Fluxes of gases and particles above a deciduous forest in wintertime

Technical Report · Sat Jan 01 04:00:00 EST 1983

OSTI ID:6503648

Wesely, M L; Cook, D R; Hart, R L

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, were 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.

• Research Organization: Argonne National Lab., IL (USA). Environmental Research Div.
• OSTI ID: 6503648
• Report Number(s): PB-87-177077/XAB
• Country of Publication: United States
• Language: English

Related Subjects

500200* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
AIR POLLUTION
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CHALCOGENIDES
DEPOSITION
ELEMENTS
FLUIDS
FORESTS
GASES
NONMETALS
OXIDES
OXYGEN COMPOUNDS
OZONE
PARTICLES
PARTICULATES
POLLUTION
SULFUR