/r/atoptics
Atmospheric Optics. The subreddit for anything related to optic sky phenomena: rainbows, ice halos, aurorae, mirages, cloud iridescence, green flashes, crepuscular rays and spectres of the Brocken.
Atmospheric Optics
The subreddit for anything related to optic sky phenomena: rainbows, ice halos, aurorae, mirages, cloud iridescence, green flashes, crepuscular rays and spectres of the Brocken.
Have a nice picture to show? Want to know what causes that light in the sky? Here is the place to share, discuss and learn.
Useful links:
Atmospheric Optics (back from the dead, yay)
Glows, bows and halos *new*
The Youtube Atmospheric Optics Playlist
Glossary of common terms:
Aurora: the veils of green, red and/or blue seen in the polar regions when the solar wind hits the Earth’s magnetic field. Goes by two names, dependent on the hemispere: aurora borealis or northern lights, and aurora australis, aka southern lights.
Corona: a subtly colored disc directly around the sun or moon, caused by light diffraction through the clouds.
Crepuscular rays: bands of shadow that seem to radiate outwards from the sun, caused by its light being partially obstructed by clouds, mountain ranges etc. Called anticrepuscular rays when seen on the opposite side of the sky.
Glory: a dimly rainbow-colored ring opposite the sun or moon, often visible from planes or in misty circumstances, in which case it tends to come with a Brocken spectre. Sometimes mistaken for a circular rainbow.
Green flash: a rare occurrence where the topmost bit of the setting sun is refracted by the atmosphere, turning it bright green. Even rarer is the blue flash.
Halos: a collective term for a wide range of arcs, rings, spots etc. caused by light refracting and/or reflecting inside ice crystals. Common halos are the 22º ring (sometimes also simply called “halo”), sundogs and the circumzenithal arc, but there are many more.
Iridescence or irisation: a "mother of pearl" colored effect in certain clouds caused by light diffraction through water drops.
Light pillar: a vertical beam of light that extends from a natural or artificial light source as a result of reflection by ice crystal plates.
Nacreous clouds: a specific type of cloud iridescence in high atmosphere clouds.
Rainbow: the proverbial arc directly opposite the sun or moon, resulting from light reflection & refraction inside water drops. When caused by the moon, it is sometimes called a moonbow. Technically, all rainbows are circular, but the lower part is normally hidden by the horizon. Rainbows consist of a primary bow and a secondary bow. The secondary bow has a reversed color sequence and is dimmer than the primary, which explains why it is not always visible.
Sprite: An enigmatic lightning phenomenon above the clouds instead of below them and many times larger.
Sundog (aka parhelion (plural parhelia) or mock sun): often incorrectly used for the 22º ring or halo phenomena in general, but refers specifically to the two bright patches to the left and right of the sun. They're the sun's "companions"; hence, dogs. When caused by the moon, they are called moondogs or paraselenae (singular paraselene).
/r/atoptics
I was unaware if this sub so credit to u/C7XC for recommending the share.
Original source - https://www.salisburyjournal.co.uk/news/24193054.amazing-photo-shows-full-circle-rainbow-stonehenge/
Is there any term for this phenomenon?
A very faint upper tangent arc also visible? There were also extremely bright sun dogs but I couldn't catch the whole sky unfortunately.
I took this photo of the left leg of a rainbow with multiple inner rainbow fragments. I thought it might be a reflection rainbow, but there are no significant bodies of water in the direction of the rainbow. Any ideas?
Lunar picture, I could see both halos without the camera, though the center is a little exaggerated compared to reality.