HR: 1340h
AN: A23A-0761    [Abstracts]
TI: Analysis of the Weekend Effect in Ozone in Central California Using Speciated NO$_{y}$ and VOC Measurements
AU: * Murphy, J G
EM: jgmurphy@berkeley.edu
AF: Department of Chemistry, University of California , Berkeley, CA 94720 United States
AU: Day, D A
AF: Department of Chemistry, University of California , Berkeley, CA 94720 United States
AU: Day, D A
AF: Department of Land, Air and Water Resources, University of California , Davis, CA 95616 United States
AU: Cleary, P A
AF: Department of Chemistry, University of California , Berkeley, CA 94720 United States
AU: Cleary, P A
AF: School of Chemistry, University of Leeds, Leeds, LS2 9JT United Kingdom
AU: Farmer, D K
AF: Department of Chemistry, University of California , Berkeley, CA 94720 United States
AU: Wooldridge, P J
AF: Department of Chemistry, University of California , Berkeley, CA 94720 United States
AU: Cohen, R C
AF: Department of Chemistry, University of California , Berkeley, CA 94720 United States
AU: Millet, D B
AF: Department of Ecosystem Sciences Policy, and Management, University of California, Berkeley, CA 94720 United States
AU: Schade, G W
AF: Department of Ecosystem Sciences Policy, and Management, University of California, Berkeley, CA 94720 United States
AU: Schade, G W
AF: Institute for Environmental Physics, University of Bremen, NW1, Bremen, 28359 Germany
AU: McKay, M
AF: Department of Ecosystem Sciences Policy, and Management, University of California, Berkeley, CA 94720 United States
AU: Goldstein, A H
AF: Department of Ecosystem Sciences Policy, and Management, University of California, Berkeley, CA 94720 United States
AB: The Sacramento Valley and Mountain Counties of California routinely violate the federal 8-hour O$_{3}$ standard between May and October. We present an analysis of the weekend effect in O$_{3}$ at several sites in the area for the last five years, showing that sites in the valley generally have higher weekend ozone while sites downwind have lower ozone. Long term NO$_{x}$, NO$_{y}$, VOC and O$_{3}$ observations at UC Blodgett Forest and detailed measurements of composition at Granite Bay during summer 2001 and at Big Hill during 2003 are used to examine our understanding of the mechanisms responsible for the weekend/weekday differences in O$_{3}$. We will describe weekend/weekday differences in NO$_{2}$ mixing ratio and in VOC reactivity. Ratios of HNO$_{3}$ and peroxynitrates to NO$_{2}$, and relationships among the hydrocarbons will be used to compare and contrast HO$_{x}$ chemistry and the rate of ozone production on weekdays and weekends.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0322 Constituent sources and sinks
DE: 0345 Pollution--urban and regional (0305)
DE: 0365 Troposphere--composition and chemistry
DE: 0368 Troposphere--constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting