Acid rain and atmospheric chemistry at Allegheny Mountain

Journal Article · Wed Jul 01 00:00:00 EDT 1987 · Environ. Sci. Technol.; (United States)

DOI:https://doi.org/10.1021/es00161a009· OSTI ID:6176633

Pierson, W R; Brachaczek, W W; Gorse, Jr, R A; Japar, S M; Norbeck, J M; Keeler, G J

Rain chemistry was measured in August 1983 on Allegheny Mountain and Larel Hill in southwester Pennsylvania. The average composition approximated an H/sub 2/SO/sub 5//HNO/sub 3/ mixture with a volume-weighted average pH of 3.5 and an SO/sub 4//sup 2 -//NO/sub 3//sup -/ mole ratio of 1.8. There was very little undissociated (weak) acidity and very little S(IV). The acidic rains were associated with air masses traversing SO/sub 2/ source regions west of the sites; stagnation and intervening precipitation were important influences. The geographic scale for a halving of rain SO/sub 4//sup 2 -/ concentration downwind of SO/sub 2/ sources was approx.440 km. Scavenging ratios were inferred for SO/sub 2/, aerosol SO/sub 4//sup 2 -/, and HNO/sub 3/. On average about half of the rain SO/sub 4//sup 2 -/ resulted from scavenging of SO/sub 2/, the rest from scavenging of SO/sub 4//sup 2 -/. The rain H/sup +/ was attributed about 25% to HNO/sub 3/, 55% to scavenging of SO/sub 2/, and 20% to scavenging of aerosol acid SO/sub 4//sup 2 -/. Cumulative deposition totals in rain were compared with deposition in fog and with dry deposition in the same experiment. A crude acid-deposition budget was calculated as follows: 47%, H/sub 2/SO/sub 4/ in rain; 23%, SO/sub 2/ dry deposition without dew; 16%, HNO/sub 3/ in rain; 11%, HNO/sub 3/ dry deposition without dew; 2%, HNO/sub 3/ and H/sub 2/SO/sub 4/ in fog and dew; 0.5%, aerosol dry deposition without dew. 86 references, 4 figures, 8 tables.

• Research Organization: Ford Motor Company, Dearborn, MI
• OSTI ID: 6176633
• Journal Information: Environ. Sci. Technol.; (United States), Vol. 21:7
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ACID RAIN
CHEMICAL COMPOSITION
CHEMICAL REACTIONS
NITRIC ACID
DEPOSITION
SULFATES
SULFUR DIOXIDE
SULFURIC ACID
ATMOSPHERIC CHEMISTRY
EXPERIMENTAL DATA
PENNSYLVANIA
PH VALUE
ATMOSPHERIC PRECIPITATIONS
CHALCOGENIDES
CHEMISTRY
DATA
FEDERAL REGION III
HYDROGEN COMPOUNDS
INFORMATION
INORGANIC ACIDS
NORTH AMERICA
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
RAIN
SULFUR COMPOUNDS
SULFUR OXIDES
USA
500200* - Environment
Atmospheric- Chemicals Monitoring & Transport- (-1989)