SOMORA

The Stratospheric Ozone MOnitoring RAdiometer (SOMORA) measures ozone volume mixing ratio in the stratosphere and lower mesosphere (20 to 65 km) with a vertical resolution of 8-15 km and a time resolution of 30 min. SOMORA is continuously operated in Switzerland since January 2000 and is delivering data to the Network for the Detection of Atmospheric Composition Change (NDACC).

The vertical distribution of ozone is retrieved from the pressure-broadened ozone emission spectra by mean of the optimal estimation method described by Rodgers. The ozone vertical distribution is calculated from the measurement of the ozone spectral line at 142.17 GHz. The line intensity is proportional to the mixing ratio of the emitting species and the line width depends on the emitting medium pressure.
The ozone quantity is given in ppm, which is representative of the number of ozone molecules with respect to the total number of molecules in a given air volume. Drawn end to end, the 48 daily ozone profiles are presented in a time series as below.