As with most days this week, there has been a majority of the United States covered with smoke and wildfires. The first image below, courtesy NOAA HMS, shows the areas that the smoke plumes are reaching. This has caused raised levels of particulates in the air, causing poor air quality throughout certain regions. The second image shows that today there has been a code orange and yellow issued for the surrounding Baltimore/Washington D.C. area. This area is also the playing field for the upcoming NASA Discover AQ mission, which begins on July 1st.
A majority of the lower air quality in this region has been caused by the large smoke and particulates being deposited from Canadian Fires. The first image shows a back-trajectory from the heart of the code orange in Washington D.C. This is a 48 back trajectory at 500, 1000, and 1500 m. These heights correspond to heights that smoke typically travels in due to the relatively large mass of the smoke particles. Also, you can inspect the LIDAR backscatter profile (527 nm) shown in the second image. This is taken from MPLNET, specifically at GSFC, and shows the strong layering that has occurred throughout the day.