Different Kinds of Clouds

Different Kinds of Clouds

What is Cloud?

In meteorology, a cloud is an aerosol comprising a visible mass of minute liquid droplets, frozen crystals, or particles suspended in the atmosphere above the surface of a planetary body. The droplets and crystals may be made of water or various chemicals. On Earth, clouds are formed as a result of saturation of the air when it is cooled to its dew point, or when it gains sufficient moisture usually in the form of water vapor from an adjacent source to raise the dew point to the ambient temperature. They are seen in the Earth's homo sphere which includes the troposphere, stratosphere, and mesosphere. Nephology is the science of clouds which is undertaken in the cloud physics branch of meteorology.

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 5 kilometres (16,000 ft) to 12 kilometres (39,000 ft). Like lower altitude cumuliform and stratocumuliform clouds, cirrocumulus signifies convection. Unlike other high 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 of a virga consisting of ice or snow. Thus cirrocumulus clouds are usually short-lived. They usually only form as part of a short-lived transitional phase within an area of cirrus clouds and can also form briefly as a result of the breaking up of part of a cumulonimbus anvil.

Altocumulus Cloud

Altocumulusis 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 starting to fragment, resulting in patches of altocumulus perlucidus between the areas of altostratus. Altocumulus is also commonly found between the warm and cold fronts in a depression, although this is often hidden by lower clouds.

Towering altocumulus, known as altocumulus castellanus, frequently signals the development of thunderstorms later in the day, as it shows instability and convection in the middle levels of the troposphere( the lowest layer of the atmosphere), the area where towering cumulus clouds can turn into cumulonimbus. It is therefore one of three warning clouds often recorded by the aviation industry, the other two being towering cumulus and cumulonimbus. Altocumulus generally forms about 2,000 to 6,100 meters (6,600 to 20,000 ft) above ground level, a similar level to altostratus formations, and satellite photography has revealed that the two types of cloud can create formations that can stretch for thousands of square miles. Extensive altocumulus formations, particularly if they take the form of undulatus are often referred to as altocumulus mackerel sky.

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 altitude, usually below 2,400 meters (8,000 ft). Weak convective currents create shallow cloud layers because of drier, stable air above preventing continued vertical development.

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 altitudebetween 16,500 ft (5.0 km) and 45,000 ft (14 km) above sea level. The strands of cloud sometimes appear in tufts of a distinctive form referred to by the common name of "mares' tails".

On planet Earth, cirrus generally appears white or light grey in color. It forms when water vapor undergoes deposition at altitudes above 5,500 m (18,000 ft) in temperate regions and above 6,400 m (21,000 ft) in tropical regions. It also forms from the outflow of tropical cyclones or the anvils of cumulonimbus clouds. Since cirrus clouds arrive in advance of the frontal system or tropical cyclone, it indicates that weather conditions may soon deteriorate. While it indicates the arrival of precipitation (rain), cirrus clouds only produce fall streaks (falling ice crystals that evaporate before landing on the ground).

Altostratus Cloud

Altostratus is a middle altitude cloud genus belonging to the stratiform physical category characterized by a generally uniform gray to bluish-green and sheet or layer. It is lighter in color than nimbostratus and darker than high cirrostratus. The sun can be seen through thin altostratus, but thicker layers can be quite opaque.

Altostratus most often takes the form of a featureless sheet of cloud but can be wavy (undulatus) as a result of wind shear through the cloud. It can also be fragmented (fibratus) with clear sky visible, which often the approach of a weakened or upper level warm frontAltostratus is formed by the lifting of a large mostly stable air mass that causes invisible water vapor to condense into cloud. It can produce light precipitation, often in the form of virga. If the precipitation increases in persistence and intensity, the altostratus cloud may thicken into nimbostratus.

Stratus Cloud

Stratus clouds are low-level clouds characterized by horizontal layering with a uniform base, as opposed to convective or cumuliformclouds that are formed by rising thermals. More specifically, the term stratus is used to describe flat, hazy, featureless clouds of low altitude varying in color from dark gray to nearly white. The word "stratus" comes from the Latin prefix "strato-", meaning "layer". Stratus clouds may produce a light drizzle or a small amount of snow. These clouds are essentially above-ground fog formed either through the lifting of morning fog or through cold air moving at low altitudes over a region. Some call these clouds "high fog" for the fog-like cloud. While light rain may fall, this cloud does not indicate much meteorological activity.

Cumulus Cloud

Cumulus clouds are clouds which have flat bases and are often described as "puffy", "cotton-like" or "fluffy" in appearance. Their name derives from the Latin cumulo-, meaning heap or pile. Cumulus clouds are low-level clouds, generally less than 2,000 m (6,600 ft) in altitude unless they are the more vertical cumulus congestus form. Cumulus clouds may appear by themselves, in lines, or in clusters.

Cumulus clouds are often precursors of other types of clouds, such as cumulonimbus, when influenced by weather factors such as instability, moisture, and temperature gradient. Normally, cumulus clouds produce little or no precipitation, but they can grow into the precipitation-bearing congestus or cumulonimbus clouds. Cumulus clouds can be formed from water vapor, supercooled water droplets, or ice crystals, depending upon the ambient temperature. They come in many distinct subforms, and generally cool the earth by reflecting the incoming solar radiation. Cumulus clouds are part of the larger category of free-convective cumuliform clouds, which include cumulonimbus clouds. The latter genus-type is sometimes categorized separately as cumulonimbiform due to its more complex structure that often includes a cirriform or anvil top. There are also cumuliform clouds of limited convection that comprise stratocumulus (low-étage), altocumulus (middle-étage) and cirrocumulus (high-étage). These last three genus-types are sometimes classified separately as stratocumuliform.

Cumulonimbus Cloud

Cumulonimbus, from the Latin cumulus ("heaped") and nimbus ("rainstorm"), is a dense, towering vertical cloud, forming from water vapor carried by powerful upward air currents. If observed during a storm, these clouds may be referred to as thunderheads. Cumulonimbus can form alone, in clusters, or along cold front squall lines. These clouds are capable of producing lightning and other dangerous severe weather, such as tornadoes. Cumulonimbus progress from overdeveloped cumulus congestus clouds and may further develop as part of a supercell.

Nimbostratus Clouds

Nimbostratus is a stratiform genus formerly classified as "Family C” low-level, but now considered by the World Meteorological Organization (WMO) to be a middle- or multi-level stratus type.. Although it is usually a low-based cloud, it actually forms most commonly in the middle level of the troposphere and then spreads vertically into the low and high levels. This change in classification would once have made it a "Family D" cloud, but this style of letter-based family nomenclature was discontinued by the WMO in 1956. Nimbostratus usually produces precipitation over a wide area. Nimbo- is from the Latin word nimbus, which denotes precipitation. Downward-growing nimbostratus can have the same vertical extent as most large upward-growing cumulus, but its horizontal extent tends to be even greater. This sometimes leads to the exclusion of nimbostratus from the group of vertical clouds by some independent meteorologists and educators. Classifications that follow this approach usually show nimbostratus as low-level based on its normal base height range.