摘要：Atmospheric density and pressure in the upper mesosphere-lower thermosphere (MLT) region, around 90 km, are inferred from the meteor trail ambipolar diffusion coefficients, D , and simultaneously observed airglow O 2 b rotational temperatures. For the present study simultaneous observation data from the meteor radar and SATI imaging spectrometer taken at Shigaraki MU radar observatory (34.9°N, 136.1°E) were used. From the 18 winter nights of data, it is observed that in most of the cases nocturnal variation of the O 2 temperature has a good correlation with D at 90 to 92 km. The inferred densities at 90 km showed a negative correlation with temperature variation, suggesting a constant pressure process. The O 2 emission intensity shows a good correlation with the temperature, and negative correlation with the density variation. The OH rotational temperature and D at 87 km also showed similar results to the case of the O 2 temperature.
