January 12, 2010
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Some occasional winter days have air inversions leading to a "brown cloud" visual effect. Looking north from Erie, Colorado. Denver is in the opposite direction.
Nikon D300 with 50-135mm Tokina f2.8 lens at f5 1/640 sec ISO 400. Photographed through a chain link fence - get your lens close and centered on an opening - fence won't show.