Which genus of cloud is denoted by the letters 'Ns'?
"size again. During the sampling of one cloud, the scientists noted a halo while flying near the top of the cloud, which indicated that the ice crystals were hexagonal near the top. However, farther down, the ice crystals became more conglomerated. Altostratus tends to form ahead of a warm or occluded front, the altostratus gradually thickening into rain bearing nimbostratus. However it can also occur together with cumulus congestus or cumulonimbus at a cold front. ""Velum"" This is considered a type of cumulonimbus cloud so it is not listed. Altostratus cloud Altostratus is a middle altitude cloud genus belonging to"
"though not all high clouds are of the cirrus form or genus). Non-vertical clouds in the middle level are prefixed by ""alto-"", yielding the genus names ""altocumulus"" (Ac) for stratocumuliform types and ""altostratus"" (As) for stratiform types. These clouds can form as low as above surface at any latitude, but may be based as high as near the poles, at mid latitudes, and in the tropics. As with high clouds, the main genus types are easily identified by the human eye, but it is not possible to distinguish between them using satellite photography. Without the support of human observations, these"
"according to WMO classification, nimbostratus. These clouds are formed from ice crystals, supercooled water droplets, or liquid water droplets. Low-étage clouds form at less than . The two genera that are strictly low-étage are stratus, and stratocumulus. These clouds are composed of water droplets, except during winter when they are formed of supercooled waterdroplets or ice crystals if the temperature at cloud level is below freezing. Two additional genera usually form in the low altitude range, but may be based at higher levels under conditions of very low humidity. They comprise the genera cumulus, and cumulonimbus, which along with nimbostratus,"
"main genera in the family of high clouds: cirrus, cirrocumulus, and cirrostratus. Cirrostratus clouds commonly produce halos because they are composed almost entirely of ice crystals. Cirrocumulus and cirrostratus are sometimes informally referred to as ""cirriform clouds"" because of their frequent association with cirrus. They are given the prefix ""cirro-"", but this refers more to their altitude range than their physical structure. Cirrocumulus in its pure form is actually a high cumuliform genus, and cirrostratus is stratiform, like altostratus and lower based sheet clouds. Cirrocumulus clouds form in sheets or patches and do not cast shadows. They commonly appear in"
"the clouds include cirrus castellanus, cirrocumulus castellanus, altocumulus castellanus and stratocumulus castellanus. Sometimes cumulus castellanus are referred to, but the type is not recognised by the France's national meteorological service Météo-France, or by the American Meteorological Society and World Meteorological Organisation. Those clouds some would classify as cumulus castellanus typically do not have a common base and are not arranged in a line, thus differing to some extent from the more universally-recognised castellanus types. Some scientists also think that the ""castellanus"" should be a full cloud genus, and not just a cloud species. The Federal Aviation Administration ""implicitly"" considers a"
"Cirrus cloud 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. This cloud can form at any altitude between and above sea level. The strands of cloud sometimes appear in tufts of a distinctive form referred to by the common name of ""mares' tails"". From the surface of Earth, cirrus typically appears white, or a light grey in color. It forms when water vapor undergoes deposition at altitudes above in temperate regions and above"
"tropics. Cumulus congestus clouds are formed by the development of cumulus mediocris generally, though they can also be formed from altocumulus castellanus or stratocumulus castellanus as well. The ""congestus"" species of cloud can only be found in the genus ""cumulus"" and is designated as ""towering cumulus"" (Tcu) by the International Civil Aviation Organization. Congestus clouds are capable of producing severe turbulence and showers of moderate to heavy intensity. This species is classified as vertical or multi-étage and is coded C2 in the synop report. These clouds are usually too large and opaque to have any opacity or pattern-based varieties. Pyrocumulus"
"is called ""Cumulus homogenitus"" and abbreviated as CUa. If a ""homogenitus"" cloud of one genus changes to another genus type, it is termed a ""homomutatus"" cloud. The international cloud classification divide the different ""genera"" in three main groups of clouds according to their altitude: Homogenitus clouds will be generated by different sources at those different levels. Despite the fact that the three genera of high clouds, ""Cirrus"", ""Cirrocumulus"" and ""Cirrostratus"", form at the top of the troposphere, far from the earth surface, they may have an anthropogenic origin. In this case, the process that causes their formation is almost always"
