I am working with ozone measurements from two different sites (one rural and one urban). I am looking at the distribution of hourly averaged concentrations in air. The first figure shows the ozone distribution from the rural site and the second one from the urban site.
The first one (rural) looks normally (or lognormally) distributed, whereas the second one (urban) looks exponentially distributed.
My hypothesis is that it is caused by the fact that there is more pollution in an urban area, therefore more ozone depleting substances and this is why we have mostly small values, creating an exponential distribution. I am wondering if there is a more precise explanation that these distributions of the same molecules are so different.