Atmospheric precipitation and their chemical composition. Precipitation. Scheme and types of precipitation What are the types of precipitation

Precipitation is water that falls from the atmosphere onto the earth's surface. Atmospheric precipitation also has a more scientific name - hydrometeors.

They are measured in millimeters. To do this, measure the thickness of the water that has fallen to the surface with the help of special instruments - precipitation gauges. If it is necessary to measure the water column over large areas, then weather radars are used.

On average, our Earth receives almost 1000 mm of precipitation annually. But it is quite predictable that their amount of moisture that has fallen out depends on many conditions: the climate and weather conditions, the terrain, and the proximity of water bodies.

Types of precipitation

Water from the atmosphere falls to the earth's surface, being in its two states - liquid and solid. According to this principle, all atmospheric precipitation is usually divided into liquid (rain and dew) and solid (hail, frost and snow). Let's consider each of these types in more detail.

Liquid precipitation

Liquid precipitation falls to the ground in the form of water droplets.

Rain

Evaporating from the surface of the earth, water in the atmosphere collects into clouds, which consist of tiny drops, ranging in size from 0.05 to 0.1 mm. These tiny droplets in the clouds merge with each other over time, becoming larger and noticeably heavier. Visually, this process can be observed when the snow-white cloud begins to darken and become heavier. When there are too many such drops in the cloud, they spill onto the ground in the form of rain.

In summer it rains in large drops. They remain large because the heated air rises from the ground. It is these ascending jets that do not allow drops to break into smaller ones.

But in spring and autumn, the air is much cooler, so at these times of the year the rains are drizzling. Moreover, if the rain comes from stratus clouds, it is called oblique, and if the drops begin to fall from the kune-rain, then the rain turns into a downpour.

Almost 1 billion tons of water is poured onto our planet every year in the form of rain.

It is worth highlighting in a separate category drizzle. This type of precipitation also falls from stratus clouds, but its drops are so small and their speed is so negligible that the water droplets seem to be suspended in the air.

Dew

Another type of liquid precipitation that falls at night or early in the morning. Dew drops are formed from water vapor. During the night, this vapor cools, and the water turns from a gaseous state into a liquid one.

The most favorable conditions for the formation of dew: clear weather, warm air and almost no wind.

Solid atmospheric precipitation

We can observe solid precipitation during the cold season, when the air cools to such an extent that the water droplets in the air freeze.

Snow

Snow, like rain, forms in clouds. Then, when the cloud enters a stream of air in which the temperature is below 0 ° C, the water droplets in it freeze, become heavy and fall to the ground in the form of snow. Each drop freezes in the form of a kind of crystal. Scientists say that all snowflakes have a different shape and it is simply impossible to find the same ones.

By the way, snowflakes fall very slowly, since they are almost 95% air. For the same reason they are white. And the snow crunches underfoot because the crystals break. And our ears are able to pick up this sound. But for fish, this is a real torment, since snowflakes falling on the water emit a high-frequency sound that fish hear.

hail

falls only in the warm season, especially if it was very hot and stuffy the day before. The heated air rushes up in strong streams, carrying the evaporated water with it. Heavy cumulus clouds form. Then, under the influence of ascending currents, the water droplets in them become heavier, begin to freeze and grow into crystals. It is these lumps of crystals that rush to the ground, increasing in size along the way due to merging with drops of supercooled water in the atmosphere.

It should be borne in mind that such ice "snowballs" rush to the ground with incredible speed, and therefore hail is able to break through slate or glass. Hail causes great damage to agriculture, so the most "dangerous" clouds that are ready to burst into hail are dispersed with the help of special guns.

Frost

Hoarfrost, like dew, is formed from water vapor. But in the winter and autumn months, when it is already cold enough, the water droplets freeze and therefore fall out in the form of a thin layer of ice crystals. And they do not melt because the earth cools even more.

rainy seasons

In the tropics, and very rarely in temperate latitudes, there comes a time of the year when an unreasonably large amount of precipitation falls. This period is called the rainy season.

