Everyone has seen the clouds. They are large and small, almost transparent and very thick, white or dark, thunderstorm. Taking a different shape, they resemble animals and objects. But what makes clouds form and why do they look like this? We will talk about this below.
What is a cloud?
Anyone who flew on an airplane probably “passed” through the cloud and noticed that it looked like fog, only it was not located directly above the ground, but high in the sky. The comparison is quite logical, because both of them are ordinary pairs. And he, in turn, consists of microscopic droplets of water. Where do they come from?
This water rises into the air as a result of evaporation from the surface of the earth and water bodies. Therefore, the largest accumulation of clouds is observed over the seas. About 400 thousand cubic kilometers evaporate from their surface in a year, which is 4 times higher than the corresponding land indicator.
What types of clouds are there? It all depends on the state of the water that forms them. It may be gaseous, liquid or solid. It may seem surprising, but some clouds really are made of ice.
We have already found out that clouds form as a result of the accumulation of a large number of particles of water. But to complete the process, a connecting link is needed, to which drops will “stick” and come together. Often this role is played by dust, smoke or salt.
Classification
Depends on the height of the location, from what the clouds are formed and how they will look. As a rule, the white masses that we are used to seeing in the sky appear in the troposphere. Its upper boundary varies depending on geographic location. The closer the area to the equator, the higher standard clouds can form. For example, over a tropical climate area, the border of the troposphere is located at an altitude of about 18 km, and beyond the Arctic Circle - 10 km.
Cloud formation is also possible at high altitudes, but they are currently poorly understood. For example, pearlescent ones appear in the stratosphere, while silver ones appear in the mesosphere.
Clouds of the troposphere are conventionally divided into types depending on what height they are located in the upper, middle or lower tier of the troposphere. Air movement also has a big impact on cloud formation. Cirrus and stratus clouds form in a calm environment, but if the air masses of the troposphere move unevenly, the likelihood of cumulus occurrence increases.
Upper tier
This gap covers a portion of the sky at an altitude of more than 6 km and to the edge of the troposphere. Given that the air temperature here does not rise above 0 degrees, it is not difficult to guess what clouds form in the upper tier. It can only be ice.
In appearance, the clouds located here are divided into 3 genera:
- Cirrus . They have a wavy structure and can look like separate threads, stripes or whole ridges.
- Cirrocumulus are composed of small balls, curls or flakes.
- Cirrostratus is a translucent semblance of fabric that “covers” the sky. Clouds of this type can stretch across the sky or occupy only a small area.
The height of the cloud located in the upper tier can vary greatly depending on various factors. It can be several hundred meters or tens of kilometers.
Middle and lower tier
The middle tier is a part of the troposphere, usually located between 2 and 6 km. There are high cumulus clouds, which are voluminous gray or white masses. They consist of water in the warm season and, accordingly, from ice to cold. The second type of cloud is highly layered. They have a milky gray color and often completely cover the sky. Such clouds carry precipitation in the form of drizzling rain or light snow, but they rarely reach the surface of the earth.
The lower tier is the sky directly above us. The clouds here can be 4 types:
- Stratocumulus in the form of blocks or shafts of gray color. May be precipitated unless the temperature is too low.
- Layered . They are located below all others, have a gray color.
- Layered rain. As the name implies, precipitation is carried, and, as a rule, they have a cover character. These are gray clouds that do not have a specific shape.
- Cumulus . One of the most recognizable clouds. They look like powerful heaps and clubs with an almost flat base. Such clouds do not bring precipitation.
There is another species that is not included in the general list. These are cumulonimbus clouds. They develop vertically and are present in each of the three tiers. Such clouds bring downpours, thunderstorms and hail, so they are often called thunderstorms, or rainstorms.
Cloud lifespan
For those who know what clouds form from, the question of their lifespan may be interesting. Here the moisture level is of great importance. It is a unique source of vitality for the clouds. If the air in the troposphere is dry enough, then the cloud cannot last long. If the humidity is high, it can soar longer in the sky until it becomes more powerful in order to produce precipitation.
As for the shape of the cloud, its lifespan is very short. Water particles tend to constantly move, evaporate and reappear. Therefore, the same cloud shape cannot be maintained even for 5 minutes.