How is rain and snow formed

How does it rain, knows in our time, any schoolboy, but still worth refreshing knowledge. Water vapor is an invisible, but always present component of the air surrounding the Earth. In all terrestrial reservoirs, from oceans and seas to small ponds, the process of evaporation of water constantly occurs. From the liquid, it turns into gaseous vapor. The warmer the water, the faster it evaporates, and the larger the area of the pond, the more water turns into steam. People do not see this evaporation, water vapor becomes visible where it cools, where condensation occurs, that is, at high altitude. Condensation is the process of converting an invisible vapor into a visible liquid. The main role in this belongs to solar energy. She lifts the steam high into the sky and turns into clouds. The wind, in turn, carries these clouds over long distances, distributing the vital moisture over the territory of the earth.

Mechanism of rain formation

How are raindrops formed? As soon as the cloud is completely saturated and can not take moisture, the process of falling of the small droplets begins inside it. Falling, they are associated with other droplets, which create drops even more, and as a result, you can observe how the rain is formed.

During the shower, large drops are created, which can reach 7 mm in diameter. A drop of fine rain is less than half a millimeter. During the shallow rain, the droplets practically do not separate into separate ones, but everything becomes wet. Rain is actually a cloud that sheds itself. This is observed when the droplets or crystals from which it is created are made excessively heavy and drop out in the direction of the Earth. Meteorologists distinguish several methods of converting droplets into rain. How the rain is formed depends on what kind of clouds the drops pass - warm or cold. Warm clouds are created from tiny bits of water. Falling drops often turn into steam in flight to the ground. And there are so big that they fall on the ground in the form of a shower. A tiny droplet passes through the cloud, while it collides with other droplets, and, having united, they create a large drop. Such a drop collects other drops on its way down. The air that sweeps around the velocity drop attracts tiny drops, increasing its weight. Sometimes it becomes so heavy that it falls from a height into a puddle.

Where do snowflakes come from?

How frost, rain, snow are formed - all these phenomena are studied by meteorologists and weather forecasters to provide for them and in time to warn the population about the bad weather. In cold clouds, droplets are formed by ice crystals. Cold clouds form high in the sky and are transported to areas where the temperature is always outside the freezing point (0 ° C). Such clouds are a mixture of water droplets and ice crystals. When water evaporates from liquid drops, it adjoins the crystals, freezing and becoming a solid. When the crystals grow and collect moisture, they turn into snowflakes and fall through the cloud. But if it's not too cold outside, snowflakes do not last long. They descend into the layers of warm air and begin to melt, again turning into raindrops. How do snowflakes arise? If there are zones of different temperature and humidity in the cloud, it turns into a snow machine. Wet warm air, which carries with it a drop of water, passes into dry cold clouds. Due to the low temperature, the droplets freeze and form the core of the future snowflake. Around the core in a certain order, particles of warm water collect, turning into a snow crystal. Each snowflake consists of 2-200 individual crystals. Crystalline crystals are formed in cold clouds high above the ground, where the temperature can drop to -40 ° C and the water vapor freezes to ice. The snow crystal leaves a cloud and falls to the ground. The snow seems crystal clear when it falls, but in fact most snowflakes are created around the tiny dust particles that the wind brought to the sky, water vapor can crystallize even around small particles of smoke. If you look at powerful microscopes, you can see these particles that are hidden inside the snowflakes. Three-quarters of the snowflakes have grown up around tiny, invisible pieces of clay or earth.

The shape of snowflakes

Probably, each person had the opportunity to admire the intricate shape of snowflakes, when, gradually descending from the sky, they settle on a mitten or a coat. Each snowflake differs form and its own special structure. The basic shape of the snow crystal depends on the temperature at which a snowflake has formed. The higher the cloud, the colder it is. From high cirrus clouds, in which the temperature is below -35 ° C, hexagons are created, when the temperature of the clouds is within -3-0 ° C, snowflakes are formed in the form of plates. At a temperature of -5-3 ° C, needle snowflakes are formed, and from -8 ^to -5 ° C in the form of columns. At -12-8 ° C, plates are again formed. If the temperature drops below - snowflakes take the form of stars. Increasingly, snowflakes become heavier and fall in the direction of the earth, their shape changes. If the snowflakes fall, rotating, their shape will be perfectly symmetrical, if they fall, swaying to the sides, their shape becomes wrong.

If the air under the snow cloud is warmer than 0 ° C, the snowflakes may melt when falling, turning into raindrops, this explains how rain and snow form in the rain. But if the air is cold enough, snowflakes will fly to the ground, covering it with a white veil. Having found themselves on the ground, the snow crystals gradually lose their refined patterns, compressed by the action of other snowflakes.

When the frost falls?

Hoarfrost refers to solid precipitation, which falls out a thin layer of ice crystals. Appears on the ground and objects with freezing soil, quiet wind and clear sky. At temperatures below zero, it falls in the form of hexagonal crystals, at a lower temperature-in the form of plates, below -15 ° C, the frost crystals take the form of blunt-needle needles. It is formed frost on any objects, whose surface is colder than air: on grass, earth, roofs, on glass.

Acid rain

Atmospheric precipitation (rain, snow) with a high acid content is acid rain. How are they formed? The sources of acid rain can be both natural processes (volcanic activity, decomposition of plant residues) and industrial emissions, primarily sulfur dioxide (SO ₂ ) and nitrogen oxides (NO, NO ₂ , N ₂ O ₃ ), by burning various Types of fuel. Connecting with moisture in the atmosphere, form sulfuric and nitric acid. If acidic substances, dissolved in the air, enter the atmosphere saturated with moisture, then the acids fall to the ground in the form of precipitation. If water, including acids, falls on the vegetation and on the ground, it damages the flora and fauna of the earth.

Colorful rains

Sometimes people can observe such phenomena as colored rains. Color rain is a rarity, but it can actually be colored. How does it rain with different colors? For example, a red rain was seen in April 1970 in Thessaloniki in Greece. A powerful wind over the Sahara desert lifted a lot of particles of red clay high into the sky, and then carried them to clouds in the sky over Greece. The stream of rain washed away the clay from the clouds, but the color of the rain was red for a while. In 1959, the state of Massachusetts was a rain of yellow-green color. The culprit was spring pollen from plants, raised upwards. And in March 1972, blue snow fell in the French Alps: this snow was colored with minerals brought from the Sahara.