Research Summary

Estimation of Human Impact in the Presence of Natural Fluctuations
Peter Guttorp, Paul D. Sampson
NRCSE researchers are collaborating with European colleagues from seven countries on an EU-sponsored research project called "IMPACT: Estimation of Human Impact in the Presence of Natural Fluctuations." The general objective of the project is to develop, test and disseminate generic decision support tools that can: (i) match technological advances in environmental monitoring, (ii) facilitate estimation of environmental impact in the presence of natural fluctuations in the state of the environment, and (iii) bridge the gap between statistical data analysis and mechanistic modeling. More specifically, the project aims at creating tools involving the following procedures: (i) Time series decomposition methods in which a given series of environmental data is divided into two components respective representing meteorologically induced fluctuations and meteorologically normalized estimates of human impact; (ii) Significance tests that permit retrospective impact assessment in the presence of covariates representing natural fluctuations; (iii) Model reduction procedures that facilitate merging of statistical and mechanistic approaches. The NRCSE group is responsible for development and application of methods of meteorological adjustment of tropospheric ozone based on the methodological review in NRCSE TRS number 26. The group is currently collaborating with colleagues from the Ecole des Mines in France on analysis of Paris region air quality data. We will also advise and collaborate with Finnish Meteorological Institute colleagues on analyses of background ozone levels in Finland. For further information on the project, see the IMPACT web site at