"The climate is changing, and nowhere is this more evident than in the polar regions. The effects of climate change in the Arctic are also likely to have profound impacts on our climate in Europe. While the general role that aerosols play in this complex system is conceptually understood, the detailed mechanisms and their quantitative effects are not well known. The accurate quantification of climate forcing due to Arctic aerosols requires a systematic process for collating, analysing and interpreting data from different sources. This is a complex problem because measurements themselves are not directly comparable inasmuch as they vary in spatial/temporal resolution and in terms of the basic aerosol properties being quantified. Measurements in the Arctic are sparse; the general objective of the research proposed in this fellowship is to bring together the different expertise and data information sources of two key monitoring sites in the European and Canadian Arctic. The specific scientific objectives are focussed on achieving a more quantitative (climatological) understanding of the aerosol-cloud-climate interaction. This project is of a multidisciplinary nature since as it seeks to combine measurements from different disciplines and apply various mathematical approaches in order to extract coherent information from data sets of differing spatial/temporal scales. The parameterisation of this information for use in climate models will represent a significant advance in our understanding of aerosol related processes in the sensitive Arctic environment."