By a News Reporter-Staff News Editor at Physics Week -- New research on Atmospheric Chemistry is the subject of a report. According to news reporting originating from Upton, New York, by VerticalNews correspondents, research stated, "Atmospheric aerosols play critical roles in air quality, public health, and visibility. In addition, they strongly influence climate by scattering solar radiation and by changing the reflectivity and lifetime of clouds."
Our news editors obtained a quote from the research from Brookhaven National Laboratory, "One major but still poorly understood source of atmospheric aerosols is new particle formation, which consists of the formation of thermodynamically stable clusters from trace gas molecules (homogeneous nucleation) followed by growth of these clusters to a detectable size (similar to 3 nm). Because freshly nucleated clusters are most susceptible to loss due to high rate of coagulation with pre-existing aerosol population, the initial growth rate strongly influences the rate of new particle formation and ambient aerosol population. Whereas many field observations and modeling studies indicate that organics enhance the initial growth of the clusters and therefore new particle formation, thermodynamic considerations would suggest that the strong increase of equilibrium vapor concentration due to cluster surface curvature (Kelvin effect) may prevent ambient organics from condensing on these small clusters. Here, the contribution of organics to the initial cluster growth is described as heterogeneous nucleation of organic molecules onto these clusters. We find that the strong gradient in cluster population with respect to its size leads to positive cluster number flux. This positive flux drives the growth of clusters substantially smaller than the Kelvin diameter, conventionally considered the minimum particle size that can be grown through condensation."
According to the news editors, the research concluded: "The conventional approach neglects the contribution from the cluster concentration gradient, and underestimates the cluster survival probabilities by a factor of up to 60 if early growth of clusters is due to both condensation of sulfuric acid and heterogeneous nucleation of organic vapors."
For more information on this research see: Growth of atmospheric nano-particles by heterogeneous nucleation of organic vapor. Atmospheric Chemistry and Physics, 2013;13(13):6523-6531. Atmospheric Chemistry and Physics can be contacted at: Copernicus Gesellschaft Mbh, Bahnhofsallee 1E, Gottingen, 37081, Germany. (Copernicus Publications - www.copernicus.org; Atmospheric Chemistry and Physics - publications.copernicus.org)
The news editors report that additional information may be obtained by contacting J. Wang, Brookhaven Natl Lab, Div Atmospher Sci, Upton, NY 11973, United States. Additional authors for this research include R.L. McGraw and C. Kuang.
Keywords for this news article include: Upton, New York, United States, Atmospheric Chemistry, North and Central America
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