A mid-latitude ground-based lidar study of stratospheric warmings and planetary wave propagation

Abstract

A survey of stratospheric and mesospheric temperature was performed on a regular basis during winter conditions from the lidar station of the Observatory of Haute Provence (44°N, 6°E). The method uses the range resolved Rayleigh scattering of a laser beam and its latest performances are given. The data presented in this paper cover two winter periods and include the major stratospheric warmings of 1980 and 1981; the results obtained by lidar are compared with global stratospheric data obtained by the radiosonde network and from the SSU satellite experiment. It is shown how the extension of the measurements into the mesosphere (and simultaneously in the stratosphere) and the height resolution achievable with the lidar technique permits one to estimate the time-delay of the downward propagation of a warming from the mesosphere to the low stratosphere in about 20 days. The influence of planetary wave propagation is also shown to produce a periodic variation in the stratopause height even in the absence of the stratospheric warming reported by the STRATALERT messages.