Why do cumulus clouds form thunderstorms? Why are clouds not the same shape?
Clouds fly across the sky, high above our heads. They often attract the attention of adults and children. It is not surprising that you may have many questions about how clouds appear, what they are made of, how they float in the sky, what they are like, etc. In this article you will get answers to all these questions and be able to satisfy your curiosity.
What are clouds made of?
Clouds are made up of many tiny water droplets or ice crystals floating in the sky at different altitudes.
How are clouds formed?
As the Sun heats the water, it turns into a gas called water vapor. This process is called evaporation. As water vapor rises to the sky, it cools. The higher you go, the cooler the air. Eventually, the steam becomes cool enough and condenses into water droplets, forming the clouds we see in the sky.
How do clouds float across the sky?
Clouds are lighter than the surrounding air. This means they can literally float across the sky. At the same time, air flows can increase their speed.
When clouds accumulate a lot of moisture and become heavy, it begins to rain, hail or snow.
Where do the clouds meet?
Diagram of the main layers of the Earth's atmosphere
All major types of clouds float in the troposphere; this is the lowest part closest to the Earth. Above the troposphere is the stratosphere, and above that are the mesosphere, thermosphere and exosphere.
Why are the clouds different?
There are 10 main types of clouds:
Cumulus clouds
They look like fluffy cotton balls. Typically, cumulus clouds occur on calm, clear days and indicate good weather. However, under certain conditions they can become thunderstorm.
Stratus clouds
These are flat, gray, featureless layers that often lie close to the Earth's surface, obscuring the clouds above. Sometimes they can cause light rain. Fog is simply a layered cloud that has descended to ground level. And when you walk in foggy weather, you are actually walking through clouds.
Stratocumulus clouds
Stratus clouds can break up to form cumulus clouds. Or several cumulus clouds are able to join together to form layers. The distance between them characterizes this type as stratocumulus clouds.
Altostratus clouds
Altostratus clouds are found in the middle of the troposphere. They are usually thinner and lighter than laminated ones. If you look closely at the sky, you can see the sun's rays through such a cloud.
Altocumulus clouds
Like altostratus, altocumulus clouds are found in the middle of the troposphere. However, there is a difference, altocumulus clouds are much smaller than cumulus clouds and consist of both ice crystals and water droplets.
Cirrus clouds
Cirrus clouds are the highest level clouds made entirely of ice crystals. These are thin clouds that look like a horse's tail.
Cirrocumulus clouds
These are cumulus clouds at the height of cirrus. Cirrocumulus clouds are composed entirely of ice crystals. They look like little fish scales in the sky.
Cirrostratus clouds
Cirrostratus clouds are high in the sky. They can produce wonderful optical phenomena such as Halos. The sun still shines brightly through these layers, even though the sky may be completely covered in them.
Nimbostratus clouds
Nimbostratus clouds produce persistent rain or snow that can be light to moderate. These high stratus clouds exist at low to mid-levels in the troposphere.
Cumulonimbus clouds
Also known as “cloud kings,” cumulonimbus clouds are responsible for very heavy rain and hail. Precipitation occurs over a short period of time.
They are also the only clouds that can generate lightning and thunder. Cumulonimbus clouds are very tall and often spread across different layers of the sky.
How to distinguish between cumulus, altocumulus and cirrocumulus clouds in the sky?
You can distinguish between these types of clouds using your hand. Extend your hand towards the cloud and clench your fingers into a fist. If the cloud is larger than a fist, it is a cumulus cloud.
If the cloud is smaller than your fist, move your thumb out to the side. When the cloud is larger than a finger, it is altocumulus, and if it is smaller, it is most likely a cirrocumulus cloud.
Why are the clouds white?
Clouds are white because the droplets inside them are larger than the particles around them. This makes the cloud droplets capable of scattering and breaking up light into different colors, which are then combined into white.
Clouds appear gray when they become dense enough to block sunlight.
What is an airplane contrail?
Condensation trails form when planes pass through cool air. The release of warm, moist air from an airplane's exhaust causes a trail of clouds in its path.
How to determine the weather by clouds?
It's difficult to accurately predict the weather using clouds, but there are some signs that can help! If the clouds are high, dark and cover the entire sky, the rain will continue. When most of the sky is blue, light rain can be expected.
