Clouds Types their Meanings, Formation and Characteristics
» Cloud a visible mass of condensed watery vapour floating in the atmosphere, typically high above the general level of the ground.
» Clouds are made up of tiny droplets or frozen crystals of water.
» As the clouds are formed at some height over the surface of the earth, they take various shapes.
» Clouds develop out of the process of changing moisture from a gas to liquid. This occurs through a process called convection. As solar radiation heats the ground and the air immediately above it, the warm air becomes lighter and the flow of air carries this warm air upward. As the air rises, the temperature decreases and so does the amount of water vapour that the air can hold. This vapour rapidly condenses and soon clouds
» Clouds usually appear white because the tiny water droplets inside them are tightly packed, reflecting most of the sunlight that hits them. White is how our eyes perceive all wavelengths of sunlight mixed together.
» When it’s about to rain, clouds darken because the water vapour is clumping together into raindrops, leaving larger spaces between drops of water. Less light is reflected.
» The rain cloud appears black or grey.
» Clouds are usually grouped into different types based on their altitude (how high they are in the sky) and their shape. There are ten cloud shapes that fall into four major altitude groups.
High: Cirrus, cirrocumulus, cirrostratus.
Middle: Altocumulus, altostratus.
Vertical: Cumulonimbus, cumulus, nimbostratus.
Low: Stratocumulus, small Cu, stratus.
» Following is the four main types of clouds found:
1. Cirrus
2. Cumulus
3. Stratus
4. Nimbus
Cirrus Clouds [High up/wispy]
» Cirrus clouds are ice clouds. They can look like delicate white feathers or streamers.
» They are always more than five kilometres up where the temperature is below freezing, even in summer.
» Cirrus clouds are formed at high altitudes (8,000 - 12,000m).
» Cirrus clouds are the highest of all clouds and are composed entirely of ice crystals. Wind currents twist and spread the ice crystals into wispy strands.
» Cirrus clouds are precipitating clouds, although the ice crystals evaporate high above the earth’s surface.
» They are thin and detached clouds having a feathery appearance. They are always white in colour.
» Contrails (Vapour trails) are made by high-flying jet airplanes. They are still clouds, though, because they are made of water droplets condensed from the water vapour in the exhaust of the jet engines.
Cumulus Clouds [heaped up/puffy, like cauliflower]
» Cumulus clouds are the fluffy, white cotton ball or cauliflower-looking clouds with sharp outlines.
» They are generally formed at a height of 4,000 -7,000 m.
» Cumulus clouds look like cotton wool.
» They are "fair weather clouds" and they are fun to watch as they grow and change in shape and size.
» They exist in patches and can be seen scattered here and there and have a flat base.
» Cumulus clouds are common over land on sunny days, when the sun heats the land creating thermal convection currents.
» Cumulus clouds make beautiful sunsets.
Stratus Clouds [flat/layered and smooth]
» Stratus clouds are formed when large air masses cool, also known as fog or mist.
» Stratus clouds are also the lowest forming clouds.
» As their name implies, these are layered clouds covering large portions of the sky.
» These clouds are generally formed either due to loss of heat or the mixing of air masses with different temperatures.
» Thees clouds are often dark and signal rain and lighting.
» When these clouds are very close to the ground they are called fog.
Nimbus Clouds [Rain-bearing cloud]
» Nimbus clouds often mean that a thunderstorm is brewing: there may soon be thunder and lightning.
» Nimbus clouds are black or dark grey.
» These clouds form at middle levels or very near to the surface of the earth.
» These are extremely dense and opaque to the rays of the sun.
» Nimbus clouds are shapeless masses of thick vapour.
Most of our names for clouds come from Latin and are usually a combination of the following prefixes and suffixes:
Stratus/strato
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Flat/Layered & Smooth
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Cumulus/cumulo
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Heaped Up/Puffy, Like Cauliflower
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Cirrus/cirro
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High Up/Wispy
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Alto
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Medium Level
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Nimbus/Nimbo
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Rain-Bearing Cloud
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By combining two names different types of clouds are formed which are having the characteristics of both of its parts. For example, Nimbostratus is consists of Nimbus+ Stratus Which mean a flat layered rain bearing cloud.
A combination of these four basic types can give rise to the following types of clouds:
High clouds
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Cirrus, Cirrostratus, Cirrocumulus
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Middle clouds
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Altostratus & Altocumulus
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Low clouds
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Stratocumulus & Nimbostratus
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» Clouds with extensive vertical development – cumulus and cumulonimbus
Frequently asked questions about cloud types and formation:
What are the five major types of clouds?
Visit the Cloud Gallery to see photos of the different cloud types.
The highest clouds in the atmosphere are cirrocumulus, cirrus, and cirrostratus. ...
Mid-level clouds include altocumulus and altostratus.
The lowest clouds in the atmosphere are stratus, cumulus, and stratocumulus.
Where do the clouds come from?
When warm air rises due to the sun, it expands and cools. Cool air cannot hold much water vapour, so some of the vapour is compacted to form a small droplet of dust in the air. It takes several billion of these droplets to come together and create a visible cloud.
What kind of weather comes with cumulus clouds?
Cumulus humilis clouds usually indicate fair weather. Cumulus mediocris cloudsare similar, except that they have some vertical development, which implies that they can grow into cumulus congestus or even cumulonimbus clouds, which can produce heavy rain, lightning, severe winds, hail, and even tornadoes.
What kind of weather is found in stratus clouds?
Stratus clouds are low clouds that produce a hazy, grey veil with a uniform base throughout the sky. They do not usually produce precipitation, though drizzle or snow grains are possible with stratus clouds. One particular stratus cloud that affects transportation is fog.
How does a cumulus cloud form?
The word "cumulus" is Latin for the word "heap.".When warm, moist air rises, water vapour eventually cools and condenses on particles (called condensation nuclei) into tiny water droplets. As the process continues, water droplets continue to accumulate upwards, creating heaps visible in the sky as white, fluffy clouds.
What are stratocumulus clouds made up of?
Stratocumulus clouds belong to the Low Cloud (surface-2000m) group. These clouds are low, lumpy, and grey. These clouds can look like cells under a microscope - sometimes they line up in rows and other times they spread out. Only light precipitation, generally in the form of drizzle, occurs with stratocumulus clouds.
How does a nimbostratus cloud form?
Formation. Nimbostratus occurs along a warm front or occluded front where the slowly rising warm air mass creates nimbostratus along with shallower stratus clouds producing less rain, these clouds being preceded by higher-level clouds such as cirrostratus and altostratus.
What is a nimbus cloud look like?
Nimbus really just means a cloud that already has rain or snow falling out of it. ... So you often see the names of clouds combined: a cumulonimbus cloud is a cumulus cloud, a puffy thick cloud, with rain falling out of it, and a strato- nimbus cloud is a stratus cloud, a grey blanket cloud, with rain falling out of it.
