Formation of reactive nitrogen oxides from urban grime photochemistry

Formation of Reactive Nitrogen Oxides from Urban Grime Photochemistry

Impervious surfaces are ubiquitous in urban environments and constitute a substrate onto which atmospheric 10 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 ...

Supplement of Formation of reactive nitrogen oxides from urban grime photochemistry

Interactive comment on “Formation of Reactive Nitrogen Oxides from Urban Grime Photochemistry” by A. M. Baergen and D. J. Donaldson

Manuscript by Alyson Baergen and D. J. Donaldson focuses on formation of HONO, a key chemical species and/or reaction intermediate in atmospheric chemistry, during photolysis of urban grime. Given the fact that sources and formation of daytime HONO in urban setup are poorly understood, this study reveals potential chemical and photochemical reaction pathways and mechanisms to yield HONO. The kn...

Interactive comment on “Formation of Reactive Nitrogen Oxides from Urban Grime

It is believed that the deposition of NOy (mainly HNO3, even if N2O5 is also discussed here) is a sink process for NOx, however this study challenges this point of view and demonstrates, for the time, that photochemistry of photochemistry of urban grime is as a potential source of gaseous nitrous acid (HONO). This has been suggested before but never demonstrated. This study therefore a nice pie...

Reactive nitrogen transport and photochemistry in urban plumes over the North Atlantic Ocean