation. Th e diurnal and seasonal variations of the measured column abundance are found to be reproduced qualitatively by a one-dimensional photochemic al-diffusive model; however, the measured column abundances are smalle r than the calculated by 20 to 30% systematically.