Cirrus cloud

cirruscirrus cloudsCirriformcirriform cloudcirrus cloud regulationcirrus outflowcirrus tuftscirrus-cloudMares' tails
Cirrus (cloud classification symbol: Ci) is a genus of atmospheric cloud generally characterized by thin, wispy strands, giving the type its name from the Latin word cirrus, meaning a ringlet or curling lock of hair.wikipedia
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List of cloud types

cloud typescloud typetranslucidus
Cirrus (cloud classification symbol: Ci) is a genus of atmospheric cloud generally characterized by thin, wispy strands, giving the type its name from the Latin word cirrus, meaning a ringlet or curling lock of hair.

Cloud

cloudscloud formationcloudy
Cirrus (cloud classification symbol: Ci) is a genus of atmospheric cloud generally characterized by thin, wispy strands, giving the type its name from the Latin word cirrus, meaning a ringlet or curling lock of hair.
Cirriform clouds in the troposphere are of the genus cirrus and have the appearance of detached or semimerged filaments.

Halo (optical phenomenon)

halohalosaura
When visible light interacts with the ice crystals in cirrus cloud, it produces optical phenomena such as sun dogs and halos. Common halo varieties are the 22° halo, sun dogs, the circumzenithal arc and the circumhorizontal arc (also known as fire rainbows).
The ice crystals responsible for halos are typically suspended in cirrus or cirrostratus clouds in the upper troposphere, but in cold weather they can also float near the ground, in which case they are referred to as diamond dust.

Cirrocumulus cloud

cirrocumulusCc
Convection at high altitudes can produce another high-based genus called cirrocumulus, a pattern of small cloud tufts that contain droplets of supercooled water.
Cirrocumulus is one of the three main genus-types of high-altitude tropospheric clouds, the other two being cirrus and cirrostratus.

Contrail

contrailscondensation trailsVapor trail
The ice crystals in contrails are much smaller than those in naturally occurring cirrus cloud, as they are around 0.001 millimeters to 0.1 millimeters in length.
Depending on the temperature and humidity at the altitude the contrails form, they may be visible for only a few seconds or minutes, or may persist for hours and spread to be several miles wide, eventually resembling natural cirrus or altocumulus clouds.

Mars

MartianCoordinatesplanet Mars
Cirrus clouds form on other planets, including Mars, Jupiter, Saturn, Uranus, and possibly Neptune.
These seasonal actions transport large amounts of dust and water vapor, giving rise to Earth-like frost and large cirrus clouds.

Ice crystals

ice crystalicecrystalline
Cirrus clouds range in thickness from 100 m to 8000 m, with an average thickness of 1500 m. There are, on average, 30 ice crystals per liter (96 ice crystals per gallon), but this ranges from one ice crystal per 10,000 liters (3.7 ice crystals per 10,000 gallons) to 10,000 ice crystals per liter (37,000 ice crystals per gallon), a difference of eight orders of magnitude.
Ice clouds are composed of ice crystals, the most notable being cirrus clouds and ice fog.

Tropical cyclone

hurricanetropical stormhurricanes
It also forms from the outflow of tropical cyclones or the anvils of cumulonimbus clouds.
Once aloft, air flows away from the storm's center, producing a shield of cirrus clouds.

Cirrus castellanus cloud

cirrus castellanus
If the cloud is a cirrus castellanus, there might be instability at the high altitude level.
Cirrus castellanus is a species of cirrus cloud.

Noctilucent cloud

noctilucent cloudsnoctilucentmesospheric cloud
Some polar stratospheric clouds can resemble cirrus, while noctilucent clouds are typically structured in a way that is similar to cirrus.
Noctilucent clouds may be confused with cirrus clouds, but appear sharper under magnification.

Warm front

warm sectorwarmGulf moisture
These conditions commonly occur at the leading edge of a warm front.
The first clouds that indicate an approaching warm front tend to be mostly high cirrus at first, changing to cirrostratus as the front approaches.

Environmental impact of aviation

Aviation and the environmentAviationAviation and climate change
One of the environmental impacts of aviation is that persistent contrails can form into large mats of cirrus, and increased air traffic has been implicated as one possible cause of the increasing frequency and amount of cirrus in Earth's atmosphere.
Cirrus clouds have been observed to develop after the persistent formation of contrails and have been found to have a global warming effect over-and-above that of contrail formation alone.