"Castellanus A castellanus (or castellatus) (from latin ""castellanus"", castle) is a cloud that displays at least in its upper part cumuliform protuberances having the shape of turrets that give a crenellated aspect. Some of these turrets are higher than they are wide; they have a common base and seem to be arranged in a line. The castellanus characteristic is particularly obvious when the clouds are observed from the side (i.e., from a vantage point on a line perpendicular to the line of orientation). It is a cloud species attached to the cloud genera cirrus, cirrocumulus, altocumulus and stratocumulus. Species of"
"variety. This is the ""stratus undulatus"" variety. Mild undulations can be observed from this cloud, only associated by the nebulosus species. Though rare, this cloud formation is caused by disturbances on the gentle wind shear. Stratus undulatus clouds are more common on stratus stratocumulomutatus clouds where the wind is stronger as height increases. Stratus cumulogenitus clouds occur when the base of cumulus clouds spreads, creating a nebulous sheet of stratiform clouds. This can also occur on nimbostratus clouds (stratus nimbostratogenitus) and on cumulonimbus clouds (stratus cumulonimbogenitus). Stratus fractus clouds can also form under the base of precipitation-bearing clouds and are"
"and lesser types. High-level clouds form at altitudes of 5 to 12 kilometers. All cirriform clouds are classified as high-level and therefore constitute a single cloud genus cirrus. Stratiform and stratocumuliform clouds in the high level of the troposphere have the prefix ""cirro-"" added to their names yielding the genera cirrostratus and cirrocumulus. Similar clouds found in the middle level (altitude range 2 to 7 kilometers) carry the prefix ""alto-"" resulting in the genus names altostratus and altocumulus. Low level clouds have no height-related prefixes, so stratiform and stratocumuliform clouds based around 2 kilometres or lower are known simply as"
"cloud ""forms"" were established based on appearance and characteristics of formation: ""cirriform,"" ""cumiliform"" and ""stratiform."" These were further divided into upper and lower types depending on altitude. In addition to these three main types, Howard added two names to designate multiple cloud types joined together: ""cumulostratus,"" a blending of cumulus clouds and stratus layers, and ""nimbus,"" a complex blending of cirriform, cumuliform, and stratiform clouds with sufficient vertical development to produce significant precipitation. Later, in the 20th Century, an IMC commission for the study of clouds put forward a refined and more restricted definition of the genus nimbus, effectively reclassifying"
"of instability or convective activity. High clouds form at altitudes of in the polar regions, in the temperate regions and in the tropics. All cirriform clouds are classified as high and thus constitute a single genus ""cirrus"" (Ci). Stratocumuliform and stratiform clouds in the high altitude range carry the prefix ""cirro-"", yielding the respective genus names ""cirrocumulus"" (Cc) and ""cirrostratus"" (Cs). When limited-resolution satellite images of high clouds are analysed without supporting data from direct human observations, it becomes impossible to distinguish between individual forms or genus types, which are then collectively identified as ""high-type"" (or informally as ""cirrus-type"" even"
"Cirrocumulus cloud Cirrocumulus is one of the three main genus-types of high-altitude tropospheric clouds, the other two being cirrus and cirrostratus. They usually occur at an altitude of to . Like lower altitude cumuliform and stratocumuliform clouds, cirrocumulus signifies convection. Unlike other high-altitude-tropospheric clouds like cirrus and cirrostratus, cirrocumulus includes a small amount of liquid water droplets, although these are in a supercooled state. Ice crystals are the predominant component, and typically, the ice crystals cause the supercooled water drops in the cloud to rapidly freeze, transforming the cirrocumulus into cirrostratus. This process can also produce precipitation in the form"
"at surface level, and the two additional major types above the troposphere. The cumulus genus includes three species that indicate vertical size. Clouds with sufficient vertical extent to occupy more than one altitude level are officially classified as ""low-"" or ""mid-level"" according to the altitude range at which each initially forms. However they are also more informally classified as ""multi-level"" or ""vertical"". The origin of the term ""cloud"" can be found in the old English ""clud"" or ""clod"", meaning a hill or a mass of rock. Around the beginning of the 13th century, the word came to be used as"
"of this species are associated with precipitating cloud systems of considerable vertical and sometimes horizontal extent, they are also classified as ""accessory clouds"" under the name ""pannus"" (see section on supplementary features). These species are subdivisions of genus types that can occur in partly unstable air. The species ""castellanus"" appears when a mostly stable stratocumuliform or cirriform layer becomes disturbed by localized areas of airmass instability, usually in the morning or afternoon. This results in the formation of cumuliform buildups arising from a common stratiform base. Castellanus resembles the turrets of a castle when viewed from the side, and can"