In countries that are located in these latitudes, there are no severe winters. But spring, summer and autumn are incredibly hot. During this hot period, a huge amount of moisture accumulates in the atmosphere, which then pours out in the form of prolonged rains.

At the equator, the rainy season occurs twice a year. And in the tropical zone, south and north of the equator, such a season happens only once a year. This is due to the fact that the rain belt gradually runs from south to north and back.

In the understanding of an ordinary person, precipitation is rain or snow. In fact, there are many more species and all of them, one way or another, are found throughout the year. Among them there are very unusual phenomena that lead to beautiful effects. What kind of precipitation are there?

Rain

Rain is the fall of drops of water from the sky to the ground as a result of its condensation from the air. In the process of evaporation, water collects into clouds, which later turn into clouds. At a certain moment, the smallest droplets of steam increase, turning into the size of raindrops. Under their own weight, they fall to the surface of the earth.

Rains are heavy, torrential and drizzling. The continuous rain is observed for a long time, it is distinguished by a smooth beginning and end. The intensity of the fall of drops during the rain practically does not change.

Heavy rains are characterized by short duration and large droplets. They can reach five millimeters in diameter. A drizzle has drops less than 1 mm in diameter. It is practically fog that hangs above the surface of the earth.

Snow

Snow is the precipitation of frozen water, in the form of flakes or frozen crystals. In another way, snow is called dry residue, since falling on a cold surface, snowflakes do not leave wet traces.

In most cases, heavy snowfalls develop gradually. They are characterized by smoothness and the absence of a sharp change in the intensity of precipitation. In a severe frost, the situation of the appearance of snow from a seemingly clear sky is possible. In this case, snowflakes are formed in the thinnest cloud layer, which is practically invisible to the eye. Such a snowfall is always very light, since a large snow load requires appropriate clouds.

Rain with snow

This is a classic type of precipitation in autumn and spring. It is characterized by the simultaneous fall of both raindrops and snowflakes. This happens due to small fluctuations in air temperature around 0 degrees. In different layers of the cloud, different temperatures are obtained, and it also differs on the way to the ground. As a result, some of the drops freeze into snow flakes, and some fly in a liquid state.

hail

Hail is called pieces of ice, into which, under certain conditions, water turns before falling to the ground. The size of the hailstones ranges from 2 to 50 millimeters. This phenomenon occurs in summer, when the air temperature is above +10 degrees and is accompanied by heavy rain with a thunderstorm. Large hailstones can cause damage to vehicles, vegetation, buildings and people.

snow grits

Snow groats are called dry precipitation in the form of dense frozen snow grains. They differ from ordinary snow in high density, small size (up to 4 millimeters) and almost round shape. Such croup appears at temperatures around 0 degrees, while it may be accompanied by rain or real snow.

Dew

Dew drops are also considered precipitation, however, they do not fall from the sky, but appear on various surfaces as a result of condensation from the air. For the appearance of dew, a positive temperature, high humidity, and the absence of strong winds are required. Abundant dew can lead to water leaks on the surfaces of buildings, structures, and transport bodies.

Frost

This is winter dew. Hoarfrost is water that has condensed from the air, but at the same time the past stage of the liquid state. It looks like a lot of white crystals covering, as a rule, horizontal surfaces.

frost

It is a type of frost, but does not appear on horizontal surfaces, but on thin and long objects. As a rule, hoarfrost in wet and frosty weather covers umbrella plants, wires of power lines, tree branches.

Ice

Icing is a layer of ice on any horizontal surfaces, which appears as a result of cooling fog, drizzle, rain or sleet with a subsequent drop in temperature in the range below 0 degrees. As a result of ice buildup, weak structures can collapse, and power lines can be torn.

Black ice is a special case of ice that forms only on the surface of the earth. Most often, it is formed after a thaw and a subsequent decrease in temperature.

ice needles

This is another type of precipitation, which is the smallest crystals floating in the air. Ice needles are perhaps one of the most beautiful winter atmospheric events, as they often result in various lighting effects. They are formed at air temperatures below -15 degrees and refract transmitted light in their structure. This results in halos around the sun, or beautiful "pillars" of light that extend from streetlights into clear, frosty skies.

