U.S. Air Quality

Smoke Persists in the Great Lakes and Ohio River Valley

The large smoke plume that Ray discussed yesterday and other bloggers have been tracking across the country over the past week persisted today across the Great Lakes and Ohio River Valley regions. The smoke is very visible in today’s MODIS Terra true color image from MODIS Today, shown in Google Earth (below on left). The corresponding MODIS Terra AOD image from the IDEA website (below on right) shows that AOD levels are elevated across the region influenced by the smoke.

There is evidence that the smoke is reaching the surface, as PM2.5 levels are Code Yellow (Moderate) and Code Orange (Unhealthy for Sensitive Groups) in the much of the Mid-West, Ohio River Valley, and portions of the central Mid-Atlantic, as seen in the map of 24-hour average PM2.5 AQI values (below on left). As Ruben noted in his post, PM2.5 levels are elevated in the Baltimore-Washington, DC area today. As I blog in Arlington, VA at this hour, it is quite hazy looking outside my window at the Capitol and Washington Monument. The smoke is likely to persist for the next several days, and it will continue to move north and east, as shown in the September 21 48-hour aerosol trajectory forecast from the IDEA website (below on right). High pressure over southeastern Canada will move slowly to the east over the next few days, keeping the smoke and haze circulating around the Ohio River Valley, Northeast, and Mid-Atlantic. By Thursday, a cold front will approach from the west and a coastal low pressure system will form off of the Carolinas, which should begin to clean out the region.