Atmospheric precipitation types and causes of formation. Precipitation. Scheme and types of precipitation. Why doesn't it always rain on cloudy days?

The main factor that has a significant impact on the progress of the flora and fauna of planet Earth is the presence of a climate favorable for the development of life (temperature, humidity, various types of precipitation).

From this list, it is atmospheric phenomena that create numerous climatic zones, which, in turn, are distinguished by a variety of life forms.

All precipitation is inextricably linked with the water cycle in nature - this includes all phenomena that are formed on the basis of the physicochemical properties of water and its ability to be in three states of aggregation - liquid, solid and vapor (3 types of precipitation).

At school, this topic is taught in the 2nd grade in the subject "World around".

What is precipitation

A strict definition of precipitation in geography is usually given as follows. This term refers to such phenomena that occur in the Earth's atmosphere, which are based on the concentration of water in air layer, and are also associated with the transition of water dispersion into various states of aggregation and precipitation onto the surface of the planet.

The main classification of precipitation is division by temperature of atmospheric fronts:

• obligatory– associated with warm air currents;
• storm associated with cold air masses.

To account for the amount of precipitation that falls on the Earth's surface in a certain region, meteorologists use special equipment - rain gauges, which provide data measured in the thickness of the layer of liquid water that has fallen on a solid surface. The units of measurement are millimeters per year.

Natural precipitation plays a key role in the formation of the earth's climate and forms the circulation of water in nature.

Types of precipitation

It is possible to conditionally divide the types of precipitation on the basis of the state of aggregation of water in which it enters the Earth. In principle, this is possible in only two versions - solid and liquid form.

Based on this, the classification is as follows:

• liquid- (rain and dew);
• solid- (snow, hail and frost).

Let's figure out what each type of such precipitation represents.

The most common type of precipitation is rain(applies to convective precipitation). This phenomenon is formed under the influence of the radiant energy of the Sun, which heats the moisture on the surface of the Earth and evaporates it.

Getting into the upper layers of the atmosphere, which are noticeably colder, water condenses, forming a cluster of tiny droplets. As soon as the amount of condensate reaches a large mass, the water spills onto the ground in the form of heavy rain.

Types of rain are classified according to the size of the drops, which in turn is related to the currents and air temperature.

A variety of rains is formed as follows - if the air is warm, then it forms larger drops, and if it is cold, then drizzling light rain (supercooled rain) can be observed. When the temperature drops, it rains with snow.

Another process related to condensation is dew drop. This physical phenomenon It is based on the fact that a certain volume of air can contain a strictly defined amount of steam at a given temperature.

Until the limiting volume of vapor is reached, condensation does not occur, but as soon as the amount exceeds the desired value, the excess precipitates into a liquid state. We can observe this in the early morning on the street, looking at the dew, flowers and other solid objects.

Another common type of precipitation is snow. In principle, its formation is similar to the formation of rain, however, rain differs from snow in that when it falls on the ground, the drops are significantly cooled by air jets that have a negative temperature, and microscopic ice crystals form.

Since the process of formation of snowflakes occurs in the air and under the influence of different temperature, then this causes a large number of shapes and crystals of snowflakes.

If the temperature is very low, then blanket snow forms, if it is closer to zero, then heavy snow. Wet snow forms at temperatures slightly above freezing.

One of the dangerous atmospheric phenomena- This deg. Its formation occurs mainly in summer, when heated air flows carry vaporous moisture to the upper layers of the atmosphere, where, supercooling, the water freezes, forming ice pieces.

They do not have time to melt when flying to the earth's surface and are often the cause of the destruction of crops or damage to buildings.

Condensation of water from steam is also possible in winter. Basically, this is due to low rate relative humidity air.

At the same time, given the negative temperature, the condensed moisture immediately freezes on solid surfaces, forming frost.

Types of precipitation by seasons of the year

Often a characteristic based on the seasonality of precipitation is used.