"varying densities and temperatures. The cloud is divided into three main cores, designated north (N), middle or main (M) and south (S) respectively. Thus Sgr B2(N) represents the north core. The sites Sgr B2(M) and Sgr B2(N) are sites of prolific star formation. The first 10 H II regions discovered were designated A through J. H II regions A-G, I and J lie within Sgr B2(M), while region K is in Sgr B2(N) and region H is in Sgr B2(S). The 5-parsec-wide core of the cloud is a star-forming region that is emitting about 10 million times the luminosity of"
"Altocumulus cloud Altocumulus (From Latin ""Altus"", ""high"", ""cumulus"", ""heaped"") is a middle-altitude cloud genus that belongs mainly to the ""stratocumuliform"" physical category characterized by globular masses or rolls in layers or patches, the individual elements being larger and darker than those of cirrocumulus and smaller than those of stratocumulus. However, if the layers become tufted in appearance due to increased airmass instability, then the altocumulus clouds become more purely ""cumuliform"" in structure. Like other cumuliform and stratocumuliform clouds, altocumulus signifies convection. A sheet of partially conjoined altocumulus perlucidus is sometimes found preceding a weakening warm front, where the altostratus is"
"""upward-growing"" cumulus mediocris produces only isolated light showers, while ""downward growing"" nimbostratus is capable of heavier, more extensive precipitation. Towering vertical clouds have the greatest ability to produce intense precipitation events, but these tend to be localized unless organized along fast-moving cold fronts. Showers of moderate to heavy intensity can fall from cumulus congestus clouds. Cumulonimbus, the largest of all cloud genera, has the capacity to produce very heavy showers. Low stratus clouds usually produce only light precipitation, but this always occurs as the feature praecipitatio due to the fact this cloud genus lies too close to the ground to"
"They range from a few light years to dozens of light years across. While they are not technically cirrus clouds, the dust clouds are referred to as ""cirrus"" because of their similarity to the clouds on Earth. They also emit infrared radiation, similar to the way cirrus clouds on Earth reflect heat being radiated out into space. Footnotes Bibliography Cirrus cloud 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. This cloud can form"
"Nu Sagittarii The Bayer designation Nu Sagittarii (Nu Sgr, ν Sagittarii, ν Sgr) is shared by two star systems, ν Sagittarii and ν Sagittarii, in the zodiac constellation Sagittarius. The two stars are separated by 0.23° in the sky. Nu Sagittarii has the traditional name Ain al Rami, which is from the Arabic عين الرامي ""ain ar-rāmī"" meaning ""eye of the archer"". Both of the ν stars, together with τ Sgr, ψ Sgr, ω Sgr, 60 Sgr and ζ Sgr were ""Al Udḥiyy"", the Ostrich's Nest. Nu Sagittarii is often cited as one of the earliest identified double stars. In"
"N11 (emission nebula) N11 (also known as LMC N11, LHA 120-N 11) is the brightest emission nebula in the north-west part of the Large Magellanic Cloud in the Dorado constellation. The N11 complex is the second largest H II region of the Large Magellanic Cloud after the Tarantula Nebula. It covers an area of approximately 6 arc minutes across. It has an elliptical shape and consists of a large bubble surrounded by nine large nebulae. It was named by Karl Henize in 1956. When close-up, the nebula has pink clouds of glowing gas which resembles candy floss. It has been"
"Stratocumulus cloud A stratocumulus cloud belongs to a genus-type of clouds characterized by large dark, rounded masses, usually in groups, lines, or waves, the individual elements being larger than those in altocumulus, and the whole being at a lower height, usually below . Weak convective currents create shallow cloud layers because of drier, stable air above preventing continued vertical development. Vast areas of subtropical and polar oceans are covered with massive sheets of stratocumulus. These may organize into distinctive patterns which are currently under active study. In subtropics, they cover the edges of the horse latitude climatological highs, and reduce"
"and typically appears as white, patchy sheets with ripples or tufts without gray shading. Each cloudlet appears no larger than a finger held at arm's length. These often are organized in rows like other cumuliform and stratocumuliform clouds, but since they are so small, cirrocumulus patches take on a finer appearance, sometimes also referred to colloquially as ""herringbone"" or as a ""mackerel sky"". Cirrocumulus is coded C9 for the main genus-type and all subforms. Cirrocumulus is distinguished from altocumulus in several ways, although the two stratocumuliform genus types can occasionally occur together with no clear demarcation between them. Cirrocumulus generally"
"newly formed cloud is determined mainly by air mass characteristics such as stability and moisture content. If these characteristics change over time, the genus tends to change accordingly. When this happens, the original genus is called a ""mother cloud"". If the mother cloud retains much of its original form after the appearance of the new genus, it is termed a ""genitus"" cloud. One example of this is ""stratocumulus cumulogenitus"", a stratocumulus cloud formed by the partial spreading of a cumulus type when there is a loss of convective lift. If the mother cloud undergoes a complete change in genus, it"
