Popis: |
Measurements of atmospheric ozone at altitudes from 5 to 50 km using the lidar (DIAL) differential absorption technique are described. A XeCl excimer laser with a repetition rate of up to 50 Hz and a wavelength of 308 nm was used for the measurements. The reference line was produced by the stimulated Raman effect in a hydrogen gas cell, leading to a wavelength of 353 nm. The time-resolved measurement of the backscattered light allows one to evaluate the ozone concentration as a function of the altitude. Exceptionally good agreement between the lidar data and those measured with chemical balloonsondes was obtained. A narrow-band laser and a receiving system, including a set of three Fabry-Perot filters, also allow daytime measurements. Thus investigations in polar regions are possible even in summer periods. Measurements performed in arctic and equatorial regions with the lidar system installed on board the research vessel Polarstern are reported. |