Rain, snow or hail - we have been familiar with all these concepts since childhood. We have a special relationship with each of them. So, rain evokes sadness and dull thoughts, snow, on the contrary, amuses and cheers up. But hail, for example, few people love, as it can cause enormous damage to agriculture and serious injuries to those who find themselves on the street at this time.

We have long learned how to determine the approach of certain precipitation by external signs. So, if in the morning it is very gray and cloudy outside, precipitation in the form of prolonged rain is possible. Usually such rain is not very heavy, but can last all day. If thick and heavy clouds appeared on the horizon, precipitation in the form of snow is possible. Light clouds in the form of feathers portend heavy rain showers.

It should be noted that all types of precipitation are the result of very complex and very long processes in the earth's atmosphere. So, in order to form ordinary rain, the interaction of three components is necessary: ​​the sun, the surface of the Earth and the atmosphere.

Precipitation is...

Precipitation is water in liquid or solid state that falls out of the atmosphere. Precipitation can either fall on the surface of the Earth directly or settle on it or on any other objects.

The amount of precipitation in a particular area can be measured. They are measured by the thickness of the water layer in millimeters. In this case, solid types of precipitation are pre-melted. The average amount of precipitation per year on the planet is 1000 mm. In no more than 200-300 mm falls, and the driest place on the planet is where the recorded annual precipitation is about 3 mm.

Education process

How are they formed, different types of precipitation? The scheme of their formation is one, and it is based on continuous Let us consider this process in more detail.

It all starts with the fact that the Sun begins to warm up. Under the influence of heating, the water masses that are contained in the oceans, seas, rivers, are converted into mixing with air. Vaporization processes occur throughout the day, constantly, to a greater or lesser extent. The volume of vaporization depends on the latitude of the area, as well as on the intensity of solar radiation.

Further, moist air heats up and begins, according to the immutable laws of physics, to rise up. Having risen to a certain height, it cools, and the moisture in it gradually turns into drops of water or ice crystals. This process is called condensation, and it is these water particles that make up the clouds that we admire in the sky.

Droplets in the clouds grow and become larger, taking in more and more moisture. As a result, they become so heavy that they can no longer be held in the atmosphere, and fall down. This is how atmospheric precipitation is born, the types of which depend on specific weather conditions in a particular area.

The water that falls on the surface of the Earth eventually flows in streams into rivers and seas. Then the natural cycle repeats over and over again.

Atmospheric precipitation: types of precipitation

As already mentioned here, there are a huge number of varieties of precipitation. Meteorologists distinguish several dozen.

All types of precipitation can be divided into three main groups:

• drizzling;
• overlay;
• storm.

Precipitation can also be liquid (rain, drizzle, fog) or solid (snow, hail, frost).

Rain

This is a type of liquid precipitation in the form of water droplets that fall to the ground under the influence of gravity. The size of the droplets can be different: from 0.5 to 5 millimeters in diameter. Raindrops, falling on the water surface, leave diverging circles of perfectly round shape on the water.

Depending on the intensity, the rain can be drizzling, patchy or torrential. There is also a type of precipitation such as rain with snow.

This is a special type of precipitation that occurs at sub-zero air temperatures. They should not be confused with hail. Freezing rain is drops in the form of small frozen balls, inside of which there is water. Falling to the ground, such balls break, and water flows out of them, leading to the formation of dangerous ice.

If the intensity of the rain is too high (about 100 mm per hour), then it is called a downpour. Showers form on cold atmospheric fronts, within unstable air masses. As a rule, they are observed in very small areas.

Snow

These solid precipitations fall at sub-zero air temperatures and take the form of snow crystals, colloquially referred to as snowflakes.

During snow, visibility is significantly reduced, with heavy snowfall it can be less than 1 kilometer. During severe frosts, light snow can be observed even with a cloudless sky. Separately, such a type of snow as sleet stands out - this is precipitation that falls at low positive temperatures.

hail

This kind of solid atmospheric precipitation is formed at high altitudes (at least 5 kilometers), where the air temperature is always lower - 15 ° C.

