Clouds form in the next layer of the atmosphere. How are clouds formed? Types of clouds with descriptions and photos. Genetic classification, according to the conditions of education

Clouds…we encounter them every day.

What is a cloud

Each time, raising our heads to the sky, by the number, shape and color of the clouds, we try to either make a weather forecast, or simply admire their beauty.

Let us give some precise definitions.

Clouds are...

CLOUD, the visible mass of water particles or ice crystals suspended in the lower atmosphere. Clouds are formed when water on the Earth's surface turns into steam through the process of EVAPORATION. As it rises into the atmosphere, the vapor cools and condenses around microscopic particles of salt and dust, turning into droplets. Where the temperature of the atmosphere is low (below the freezing point of water), the droplets turn into ice. Clouds are divided into 10 types.

Scientific and technical encyclopedic dictionary

Geography. Modern Illustrated Encyclopedia

Clouds - accumulations of water vapor condensation products suspended in the atmosphere - water drops, ice crystals, or a mixture thereof; the main source of precipitation falling on the Earth's surface during the enlargement of cloud particles. The content of condensed particles in clouds ranges from a few hundredths of a gram to several grams per 1 m³ of cloudy air. The clouds are playing essential role in the climate system, reflecting solar radiation into space and thereby preventing the heating of the surface layers of the atmosphere.

Geography. Modern illustrated encyclopedia. - M.: Rosman. Under the editorship of prof. A.P. Gorkina. 2006

Naval Dictionary

Clouds - an accumulation of tiny water droplets, ice crystals or snowflakes suspended in the air at a greater or lesser height. The smallest droplets that make up clouds are released when moist air cools, which occurs mainly when air masses rise from the bottom up as a result of convection (cumulus and storm clouds), when warm air currents rise on warm and cold fronts (stratified nimbus, showers). and some clouds of higher tiers) and when warm moist air mixes with cold during winds (stratus clouds).

Edwart. Explanatory Naval Dictionary, 2010

Clouds - atmospheric, the accumulation in the atmosphere of the condensation products of water vapor in the form of a huge number of tiny droplets of water or ice crystals, or both. Similar clusters directly at earth's surface called fog. Region - a significant weather-forming factor that determines the formation and regime of precipitation, affecting the thermal regime of the atmosphere and the Earth, etc. O. cover on average about half of the sky of the Earth and at the same time contain up to 109 tons of water in suspension. O. are an important link in the moisture cycle on Earth; they can move thousands of kilometers, carrying and thereby redistributing huge masses of water.

Great Soviet Encyclopedia. - M.: Soviet Encyclopedia. 1969-1978

The region, like many other phenomena and forms associated with water, has a romantic aura and mythology… They have always been and will be an inexhaustible source of inspiration for many artists, poets and just dreamers.

Nevertheless, in this material we will talk, to a greater extent, about their physical essence, about physical properties and types.

Unlike poetry, physics is a prosaic, strict science :) and gives clouds definition in accordance with the established canons of academic science, and determines the region. as an accumulation of "cloud elements" - water droplets and ice crystals, which were formed in the process of condensation.

How clouds are formed

Water vapor, thanks to air currents rising from the surface of the Earth, enters the upper atmosphere, where it turns into cloud as a result of the condensation process. The process of steam rising is a consequence of the difference in temperatures in different layers of the atmosphere, the temperature of the atmosphere in the upper layers is significantly lower than at the surface of the earth. For the successful formation of the region, at the very beginning of the process, the smallest dust particles are required, which provide the water molecules with a base and to which they can “attach”. These tiny particles are called condensation grains. At temperatures above -10 degrees Celsius region. consist of drop elements, at temperatures from -10 to -15 mixed (drop and crystalline), and at temperatures below -15 degrees they consist of crystalline elements.

Region cover about 40% of the Earth's surface and contain approximately 10 to the tenth power of tons the purest water. The temperature is more than a third of all the water contained in the clouds is negative.

Despite the apparent diversity, classified into several species and types.

Types of clouds - cumulus, cirrus, stratus, rain...

