U.S. Air Quality

Air Quality Improves in the Pacific Northwest; PM2.5 AQI No Greater than Moderate Along the US

The air quality improved in the Pacific Northwest states with PM2.5 concentrations only reaching Moderate AQI levels, according to Airnow AQI animation. Moderate PM2.5 AQI levels were also recorded in California, Oklahoma, the Great Lakes and Mid-Atlantic States. Light winds and limited vertical mixing associated with the high pressure systems (National Weather Service Surface Analysis map) favored particle formation. Tropospheric NO2 concentrations retrievals indicate that were greatest along this region. The presence of clouds (MODIS "true color image") did not allow an adequate AOD retrieval.