How is hail produced? It is formed from drops of water that either fall or rise sharply in eddies of cold air. Thus, large ice balls are formed. Their size depends on how long these processes took place in the atmosphere. There were cases when hailstones weighing up to 1-2 kilograms fell on the ground!

A hailstone in its internal structure is very similar to an onion: it consists of several layers of ice. You can even count them, like you count the rings on a cut tree, and determine how many times the droplets have made rapid vertical journeys through the atmosphere.

It is worth noting that hail is a real disaster for agriculture, because it can easily destroy all the plants on the plantation. In addition, it is almost impossible to determine the approach of hail in advance. It starts instantly and happens, as a rule, in the summer season of the year.

Now you know how precipitation is formed. The types of precipitation can be very different, which makes our nature beautiful and unique. All the processes taking place in it are simple, and at the same time ingenious.

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. The weight of hailstones in some 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 of daily precipitation patterns - 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 of the Pacific Ocean, precipitation is 4000-5000 mm, and on the leeward slopes of tropical islands up to 10,000 mm. Heavy rainfall is caused by powerful upward currents of 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, 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

				Australia		Northern
Below 500mm
500 -1000 mm
Over 1000 mm

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 with different temperatures and other physical properties meet, fall out of warmer air that forms cyclonic eddies, are typical of the 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 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. the change in their number by months is not the same in different places on the Earth. 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 two small maximums are noted - 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 the eastern coasts of 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, the total amount of 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.

Water that falls on the Earth's surface in the form of rain, snow, hail or condensed on objects as frost or dew is called precipitation. Precipitation can be heavy rainfall associated with warm fronts or showers associated with cold fronts.

The appearance of rain is due to the merging of small droplets of water in a cloud into larger ones, which, overcoming gravity, fall to the Earth. In the event that the cloud contains small particles of solid bodies (dust particles), the condensation process proceeds faster, since they act as condensation nuclei. At negative temperatures, the condensation of water vapor in the cloud leads to snowfall. If snowflakes from the upper layers of the cloud fall into the lower ones with a higher temperature, which contains a large number of cold drops of water, then the snowflakes combine with water, losing their shape and turning into snowballs up to 3 mm in diameter.

Precipitation formation

Hail is formed in clouds of vertical development, the characteristic features of which are the presence of positive temperatures in the lower layer and negative temperatures in the upper one. In this case, spherical snowballs with ascending air currents rise to the upper parts of the cloud with lower temperatures and freeze with the formation of spherical ice - hailstones. Then, under the influence of gravity, the hailstones fall to the Earth. They usually vary in size and can be as small as a pea to a chicken egg.

Types of precipitation

Such types of precipitation as dew, hoarfrost, hoarfrost, ice, fog, are formed in the surface layers of the atmosphere due to the condensation of water vapor on objects. Dew appears at higher temperatures, frost and frost - at negative temperatures. With an excessive concentration of water vapor in the surface atmospheric layer, fog appears. If fog mixes with dust and dirt in industrial cities, it is called smog.
Precipitation is measured by the thickness of the water layer in millimeters. On our planet, on average, about 1000 mm of precipitation falls annually. A rain gauge is used to measure the amount of precipitation. For many years, observations have been made of the amount of precipitation in different regions of the planet, thanks to which the general patterns of their distribution over the earth's surface have been established.

The maximum amount of precipitation is observed in the equatorial zone (up to 2000 mm per year), the minimum - in the tropics and polar regions (200-250 mm per year). In the temperate zone, the average annual rainfall is 500-600 mm per year.

In each climatic zone, uneven precipitation is also noted. This is due to the peculiarities of the relief of a certain area and the prevailing wind direction. For example, on the western outskirts of the Scandinavian mountain range, 1000 mm falls per year, and on the eastern outskirts - more than two times less. Areas of land were identified, on which precipitation is almost completely absent. These are the Atacama Deserts, the central regions of the Sahara. In these regions, the average annual rainfall is less than 50 mm. A huge amount of precipitation is observed in the southern regions of the Himalayas, in Central Africa (up to 10,000 mm per year).

Thus, the determining features of the climate of a given area are the average monthly, seasonal, average annual precipitation, their distribution over the Earth's surface, and intensity. These climate features have a significant impact on many sectors of the human economy, including agriculture.

Related content:

Atmosphere

Atmosphere pressure

The value of the atmosphere

Types of precipitation

For precipitation, there are different classifications.

Atmospheric precipitation and its chemical composition

A distinction is made between heavy rainfall, which is associated with warm fronts, and heavy rainfall, which is associated with 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 on the globe as a whole, 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.

There are different types of 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 the 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, atmospheric pressure, air humidity and temperature, precipitation and wind direction, wind force and cloud cover.

If we talk about the changeability of the weather, then most often it changes in temperate latitudes - in regions with a continental climate. And the weather is most stable in the polar and equatorial latitudes.

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

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.

In other words, climate can be called the average value of weather over a long period of time. Often this period is more than several decades.

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Heavy rainfall

Prolonged (from several hours to a day or more) atmospheric precipitation in the form of rain (common rain) or snow (common snow), falling over a large area with a fairly uniform intensity from nimbostratus and altostratus clouds on a warm front. Heavy rainfall keeps the soil moist.

Rain- liquid precipitation in the form of droplets with a diameter of 0.5 to 5 mm. Separate raindrops leave a trace in the form of a diverging circle on the surface of the water, and in the form of a wet spot on the surface of dry objects.

supercooled rain- liquid precipitation in the form of drops with a diameter of 0.5 to 5 mm, falling out at negative air temperatures (most often 0 ... -10 °, sometimes up to -15 °) - falling on objects, the drops freeze and ice forms. Supercooled rain is formed when falling snowflakes hit a layer of warm air deep enough for the snowflakes to completely melt and turn into raindrops. As these droplets continue to fall, they pass through a thin layer of cold air above the earth's surface and become below freezing. However, the droplets themselves do not freeze, which is why this phenomenon is called supercooling (or the formation of "supercooled droplets").

freezing rain- solid precipitation falling at negative air temperature (most often 0 ... -10 °, sometimes up to -15 °) in the form of solid transparent ice balls with a diameter of 1-3 mm. Formed when raindrops freeze as they fall through a lower layer of sub-zero air. There is unfrozen water inside the balls - falling on objects, the balls break into shells, water flows out and ice forms.

Snow- solid precipitation falling (most often at negative air temperatures) in the form of snow crystals (snowflakes) or flakes. With light snow, horizontal visibility (if there are no other phenomena - haze, fog, etc.) is 4-10 km, with moderate 1-3 km, with heavy snow - less than 1000 m (at the same time, snowfall intensifies gradually, so that visibility values ​​of 1-2 km or less are observed no earlier than an hour after the start of snowfall). In frosty weather (air temperature below -10…-15°) light snow can fall from a cloudy sky. Separately, the phenomenon of wet snow is noted - mixed precipitation that falls at a positive air temperature in the form of flakes of melting snow.

Rain with snow- mixed precipitation falling (most often at positive air temperature) in the form of a mixture of drops and snowflakes.

Precipitation

If rain with snow falls at a negative air temperature, particles of precipitation freeze on objects and ice forms.

Drizzling precipitation

drizzle- liquid precipitation in the form of very small drops (less than 0.5 mm in diameter), as if floating in the air. A dry surface gets wet slowly and evenly. Settling on the surface of the water does not form diverging circles on it.

supercooled drizzle- liquid precipitation in the form of very small drops (less than 0.5 mm in diameter), as if floating in the air, falling out at negative air temperature (most often 0 ... -10 °, sometimes up to -15 °) - settling on objects, drops freeze and form ice.

snow grains- solid precipitation in the form of small opaque white particles (sticks, grains, grains) with a diameter of less than 2 mm, falling out at negative air temperatures.

