HR: 11:20h
AN: A52B-04    [Abstracts]
TI: A Vertical Integration of the Forest Canopy to Assess the Atmospheric Impacts of Terpenes
AU: * Lee, A
EM: alee@nature.berkeley.edu
AF: University of California, Dept. of ESPM - Ecosystem Sciences, 151 Hilgard Hall, Berkeley, CA 94720-3110 United States
AU: Holzinger, R
EM: holzing@nature.berkeley.edu
AF: University of California, Dept. of ESPM - Ecosystem Sciences, 151 Hilgard Hall, Berkeley, CA 94720-3110 United States
AU: Goldstein, A H
EM: ahg@nature.berkeley.edu
AF: University of California, Dept. of ESPM - Ecosystem Sciences, 151 Hilgard Hall, Berkeley, CA 94720-3110 United States
AB: Models predicting secondary organic aerosol production require input from measurements of the total terpenes emitted by an ecosystem, not just measurements of the few species typically obtained by above-canopy flux measurements. While these above-canopy fluxes are a useful measure of the terpenes that escape the forest canopy, they provide no information on the terpenes that react within the canopy. The different lifetimes of "reacted" and "escaped" terpenes result in different scales of impact (local versus regional) on the chemistry of the atmosphere. To improve our understanding of the atmospheric impacts of terpenes, we conducted measurements that vertically integrate over the forest canopy, using branch enclosure techniques, vertical gradient measurements, and above-canopy flux measurements using both PTR-MS and GC-FID. Measurements were conducted in a Ponderosa pine plantation on the western slope of the Sierra Nevada, California, in the summer of 2003. This presentation will focus on changes in the monoterpene species composition as we ascend the canopy, comparing the branch-level fluxes with the vertical concentration gradients and above-canopy fluxes.
DE: 0315 Biosphere/atmosphere interactions
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting