PM2.5 concentrations along the west coast of the US continue to range from Moderate to Unhealthy (Code Yellow to Red AQI levels), according to EPA's Airnow. This region of enhanced PM2.5 concentrations correlates with the large NO2 concentrations retrieved from OMI, suggesting nitrates as a major contributor to today's PM2.5 production on the west coast.
NOAA's Hazard Mapping System Fire and Smoke Product reports of an area of thin remnant smoke from numerous agricultural fires that were burning in the Gulf Coast states yesterday. Smoke was spreading southward and westward over the northern Gulf of Mexico. Today's MODIS-Aqua rgb image show agricultural fires over Louisiana (bottom left), while the rgb image over Tennessee shows a plume of black smoke from a fire in Hickman County (bottom right). Local news sources indicate that the fire is at a plastics recycling plant.