Messungen atmosphärischer Spurengase mit der DOAS-Methode

Abstract

Spectrometers from the Swedish company OPSIS were used to measure trace gas concentrations of NO ₂, NO, SO ₂ and ozone in rural sites. Simultaneous measurements with conventional gasanalyzers from the Californian company MonitorLabs were used to check possible cross-sensitivities of the DOAS system to other atmospheric gases. Considering the fundamental difference between long path integral and single point measurement the comparability of both systems is good with correlation coefficients better than 0.94 for a few thousend data pairs of each of the four gases.

During July 1990 a large field study showed results of the transport mechanisms of atmospheric pollutants from the Swiss Midlands to the higher alpine regions. Measurements of ozone, toluene, SO ₂,formaldehyde and NO ₂ with a DOAS lightbeam over the lake of Vierwaldstätten were performed. With the help of additional wind measuring stations, these DOAS-results lead to a detailed understanding of the transportation and chemical transformation processes of air from the agglomerations in the Swiss Midlands towards the alps.