A Fire Rainbow Over New Jersey
Credit & Copyright:
Paul Gitto
(Arcturus Observatory)
What is that inverted rainbow in the sky?
Sometimes known as a fire rainbow for its flame-like appearance, a
circumhorizon arc
is created by ice, not fire.
For a circumhorizon arc
to be visible, the Sun must be at least 58 degrees high in a sky where
cirrus clouds are present.
Furthermore, the numerous, flat,
hexagonal ice-crystals
that compose the
cirrus cloud must be
aligned horizontally
to properly
refract sunlight
like a single gigantic
prism.
Therefore, circumhorizon arcs are quite unusual to see.
Pictured
above,
however, a rare fire rainbow was captured above trees in
Whiting,
New Jersey,
USA in late
May.