Brilliant Subsun

Provided and copyright by: James Kaler
Summary author: James Kaler

A brilliant subsun, seen here from the window of an airplane flying near 25,000 feet, seems to float in clear air over a river gorge in California, to the east of San Jose. This photo was taken on March 3, 2005, over the Central Valley of California -- to the east of San Jose. Subsuns are caused by reflection of the Sun off of flat (horizontally aligned) ice crystals that act like tiny mirrors. They're usually seen in association with clouds lying below the aircraft. Here, however, the cloud layer is so thin as to be completely invisible, making the subsun appear to be of mysterious origin. Far below, the river also reflects sunlight (sunglint) as it winds its way through the narrow canyon it has created over the ages.

Related Links:

• Jim Kaler's U. of Illinois Page
• U. of Illinois Astronomy Dept.
• Atmospheric Phenomena

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