Episodic stream acifification caused by atmospheric deposition of sea salts at Acadia National Park, Maine, United States

Heath, RH; Kahl, JS; Norton, SA; Fernandez, IJ

HERO ID

2459970

Reference Type

Journal Article

Year

1992

HERO ID 2459970
In Press No
Year 1992
Title Episodic stream acifification caused by atmospheric deposition of sea salts at Acadia National Park, Maine, United States
Authors Heath, RH; Kahl, JS; Norton, SA; Fernandez, IJ
Journal Water Resources Research
Volume 28
Issue 4
Page Numbers 1081-1088
Abstract Major episodic acidifications were observed on several occasions in first-order brooks at Acadia National Park, Mount Desert Island, Maine. Short-term declines of up to 2 pH units and 130-mu-eq L-1 acid-neutralizing capacity were caused by HCl from soil solutions, rather than by H2SO4 or HNO3 from precipitation, because (1) SO4 concentrations were constant or decreased during the pH depression, (2) Cl concentrations were greatest at the time of lowest pH, and (3) Na:Cl ratios decreased from values much greater than those in precipitation (a result of chemical weathering), to values equal to or less than those in precipitation. Dilution, increases in NO3 concentrations, or increased export or organic acidity from soils were insufficient to cause the observed decreases in pH. These data represent surface water acidifications due primarily to an ion exchange "salt effect" of Na+ for H+ in soil solution, and secondarily to dilution, neither of which is a consequence of acidic deposition. The requisite conditions for a major episodic salt effect acidification include acidic soils, and either an especially salt-laden wet precipitation event, or a period of accumulation of marine salts from dry deposition, followed by wet inputs.
Doi 10.1029/91WR03031
Wosid WOS:A1992HN11300013
Is Certified Translation No
Dupe Override No
Is Public Yes