Lidar studies of stratospheric gravity waves: a comparison of analysis techniques

Rayleigh-scatter observations of molecular densities at stratospheric heights over Aberystwyth (52.4°N, 4.1°E) are examined to reveal the presence of gravity-wave motions in the height range 30-60 km. Three separate analytic approaches are applied, and it is found that significant differences in measured gravity wave parameters arise from those different methods. Examples of density and temperature profiles are presented which illustrate both these differences and some of the limitations of each technique. In particular, it is shown that one technique is insensitive to the presence of gravity-wave motions of period greater than about twice the data set length, and that the other two can produce spurious wave-like features of very low or zero vertical phase velocity. -from Authors