Are seasonal patterns in marine tracers evidence of an oceanic source of Hg deposited on forested watersheds at Acadia National Park, Maine, USA?
Nelson S, Norton S, Kahl J. 2003. Are seasonal patterns in marine tracers evidence of an oceanic source of Hg deposited on forested watersheds at Acadia National Park, Maine, USA?
From report abstract: 'We evaluated seasonal patterns for three years of Hg deposition at three sites that are part of the National Atmospheric Deposition Program/Mercury Deposition Newwork (NADP/MDN). Winter deposition of mercury (Hg) was two to five times higher for the Acadia National Park site in coastal Maine than for a site in Wisconsin, and equaled or exceeded winter deposition at a site in South Carolina. The literature attributes low winter deposition to differences in scavenging of Hg by snow, and inhibition of in-cloud oxidation to Hg0 by colder temperatures. Higher hydrologic inputs may partly drive higher winter deposition in Maine. Seasonal patterns in chloride (Cl-) concentration were out of phase with those of Hg; Cl- was highest in winter while Hg concentration was highest in summer. Both Cl- concentrations and sulfate S042-):Cl- ratios indicated high relative contribution of marine aerosol flux in winter at the Acadia site. A pilot study of bromide (Br-) in precipitation and possible relationships with Hg was inconclusive because of low Br- concentration in the sample matrix.' /STUDY LOCATIONS:/ /MOUNT DESERT ISLAND/McFarland Hill/
- Type
- Published Report
- Authors
- Nelson, S.J.; Norton, S.A.; Kahl, J.S.
- Date of Issue
- 2003
- Units
- ACAD
- Keywords
- bromide, cloride (Cl-), Heavy Metals, McFarland Hill, Mercury (Hg), Mount Desert Island, Precipitation, SOx, SOx, Sulfates (SO4), Sulfuric acid (H2SO4), Wet Deposition