Even though observational data on atmospheric ozone has been steadily increasing during the last few decades, ozone in the upper stratosphere is still poorly resolved. A feasible method for retrieving this information is ground-based spectrophotometer observation of the Umkehr effect. At Sodankyla Observatory in northern Finland, Umkehr-observations have been performed for some years now. Here we present the first results from this work and show some of the potential of the technique.
"First analysis of Brewer Umkehr data from a high-latitude observatory", Proc. SPIE 2047, Atmospheric Ozone, (2 November 1993); doi: 10.1117/12.163493; http://dx.doi.org/10.1117/12.163493