In this Chapter we will make a detailed analysis of a comprehensive set of air pollution concentrations and their associated meteorological measurements. I would like to thank Professor David Fowler and Dr Robert Storeton-West of the Centre for Ecology and Hydrology (CEH) for their help in supplying the data. The measurements were taken over the period 1 January-31 December 1993 at an automatic monitoring station operated by CEH at their Bush Estate research station, Penicuik, Midlothian, Scotland. Three gas analysers provided measurements of O3, SO2, NO, and NOx; NO2 was obtained as the difference between NOx and NO. Windspeed, wind direction, air temperature and solar radiation were measured by a small weather station. The signals from the instruments were sampled every 5s by a data logger, and hourly average values calculated and stored.