May 4, 2009
Another Day of Mostly Good Air Quality across the Nation
It’s been a quiet day for air quality across the nation today, with both PM2.5 and ozone mostly in the Code Green (Good) range, as shown by the loops of AQI values (below). There were only a few scattered areas of Code Yellow (Moderate) PM2.5 in the Great Lakes region, south Texas, and southern California, and the Houston-Galveston-Brazoria area reported 8-hour average ozone values just into the Code Orange (Unhealthy for Sensitive Groups) range.
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A stationary front that has brought steady rain to much of the eastern half of the country for the past two days was the main source of today’s good air quality. Today’s MODIS Terra true color image, overlaid with this morning’s synoptic analysis and the current AQI values (below, in Google Earth) shows the location of the stationary front and associated cloud cover.