So, there are:

• precipitation falling mainly during the warm season- rain, drizzle (subtype of rain), dew, hail;
• precipitation that occurs during the cold season- snow, groats (a subspecies of snow), hoarfrost, frost, ice.

Types of precipitation by formation height

More accurate is the classification, which takes into account at what height the condensate turned into one of the types of precipitation:

• precipitation that forms in the upper and middle layers of the atmosphere includes rain, drizzle, hail, grains and snow - falling from clouds;
• Precipitation that forms in the immediate vicinity of the earth's surface (orographic precipitation) includes mainly condensation phenomena (examples - dew, hoarfrost, frost and ice) - falling out of the air.

How precipitation is measured

Often in the weather forecast you can hear that 2 millimeters of precipitation fell per day. Such data are determined by meteorologists and weather forecasters at weather stations using special equipment - precipitation gauges.

These are graduated buckets (on which conventional signs), made in a certain standard size, which are installed on the street.

Every day, in the time interval from 9-00 to 21-00 (time is taken according to the GMT 0 time zone), the meteorologist collects all the moisture that accumulates in the bucket and pours it into a graduated cylinder (cylinder divisions are made in mm).

The obtained values ​​are recorded in the log book, forming a table of precipitation. If the precipitates were solid, then it is allowed to melt them.

To build a visual picture, points with measured precipitation are marked on the map. These points are connected into a diagram by lines - isohyets, and the space is painted over with the colors of precipitation with increasing intensity.

How precipitation affects aviation operations

There are a number of very important atmospheric factors that hinder the operation of aviation. First of all, it is connected with ensuring flight safety.

The main ones are:

1. First of all, this is a deterioration in visibility for aircraft pilots. Reduced visibility in heavy rain or a snowstorm occurs up to 1.5-2 km, which makes it difficult to visually control the course.
2. During takeoff or landing, moisture condensation on windows or optical reflectors can lead to a distorted perception of information by the pilot.
3. A large amount of water fine dust, if it enters the engine, can make it difficult and disrupt its operation.
4. When the aerodynamic elements of the aircraft (wings, steering elements) are iced, there is a loss of flight characteristics.
5. When a significant amount of precipitation falls, contact with the runway coating is difficult.

Thus, all precipitation, in relation to aviation, is extremely unfavorable.

Precipitation is a key factor contributing to the formation of the Earth's climate, as well as geographical areas. Conditional division is carried out depending on seasonality, however, it should be remembered that combinations can occur in the off-season. Also, precipitation is essential element water circulation on the planet.

Atmospheric precipitation is moisture that has fallen to the surface from the atmosphere in the form of rain, drizzle, grains, snow, hail. Precipitation falls from clouds, but not every cloud produces precipitation. The formation of precipitation from the cloud is due to the coarsening of droplets to a size that can overcome ascending currents and air resistance. The coarsening of drops occurs due to the merging of drops, the evaporation of moisture from the surface of drops (crystals) and the condensation of water vapor on others.

Precipitation forms:

1. rain - has drops ranging in size from 0.5 to 7 mm (average 1.5 mm);
2. drizzle - consists of small drops up to 0.5 mm in size;
3. snow - consists of hexagonal ice crystals formed in the process of sublimation;
4. snow groats - rounded nucleoli with a diameter of 1 mm or more, observed at temperatures close to zero. Grains are easily compressed by fingers;
5. ice groats - the nucleoli of the groats have an icy surface, it is difficult to crush them with your fingers, when they fall to the ground they jump;
6. hail - large rounded pieces of ice ranging in size from a pea to 5-8 cm in diameter. Hailstone weight in individual cases exceeds 300 g, sometimes it can reach several kilograms. Hail falls from cumulonimbus clouds.

Types of precipitation:

1. Heavy precipitation - uniform, long in duration, falls from nimbostratus clouds;
2. Heavy rainfall - characterized by a rapid change in intensity and short duration. They fall from cumulonimbus clouds as rain, often with hail.
3. Drizzling precipitation- in the form of drizzle fall out of stratus and stratocumulus clouds.

