PHOTOENHANCED DEPOSITION OF TRACE GASES AT THE INTERFACE OF ORGANIC SURFACES
Abstract
Atmospheric aerosol particles have been found to contain moderate to high fractions by mass of organic compounds. These may be biogenic or anthropogenic in origin, depending on the location and history of the individual particle. The recent and growing awareness of this has spurred a significant effort in understanding how organic compounds on particle surfaces influence water condensation there; how this changes as the particle becomes “processed” (i.e. oxidized) in the atmosphere, and how these processes influence the gas phase composition in volumes containing such particles. Most of these studies evaluated the uptakes or the deposition of some trace gases at the organic interface under dark conditions. However, very few investigations focus on the effect of solar irradiation on atmospheric heterogeneous chemistry, although recent findings confirm the presence of UV-A/Visible light absorbing material in airborne particles and environmental surfaces which can allow photo-induced (or photosensitized) processes. The present work demonstrates the photo-enhanced uptake of NO2 and O3 on various organic surfaces as various aromatic compounds used as proxy of biogenic and anthropogenic emissions (PAHs, phenolic compounds) and humic acid coatings and submicron particles. The results suggest that photo-induced uptake can be important under atmospheric conditions with respect irradiance, humidity, temperature and gas trace mixing ratio.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFM.A13N..02G
- Keywords:
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- 0305 ATMOSPHERIC COMPOSITION AND STRUCTURE / Aerosols and particles;
- 0317 ATMOSPHERIC COMPOSITION AND STRUCTURE / Chemical kinetic and photochemical properties;
- 0345 ATMOSPHERIC COMPOSITION AND STRUCTURE / Pollution: urban and regional;
- 0365 ATMOSPHERIC COMPOSITION AND STRUCTURE / Troposphere: composition and chemistry