The Central California Air Quality Studies (CCAQS) comprise two studies, the California Regional Particulate Air Quality Study (CRPAQS) and the Central California Ozone Study (CCOS). CCAQS is a multi-year effort of meteorological and air quality monitoring, emission inventory development, data analysis, and air quality simulation modeling.

CRPAQS monitoring occurred during a 14-month study period, between December 1999 and February 2001.

CCOS monitoring took place during the summer of 2000.

These studies utilized 500 instruments at over 100 monitoring locations to measure and analyze for 600 parameters. Additional data was obtained from supplemental data sources. It is anticipated that the database management system will manage 150 million records.