"which causes the cloud to expand, is counteracted by gravity, which causes the cloud to collapse. It is named after the British astronomer Sir James Jeans, who concerned himself with the stability of spherical nebulae in the early 1900s. The formula for Jeans length is: where formula_33 is Boltzmann's constant, formula_34 is the temperature of the cloud, formula_35 is the mass per particle in the cloud, formula_6 is the gravitational constant and formula_14 is the cloud's mass density (i.e. the cloud's mass divided by the cloud's volume). Perhaps the easiest way to conceptualize Jeans' length is in terms of a"
"it as a stratiform cloud type. It was then renamed ""nimbostratus,"" and published with the new name in the 1932 edition of the ""International Atlas of Clouds and of States of the Sky"". This left cumulonimbus as the only nimbiform type as indicated by its root-name. Multi-level nimbostratus is physically related to other stratiform genus-types by way of being non-convective in nature. However, the other sheet-like clouds usually each occupy only one or two levels at the same time. Stratus clouds are low-level and form from near ground level to at all latitudes. In the middle level are the altostratus"
"then dissipates into cirrus. Cirrocumulus clouds come in four species which are common to all three genus-types that have limited-convective or stratocumuliform characteristics: ""stratiformis"", ""lenticularis"", ""castellanus"", and ""floccus"". They are iridescent when the constituent supercooled water droplets are all about the same size. Altocumulus clouds are a mid-level cloud that forms from high to in polar areas, in temperate areas, and in tropical areas. They can have precipitation and are commonly composed of a mixture of ice crystals, supercooled water droplets, and water droplets in temperate latitudes. However, the liquid water concentration was almost always significantly greater than the concentration"
"filaments that may be straight, wavy, or occasionally twisted by non-convective wind shear. The species ""uncinus"" is similar but has upturned hooks at the ends. Cirrus ""spissatus"" appear as opaque patches that can show light grey shading. Stratocumuliform genus-types (cirrocumulus, altocumulus, and stratocumulus) that appear in mostly stable air have two species each. The ""stratiformis"" species normally occur in extensive sheets or in smaller patches where there is only minimal convective activity. Clouds of the ""lenticularis"" species tend to have lens-like shapes tapered at the ends. They are most commonly seen as orographic mountain-wave clouds, but can occur anywhere in"
"cloud forest. Given its sedentary habits, the phylogeny seems to be a result of a combination of habitat expanding and constricting due to Pliocene climate changes and, less frequently, accidental dispersal (such as to the Sierra de los Tuxtlas and, earlier, to Mesoamerica in general). The five northern clades are: ""Chlorospingus ophthalmicus regionalis"" is found in Costa Rica. Its relationship to the ""postocularis"" group and the Panamanian ""C. o. novicius"" warrants thorough study, as these three taxa appear to be rather intermediate between the main northern and the South American groups, with whitish ears but a fairly brownish crown. Meanwhile,"
"this may also be seen in conjunction with showers and thunderstorms). If it is seen after rain it usually means improving weather. Cirrocumulus cloud Cirrocumulus is one of the three main genus-types of high-altitude tropospheric clouds, the other two being cirrus and cirrostratus. They usually occur at an altitude of to . Like lower altitude cumuliform and stratocumuliform clouds, cirrocumulus signifies convection. Unlike other high-altitude-tropospheric clouds like cirrus and cirrostratus, cirrocumulus includes a small amount of liquid water droplets, although these are in a supercooled state. Ice crystals are the predominant component, and typically, the ice crystals cause the supercooled"
"be common to more than one genus or species. Of the stratiform group, high-level cirrostratus comprises two species. Cirrostratus ""nebulosus"" has a rather diffuse appearance lacking in structural detail. Cirrostratus ""fibratus"" is a species made of semi-merged filaments that are transitional to or from cirrus. Mid-level altostratus and multi-level nimbostratus always have a flat or diffuse appearance and are therefore not subdivided into species. Low stratus is of the species nebulosus except when broken up into ragged sheets of stratus fractus (see below). Cirriform clouds have three non-convective species that can form in mostly ""stable"" airmass conditions. Cirrus fibratus comprise"
"location of the jet stream. Cirrus vertebratus Cirrus vertebratus is a type of cirrus cloud. The name ""cirrus vertebratus"" is derived from Latin, meaning ""jointed, articulated, vertebrated"". Like cirrus intortus, the vertebratus species is exclusive to the cirrus genus. Cirrus vertebratus gives the impression of vertebrae in a spinal column, ribs, or a fish skeleton. The species is an unusual form of cirrus clouds and is formed by air moving parallel to the main cloud line. The gaps in the cloud occur where air is descending, while the ""ribs"" of the cloud correspond with areas of uplift. Their occurrence appears"