Abstract. Five Dobson and two Brewer spectrophotometers were used for total ozone observations at Arosa, beginning in 1926 and providing the world's longest series. In this paper we present the results of our attempts to provide a homogeneous series and discuss the data quality problems of the record.

No abstract

No abstract

The ozone layer still seems to be the most probable link for a solar-weather relationship, and its association with the solar cycle must therefore be studied and separated from anthropogenically produced trends. The extensive Swiss records of total ozone and vertical distribution from Umkehr and soundings (6, 3 and 2 solar cycles respectively) are used for this purpose and the results compared with those obtained from the corresponding world network data. Total ozone shows a measurable but weakly significant solar cycle signal and a pronounced negative trend since 1970. With the main contribution coming from the ozone maximum layer, the solar cycle effect in mid-latitudes seems to be predominantly produced by variations in the ozone transport. The highest contribution to the negative trend stems, in contradiction to present model results, from a strong ozone depletion in the ozone maximum layer. It is partly compensated for by a pollution produced ozone increase in the troposphere. The variation in the upper stratosphere seems to be damped by the negative temperature feedback.

No abstract