Some recent mesospheric and lower thermospheric data and models.

Data for these regions of the atmosphere are provided by measurements with instrumented rockets and satellites and ground-based detectors, including photometers, partial reflection and incoherent backscatter radars. The quantitites and types of data for the lower thermosphere have expanded dramatically during the past few years, primarily due to increased results from incoherent backscatter radars and low altitude satellites. Major emphasis in the review is placed on the development of models of tidal motions and of systematic variations with season and latitude of turbulence intensity and turbopause altitude. Joule and particle precipitation heating rates have been derived from Chatanika incoherent scatter data. Recent models of excitation and propagation of gravity waves and global circulation patterns during magnetic storms are reviewed and compared with satellite data.