HR: 08:30h
AN: A51G-02    [Abstracts]
TI: A Comparative Study of Ozone Production in 5 U.S. Metropolitan Areas
AU: * Kleinman, L I
EM: kleinman@bnl.gov
AF: Brookhaven National Laboratory, Atmospheric Sciences Divisions, Upton, NY 11973 United States
AU: Daum, P H
EM: phdaum@bnl.gov
AF: Brookhaven National Laboratory, Atmospheric Sciences Divisions, Upton, NY 11973 United States
AU: Lee, Y
EM: ynlee@bnl.gov
AF: Brookhaven National Laboratory, Atmospheric Sciences Divisions, Upton, NY 11973 United States
AU: Nunnermacker, L J
EM: lindan@bnl.gov
AF: Brookhaven National Laboratory, Atmospheric Sciences Divisions, Upton, NY 11973 United States
AU: Springston, S R
EM: srs@bnl.gov
AF: Brookhaven National Laboratory, Atmospheric Sciences Divisions, Upton, NY 11973 United States
AU: Weinstein-Lloyd, J
EM: jlloyd@bnl.gov
AF: SUNY/Old Westbury, Chemistry/Physics Department, Old Westbury, NY 11568 United States
AB: We present observations of O$_{3}$ and O$_{3}$ precursors measured at mid boundary layer altitude during field campaigns in Nashville, TN (1995), New York City, NY (1996), Phoenix, AZ (1998), Philadelphia, PA (1999), and Houston, TX (2000). Ozone production rates, P(O$_{3}$) and their sensitivity to NO$_{x}$ and VOCs, are calculated using observed concentrations as inputs to a steady state box model. City to city comparisons are made to illustrate common features of urban photochemistry and features that are unique to specific cities. Ozone production rates vary from nearly zero to 155 ppb h$^{-1}$. Differences in P(O$_{3}$) depend on precursor concentrations; namely, radical sources, NO$_{x}$ and VOCs. Under conditions where P(O$_{3}$) is greater than 25 ppb h$^{-1}$, there is a potential to produce enough same-day O$_{3}$ to transform a typical regional background into a severe O$_{3}$ episode. Six such cases were observed, in Nashville, Philadelphia, and Houston, with elevated O$_{3}$ concentrations in the afternoon (130-211 ppb) following a morning in which P(O$_{3}$) was 25 - 140 ppb h$^{-1}$. High P(O$_{3}$) occurs when NO$_{x}$ concentrations are 5 to 25 ppb and OH-VOC reactivity is above 5 s$^{-1}$. These conditions are infrequent and aside from a common dependence on calm winds reasons vary from city to city.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0317 Chemical kinetic and photochemical properties
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