| Popis: |
Publisher Summary The CN measurements are carried out at an air chemistry container separated from the main building to the south. So local contamination is avoided for most of the time. The concentrations are measured continuously. The data in Antarctica show a pronounced seasonality with the minimum in winter and a maximum in summer time. Earlier reports showed a significant increase of the concentration of 9.63 % per year during the years 1982 to 1989. The average concentration was 350 cm -3 . The new evaluation for the period 1990 to 1994 again showed an increase. However, because of communication problems, only the observations during winter time could be used. If the winter data of the complete period 1982 to 1994 are approximated with an exponential model, an increase of 5.8 % per year is observed. Such an increase over so many years is alarming, even if the reasons are not yet unveiled. |
