sulphur dioxide- space and time Marian Scott Dept of Statistics, University of Glasgow NERC August 2013

Example: trends in atmospheric SO 2 levels over space- EMEP network Daily measurements made at more than 100 monitoring stations over a 20 year period over Europe: Complex statistical model developed to describe the pattern, the model portions the variation to trend, seasonality, residual variation and to include changepoints Main question: – what is the long term trend and is it the same over Europe?

Additive models for trend but including space ln(SO 2 ) = f ym (years, months) + f ll (latitude, longitude) + ln(SO 2 ) = f y (years) + f m (months) + f ll (latitude, longitude) + with appropriate assumptions on

ln(SO 2 ) = f y (years) + f m (months) + f ll (latitude, longitude) + ln(SO 2 ) = f ym (years, months) + f ll (latitude, longitude) +