Recently we have demonstrated that grass and cut grass are important sources of volatile organic compound (VOC) emissions into the atmosphere. The production of these VOCs can be traced back to plant growth, maintenance and wound defence mechanisms. The gases emitted as part of these wound defence mechanisms are responsible for the smell of freshly cut grass, and are also highly photochemically...

Combustion catalysts have been extensively explored to reduce the emission of hydrocarbons that are capable of triggering photochemical smog and greenhouse effect. Palladium as the most active material is widely applied in exhaust catalytic converter and combustion units, but its high capital cost stimulates the tremendous research on non-noble metal candidates. Here we fabricate highly defecti...

New particle formation in the atmosphere is an important parameter in governing the radiative forcing of atmospheric aerosols. However, detailed nucleation mechanisms remain ambiguous, as laboratory data have so far not been successful in explaining atmospheric nucleation. We investigated the formation of new particles in a smog chamber simulating the photochemical formation of H(2)SO(4) and or...

The organic fraction of secondary particles, commonly known as secondary organic aerosols (SOA), constitutes a significant part of fine aerosols. The formation of SOA is subject to complicated coupling among gas-phase chemical reactions, aqueous -phase, aerosol-phase, and meteorological processes. To correctly predict total particle concentrations in the atmosphere it is necessary to understand...

Scientists are increasingly turning to numerical simulation in order to investigate and model complex environmental systems. Numerical simulation has enormous advantages over laboratory or field experimentation because it has the potential to allow a much greater parameter space to be considered. Numerical simulation is being used for simulating the formation of photochemical air pollution (smo...

The analysis and forecast of elevated boundary layer ozone is of particular concern since it is known to have adverse effects on health, vegetation and material. The main contributors to the formation of photochemical smog, and high ozone levels are the emissions of Volatile Organic Compounds (VOC) and NOx. There is a complex relationship between VOC and NOx leading to ozone generation, which v...

Similar populations of male and female office workers in San Francisco, which has little air pollution, and in Los Angeles, which experiences frequent photochemical smog episodes, were surveyed in an attempt to document excess respiratory symptoms and dysfunction in Los Angeles relatable to air pollution. Most results of forced expiratory tests, single-breath N2 tests, and questionnaire intervi...

Diluted exhaust from a diesel engine was photo-oxidized in a smog chamber to investigate secondary organic aerosol (SOA) production. Photochemical aging rapidly produces significant SOA, almost doubling the organic aerosol contribution of primary emissions after several hours of processing at atmospherically relevant hydroxyl radical concentrations. Less than 10% of the SOA mass can be explaine...

During two field campaigns in 1993 and 1994, measurements of aromatic compounds [benzene, toluene, ethylbenzene, m-/p-/o-xylenes (BTEX)] were carried out at urban and rural sites in the greater Munich area. These field campaigns represent a unique study using quasi-continuous gas chromatography/flame ionization detection methods concurrently at various sites. The impact of Munich’s urban plume ...

The use of computational steering for smog prediction is described. This application is representative for many underlying issues found in steering high performance applications: high computing times, large data sets, and many di erent input parameters. After a short description of the smog prediction model, its visualization and steering are described. The amount of computation needed to solve...