Cirrus (Ci) - pinnate; Cirrostratus (Cs) - pinnatiform; Cirrocumulus (Cc)- pinnate - cumulus; Altostratus (As) - High - layered; Altocumulus (Ac)- high - cumulus; Nimbostratus (Ns) - stratified rain; Stratocumulus (Sc) - stratified - cumulus; Stratus (St) layered; Cumulus (Cu)- cumulus; Cumulonimbus (Cb)- cumulus - rain.

Morphological classification, depending on the height of the lower boundary of the cloud and its appearance:

• Region the upper tier - the lower limit is more than 6 km:

  • Pinnate, Cirrus (Ci);
  • Pinnately stratified, Cirrostratus (Cs);
  • Cirrocumulus (Cc).

• Middle tier - lower limit from 2 to 6 km:

  • Highly stratified, Altostratus (As);
  • High - cumulus, Altocumulus (Ac);
  • Nimbostratus, Nimbostratus (Ns).

• The lower tier - the lower limit is less than 2 km:

  • Layered - rain, Nimbostratus (Ns);
  • Broken - rain, Fractonimbus (Fr nb);
  • Stratocumulus, Stratocumulus (Sc);
  • Layered, Stratus (St);
  • Broken - layered, Fractostratus (Fr st).

• Region vertical development (convection clouds)— lower limit less than 2 km:

  • Cumulus, Cumulus (Cu);
  • Powerfully - cumulus, Cumulus congestus (Cu cong);
  • Cumulonimbus, Cumulonimbus (Cb).

Genetic classification, according to the conditions of education:

• Cumulus regions:

  • Powerfully - cumulus regions;
  • Cumulonimbus;
  • High - cumulus flocculent or turret-shaped;
  • Peristo-cumulus region.

• Layered regions:

  • Layered - rain regions;
  • Broken - rain;
  • High - layered;
  • Peristo-stratified regions.

• Wavy regions:

  • layered;
  • Stratocumulus;
  • Altocumulus and cirrocumulus regions.

There are also more rare species region - mother-of-pearl clouds and noctilucent, which are located at altitudes of 20-25 km and 70-80 km, respectively.

Probably many will be interested to know that the region. have a direct impact on more than just the weather. Clouds affect industries such as radar, radio and mobile communication, aviation, agricultural technology ... and even politics.

I remember how as a child, looking at the clouds in the sky, I always fantasized different figures for myself. It seemed to me that one cloud looked like a bear, and the other like an apple. At that time, I had no idea what a cloud is, how and from what it is formed. Now, together with my daughter, I also like to watch floating clouds, but now, of course, I know much more about them. I am happy to share this information with you.

Where do clouds appear in the sky?

Air contains water vapor. When the temperature rises, it can hold a lot of water vapor, but when the temperature drops, it becomes more and more difficult to retain moisture. At this time, her excess are released from the air in the form of very fine water droplets. Such a process occurs when the thermometer rises above 0. If it is minus outside the window, then from the air ice crystals are released.

In other words, a substance, in this case water, changes from a gas state to a liquid state. This process is called condensation. So, if air condensation has occurred near the earth's surface, then we will observe fog. But if high from the ground, then clouds form at this moment. All this is due to a decrease in air temperature at altitude. In other words, clouds are accumulations of water droplets or ice crystals in the troposphere.

What are the clouds

I think, looking up at the sky, many paid attention to the fact that the clouds are all different. So there are different classifications of clouds. I'll tell you what they are depending on height location. So, they are divided into clouds:

• upper tier;
• middle tier;
• lower tier;
• clouds of vertical development.

Upper clouds soar at an altitude of 6 km from the earth's surface. mid-tier clouds meet at an altitude of 2 to 6 km. They are much larger in size than the clouds from the first group. They are very dense, so you can see the shadow of such a cloud on the ground. Lower clouds float across the sky at an altitude of up to 2 km. They are dark in color, it is these clouds that are the messengers of precipitation. The bases of vertical clouds are at a height of about 2 km, and the rest of it rises up and can reach 6-8 km.

The clouds are actually quite high, and when you look up into the sky, it seems that they seem to be floating overhead and you can easily touch them.

Droplets of water or ice crystals located at a considerable height above the earth's surface. The formation of clouds occurs as follows: air heated from the Earth expands, becomes light and rises. It is known that it decreases with height, so the rising air gradually cools, and the water from the vapor state passes into the liquid state, forming an accumulation of water droplets. The reason for cloud formation is also the forced rise of water saturated on mountain barriers, while the air rising along the mountain slope meets with increasingly cold layers of the atmosphere. The water vapor turns into water droplets and clouds form. Most often, the formation of clouds is associated with the onset of warm or cold weather.

