The storm cloud. Thunderclouds and lightning

Thunderstorm is a natural phenomenon in which electric discharges form inside clouds or between a cloud and the earth's surface. In this weather, dark storm clouds arise. As a rule, this event is accompanied by thunder, rain, hail and a strong wind.

Education

In order to create a thundercloud, several factors are necessary for the development of such a concept as convection. These structures are a sufficient amount of moisture for precipitation and elements of cloud particles in the liquid and ice state.

Convection contributes to the development of thunderstorms in such cases:

• uneven heating of air near the surface of the earth and in its upper layers. An example is a different temperature of land and water surface;

• during the expulsion of warm air cold in the atmospheric layers;

• A thundercloud appears in the mountains as the air rises.

Each such cloud passes through the stages of a cumulus, a mature thunderstorm and a stage of decay.

Structure

The movement and distribution of electric charges around and inside a thundercloud is a continuous and ever-changing process. The dipole structure is dominant. Its meaning is that the negative charge is located in the lower part of the cloud, and the positive charge is in the upper part. Atmospheric ions moving under the influence of an electric field create so-called shielding layers on the boundaries of the cloud, covering them with an electrical structure.

Depending on the geographical location, the main negative charge is located where the air temperature is from -5 to -17 ° C. The density of the space charge is 1-10 Cl / km³.

Moving thunderclouds

The speed of any clouds, including thunderstorms, directly depends on the movement of the earth. The rate of movement of an isolated thunderstorm usually reaches 20 km / h, and sometimes even 65-80 km / h. The latter phenomenon occurs during the movement of active cold fronts. In most cases, during the decay of the former thunderstorm cells, new ones are formed.

The thunderstorm is powered by energy. It is enclosed in latent heat, which is released by the condensation of water vapor, forming a cloud drop. Estimating the energy of thunderstorms as a whole can be done on the basis of the amount of precipitation.

Distribution

At the same time, there are thousands of thunderclouds on our planet in which the average number of lightnings reaches a mark of one hundred per second. They are distributed unevenly over the Earth's surface. Over the oceans, such weather is observed ten times less often than over the continents. Storm clouds are often found in tropical and subtropical climates. The maximum of lightning discharges is concentrated in Central Africa.

In areas such as the Antarctic and the Arctic, thunderstorm activity is mostly not. Conversely, mountain territories such as the Cordillera and the Himalayas are habitual areas for such lightning phenomena as a storm cloud. By the seasons, this weather happens in most cases in the summer during the daytime hours and rarely in the evening and in the morning.

Thunderstorms in other natural phenomena

A storm cloud is usually accompanied by heavy rain-showers. On average, with this weather, there are 2 thousand cubic meters of precipitation. At larger thunderstorms - ten times more.

A tornado (and also a tornado) is a whirlwind that creates a thundercloud. He goes down, often to the very ground level. It looks like a trunk formed from a cloud hundreds of meters in size. The diameter of the funnel is usually about four hundred meters.

In addition to these natural phenomena, a thundercloud contributes to the appearance of squalls and a descending flow. The latter occurs at a height where the air temperature is lower than in the environment. The stream becomes even colder when the particles of ice precipitated in it, which evaporate into cloud drops.

The spreading downward flow forms a clear difference in colors between warm moist and cold air. The motion of the squall front can be easily recognized by a sharp drop in temperature - five degrees Celsius and more - and a strong wind (can reach and exceed 50 m / s).

Tornado fractures have a circular shape, and a downward flow is straight. Both phenomena result in rain in the end result. In rare cases, the precipitation evaporates during the fall. This phenomenon is called "dry thunderstorm". In other cases, there is a downpour, hail, and then floods.

Safety precautions

There are a number of rules of conduct during the weather, accompanied by thunder and lightning. Storm clouds are extremely dangerous for the life of all creatures, not only on the street (although this is the greatest risk), but also near the windows inside the premises. It is important to know that lightning discharges most often strike high objects. This is due to the fact that the electrical particles go along the path of least resistance.

During a thunderstorm, try not to be close to power stations and power lines, under tall, lonely trees, in open territory (such as field, valley or meadow). Dangerous is the swimming in the river, the lake and other water bodies, because the water has good electrical conductivity.

An airplane that flies through a cumulonimbus cloud falls into a zone of turbulence. At such times, traffic throws in all directions under the influence of cloud flows. Passengers feel a strong shaking, and the plane - a load that is extremely undesirable for him.

Has a high risk of using a motorcycle, bicycle or other items that are made of metal. It is also dangerous for life to be on any elevation, such as the roofs of houses, to which the thunderclouds are closest. Photos of these natural phenomena give the impression of beauty and spectacularity, but the risk of monitoring such weather from the street can cost a person his life.