Weekly cycle in particulate matter versus weekly cycle in precipitation over Switzerland

During the last few years the question has been raised if there is a weekly cycle in climatological variables due to anthropogenic activity. In this study, particulate matter (PM) data and precipitation data from 17 Swiss weather stations are analyzed for weekly cycles with three different methods: a nonparametric statistical test, a Fourier analysis on the time series, and a comparison of the regular 7-day week with either a 6- or 8-day week. Results show a well-pronounced and statistical significant weekly cycle for PM but do not show any statistically significant weekly cycle for meteorological quantities such as precipitation.