Item Details

Seasonal Variability in Gaseous Mercury Fluxes and Mercury Deposition to Dew

Converse, Amber Diane
Format
Thesis/Dissertation; Online
Author
Converse, Amber Diane
Advisor
Scanlon, Todd
Abstract
Seasonal patterns of atmospheric mercury (Hg) fluxes measured over vegetated terrestrial systems can provide insight into the underlying process controlling emission and deposition of Hg to vegetated surfaces. Gaseous elemental Hg fluxes were measured for week-long periods in each season (spring, summer, fall, and winter) over an uncontaminated high-elevation wetland meadow in Shenandoah National Park, Virginia using micrometeorological methods. Mean net deposition was observed in the spring (-4.8 ng m -2 h -1 ), emission in the summer (2.5 ng m -2 h -1 ), near zero flux in the fall (0.3 ng m -2 h -1 ), and emission in the winter (4.1 ng m -2 h -1 ). Nighttime deposition (when stomata are closed) and the poor correlation between Hg fluxes and canopy conductance during periods of active vegetation growth suggest that stomatal processes are not the dominant mechanism for ecosystem-level GEM exchange at this site. The strong springtime deposition relative to summer implies that young vegetation is better at scavenging Hg, with the highest deposition occurring at night possibly via a cuticular pathway. Note: Abstract extracted from PDF text
Language
English
Date Received
20140122
Published
University of Virginia, Department of Environmental Sciences, MS (Master of Science), 2009
Published Date
2009-12-01
Degree
MS (Master of Science)
Collection
Libra ETD Repository
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