Long-term trends in the chemistry of precipitation and lake water in the Adirondack region of New York, USA
- Syracuse Univ., NY (United States); and others
Long-term changes in the chemistry of precipitation (1978-94) and 16 lakes (1982-94) were investigated in the Adirondack region of New York, USA. Time-series analysis showed that concentrations of SO{sub 4}{sup 2-}, NO{sub 3}{sup -}, NH{sub 4}{sup +} and basic cations have decreased in precipitation, resulting in increases in pH. A relatively uniform rate of decline in SO{sub 4}{sup 2-} concentrations in lakes across the region (1.81 +/- 0.35 {mu}eq L{sup -1} yr{sup -1}) suggests that this change was due to decreases in atmospheric deposition. The decrease in lake SO{sub 4}{sup 2-} was considerably less than the rate of decline anticipated from atmospheric deposition. Model calculations suggest that this discrepancy in watershed S budgets may be due either: (1) underestimates of dry deposition of S, or (2) internal release of S from weathering or mineralization of organic S in soil. The discrepancy in watershed S budgets cannot be explained by the release of previously adsorbed SO{sub 4}{sup 2-} from soil. Despite the marked declines in concentrations of SO{sub 4}{sup 2-} in Adirondack lakes, there has been no systematic increase in pH and ANC. The decline in SO{sub 4}{sup 2-} has corresponded with a near stoichiometric decrease in concentrations of basic cations in low ANC lakes. A pattern of increasing NO{sub 3}{sup -} concentrations that was evident in lakes across the region during the 1980`s has been followed by a period of lower concentrations. Currently there are no significant trends in NO{sub 3}{sup -} concentrations in Adirondack lakes.
- OSTI ID:
- 617897
- Report Number(s):
- CONF-970145-; TRN: 98:002057-0066
- Resource Relation:
- Conference: 2. joint conference on acid rain and electric utilities, Scottsdale, AZ (United States), 20-22 Jan 1997; Other Information: PBD: 1997; Related Information: Is Part Of Acid rain & electric utilities II; PB: 1047 p.
- Country of Publication:
- United States
- Language:
- English
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