Urban aerosols, dynamics

Several steps in implementation of specific urban dynamics and energetics have already been achieved by the HIRLAM/HARMONIE community. Enviro-HIRLAM considers a surface improved description for urban areas roughness, albedo, urban heat sources (Eaklanov et al. 2008). Properties of urban aerosol used to modify the albedo characteristics and the effective radius of cloud droplets for the SW radiation (in the HIRLAM radiation scheme). In FUMAPEX two other more sophisticated urban schemes EEP (Martilli et al. 2002) and SM2-U modules (Dupont and Mestayer 2006) were tested. They are more expensive computationally. Town energy balance (TEE) module (Masson 2000) is a part of SURFEX, available in the HARMONIE framework. Handling of the finest-scale details of momentum fluxes in town (forest) canopy could be developed. 

Studies of aerosol size distributions in power plant plumes clearly show that gas-Co-panicle conversion is an important source of submicron aerosol. Condensable material is formed primarily by the oxidation of SOi to sulfates and NOj, to nitrates, both usually present as ammonium salts. It is somewhat easier to analyze plume aerosol dynamics than urban aerosol behavior because (in selected cases) the plume aerosol originates from a single source and is sufficiently well-defined to follow many kilometers downwind. By using ground-based mobile laboratories and/or suitably instrumented aircraft, the aerosol and associated gasc.s can be measured. 

Ultrajine Range (dp <0.1 fim) 366 Residence Time and Diy Deposition 366 Aerosol Dynamics in Power Plant Plumes 368 Chemical Composition of Urban Aerosols 370 /mmduction 370... 

Young K (1998) Population health concepts and methods. Oxford University Press, New York Zhang M, Wexler A (2002) Modeling the number distributions of urban and regional aerosols theoretical foundations. Atmos Environ 36 1863-1874 Zhang M, Wexler A (2004) Evolution of particle number distribution near roadways—Part I analysis of aerosol dynamics and its implications for engine emission measurements. Atmos Environ 38 6643-6653... 

The atmospheric aerosol—that is, the particles that are normally found in oiu atmosphere—is a complex and dynamic mixture of solid and liquid particles from natural and anthropogenic sources. We consider first the natural background aerosol—the aerosol that would be present in the absence of human activity. At the other extreme the urban aerosol is dominated by anthropogenic sources. In both cases, primary particles are continuously emitted into, and secondary particles are formed in, the atmosphere. Both kinds of particles may undergo growth, evaporation, or chemical reactions and are subject to various removal mechanisms. The size distributions one finds in the atmosphere reflect the complex interaction of all these processes. We omit from this discussion the largest and most important atmospheric aerosol natural clouds of water droplets. 

Dragoescu, C., Friedlander, S. (1989) Dynamics of the aerosol products of incomplete combustion in urban atmospheres. Aerosol... 

Ondov, J. M., and A. S. Wexler, "Where Do Particulate Toxins Reside An Improved Paradigm for the Structure and Dynamics of the Urban Mid-Atlantic Aerosol, Environ. Sci. Technol., 32, 2547-2555 (1998). 

Kumar P, Ketzel M, Vardoulakis S, Pirjola L, Britter R (2011) Dynamics and dispersion modelling of nanoparticles from road traffic in the urban atmospheric environment -a review. J Aerosol Sci 42 580-603... 

Baklanov A (2002) Modelling of formation and dynamics of radioactive aerosols in the atmosphere. Res Theory Elem Part Solid State 4 135-148 Baklanov AA, Nuterman RB (2009) Multi-scale atmospheric environment modelling for urban areas. Adv Sci Res 3 53-57... 

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