Distribution of annual precipitation (mm) (according to S.G. Lyubushkin et al.)

(lines on a map connecting points with the same amount of precipitation over a certain period of time (for example, for a year) are called isohyets)

The daily course of precipitation coincides with the daily course of cloudiness. There are two types daily course precipitation - continental and marine (coastal). The continental type has two maxima (in the morning and afternoon) and two minima (at night and before noon). marine type– one maximum (night) and one minimum (day).

The annual course of precipitation is different at different latitudes and even within the same zone. It depends on the amount of heat, thermal regime, air circulation, distance from the coast, the nature of the relief.

Precipitation is most abundant in equatorial latitudes, where their annual amount (GKO) exceeds 1000-2000 mm. On the equatorial islands Pacific Ocean falls 4000-5000 mm, and on the lee slopes of tropical islands up to 10,000 mm. The cause of heavy rainfall are powerful ascending currents very humid air. To the north and south of the equatorial latitudes, the amount of precipitation decreases, reaching a minimum of 25-35º, where the average annual value does not exceed 500 mm and decreases in inland regions to 100 mm or less. IN temperate latitudes ah, the amount of precipitation slightly increases (800 mm). At high latitudes, the GKO is insignificant.

The maximum annual amount of precipitation was recorded in Cherrapunji (India) - 26461 mm. The minimum recorded annual precipitation is in Aswan (Egypt), Iquique - (Chile), where in some years there is no precipitation at all.

Distribution of precipitation on the continents in% of the total

Origin There are convective, frontal and orographic precipitation.

1. convective precipitation are characteristic of the hot zone, where heating and evaporation are intense, but in summer they often occur in the temperate zone.
2. Frontal precipitation formed when two air masses meet different temperatures and other physical properties, fall out of warmer air forming cyclonic whirlwinds, are typical of temperate and cold zones.
3. Orographic precipitation fall on the windward slopes of mountains, especially high ones. They are plentiful if the air comes from the side warm sea and has high absolute and relative humidity.

Types of precipitation by origin:

I - convective, II - frontal, III - orographic; TV - warm air, HV - cold air.

The annual course of precipitation, i.e. change in their number by months, in different places The earth is not the same. It is possible to outline several basic types of annual precipitation patterns and express them in the form of bar charts.

1. equatorial type - Precipitation falls fairly evenly throughout the year, there are no dry months, only after the equinoxes there are two small maximums - in April and October - and after the solstice days two small minimums - in July and January.
2. Monsoon type – maximum precipitation in summer, minimum in winter. It is characteristic of subequatorial latitudes, as well as east coasts continents in subtropical and temperate latitudes. The total amount of precipitation at the same time gradually decreases from the subequatorial to the temperate zone.
3. mediterranean type - maximum precipitation in winter, minimum - in summer. It is observed in subtropical latitudes on the western coasts and inland. Annual rainfall gradually decreases towards the center of the continents.
4. Continental type of precipitation in temperate latitudes - in the warm period, precipitation is two to three times more than in the cold. As the continentality of the climate increases in the central regions of the continents total precipitation decreases, and the difference between summer and winter precipitation increases.
5. Marine type of temperate latitudes - Precipitation is distributed evenly throughout the year with a small maximum in autumn and winter. Their number is greater than observed for this type.

Types of annual precipitation patterns:

1 - equatorial, 2 - monsoon, 3 - Mediterranean, 4 - continental temperate latitudes, 5 - maritime temperate latitudes.

Literature

1. Zubashchenko E.M. Regional physical geography. Climates of the Earth: teaching aid. Part 1. / E.M. Zubashchenko, V.I. Shmykov, A.Ya. Nemykin, N.V. Polyakov. - Voronezh: VGPU, 2007. - 183 p.

The atmosphere of our planet is constantly in motion - it is not for nothing that it is called the fifth ocean. In its thickness, movements of warm and cold air masses are observed - winds blow at different speeds and directions.


