U.S. Air Quality

Good air quality signals Autumn...

The first day of Fall is quickly approaching and we can already see some change in the air quality (EPA AIRNow; top image) over the United Sates. The air quality index is good overall with the exception of some moderate reports in the East, Midwest and California. Haze was noticeable, earlier in the day (bottom left image; UW MODIS Direct), over the Midwest/Central U.S. and can be seen drifting off shore over the Atlantic. The afternoon AQUA (bottom right; UW MODIS Direct) overpass revealed less hazy/cloudy conditions. Some of the haze seen over the Nation may be due to smoke from Canadian fires. However, nitrates and sulfates produced from local pollution sources are likely primarily responsible for moderate AQI near the surface.