Comparison of 19th Century and Present Concentrations and Depositions of Ozone in Central Europe

Abstract

Ozone, one of the most important trace gases in atmosphere was discovered by Christian Friedrich Schönbein (1799–1886), a chemistry professor at the University of Basel. The method developed by him was used from the middle of nineteenth century until the 1920’s in much of the world. The measurement method is based essentially on the color-change of an indicator test paper. We obtained records for ozone measured in the Habsburg Empire using Schönbein’s method for analyze the long term environmental processes. According to records kept in the Habsburg Empire, ozone was measured at more than twenty sites between 1853–1856. On the territory of the Kingdom of Hungary, ozone was measured at Szeged, Buda and Selmecbánya (Schemnitz, Banska Štiavnica) among others. Long term datasets are available from Buda (1871–1898) and Ó-Gyalla (Altdala, Hurbanovo, 1898–1905). Ozone was measured during both day- and nighttime. Additionally meteorological variables (like air temperature, relative humidity, air pressure, wind speed, cloud cover, precipitation) were also observed several times a day. The data reported in the yearbooks were collected and evaluated in this study to reconstruct the ozone dataset. Depending on concentrations and deposition velocity over different vegetated surfaces the ozone deposition can be estimated. The reliability of estimations and reconstructed ozone deposition values are also discussed. Finally ozone datasets from the 19th and 21st century and the differences in ozone concentration and deposition between rural and urban areas are compared. Ozone concentrations and deposition are found to be approximately three times higher now than in the 19th century.