The California Regional PM10/PM2.5 Air Quality Study was designed to improve the scientific understanding of excessive PM concentrations in central California. Specifically, it was designed to determine where and when populations experience excessive PM exposures and how to cost-effectively reduce those exposures to acceptable levels. STI performed four major tasks in this air quality study. First, we set up two state-of-the-science research-grade air quality monitoring stations and operated them for 14-months (anchor stations for the long-term program). Surface and tower measurements were collected for a large suite of trace gases and aerosol components. Second, we set up and operated two additional anchor sites and several satellite air quality monitoring stations for fall and winter intensive monitoring programs. Third, we set up and operated radar wind profilers to collect upper-air meteorological data at several locations. All of the air quality and meteorological data were subjected to extensive quality assurance. Fourth, we updated the California Air Resources Board's emissions-related activity data for central California and collected detailed activity data for areas surrounding CRPAQS monitoring sites. STI developed a customized software program for data acquisition and data management, and GIS applications for the study. (Read about CRPAQS data analysis.)
STI scientists coordinated field activities between the Texas Commission on Environmental Quality Coastal Oxidant Assessment for Southeast Texas (COAST) Project and the U.S. Minerals Management Service Gulf of Mexico Air Quality Study (GMAQS). Both studies involved upper-air and surface air quality and meteorological measurements during the summer of 1993 in support of air quality modeling. The COAST project focused on the Houston area, while GMAQS covered the northern Gulf Coast. In addition to field activities coordination, STI staff made airborne air quality measurements from two instrumented aircraft. These data included continuous measurements of ozone, oxides of nitrogen, ambient temperature, location and altitude, and grab samples of reactive organic gases and carbonyl compounds.
The U.S. Minerals Management Service sponsored this $5 million study to examine the contribution of offshore emissions to exceedances of the ozone standard in the Gulf Coast region. STI was responsible for the field design and management, measurement, and data analysis components. We operated a network of 915-MHz Doppler radar wind profilers with RASS (Radio Acoustic Sounding System). This network measured vertical profiles of wind and virtual temperature continuously during a six-month period beginning in spring 1993. One rawinsonde sounding system was used to supplement collection of upper-air data offshore during special observation periods. STI staff also operated three air quality research aircraft in the Texas-Louisiana areas and over the Gulf of Mexico. After the 1993 field study, we performed an extensive array of meteorological and air quality data analyses.
A major air quality study was conducted from 1995 to 1997 in the Northeastern United States as part of the North American Research Strategy for Tropospheric Ozone, Northeast (NARSTO-Northeast Study). Under EPRI sponsorship, STI coordinated planning of the meteorological and air quality field measurements and collected airborne measurements using our Aztec aircraft. STI coordinated data submittal activities; documented the field activities; performed analyses of ozone formation and transport and of the meteorological phenomena affecting ozone concentrations in the Northeast; developed and maintained an Internet-accessible data archive; and developed software to perform data validation and data analyses of hourly VOC data. Under sponsorship of the Coordinating Research Council, STI performed extensive analyses of the ozone, ozone precursor, and meteorological data collected during the 1995 NARSTO-Northeast Study. We validated and analyzed hydrocarbon and carbonyl data from 13 Photochemical Assessment Monitoring Stations (PAMS) and nine special research sites. STI performed an emission inventory evaluation for three PAMS sites and also performed analyses of pollutant transport and mixing height structure, evolution, and effects on ozone concentrations in the Northeast.