Foggy Sunset Over Green Bay
June 09, 2003
As shown on this photo, a warm spring day ends in a foggy sunset over the waters of Green Bay, part of Lake Michigan. This scene was captured on May 9, 2003 using a Canon G2 digital camera. The fog bank rolling across Green Bay is called advection fog, which occurs when warm, moist air moves (advects) horizontally over a cold surface, cooling the air below the saturation point (dew point). Fog over Green Bay is a frequent sight in spring on those days when the air temperature rises above that of the slower-warming water. The fog is not so dense so that it completely obscures the Sun, but the tiny fog particles (usually less than 0.05 mm in diameter) act to increase wave interference, thereby diminishing the sometimes vivid colors observed during sunset and sunrise.