Ozone concentrations in parts per billion (ppb) are represented as blue (low concentrations) on the
left-hand side of the Legend across the top of the map, to red (high concentrations) on the right-hand side.
See Ozone maps for the U.S.:
This Southern Rockies (New Mexico and Arizona) 8-Hour Average Ozone Concentration map is from http://www.nws.noaa.gov/aq/sectors/conus.php#, a National Oceanic and Atmospheric Administration (NOAA) National Weather Service (NWS) Web site.
The map shows NOAA's National Weather Service Air Quality Forecast Guidance. Ozone is shown on the NOAA NWS site as 1-hour and 8-hour concentrations (in parts per billion or ppb), updated twice daily. Official Air Quality point forecasts, issued by state and local air quality forecasters, along with additional information on air quality can be found under EPA's AIRNow site.
For more information about New Mexico Air Quality and Ozone, see Environmental Data: Air.