Fog Plumes over the Great Lakes

 

A southerly flow of unseasonably warm, moist air (temperatures of +20° to +26° C, dew points of +14° to +16° C) over the relatively cool (generally +2° to +5° C ) water of Lake Michigan and Lake Huron contributed to the development of large advection fog plumes (caused by the horizontal motion of air) during the day on April 16, 2002. These fog plumes moved northward during the day, eventually interacting with various land features to produce patterns of wave diffraction and packets of reflected waves (resembling #8220;shock waves”) as the fog plumes impinged upon the rugged coastline of Wisconsin, the Upper Peninsula of Michigan, and Ontario. These waves remained trapped within the strong marine layer temperature inversion which was sustained by the continued flow of warm air across the cool water surface.

The above image was acquired by the Moderate-Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Terra satellite. Red = .645µm (red), green = 1.627µm, (shortwave infrared), blue = 2.13µm (shortwave infrared).

Image courtesy Space Science and Engineering Center, University of Wisconsin