Record Display for the EPA National Library Catalog


Main Title Fluxes of Gases and Particles above a Deciduous Forest in Wintertime.
Author Wesely, M. L. ; Cook, D. R. ; Hart, R. L. ;
CORP Author Argonne National Lab., IL. Environmental Research Div.;Environmental Protection Agency, Research Triangle Park, NC. Atmospheric Sciences Research Lab.
Year Published 1983
Report Number EPA/600/J-83/361;
Stock Number PB87-177077
Additional Subjects Flux(Rate) ; Gases ; Particle flux ; Ozone ; Carbon dioxide ; Sulfur ; Forest trees ; Hardwoods ; Deposition ; Velocity measurement ; Eddies ; Winter ; Reprints ;
Library Call Number Additional Info Location Last
NTIS  PB87-177077 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 21p
Eddy-correlation measurements of the vertical fluxes of ozone, carbon dioxide, fine particles with diameter near 0.1 micrometers, and particulate sulfur, as well as of momentum, heat and water vapor, have been taken above a tall leafless deciduous forest in wintertime. During the experimental period of one week, ozone deposition velocities vary from about 0.1 cm s(-1) at night to more than 0.4 cm s(-1) during the daytime, with the largest variations associated primarily with changes in solar irradiation. Carbon dioxide fluxes are directed upward, due to respiration in the leaf litter and soil beneath the canopy, and exhibit a strong dependence on air temperature. The fluxes are approximately zero at air temperatures less than 5 C and approach 0.8 mg m(-2) s(-1) when temperatures exceed 15 C during the daytime. Fine-particle deposition rates are large at times, with deposition velocities near 0.8 cm s(-1) when turbulence levels are high, but fluxes directed upward are measured above the canopy when the surface beneath is covered with snow. Deposition velocities for particulate sulfur are highly variable and average to a value small in magnitude as compared to similar measurements taken previously over a pine forest in summer. (Copyright (c) 1983 by D. Reidel Publishing Company.)