Sometimes the moisture in the atmosphere condenses and falls to the earth's surface in the form of rain or snow. Forecasters call it precipitation.

Scientific definition of precipitation

Precipitation in the scientific community is usually called ordinary water, which in liquid (rain) or solid (snow, hoarfrost, hail) form falls from the atmosphere to the surface of the Earth.

Precipitation can fall from clouds, which themselves are water condensed into tiny droplets, or form directly in air masses when two atmospheric streams with different temperatures collide.

Precipitation determines climatic features terrain, and also serves as the basis for crop yields. Therefore, meteorologists constantly measure how much precipitation fell in a particular area for a certain period. This information forms the basis of yields, etc.

Precipitation is measured in millimeters of the layer of water that would cover the surface of the earth if the water had not been absorbed and evaporated. On average, 1000 millimeters of precipitation falls per year, but some areas get more and others less.

So, in the Atacama Desert, only 3 mm of precipitation falls in a whole year, and in Tutunendo (Colombia) a layer of more than 11.3 meters of rainwater is collected per year.

Precipitation types

Meteorologists distinguish three main types of precipitation - rain, snow and hail. Rain is a drop of water in a liquid state, hail and - in a solid state. However, there are also transitional forms of precipitation:

- rain with snow - a frequent occurrence in autumn, when both snowflakes and drops of water alternately fall from the sky;

— freezing rain- enough rare view precipitation, which is ice balls filled with water. Falling to the ground, they break, the water flows out and immediately freezes, covering the asphalt, trees, roofs of houses, wires, etc. with a layer of ice;

- snow groats - small white balls, resembling groats, falling from the sky when the air temperature is close to zero. The balls consist of ice crystals slightly frozen together and are easily crushed in the fingers.

Precipitation can be torrential, continuous and drizzling.

— Heavy precipitation usually falls suddenly and is characterized by high intensity. They can last from several minutes to several days (in tropical climates), often accompanied by lightning and strong winds.

- Heavy precipitation falls for a long time, several hours or even days in a row. They begin with a weak intensity, gradually increase and then continue without changing the intensity, all the time until the end.

- Drizzling precipitation differs from heavy precipitation in a very small droplet size and in that it falls not only from clouds, but also from fog. Quite often, drizzling precipitation is observed at the beginning and end of extensive precipitation, but can last for several hours or days as an independent phenomenon.

Precipitation formed on the surface of the earth

Some types of precipitation do not fall from above, but are formed directly in the bottom layer atmosphere in contact with the earth's surface. In the total amount of precipitation, they occupy a small percentage, but are also taken into account by meteorologists.

- Frost - ice crystals that freeze in the early morning on protruding objects and the ground surface if the night temperature drops below zero.

- Dew - drops of water that condense in the warm season as a result of night air cooling. Dew falls on plants, protruding objects, stones, walls of houses, etc.

- Rime - ice crystals that form in winter at a temperature of -10 to -15 degrees on tree branches, wires in the form of fluffy fringe. Appears at night and disappears during the day.

- Icing and ice - freezing of the ice layer on the surface of the earth, trees, walls of buildings, etc. as a result of the rapid cooling of the air during or after sleet and freezing rain.


All types precipitation formed as a result of the condensation of water evaporated from the surface of the planet. The most powerful "source" of precipitation is the surface of the seas and oceans, land gives no more than 14% of all atmospheric moisture.

Precipitation is called water in liquid and solid state, which falls from clouds and is deposited from the air.

Types of precipitation

For precipitation, there are different classifications. Distinguish overhead precipitation, which is associated with warm fronts and showers, which are cold fronts.

Precipitation is measured in millimeters - the thickness of the layer of fallen water. On average, about 250 mm per year falls in high latitudes and deserts, and in general the globe about 1000 mm of precipitation per year.

Precipitation measurement is essential for any geographic survey. After all, precipitation is one of the most important links in the moisture cycle on the globe.

