US EPA

155692 

Journal Article 

Secondary organic aerosol formation in cloud and fog droplets: a literature evaluation of plausibility 

Blando, JD; Turpin, BJ 

2000 

1 

Atmospheric Environment
ISSN: 1352-2310
EISSN: 1873-2844 

34 

10 

1623-1632 

10.1016/S1352-2310(99)00392-1 

WOS:000085995400012 

This paper investigates the hypothesis that cloud and fog processes produce fine organic particulate matter in the atmosphere. The evidence provided suggests that cloud and fog processes could be important contributors to secondary organic aerosol formation, and the contribution of this formation pathway should be further investigated. This conclusion is based on the following observations: (1) many organic vapors present in the atmosphere are sorbed by suspended droplets and have been measured in cloud and fog water, (2) organics participate in aqueous-phase reactions, and (3) organic particulate matter is sometimes found in the size mode attributed to cloud processing (i.e. the droplet mode). Specific compounds identified as potential precursors include aldehydes (e.g. formaldehyde, acetaldehyde, and propionaldehyde), acetone, alcohols (e.g. methanol, ethanol, 2-propanol, and phenol), monocarboxylic acids, and organic peroxides. Carboxylic acids (e.g. diacids and oxo-acids), glyoxal, esters, organosulfur compounds, polyols, amines and amino acids are potential products of cloud and fog processing.