A lidar system based at the Haute Provence Observatory (44¿N, 6¿E) has been used to obtain night-time density and temperature profiles in the altitude range 35--70 km. If the lidar results are normalized to an in situ rocket sounding from 35 to 40 km, the lidar and rocket profiles are in quite good agreement up to about 50 km. Differences are sometimes noted around 55 km, and these could possibly be caused by an aerosol layer. |