- Aurora borealis
|irregular, luminous phenomena, as streamers, visible at night in a
zone surrounding the north magnetic pole and produced in the ionosphere
when atomic particles strike and excite atoms; northern lights.
Brocken Bow (also known as glory)
|Belgium, Netherlands and Luxembourg.
|colored rings around shadows projected against fog
or cloud droplets.
|solar and lunar coronas consist of a series of rainbow-colored rings
around the sun or moon. Such coronas resemble halos but differ in having
a reverse sequence of the spectrum colors, red being the color of the
outer ring, and in having smaller and variable radii. This reversed
sequence of the spectrum occurs because coronas result from diffraction
of light whereas the halo is a refraction phenomenon.
|narrow inlet or arm of the sea bordered by steep cliffs.
|the green flash is caused by refractive separation of the sun’s rays
into its spectral components. This may occur at sunrise or sunset when
only a small rim of the sun is visible. When refractive conditions are
suitable, red, orange, and yellow waves of sunlight are not refracted
sufficiently to reach the eye whereas green waves are. The visual result
is a green flash in the surrounding sky.
Ice Blink/Land Blink
|a ring of light that seems to encircle the sun, moon, or other
luminous bodies. It results from the refraction of light through ice
crystals in the atmosphere.
|are reflection phenomena observed on the underside of cloud surfaces.
|a mirage is caused by refraction of light rays in a layer of air
having rapidly increasing or decreasing density near the surface. A
marked decrease in the density of the air with increasing altitude is
the cause of such phenomena known as looming, towering and superior
mirages. Looming is said to occur when objects appear to rise above
their true elevation. Objects below the horizon may actually be brought
into view. Towering has the effect of elongating the visible objects in
the vertical direction. A superior mirage is so named because of the
appearance of an image above the actual object. The inferior mirage is
due to increasing air density with height. Atmospheric zones of varying
densities and thickness’ may combine the effects of the various types
of mirages to form a complicated mirage system known as Fata Morgana.
St. Elmo’s Fire
|the refraction of light by ice crystals. Because red light is
refracted the least, the inner ring of this arc is always red with the
other colors of the spectrum following outward.
|the "fire" appears as a bluish luminous brush discharge of
electricity and is most likely to be seen leaping from ships’ masts
and spars. St. Elmo’s fire is also known as Corposan, from Corpo
Santo, or ghost because of its once supposed supernatural nature.