Abstract:
:Large quantities of mineral dust particles are frequently ejected into the atmosphere through the action of wind. The surface of dust particles acts as a sink for many gases, such as sulfur dioxide. It is well known that under most conditions, sulfur dioxide reacts on dust particle surfaces, leading to the production of sulfate ions. In this report, for specific atmospheric conditions, we provide evidence for an alternate pathway in which a series of reactions under solar UV light produces first gaseous sulfuric acid as an intermediate product before surface-bound sulfate. Metal oxides present in mineral dust act as atmospheric photocatalysts promoting the formation of gaseous OH radicals, which initiate the conversion of SO(2) to H(2)SO(4) in the vicinity of dust particles. Under low dust conditions, this process may lead to nucleation events in the atmosphere. The laboratory findings are supported by recent field observations near Beijing, China, and Lyon, France.
journal_name
Proc Natl Acad Sci U S Aauthors
Dupart Y,King SM,Nekat B,Nowak A,Wiedensohler A,Herrmann H,David G,Thomas B,Miffre A,Rairoux P,D'Anna B,George Cdoi
10.1073/pnas.1212297109subject
Has Abstractpub_date
2012-12-18 00:00:00pages
20842-7issue
51eissn
0027-8424issn
1091-6490pii
1212297109journal_volume
109pub_type
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