The track of the DOE G-1 research aircraft from an August 9, 2004 flight over central Pennsylvania is shown in black. Emissions plumes from two large power plants (Keystone and Homer) were tracked downwind. Sulfur dioxide measured along the flight track was interpolated and gridded. The independently measured winds along the flight path are shown as arrows and correspond well with the meandering of the plume.

Submitted by Stephen R. Springston of Brookhaven National Laboratory.