Inferior Mirage Over Southwestern Lake Michigan
October 09, 2012
Photographer: John Van Benthuysen; John's Web site
Summary Author: John Van Benthuysen
Atmospheric refraction creates these interesting bending dunes and chevron-shaped bow waves on the R/V Grayling as it cruises in Lake Michigan towards the Kalamazoo River and the town of Saugatuck, Michigan. The temperature of the water here, at the time of the photo, was roughly 63/64 degrees F (17 C), considerably warmer than air temperature (52 degrees F or 11 C). Light rays moving through the air just above the water surface were bent or refracted by a less dense (warmer) layer above the near-surface air layer, causing the stretched out illusions -- inferior mirage. Sunlight is bent toward the surface by this inversion layer. Note that the towering is somewhat exaggerated by the 500 mm reflex telephoto lens I used to photograph boats coming into Saugatuck harbor. Photo taken on September 27, 2012.
Photo Details: Nikon D200 camera; 500mm (35mm equivalent: 750mm) focal length; f/8 (fixed aperature); 0.001 sec. (1/1000) exposure time; ISO 400; Exposure Bias: none; Metering Mode: matrix; White balance: 5300 k; Flash Fired: No; Color space: Adobe RGB (1998). Cropped and exposure corrected with Photoshop CS5.