Dry deposition including gas and aerosol phase reactions

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:201216

Liljestrand, H M; McDonald-Buller, E C ^[1]

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1. Univ. of Texas, Austin, TX (United States)

The dry deposition flux of a species is typically parameterized by a dry deposition velocity v{sub d} independent of chemical reactions. This is appropriate for reactions with rates slower than the rate of deposition, but it is not an accurate representation for reactions with rates comparable to or faster than those for dry deposition. This study considers the simultaneous deposition of atmospheric oxidants and NO{sub x} in a modification of the surrogate chemical mechanism with additional aerosol particulate matter-gases reactions for sixteen species and forty-seven aerosol/gas reactions to a forest canopy. A one-dimensional numerical model including the second order budget equations for the fluxes of the sixteen species is solved. The assumed cases are varied with the sunlight intensity and the surface emissions of ammonia, biogenic reactive hydrocarbons, and nitric oxide. A sensitivity analysis is performed on the calculated flux of nitric acid gas, the species most dependent on the assumed conditions. A parameterization of the ratio of the effective diffusivity to the conventional turbulent diffusivity is determined for the main oxidant, acid, and base species.

• OSTI ID: 201216
• Report Number(s): CONF-9511137--; ISBN 1-880611-03-1
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AEROSOLS
AIR POLLUTION
CANOPIES
DEPOSITION
FORESTS
MATHEMATICAL MODELS
NITRIC ACID
NITROGEN OXIDES
PHASE STUDIES
PHOTOCHEMICAL OXIDANTS