Wet deposition to an upland area of England in 1988 and 1999: Measurementsand modelling

Fine spatial-scale measurements of acidic deposition have been made over tw o time frames: 1987/1988 and 1999/2000. Over this period, dramatic reductio ns in precursor emissions have occurred. The two sets of data are compared in order to quantify deposition reductions. Orographic enhancement of wet d eposition from the seeder-feeder mechanism is important in the UK at high-e levation sites such as these and the measurements were corrected for this p rocess using a standard methodology. The data were also modelled using a si mple long-term Lagrangian acid deposition model and comparisons made with b oth sets of observations at a resolution of 5 km - 5 km. Future scenarios ( 2010) of emissions were modelled to examine the impact of UK and other Euro pean sources in order to determine optimal protection of ecosystems in this region.