Exploring NOy chemistry in levitated aqueous aerosol droplets

Atmospheric aerosol Atmospheric aerosol is a variable, yet critical component of the climate system and has substantial impact on climate change. [1-3] Aerosols affect climate directly, by scattering and absorbing solar radiation, and indirectly, by acting as cloud condensation nuclei, CCN. Clouds may reduce the incident radiation on the surface, increase or decrease temperatures, and suppress rainfall. The chemical composition of aerosol alters the hydrological cycle, which affects quality and availability of fresh water. The need for an improved understanding of the factors affecting the hydrological cycle is well-illustrated by the rapidly increasing frequency of extreme flood events in the UK. The effect of aerosol on radiative forcing and cloud formation has been repeatedly identified [4,5] as the largest uncertainty in assessing the impact of particulate matter on climate change. National and international institutions declared climate change to be the greatest environmental challenge facing the world today. Atmospheric aerosol not only impacts climate, but also directly affects human health: it may suppress defence mechanisms, respiratory and cardiovascular functions and cause allergic and infectious diseases. Aerosol is important for the biosphere through spreading reproductive materials and micro-organisms.