Nick Hewitt is Professor of Atmospheric Chemistry at Lancaster University, UK. His main research interests are in understanding how the biosphere and the atmosphere interact: how emissions of trace gases from the biosphere affect the atmosphere, and how the changing atmospheric environment affects the biosphere.

Andrea Jackson is a senior lecturer of Atmospheric Chemistry within the Institute for Climate and Atmospheric Sciences at the University of Leeds, UK. Her main research interests involve investigating the gas phase chemistry of oxidant species in the atmosphere and more recently the physics and chemistry of polar frost flowers and their resultant sea-salt aerosol in order to understand their impact on the atmospheric chemistry of these regions.