Most of the eastern third of the U.S. is in an area of Moderate AQI, with spots of Unhealthy for Sensitive Groups briefly appearing in the Northwest, as seen in the EPA loop below left. There is another area on the Georgia – Alabama border that peaks at Unhealthy before dropping back to Moderate later in the day. There are some additional areas of Moderate AQI in Texas and the Pacific Southwest, with a spot of Unhealthy for Sensitive Groups around Los Angeles. HMS imagery, below right shows an area of smoke over the southwest that would explain the areas of Moderate AQI.
OMI NO2 imagery, below left, shows elevated levels over the Los Angeles and New York City areas, giving reasons for the lowered air quality in those areas. The most recent NAAPS model put out by the NRL indicates that the areas of Moderate AQI in the eastern U.S. might be the result of increased sulfate levels in the area.