Fog- accumulation of condensation products (droplets or crystals, or both), suspended in the air, directly above the earth's surface. Cloudiness of the air caused by such accumulation. Usually these two meanings of the word mist do not differ. In fog, horizontal visibility is less than 1 km. Otherwise, haze is called haze.

heavy rainfall

Shower- short-term precipitation, usually in the form of rain (sometimes - wet snow, cereals), characterized by high intensity (up to 100 mm / h). Occur in unstable air masses on a cold front or as a result of convection. Typically, heavy rain covers a relatively small area.

torrential rain- torrential rain.

shower snow- heavy snow. It is characterized by sharp fluctuations in horizontal visibility from 6-10 km to 2-4 km (and sometimes up to 500-1000 m, in some cases even 100-200 m) over a period of time from several minutes to half an hour (snow "charges").

Heavy rain with snow- Mixed precipitation of a shower character, falling out (most often at positive air temperature) in the form of a mixture of drops and snowflakes. If heavy rain with snow falls at a negative air temperature, particles of precipitation freeze on objects and ice forms.

snow grits- solid precipitation of a shower character, falling out at an air temperature of about zero ° and having the form of opaque white grains with a diameter of 2-5 mm; grains are fragile, easily crushed by fingers. It often falls before or at the same time as heavy snow.

ice grits- solid precipitation of a shower character, falling out at an air temperature of +5 to +10 ° in the form of transparent (or translucent) ice grains with a diameter of 1-3 mm; in the center of the grains is an opaque core. The grains are quite hard (they are crushed with fingers with some effort), and when they fall on a hard surface, they bounce off. In some cases, the grains can be covered with a water film (or fall out together with water droplets), and if the air temperature is below zero °, then falling on objects, the grains freeze and ice forms.

hail- solid precipitation that falls in the warm season (at an air temperature above +10 °) in the form of pieces of ice of various shapes and sizes: usually the diameter of the hailstones is 2-5 mm, but in some cases individual hailstones reach the size of a pigeon and even a chicken egg ( then hail causes significant damage to vegetation, car surfaces, breaks window panes, etc.). The duration of the hail is usually small - from 1-2 to 10-20 minutes. In most cases, hail is accompanied by heavy rain and thunderstorms.

ice needles- solid precipitation in the form of tiny ice crystals floating in the air, formed in frosty weather (air temperature below -10 ... -15 °). During the day they sparkle in the light of the rays of the sun, at night - in the rays of the moon or in the light of lanterns. Quite often, ice needles form beautiful luminous "pillars" at night, going from the lanterns up into the sky. They are observed most often in clear or slightly cloudy skies, sometimes they fall out of cirrostratus or cirrus clouds.

Many factors determine how much rain or snow falls on the earth's surface. These are temperature, altitude, location of mountain ranges, etc.

Probably the rainiest place in the world is Mount Waialeale in Hawaii, on the island of Kauai. The average annual rainfall here is 1197 cm. Cherrapunji in India arguably ranks second in terms of rainfall with an average annual level of 1079 to 1143 cm. Once, 381 cm of rain fell in Cherrapunji in 5 days. And in 1861, the amount of precipitation reached 2300 cm!

To make it clearer, let's compare rainfall in some cities around the world, London gets 61 cm of rain per year, Edinburgh about 68 cm and Cardiff about 76 cm. New York gets about 101 cm of rain. Ottawa in Canada gets 86 cm, Madrid about 43 cm and Paris 55 cm. So you see what a contrast Cherrapunji is.

The driest place in the world is probably Arica in Chile. Here the rainfall is 0.05 cm per year. The driest place in the US is Greenland Ranch in Death Valley. There, the average annual rainfall is less than 3.75 cm.

In some vast regions of the Earth, heavy rainfall occurs all year round. For example, almost every point along the equator receives 152 cm or more of precipitation each year. The equator is the junction of two large streams of air. Throughout the equator, air moving down from the north meets air moving up from the south.