The determining characteristics for a particular climate are the average monthly, annual, seasonal and long-term precipitation, their daily and annual course, their frequency and intensity.

These indicators are extremely important for most sectors of the national (agricultural) economy.

Rain is a liquid precipitation - in the form of drops from 0.4 to 5-6 mm. Raindrops can leave a trace in the form of a wet spot on a dry object, on the surface of the water - in the form of a divergent circle.

Exist different types rain: icy, supercooled and rain with snow. Both supercooled rain and icy rain fall at negative air temperatures.

Supercooled rain is characterized by liquid precipitation, the diameter of which reaches 5 mm; after this type of rain, ice can form.

And freezing rain is represented by precipitation in a solid state - these are balls of ice, inside of which there is frozen water. Snow is called precipitation, which falls in the form of flakes and snow crystals.

Horizontal visibility depends on the intensity of snowfall. Distinguish between sleet and sleet.

The concept of weather and its features

The state of the atmosphere in a particular place at a particular time is called the weather. Weather is the most variable phenomenon in environment. Sometimes it starts to rain, sometimes it starts to wind, and after a few hours the sun will shine and the wind will subside.

But even in the variability of the weather there are regularities, despite the fact that a huge number of factors influence the formation of the weather.

The main elements characterizing the weather are the following meteorological indicators: solar radiation, Atmosphere pressure, air humidity and temperature, precipitation and wind direction, wind strength and cloud cover.

If we talk about weather variability, then most often it changes in temperate latitudes - in regions with continental climate. And the most sustainable weather occurs in polar and equatorial latitudes.

The change in the weather is associated with the change of the season, that is, the changes are periodic, and over time weather are repeated.

Every day we observe the daily change of the weather - the night follows the day, and for this reason the weather conditions change.

The concept of climate

The long-term weather regime is called the climate. The climate is determined in a particular area - thus, the weather regime must be stable for a certain geographical location.

Surely, each of us has ever watched the rain through the window. But have we thought about what kind of processes occur in rain clouds? What types of precipitation can receive? That is what got me interested. I opened my favorite home encyclopedia and settled on the section titled "Types of Precipitation". What was written there, I'm going to tell.

What are the precipitation

Any precipitation falls due to the enlargement of elements in the clouds (for example, water droplets or ice crystals). Having increased to a size at which they can no longer be in suspension, the drops fall down. Such a process is called "coalescence"(which means "fusion"). And the further growth of drops occurs already in view of their merging in the process of falling.

Precipitation often take quite different forms. But in science there are only three main groups:

• massive precipitation. These are the precipitations that usually fall during very long period with medium intensity. Such rain covers itself large area and falls from special nimbostratus clouds that cover the sky, not letting in light;
• rainfall. They are the most intense, but short-lived. Originate from cumulonimbus clouds;
• drizzling rain. They, in turn, are made up of small droplets - drizzle. This kind of rain can last a very long time. for a long time. Drizzling precipitation falls from stratus (including stratocumulus) clouds.

In addition, precipitation is divided according to their consistency. This is what will be discussed now.

Other types of precipitation

Additionally, the following types of precipitation are distinguished:

• liquid precipitation. Basic. It was about them that was mentioned above (overlapping, torrential and drizzling types of rains);
• solid precipitation. But they fall out, as you know, at a negative temperature. Such precipitation takes on various shapes (snow of the most different forms, hail and so on...);
• mixed precipitation. Here the name speaks for itself. An excellent example is a cold freezing rain.

These are the different types of precipitation. And now it is worth making some interesting remarks about their loss.

The shape and size of snowflakes are determined by the temperature in the atmosphere and the strength of the wind. The purest and driest snow on the surface is capable of reflecting about 90% light from the sun's rays.

More intense and larger (in the form of drops) rains occur on small areas. There is a relationship between the size of territories and the amount of precipitation.

The snow cover is able to independently emit thermal energy, which, nevertheless, quickly escapes into the atmosphere.

Clouds with clouds have huge weight. More than 100 thousand km³ of water.