Observations of streamers in the troposphere and stratosphere using ozone lidar

We describe here a DIAL lidar system for atmospheric ozone measurements at Aberystwyth, Wales, together with a method for deriving a stratospheric ozo ne profile from a single laser wavelength. Lidar measurements are used to d epict the passage of three mesoscale ozone disturbances in the troposphere and stratosphere. In the troposphere, two small fold-like structures are sh own beneath and at the edge of streamers of high potential vorticity in ECM WF analyses. MST radar measurements at the same time show that one of these folds was actively turbulent, causing mixing of stratospheric and troposph eric air. In the stratosphere, a streamer of low-latitude air drawn into a filament by a breaking Rossby wave event was observed crossing the lidar si te.