Formation of reactive nitrogen oxides from urban grime photochemistry
Formation of reactive nitrogen oxides from urban grime photochemistry
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DOI：
10.5194/acp-16-6355-2016
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发表时间：
2016-01-01
影响因子：
6.3
通讯作者：
Donaldson, D. James
中科院分区：
文献类型：
--
作者：
Baergen, Alyson M.;Donaldson, D. James
Impervious surfaces are ubiquitous in urban environments and constitute a substrate onto which atmospheric constituents can deposit and undergo photochemical and oxidative processing, giving rise to "urban grime" films. HNO3 and N2O5 are important sinks for NOx in the lower atmosphere and may be deposited onto these films, forming nitrate through surface hydrolysis. Although such deposition has been considered as a net loss of NOx from the atmosphere, there is increasing evidence that surface-associated nitrate undergoes further reaction. Here, we examine the gas phase products of the photochemistry of real, field-collected urban grime using incoherent broadband cavity-enhanced absorption spectroscopy (IBBCEAS). Gas phase nitrogen oxides are emitted upon illumination of grime samples and their production increases with ambient relative humidity (RH) up to 35aEuro-% after which the production becomes independent of RH. These results are discussed in the context of water uptake onto and evaporation from grime films.
