Assessment of uncertainties in a long range atmospheric transport model : methodology, application and implications in a UK context.

Page, T. and Whyatt, J. Duncan and Metcalfe, Sarah E. and Derwent, R. G. and Curtis, C. (2008) Assessment of uncertainties in a long range atmospheric transport model : methodology, application and implications in a UK context. Environmental Pollution, 156 (3). pp. 997-1006. ISSN 0269-7491

Abstract

Acid deposition models are inherently simplified representations of real world behaviour and their performance is best evaluated by comparison with observations. National and international acid rain policy assessments handle observed and modelled deposition fields in different ways. Here, both the observed and modelled deposition fields are seen as uncertain and the Generalised Likelihood Uncertainty Estimation (GLUE) framework is used to choose acceptable sets of model input parameters that minimise the differences between them. These acceptable sets of model parameters are then used to estimate deposition budgets to the UK and to provide a probabilistic treatment of excess deposition over environmental quality standards (critical loads). Uncertainties in modelled depositions of S and N to the UK are quantified and their implications for planned emissions reductions considered.