1. School of Physics and Centre for Climate and Air Pollution Studies; Ryan Institute, National University of Ireland Galway; Galway Ireland
2. Environmental Protection Agency; Dublin Ireland
3. Now at NRW State Agency for Nature, Environment and Consumer Protection; Recklinghausen Germany
4. Institut de Ciències del Mar, CSIC; Barcelona Spain
5. Aerodyne Research, Inc.; Billerica Massachusetts USA
6. School of Chemistry; University of Bristol; Bristol UK