SeaWiFS satellite image from 15 November 2001. An extended polluted haze layer built up over the eastern United States since the end of October. Smoke from forest fires in Virginia, Kentucky, and West Virginia is visible, and the smoke even extended over the Chesapeake Bay. In the upper left corner an approaching cold front is visible. The red circle indicates the location of the Horton site. Credit: Journal of Geophysical Research.