STI scientists performed aircraft measurements on 20 days during the 1997 Southern California Ozone Study (SCOS) for the California Air Resources Board. The aircraft data were collected to investigate the processes that result in high ozone concentrations aloft over Los Angeles and to characterize air quality and meteorological conditions along the boundaries of the study region for modeling use.
STI made three-dimensional air quality measurements using two aircraft in support of the Central California Ozone Study during summer 2000. Boundary condition measurements were made offshore and measurements of the evolution of the boundary layer, transport between source areas, and urban plumes were made in the San Joaquin Valley. This project was sponsored by the San Joaquin Valleywide Air Pollution Study Agency.
STI scientists operated two aircraft in 1995 and one in 1996 in the Northeast Ozone Transport Region (OTR) for the North American Research Strategy for Tropospheric Ozone, Northeast (NARSTO-Northeast) study. More than 80 flights were flown during the two summers. The aircraft measurements documented the vertical distribution of ozone and its precursors throughout the OTR. Air quality measurements aboard the aircraft included ozone and high-sensitivity measurements of NO, NOy, SO2, and CO. During the 1996 sampling program, STI scientists obtained continuous nitric acid measurements in addition to NO and NOy measurements. This project was sponsored by EPRI.
To determine the impact of the Navajo Generating Station (NGS) on visibility in the Grand Canyon area, STI scientists designed and conducted an aircraft sampling program and a meteorological measurement program under sponsorship of the Salt River Project. One aircraft, five upper-air sounding systems, and a network of 12 surface meteorological stations were operated by STI staff during the field program. In addition, STI staff coordinated the data management and data analysis efforts for this $15 million study.
In summer 1990, as part of the San Joaquin Valley Air Quality Study (SJVAQS) and AUSPEX, STI scientists performed over 200 hours of aircraft measurements in the San Francisco Bay Area and San Luis Obispo County using two aircraft. The airborne measurements of ozone, NO/NOx, and VOCs were conducted under sponsorship of Pacific Gas & Electric Company. In addition, we performed extensive data analysis for the study.
STI scientists were the principal investigators and project coordinators for the U.S. EPA's Visibility Impairment Due to Sulfur Transformation and Transport in the Atmosphere (VISTTA) project. STI scientists also collected aircraft data near coal-fired power plants in the southwestern U.S. The overall objectives of the project were to determine the relationship between the emissions from the power plants and their effects on downwind visibility; to determine the source types that contribute to regional visibility impairment in the southwestern U.S.; and to evaluate visibility models as applied to southwestern coal-fired power plants. STI obtained and analyzed a massive data set on the chemical and physical properties, aerosol dynamics, and optical (visibility) effects of southwestern point source plumes. These included data from many plume transect flights.