Atmospheric optical phenomena

thumb|upright=1.35|Double rainbow and supernumerary rainbows on the inside of the primary arc. The shadow of the photographer's head at the bottom of the photograph marks the centre of the rainbow circle (the antisolar point).

An aurora ( aurorae or auroras) is a natural light display in Earth’s upper atmosphere caused by charged particles from the Sun colliding with atoms in the atmosphere. These collisions excite oxygen and nitrogen, which then emit light of different colors such as green, red, and purple. When observed in high-latitude regions they are called polar lights and aurora polaris. In the Arctic they are called northern lights (aurora borealis); in the Antarctic, the terms southern lights (aurora australis) are used. Auroras display dynamic patterns of radiant light that appear as curtains, rays, spiral

unusual apparent anomaly in the sky that is not readily identifiable

thumb|upright=1.5|Various kinds of mirages in one location taken over the course of six minutes, not shown in chronological order. A mirage is a naturally occurring optical phenomenon in which light rays bend via refraction to produce a displaced image of distant objects or the sky. The word comes to English via the French (se) mirer, from the Latin mirari, meaning "to look at, to wonder at".

optical phenomenon

elastic scattering of light, or other electromagnetic radiation, by particles of size much smaller than the wavelength of the radiation

atmospheric optical phenomenon

highly-elevated cloud-like ice crystals in the upper atmosphere of Earth visible during astronomical twilight

thumb|upright=1.2|World map showing the areas of Earth receiving daylight around 1:00 pm UTC in April

thumb|Harmattan Haze in [[Abuja]] thumb|right|Haze over the Mojave Desert from a [[brush fire in Santa Barbara, California, seen as the Sun descends on the 2016 June solstice, allows the Sun to be photographed without a filter.]] thumb|Haze as smoke pollution over the Mojave from fires in the Inland Empire, June 2016, demonstrates the loss of contrast to the [[Sun, and the landscape in general.]]

meteorological optical phenomena

period of twilight in the morning or evening

optical phenomenon

first and last hour of sunlight during the day

atmospheric optical phenomenon in the form of a vertical band of light which appears to extend above and/or below a light source

optical phenomenon that resembles an iconic saint's halo about the shadow of the observer's head

A moonbow (also known as a moon rainbow or lunar rainbow) is a rainbow produced by moonlight rather than direct sunlight. Other than the difference in the light source, its formation is the same as for a solar rainbow: It is caused by the refraction of light in many water droplets, such as a rain shower or a waterfall, and is always positioned in the opposite part of the sky from the Moon relative to the observer. thumbnail|Lunar rainbow over Kihei, Hawaii|Kihei, [[Maui, Hawaii, US]] Moonbows are much fainter than solar rainbows, due to the smaller amount of light reflected from the surface of

thumb|Airglow over Auvergne, France thumb|Yellow, green and red bands of airglow along Earth's limb as seen from space.

type of rainbow formed by airborne water droplets

rays of sunlight that appear to radiate from the point in the sky where the sun is located

pinkish glow seen before sunrise or after sunset extending roughly 10–20° above the horizon

deviation of light or other electromagnetic wave from a straight line as it passes through the atmosphere

thumb|Afterglow with its bright segment and purple light above, interrupted by crepuscular rays

ground-level cloud of ice crystals

thumb|The twinkling of the brightest star in the [[night sky Sirius (apparent magnitude of −1.1), shortly before upper culmination at the meridian, at 20° above the southern horizon. In 29 seconds, Sirius appears to move 7.5 arcminutes from left to right.]] thumb|Comparison of twinkling of a star (top) and a planet (bottom). The turbulent atmosphere (shaded blue) distorts their wavefronts (cyan lines) differently with time, like caustics on a swimming pool floor. When a dark part hits the observer (white circle), the object appears dark, and vice versa. An object with larger angular size smear

magnified shadow of an observer cast upon clouds opposite the Sun's direction

term in meteorology and astronomy

optical phenomenon visible around sun and moon in the earth athmosphere

optical phenomenon

academic discipline

solid frozen water molecules

thumb|top: reflected alpenglow; bottom: direct sunrise alpenglow from Table Mountain to Mount Baker, WA, USA.

shadow that the Earth casts on its own atmosphere

bright spot on a lunar halo

optical phenomenon arising from refraction of sunlight through ice crystals

Solar radiation scattered and absorbed in Earth's atmosphere

optical phenomenon that belongs to the family of ice halos

uncomprehended phenomenon observed over Nuremberg in 1561

polar mirage caused by high refraction of sunlight between atmospheric thermal layers

atmospheric optical phenomenon

Optical phenomenon

halo appearing as a horizontal white line on the same altitude as the Sun or the Moon

method of communicating with microwave radio signals over considerable distances

thumb|right|A cyanometer by Horace-Bénédict de Saussure (from the collection of ''Musée d'histoire des sciences de la Ville de Genève) thumb|right|An artwork in Ljubljana, Slovenia, inspired by a cyanometer A cyanometer (from cyan and -meter'') is an instrument for measuring "blueness", specifically the colour intensity of blue sky. It is attributed to Horace-Bénédict de Saussure and Alexander von Humboldt. It consists of squares of paper dyed in graduated shades of blue and arranged in a color circle or square that can be held up and compared to the color of the sky.

250px|right|thumb|Heiligenschein, or hotspot, around the shadow of a hot-air balloon cast on a field of standing crops ([[Oxfordshire, England)]]

thumb|A STEVE over Little Bow Resort, [[Alberta, in August 2015]] thumb|A STEVE over Crossfield, Alberta, in March 2018 (around 12:30 a.m.)

halo in the form of an oval ring that circumscribes the circular 22° halo centred on the sun or moon

optical phenomenon of unlit sky between rainbows

200px|right|thumb|Anthelion (bottom) and 120° parhelion (top) depicted in [[Vädersolstavlan ]] An anthelion (plural anthelia, from late Greek ανθηλιος, "opposite the sun") is a rare optical phenomenon of the halo family. It appears on the parhelic circle opposite to the Sun as a faint white spot, not unlike a sundog, and may be crossed by an X-shaped pair of diffuse arcs.

rare member of the family of ice crystal halos

thumb | right | alt=Circumzenithal arc, supralateral arc, Parry arc, tangential arc, 22 degree halo, parhelic circle, and sun dogs on right and left intersection of 22 degree halo and parhelic circle. | Various arcs, halos and sun dogsIn atmospheric optics, a photometeor is a bright object or other optical phenomenon appearing in the Earth's atmosphere when sunlight or moonlight creates a reflection, refraction, diffraction or interference under particular circumstances. The most common examples include halos, rainbows, fogbows, cloud iridescences (or irisation), glories, Bishop's rings, coron

optical path length through Earth’s atmosphere for light from a celestial source

optical phenomenon

uncomprehended phenomenon observed over Basel in 1566

thumb|Ice Islands with ice blink, watercolour by Georg Forster, made 1773 during the [[second voyage of James Cook|alt=Painting of a ship with sails traversing a rough sea with icerbergs. A white glow, the iceblink, fills the sky.]]

thumb |250px|A subsun seen from an airplane

thumb|Large ash cloud from the Mount Redoubt volcano. thumb|Lithometeor at sunset in [[Berlin on February 25, 2021, cloudless sky with Saharan dust.]]

rocket launch phenomenon

photometeor / cumulonimbus : weather phenomenon consisting of strobes of light which appear to be "dancing"