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Abstract
Concentrations of air pollutants were monitored during the May–November 1999 period on a network of forested sites in Sequoia National Park, California. Measurements were conducted with: (1) active monitors for nitric oxide (NO), nitrogen dioxide (NO
2) and ozone (O
3); (2) honeycomb denuder/filter pack systems for nitric acid vapor (HNO
3), nitrous acid vapor (HNO
2), ammonia (NH
3), sulfur dioxide (SO
2), particulate nitrate (NO
3–), ammonium (NH
4+, and sulfate (SO
42–); and (3) passive samplers for O
3, HNO
3 and NO
2. Elevated concentrations of O
3 (seasonal means 41–71 ppb), HNO
3 (seasonal means 0.4–2.9 µg/m
3), NH
3 (seasonal means 1.6–4.5 µg/m
3), NO
3 (1.1–2.0 µg/m
3) and NH
4+ (1.0–1.9 µg/m
3) were determined. Concentrations of other pollutants were low. With increasing elevation and distance from the pollution source area of O
3, NH
3 and HNO
3 concentrations decreased. Ammonia and NH
4+ were dominant N pollutants indicating strong influence of agricultural emissions on forests and other ecosystems of the Sequoia National Park. Published by Elsevier Science Ltd.
Citation
Bytnerowicz, Andrzej; Tausz, Michael; Alonso, Rocio; Jones, David; Johnson, Ronald; Grulke, Nancy. 2002. Summer-time distribution of air pollutants in Sequoia National Park, California. Environmental Pollution. 118: 187-203.
