Omega Sunrise from Buenos Aires

November 12, 2011

Omega_composite (2)

: Luis Argerich
Summary Author: Luis Argerich; Jim Foster

The photo sequence above shows the rising Sun forming the Greek letter omega also known as an Etruscan vase shape. This omega shape is a type of inferior mirage. The refracted (inverted) image is actually below the object’s true position. When the Sun protrudes above the horizon at sunrise, its inferior mirage can sometimes be seen below it, where it joins the true Sun, creating the familiar omega shape as seen in the second and third image from the left. For this mirage to occur, a layer of very warm air must lie just above the sea surface. Compare with yesterday's Earth Science Picture of the Day. Even at sunrise or sunset, be careful when looking toward the Sun. Photo taken on September 8, 2011.