Depending on the predominance of certain elements, clouds are divided into water, ice, mixed. Water clouds consist of very small droplets with a diameter of 0.01 mm - 0.001 mm. There are several hundred of them in 1 cm3 of a water cloud. Ice clouds are made up of ice crystals. Such clouds usually form over a very high altitude where the air temperature is below 0°C. Mixed clouds contain simultaneously supercooled water droplets different sizes and ice crystals. There is no sharp boundary between the location of liquid and solid elements in the cloud, since there are powerful transitional layers.

The clouds have different shape, which depends on the conditions of their formation, height, . By international agreement clouds according to the shape of the cluster are divided into 10 genera.

This is the degree of cloud cover in the sky. Evaluate it on a 10-point scale or in%. The height and speed of clouds are measured by a special device - a nefoscope. Based on the analysis of the clouds, it is possible to determine the upcoming one: the appearance of cirrus and then stratus clouds in the sky portends rain; when the clouds increase, thicken, descend, move rapidly, becoming heavier and lowering, cloudy, inclement weather must be expected.

In winter and at night, clouds prevent a decrease in the temperature of the earth's surface and the surface layer of air, as they prevent the outflow of heat from the lower layers of the atmosphere, and in summer and during the day, clouds weaken the heating of the earth's surface, since water drops in them, like lenses, reflect part of the sun's rays. The clouds soften

From the surface of the Earth, it seems that all the clouds are at about 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 necessary information to become a cloud expert!

10. Layered clouds (average height - 300-450 m)

Wikipedia info: Stratus clouds are low-level clouds characterized by horizontal layering with a uniform layer, as opposed to cumuliform clouds, which are formed by ascending warm currents.

More specifically, the term "stratus" is used to describe low-level flat, hazy clouds that range in color from dark gray to almost white.

9. Cumulus clouds (average height - 450-2000 m)


Wikipedia info: "Cumulus" in Latin means "heap, heap". Cumulus clouds are often described as "fat", "cotton-like", or "fluffy" in their appearance and have a flat bottom border.

Being lower clouds, they are usually less than 1000 meters high unless they are a more vertical form of cumulus. Cumulus clouds can appear on their own, in lines, or in clusters.

8. Stratocumulus clouds (average height - 450-2000 m)


Wikipedia Info: Stratocumulus belongs to a type of cloud characterized by large dark, rounded masses, usually in clusters, lines or waves, the individual elements of which are larger than altocumulus clouds, forming at a lower altitude, usually below 2400 meters .

Weak convective air currents create shallow cloud layers due to the drier, still air above them, preventing further vertical development.

7. Cumulonimbus clouds (average height - 450-2000 m)


Wikipedia Info: 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 swell with a squall along a cold front. These clouds are capable of producing lightning and other dangerous severe weather such as a tornado.

6. Nimbostratus clouds (average height - 900-3000 m)


Wikipedia info: Nimbostratus clouds usually generate precipitation over a vast 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.

Despite the fact that nimbostratus clouds are usually dark 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 Info: Altostratus clouds are a type of mid-layer clouds belonging to the layer-like physical category, which is characterized by a generally uniform layer that varies in color from gray to bluish-green.

They are lighter than nimbostratus and darker than high cirrostratus. The Sun can be seen through thin altostratus clouds, but thicker clouds can have a denser, opaque structure.

4. Altocumulus clouds (average height - 2000-7000 m)


Wikipedia info: Altocumulus is a type of mid-tier cloud that belongs predominantly 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 cirrocumulus clouds, and smaller. than stratocumulus clouds.

However, if the layers become flocculent due to increased air mass instability, then altocumulus clouds become more cumulus in structure.

3. Cirrus clouds (average height - 5000-13.500 m)


Wikipedia info: Cirrus clouds are a type of atmospheric cloud, usually characterized by thin, filamentous filaments.

Cloud filaments sometimes form into tufts of a characteristic shape known as common name"mare's tails". Cirrus clouds are usually white or light gray in color.