Sun dog

sun dogssundogparhelia
When visible light interacts with the ice crystals in cirrus cloud, it produces optical phenomena such as sun dogs and halos. Common halo varieties are the 22° halo, sun dogs, the circumzenithal arc and the circumhorizontal arc (also known as fire rainbows).
Sun dogs are commonly caused by the refraction and scattering of light from plate-shaped hexagonal ice crystals either suspended in high and cold cirrus or cirrostratus clouds, or drifting in freezing moist air at low levels as diamond dust.

Cold front

cold frontsArctic blastcold
When cirrus clouds precede a cold front, squall line or multicellular thunderstorm, it is because they are blown off the anvil, and the next to arrive are the cumulonimbus clouds.
Anvil cirrus clouds may spread a considerable distance downwind from the thunderstorms.

Circumhorizontal arc

Circumhorizon arccircumhorizontalcircumhorizontal arcs
Common halo varieties are the 22° halo, sun dogs, the circumzenithal arc and the circumhorizontal arc (also known as fire rainbows).
A circumhorizontal arc is an optical phenomenon that belongs to the family of ice halos formed by the refraction of sun- or moonlight in plate-shaped ice crystals suspended in the atmosphere, typically in cirrus or cirrostratus clouds.

Iris hypothesis

A similar hypothesis put forth by Richard Lindzen is the iris hypothesis in which an increase in tropical sea surface temperatures results in less cirrus clouds and thus more infrared radiation emitted to space.
The iris hypothesis is a hypothesis proposed by Richard Lindzen et al. in 2001 that suggested increased sea surface temperature in the tropics would result in reduced cirrus clouds and thus more infrared radiation leakage from Earth's atmosphere.

Circumzenithal arc

around the zenithcircumzenithal
Common halo varieties are the 22° halo, sun dogs, the circumzenithal arc and the circumhorizontal arc (also known as fire rainbows).
The circumzenithal arc, also called the circumzenith arc (CZA), upside-down rainbow, and the Bravais arc, is an optical phenomenon similar in appearance to a rainbow, but belonging to the family of halos arising from refraction of sunlight through ice crystals, generally in cirrus or cirrostratus clouds, rather than from raindrops.

Outflow (meteorology)

outflowinflowoutflow channel
A large shield of cirrus and cirrostratus typically accompanies the high altitude outflow of hurricanes or typhoons, and these can make the underlying rain bands—and sometimes even the eye—difficult to detect in satellite photographs.
This outflow produces high, thin cirrus clouds that spiral away from the center.

Infrared

IRnear-infraredinfra-red
These satellites measure where infrared radiation is absorbed in the atmosphere, and if it is absorbed at cirrus altitudes, then it is assumed that there are cirrus clouds in that location.
High, cold ice clouds such as Cirrus or Cumulonimbus show up bright white, lower warmer clouds such as Stratus or Stratocumulus show up as grey with intermediate clouds shaded accordingly.

Cirrus cloud thinning

Cirrus clouds are high cold ice that, like other clouds, both reflect sunlight and absorb warming infrared radiation.

Richard Lindzen

Richard S. Lindzen
A similar hypothesis put forth by Richard Lindzen is the iris hypothesis in which an increase in tropical sea surface temperatures results in less cirrus clouds and thus more infrared radiation emitted to space.
A sea surface temperature increase in the tropics would result in reduced cirrus clouds and thus more infrared radiation leakage from Earth's atmosphere.

22° halo

Moon ring22°halo
Common halo varieties are the 22° halo, sun dogs, the circumzenithal arc and the circumhorizontal arc (also known as fire rainbows).
Like other ice halos, 22° halos appear when the sky is covered by thin cirrus or cirrostratus clouds that often come a few days before a large storm front.

Cumulus cloud

cumulusCloudcumulus clouds
They comprise the genera cumulus, and cumulonimbus, which along with nimbostratus, are often classified separately as clouds of vertical development, especially when their tops are high enough to be composed of super-cooled water droplets or ice crystals.
However, at the same time, they heat the earth by around 7 C-change by reflecting emitted radiation, an effect largely caused by cirrus clouds.

Great Dark Spot

holes in the atmosphereanticyclone storm systemNeptune
On Neptune, thin wispy clouds which could possibly be cirrus have been detected over the Great Dark Spot.
The Great Dark Spot generated large white clouds at or just below the tropopause layer similar to high-altitude cirrus clouds found on Earth.

Latin

Latin languageLat.la
Cirrus (cloud classification symbol: Ci) is a genus of atmospheric cloud generally characterized by thin, wispy strands, giving the type its name from the Latin word cirrus, meaning a ringlet or curling lock of hair.