Trace gas measurements in Phoenix, Arizona (1998)

Conference · Sun Jan 09 04:00:00 EST 2000

OSTI ID:750665

Nunnermacker, L J ^[1]

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1. BROOKHAVEN NATIONAL LABORATORY

The DOE Atmospheric Chemistry Program, and the Arizona Department of Environmentel Quality (DEQ) conducted a field program in the Phoenix Metropolitan area in the late spring of 1998. The experiment was composed of a linked set of aircraft and surface measurements designed to characterize the chemical and meteorological processes leading to ozone episodes. The existing network of Arizona DEQ sites in Phoenix was utilized to document ground level concentrations of ozone and its precursors. West of the downtown area, a site (Usery Pass) was set up for the detailed characterization of the mature Phoenix urban plume. Detailed measurements in the source region were made at several sites in downtown Phoenix. The DOE G-1 aircraft, equipped wih a comprehensive array of instruments to characterize atmospheric trace gas and aerosol composition, flew over the region at various times during the day. All times in the following discussion are local standard time (LST). Morning flights were typically made between 08:00 and 12:00 upwind, to measure background concentrations, and over the Phoenix source region, to characterize the sources of ozone precursors. Afternoon flights over the Phoenix source region and downwind between 15:00 and 18:00 were made to examine the chemical properties and physical distribution of the photochemically aged urban plume. The aircraft flights typically included an atmospheric sounding to circa 3 km upwind and over Phoenix in the morning, and downwind in the afternoon. A total of 22 flights were made on 14 different days during the one month program. The motivation for conducting the program was to examine ozone formation rates and efficiencies in an environment where the pollutant mix is dominated by vehicle emissions, where the contribution of biogenic hydocarbons to ozone formation is thought to be low, and where processing conditions are different than they are in the Eastern US. The latter includes significant differences in atmospheric humidity, solar intensity, and boundary layer heights. The objective of this is to describe general features of the chemical and meteorological data collected during the program and present results from an aircraft case study when O{sub 3} concentrations were among the highest measured during the entire study.

• Research Organization: Brookhaven National Lab., Upton, NY (US)
• Sponsoring Organization: USDOE Office of Energy Research (ER) (US)
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 750665
• Report Number(s): BNL--66838; KP120201
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AIR POLLUTION MONITORING
AIR QUALITY
ARIZONA
ATMOSPHERIC CHEMISTRY
ECOLOGICAL CONCENTRATION
OZONE
URBAN AREAS