If cumulus clouds get higher and higher, you may experience sudden showers in the evening or even thunder and lightning. However, this often occurs on hot and humid days.
Cumulus clouds (lat. Cumulus) are individually located, dense clouds with sharp outlines, developing vertically, and having white cumulus or dome-shaped tops and flat darker (bluish or grayish) bases. With strong gusts of wind, the edges of the clouds are often torn.
Cumulus clouds form in the lower and partially in the middle troposphere with the development of convection in cooled air masses, as well as in the warm season in air masses over warmed land. The height of the lower boundary line of cumulus clouds is strongly influenced by the humidity of surface air; in humid air masses the height ranges from 800 to 1.5 km, and in dry air masses (deserts and steppes) - from 2000 to 4000 m. The vertical extent of clouds varies from hundreds meters to thousands of meters. Cumulus clouds are located in the sky both as individual rare clouds and in significant clusters, covering almost the entire sky. Scattered cumulus clouds are scattered randomly across the sky, but can form chains or ridges, with their bases located at the same level. Cumulus clouds consist of water droplets throughout their entire thickness, which are larger at the top of the cloud and smaller at the base. At temperatures below zero degrees, the droplets are in a supercooled state. The central part of cumulus clouds completely covers the sun, but the edges are still visible. There is usually no precipitation. In temperate latitudes, isolated large drops of rain may occasionally fall, and occasional short-term sparse rain may occur.
Types of cumulus clouds
Cumulus clouds are divided into four types:
1. Flat (as if flattened) - the most variable clouds, quite dense, with clear horizontal bases and little vertical development.
2. Medium- dense clouds, with clear contours and tops of tangles, with moderate vertical development.
3. Powerful- with pronounced vertical development, often in the form of high towers with multiple projections.
4. Torn- small clouds with torn edges and rapidly changing outlines.
Flat, middle and broken types of clouds are colloidal-stable clouds that do not form precipitation. Powerful cumulus clouds produce light to moderate precipitation, especially in the tropics.
The process of development of cumulus clouds occurs during the transition from flat or broken clouds to medium and powerful clouds, and the final phase can be cumulonimbus clouds. Cumulonimbus clouds always produce precipitation in the form of heavy downpours, sometimes with hail; they are thunderclouds. These clouds almost always contain ice crystals and liquid water, causing powerful electrical phenomena.
Related materials:
L. Tarasov
Like fogs, clouds arise from the condensation of water vapor into liquid and solid states. Condensation occurs either as a result of an increase in absolute air humidity or as a result of a decrease in air temperature. In practice, both factors are involved in cloud formation.
Cloud formation as a result of convection.
Formation of clouds above a warm atmospheric front.
Cloud formation over a cold front.
The decrease in air temperature is caused, firstly, by the rise (upward movement) of air masses and, secondly, by the advection of air masses - their movement in the horizontal direction, due to which warm air can appear above the cold earth's surface.
Let us limit ourselves to discussing the formation of clouds caused by a decrease in air temperature during upward movement. Obviously, such a process is significantly different from the formation of fog - after all, the fog practically does not rise upward, it remains directly at the earth's surface.
What makes air rise? Let us note four reasons for the upward movement of air masses. The first reason is air convection in the atmosphere. On a hot day, the sun's rays strongly warm the earth's surface, it transfers heat to the surface air masses - and their rise begins. Cumulus and cumulonimbus clouds most often have a convective origin.
The process of cloud formation begins with the fact that some air mass rises upward. As you rise, the air will expand. This expansion can be considered adiabatic, since the air rises relatively quickly, and therefore, if its volume is sufficiently large (and a really large volume of air is involved in the formation of a cloud), the heat exchange between the rising air and the environment simply does not have time to occur during the rise. During adiabatic expansion, air, without receiving heat from the outside, does work only due to its own internal energy, and then cools. So, the air rising will be cooled.
When the initial temperature T 0 of the rising air drops to the dew point T p, corresponding to the elasticity of the steam contained in it, the process of condensation of this steam will become possible. If there are condensation nuclei in the atmosphere (and they are almost always present), this process actually begins. The height H at which steam condensation begins determines the lower boundary of the forming cloud. This is called the condensation level. In meteorology, an approximate formula for height H is used (the so-called Ferrel formula):
H = 120(T 0 -T r),
where H is measured in meters.