2. Cirrostratus clouds ( average level- 5000-13.500 m)


Wikipedia info: Cirrostratus clouds are a type of thin, whitish stratus clouds made up of ice crystals. They are difficult to detect and are capable of halo formation when they take the form of a thin cirrostratus mist cloud.

1. Cirrocumulus clouds (average height - 5000-13.500 m)


Wikipedia info: Cirrocumulus is one of the three main varieties of upper tropospheric clouds (the other two are cirrus and cirrostratus). Like lower cumulus clouds, cirrocumulus clouds signify convection.

Unlike other tall cirrus and cirrostratus, cirrocumulus are composed of a small amount of transparent water droplets, although they are in a supercooled state.

L. Tarasov

Like fogs, clouds are formed by the condensation of water vapor into liquid and solid states. Condensation occurs either as a result of an increase in the absolute humidity of the air, or as a result of a decrease in air temperature. In practice, both factors are involved in cloud formation.

Formation of clouds as a result of convection.

Cloud formation over a warm atmospheric front.

Cloud formation over a cold atmospheric front.

The decrease in air temperature is due, firstly, to the rise (ascending movement) of air masses and, secondly, to the advection of air masses - their movement in a horizontal direction, due to which warm air can be above the cold earth's surface.

We confine ourselves to discussing the formation of clouds caused by a decrease in air temperature during an upward movement. It is obvious that such a process differs significantly from the formation of fog - after all, the fog practically does not rise up, it remains directly at the earth's surface.

What makes air rise up? There are four reasons for the upward movement of air masses. The first reason is the convection of air in the atmosphere. On a hot day, the sun's rays strongly warm the earth's surface, it transfers heat to the ground air masses - and their rise begins. Cumulus and cumulonimbus clouds are most often of convective origin.

The process of cloud formation begins with the fact that some air mass rises. As you rise, the air will expand. This expansion can be considered adiabatic, since the air rises relatively quickly, and therefore, with a sufficiently large volume (and a really large volume of air is involved in the formation of a cloud), the heat exchange between the rising air and environment simply does not have time to occur during the ascent. During adiabatic expansion, air, without receiving heat from outside, does work only due to its own internal energy, and then cools down. So, the air rising up 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 vapor contained in it, the process of condensation of this vapor will become possible. In the presence of condensation nuclei in the atmosphere (and they are almost always present), this process really begins. The height H, at which vapor condensation begins, determines the lower boundary of the forming cloud. It is called the level of condensation. In meteorology, an approximate formula for the height H is used (the so-called Ferrel formula):

H \u003d 120 (T 0 -T p),

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 already 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, an indistinctly expressed upper bound clouds. 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 ambient air.

The second reason for the rise of air masses is due to the terrain. The wind blowing along the earth's surface may meet mountains or other natural elevations on its way. Overcoming them, the air masses are forced to rise up. The clouds formed in this case are called clouds of orographic origin (from Greek word oros meaning "mountain"). It is clear that such clouds do not receive a significant development in height (it is limited by the height of the elevation overcome by the air); in this case, stratus and nimbostratus clouds arise.

The third reason for the rise of air masses is the occurrence of warm and cold atmospheric fronts. Cloud formation is particularly intense over warm front- when a warm air mass, advancing on a cold air mass, is forced to slide up the wedge of receding cold air. The frontal surface (the surface of the cold wedge) is very gentle - the tangent of its 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 consequence, the cloudiness that arises above the cold wedge develops weakly in height, but has a significant horizontal extent. Such clouds are called upslip clouds. In the lower and middle tiers, these are nimbostratus and altostratus clouds, and in the upper tier - cirrostratus and cirrus (it is clear that the clouds of the upper tier are already formed far behind the atmospheric front line). The horizontal extent of upward 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 raises it. In this case, cumulus clouds may also form in addition to upslip clouds.

The fourth reason for the rise of air masses is cyclones. air masses, moving along the surface of the earth, twist towards the center of the depression in the cyclone. Accumulating there, they create a pressure drop along the vertical and rush upward. Intense rise of air up to the border of the troposphere leads to powerful cloud formation - clouds of cyclonic origin appear. It can be stratified-nimbus, altostratus, cumulonimbus clouds. Precipitation falls from all such clouds, creating 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 the books of the publishing house "Intellect" - on the website