The AirNow AQI loop, below left, indicates areas of moderate AQI in the Mid-Atlantic, Southeast, and astern Mississippi valley growing through the afternoon, then dropping off toward the evening. A small area of AQI Unhealthy for Sensitive groups appeared in eastern Pennsylvania in the late morning before disappearing around noon.
Similar patches of Moderate AQI appeared in the southeast, although these were smaller in extent. OMI NO2 imagery, below right, suggests nitrates as the cause for the sub-optimal AQI in what areas of the Southwest it covers. The imagery also shows elevated NO2 in New England, although since this is near the edges of the clouds, this may reflect that more than a meaningful reading.
HMS smoke and fire imagery, below left, shows areas of smoke in southern Arizona and New Mexico that may be responsible for the areas of lower air quality in that region, as well as several fires in the southeast, a somewhat large fire with associated smoke plume in Alaska, and a large plume of smoke covering most of the Dakotas and part of Montana. This last plume has been drifting down from Canada for a few days now.
A check of the NAAPS output from NRL indicates a large area of sulfate over the Great Lakes region that would contribute to the Moderate AQI in this region.