The air that continues to flow from below crosses the condensation level, and the process of steam condensation occurs above this level - the cloud begins to develop in height. The vertical development of the cloud will stop when the air, having cooled, stops rising. In this case, a vaguely defined upper boundary of the cloud will form. It is called the level of free convection. It is located slightly above the level at which the temperature of the rising air becomes equal to the temperature of the surrounding air.
The second reason for the rise of air masses is due to the terrain. The wind blowing along the earth's surface may encounter mountains or other natural elevations along its path. Overcoming them, air masses are forced to rise upward. The clouds formed in this case are called clouds of orographic origin (from the Greek word oros, meaning “mountain”). It is clear that such clouds do not develop significantly in height (it is limited by the height of the elevation overcome by the air); in this case, stratus and nimbostratus clouds appear.
The third reason for the rise of air masses is the emergence of warm and cold atmospheric fronts. Cloud formation occurs especially intensely over a warm front - when a warm air mass, advancing on a cold air mass, is forced to slide up a wedge of retreating cold air. The frontal surface (the surface of the cold wedge) is very flat - the tangent of its angle of inclination to the horizontal surface is only 0.005-0.01. Therefore, the upward movement of warm air differs little from the horizontal movement; As a result, the cloudiness that appears above the cold wedge develops weakly in height, but has a significant horizontal extent. Such clouds are called ascending clouds. In the lower and middle tiers these are nimbostratus and altostratus clouds, and in the upper tier these are cirrostratus and cirrus (it is clear that the clouds of the upper tier are formed far behind the atmospheric front line). The horizontal extent of ascending slip clouds can be measured in hundreds of kilometers.
Cloud formation also occurs above a cold atmospheric front - when an advancing cold air mass moves under a mass of warm air and thereby lifts it. In this case, along with ascending clouds, cumulus clouds may also appear.
The fourth reason for the rise of air masses is cyclones. Air masses, moving along the surface of the earth, swirl towards the center of the depression in the cyclone. Accumulating there, they create a vertical pressure difference and rush upward. The intense rise of air up to the boundary of the troposphere leads to powerful cloud formation - clouds of cyclonic origin appear. These can be nimbostratus, altostratus, or cumulonimbus clouds. All these clouds produce precipitation, creating the rainy weather characteristic of a cyclone.
Based on the book by L. V. Tarasov “Winds and thunderstorms in the Earth’s atmosphere.” - Dolgoprudny:Publishing house "Intellect", 2011.
Information about books from the Intellect publishing house is on the website
From the surface of the Earth, all clouds appear to be at approximately the same height. However, there can be huge distances between them, equal to several kilometers. But what are the highest and lowest of them? This post has all the information you need to become a cloud expert!
10. Stratus clouds (average height - 300-450 m)
Wikipedia information: Stratus clouds are low-level clouds characterized by horizontal layering with a uniform layer, in contrast to cumuliform clouds, which are formed by rising warm currents.
More specifically, the term "stratus" is used to describe flat, misty clouds at the bottom, ranging in color from dark gray to almost white.
9. Cumulus clouds (average height - 450-2000 m)
Wikipedia information: "Cumulus" is Latin for "heap, heap." Cumulus clouds are often described as "plump", "cotton-like" or "fluffy" in appearance and have a flat base.
Being low level clouds, they are usually less than 1000 meters in height unless they are a more vertical form of cumulus cloud. Cumulus clouds can appear alone, in lines, or in clusters.
8. Stratocumulus clouds (average height - 450-2000 m)
Wikipedia information: Stratocumulus clouds are a type of cloud characterized by large, dark, round masses, usually in the form of groups, lines or waves, the individual elements of which are larger than those of altocumulus clouds, forming at a lower altitude, usually below 2400 meters .
Weak convective air currents create shallow layers of clouds due to the drier, still air above them, preventing their further vertical development.
7. Cumulonimbus clouds (average height - 450-2000 m)
Wikipedia information: Cumulonimbus clouds are dense, towering vertical clouds associated with thunderstorms and atmospheric instability, formed from water vapor carried by powerful updrafts.
