Photoassisted formation and growth of aerosols

CHRISTIAN GEORGE; BARBARA D'ANNA; MARIA EUGENIA MONGE; YOAN DUPART

Denver

Conferencia; 242nd National Meeting of the American-Chemical-Society (ACS); 2011

ACS

Aerosols are still considered as being one of the less understood atmospheric objects and are therefore the focus of many studies. Currently, it is believed that aerosols are being formed and growth subsequently to a series of gas phase processes leading to the formation of products having low (or even very low vapour pressures). For example, the oxidation of SO2 by gaseous OH to H2SO4 leads to nucleation events, while the oxidation by the same radical of VOCs leads to a full series of products able to change the organic content of aerosols and their aging. In this presentation, we are going to revisit this concept and suggest a few other possible pathways that do not involve gas phase chemistry but still lead to particle formation and growth. These processes will exemplified in two cases considering the long wavelength chemistry of mineral dust as a pathway leading to nucleation events and SOA photochemistry inducing particle growth.