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), Journal Name: Environ. Sci. Technol.; (United States) Vol. 21:7; ISSN ESTHA
• Country of Publication: United States
• Language: English

Related Subjects

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