Cumulonimbus clouds can form alone, in clusters, or as a squall along a cold front. These clouds are capable of producing lightning and other dangerous severe weather such as tornadoes.
6. Nimbostratus clouds (average height - 900-3000 m)
Wikipedia information: Nimbostratus clouds usually produce precipitation over a large area. They have a diffuse base, usually located somewhere near the surface at the lower levels and at an altitude of about 3000 meters at the middle levels.
Although nimbostratus clouds are typically dark in color at the base, they are often illuminated from within when viewed from the Earth's surface.
5. Altostratus clouds (average height - 2000-7000 m)
Wikipedia information: Altostratus clouds are a type of mid-level cloud belonging to the stratiform physical category, which is characterized by a generally uniform layer whose color varies from gray to bluish-green.
They are lighter than nimbostratus clouds and darker than tall cirrostratus clouds. The Sun can be seen through thin altostratus clouds, but thicker clouds may have a denser, opaque structure.
4. Altocumulus clouds (average height - 2000-7000 m)
Wikipedia information: Altocumulus clouds are a type of mid-level cloud that belongs primarily to the stratocumulus physical category, characterized by spherical masses or ridges in layers or sheets, the individual elements of which are larger and darker than those of cirrocumulus clouds, and smaller. than that of stratocumulus clouds.
However, if the layers become flocculent due to increased instability of the air mass, then altocumulus clouds become more cumuliform in structure.
3. Cirrus clouds (average height - 5000-13,500 m)
Wikipedia information: Cirrus clouds are a type of atmospheric cloud typically characterized by thin, thread-like filaments.
Cloud filaments sometimes form into tufts of characteristic shapes known collectively as “mare’s tails.” Cirrus clouds are usually white or light gray in color.
2. Cirrostratus clouds (average level - 5000-13,500 m)
Wikipedia information: Cirrostratus clouds are a type of thin, whitish stratus clouds composed of ice crystals. They are difficult to detect and are capable of forming a halo when they take the form of a thin cirrostratus cloud.
1. Cirrocumulus clouds (average height - 5000-13,500 m)
Wikipedia information: Cirrocumulus clouds are one of the three main types of upper-level tropospheric clouds (the other two are cirrus and cirrostratus clouds). Like lower-level cumulus clouds, cirrocumulus clouds signify convection.
Unlike other tall cirrus and cirrostratus, cirrocumulus consists of a small number of transparent water droplets, although they are in a supercooled state.
Meteo. Clouds in the form of thick white puffs... Dictionary of many expressions
Cumulus clouds- (cumulus)Cumulus, a cloud formation consisting of rounded shapes piled one on top of the other... Countries of the world. Dictionary
Altocumulus clouds, photo of U.S. National Oceanic and Atmospheric Administration Altocumulus clouds (lat. ... Wikipedia
- (lat. Stratocumulus, Sc) large gray ridges of plates or x ... Wikipedia
- (lat. Cirrocumulus, Cc) thin clouds consisting of small waves, flakes or ripples ... Wikipedia
stratocumulus clouds- Low clouds (symbol: Sc), predominantly stratus in the form of gray or white layers and ridges lying upwind, sometimes producing light precipitation in the form of rain, snow or drizzle... Dictionary of Geography
cirrocumulus clouds- Layers or banks of thin white clouds in the upper troposphere (above 6000 m) without shadows, consisting of small elements that look like flakes or ripples (symbol: Cc) ... Dictionary of Geography
Altocumulus clouds- (altocumulus)Altocumulus, clouds of the middle layers of the troposphere, representing rounded masses in the form of layers and ridges and consisting of tiny drops and ice crystals ... Countries of the world. Dictionary
Cirrocumulus clouds- (cirrocumulus), Cirrocumulus is the usual form of high clouds, consisting of small, round, curly clouds adjacent to each other. This kind of cloudiness is called a lamb's sky... Countries of the world. Dictionary
CLOUDS, a visible mass of water particles or ice crystals suspended in the lower atmosphere. Clouds form when water on the Earth's surface turns into steam through the process of EVAPORATION. As the steam rises into the atmosphere it cools and... Scientific and technical encyclopedic dictionary
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