The chemical composition of fogs and clouds in Southern California

Miscellaneous · Sun Jan 01 00:00:00 EST 1989

OSTI ID:7065263

Munger, J W

The major inorganic species in cloud and fog water samples were NH{sub 4}{sup +}, H{sup +}, NO{sub 3}{sup {minus}}, and SO{sub 4}{sup 2{minus}}. Concentrations in fog water samples were 1 - 10 {times} 10{sup {minus}3} M; pH values ranged from {approx equal} 2 to 6. Nitrate usually exceeded sulfate. Acidity depended on the availability of NH{sub 3} from agricultural operations. Stratus cloudwater had somewhat lower concentrations; pH values were in the range 3-4. The major factors accounting for variation in fog- or cloudwater composition were the preexisting aerosol and gas concentrations and variations in liquid water content. Deposition and entrainment or advection of different air masses were also important during extended cloud or fog episodes. The droplet size dependence of cloudwater composition was investigated on one occasion in an intercepted coastal stratus clouds. Concentrations of S(IV) and CH{sub 2}O in the range 100-1000 {mu}M were observed in fogwater from urban sites in Southern California. Lower concentrations were observed in stratus clouds. The high levels of S(IV) and CH{sub 2}O were attributed to the formation of hydroxymethanesulfonate (HMSA), the S(IV) adduct of CH{sub 2}O. Direct measurements of HMSA in fogwater samples from Bakersfield, CA were made by ion-pairing chromatography. Glyoxal and methyglyoxal were observed at concentrations comparable to CH{sub 2}O in fogwater samples from Riverside, CA and in stratus cloudwater samples from sites along the Santa Barbara Channel.

• Research Organization: California Inst. of Tech., Pasadena, CA (USA)
• OSTI ID: 7065263
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
02 PETROLEUM
AMMONIUM COMPOUNDS
ECOLOGICAL CONCENTRATION
CALIFORNIA
AIR POLLUTION
CLOUDS
CHEMICAL COMPOSITION
FOG
FORMALDEHYDE
NITRATES
SULFATES
ACID RAIN
MONITORING
PH VALUE
ALDEHYDES
ATMOSPHERIC PRECIPITATIONS
FEDERAL REGION IX
NITROGEN COMPOUNDS
NORTH AMERICA
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
POLLUTION
RAIN
SULFUR COMPOUNDS
USA
540120* - Environment
Atmospheric- Chemicals Monitoring & Transport- (1990-)
020900 - Petroleum- Environmental Aspects