Clean Air Status and Trends Network (CASTNET) Hourly Ozone Concentrations
Ground-level ozone is measured at CASTNET sites following the guidelines in 40 Code of Federal Regulations (CFR) Parts 50 and 58. Continuous measurements are averaged to hourly concentrations. Data are reported to AirNow and EPA's Air Quality System (AQS) database routinely. There are more than 80 CASTNET sites …