Mesopause temperature observed by airglow OH spectra and meteor echoes at Shigaraki (34.9°N, 136.1°E), Japan.

Simultaneous measurements of the airglow OH(6,2) band spectra by a sky scanning spectrophotometer and meteor echoes by the MU radar were carried out at Shigaraki (35 degrees N, 136 degrees E), Japan, during July 24-30, 1995. The spectrophotometer observed the P-1(2) and P-1(4) line intensities and derived rotational temperature, T-OH, in 8 cardinal points in the sky with a time sequence of 6 minutes. The MU radar was operated ina meteor radar mode, observing wind velocities and ambipolar diffusion coefficient. From the diffusion coefficient the relative temperature fluctuations, T-MU, were derived in a height range of 75 - 100 km, with a time resolution of 1/2 hour. We found that there is, in general, good agreement in the nocturnal variation between the T-OH and T-MU, indicating effectiveness of the parameter T-MU to monitor temperature variation in the mesopause region. (C) 2000 COSPAR. Published by Elsevier Science Ltd.