There is a main upward movement of hot air mixed with water vapor. As the air rises to colder altitudes, a large amount of water vapor condenses and falls as rain.

Most of the rain falls on the windward side of the mountains. The other side, called the leeward side, receives much less precipitation. An example is the Cascade Mountains in California. Westerly winds carrying water vapor move from the Pacific Ocean. Having reached the coast, the air rises along the western slopes of the mountains, cooling.

Precipitation. Scheme and types of precipitation

Cooling causes the condensation of water vapor, which falls as rain or snow.

Depending on the nature of cloudiness and the mode of precipitation, two types of their daily variation are distinguished: continental and marine. The continental type is characterized by two maxima: the main one - in the afternoon from convective cumulonimbus, and at the equator from cumulus clouds, and insignificant - early in the morning from stratus clouds, between them there are minima: at night and before noon.

What is precipitation? What types of precipitation do you know?

In the marine (coastal) type, there is one precipitation maximum at night (due to unstable air stratification and convection) and one minimum during the day. These types of daily precipitation patterns are observed throughout the year in the hot zone, while in the temperate zones they are possible only in summer.

The annual course of precipitation, i.e., their change by months during the year, is very different in different places on the Earth. This depends on many factors: the radiation regime, the general circulation of the atmosphere, the specific physical and geographical situation, etc. Several main types of annual precipitation can be identified and expressed in the form of bar graphs (Fig. 47).

Rice. 47. Types of the annual course of precipitation on the example of the northern hemisphere

Equatorial type - heavy precipitation falls fairly evenly throughout the year, there are no dry months, there are two small maximums - in April and October, after the days of the equinoxes, and two small minimums in July and January, after the days of the solstices.

Monsoon type - maximum precipitation in summer, minimum - in winter. It is characteristic of subequatorial latitudes, where the annual course of precipitation is very pronounced due to the dryness of winter, as well as the eastern coasts of continents in subtropical and temperate latitudes. However, the annual precipitation amplitude is somewhat smoothed here, especially in the subtropics, where frontal rains also fall in winter. The annual amount of precipitation at the same time gradually decreases from the subequatorial to the temperate zone.

Mediterranean type - maximum precipitation in winter due to active frontal activity, minimum - in summer. It is observed in subtropical latitudes on the western coasts and inland.

In temperate latitudes, two main types of annual precipitation are distinguished: continental and marine. The continental (inland) type is distinguished by the fact that two to three times more precipitation falls here in summer than in winter, due to frontal and convective precipitation.

Marine type - precipitation is distributed evenly throughout the year with a small maximum in autumn and winter. Their number is greater than in the previous type.

The Mediterranean and temperate continental types are characterized by a decrease in the total amount of precipitation as one moves deeper into the continents.

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Publication date: 2014-11-19; Read: 2576 | Page copyright infringement

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Atmospheric precipitation is one of the meteorological elements strongly dependent on a number of local landscape features.

Let us try, however, to trace what conditions influence their distribution.

First of all, it is necessary to note the value of air temperature. The temperature decreases from the equator to the poles; consequently, both the intensity of evaporation and the moisture capacity of the air decrease in the same direction. In cold regions, evaporation is small, and cold air is not able to dissolve much water vapor in itself; therefore, during condensation, a large amount of precipitation cannot be released from it. In warm regions, strong evaporation and a high moisture capacity of air lead, when water vapor condenses, to abundant precipitation. Thus, a regularity must inevitably manifest itself on Earth, which consists in the fact that in warm regions there is especially a lot of precipitation, while in cold regions there is little of it. This regularity actually manifests itself, but, like other phenomena in nature, it is complicated, and in some places completely obscured by a number of other influences, and above all by the circulation of the atmosphere, the nature of the distribution of land and sea, relief, height above ocean level and sea currents.

Knowing the conditions necessary for the condensation of water vapor, it is possible to predict how the circulation of the atmosphere affects the distribution of precipitation. Since air is a carrier of moisture, and its movement covers vast areas on Earth, this inevitably leads to a smoothing of differences in the amount of precipitation caused by the distribution of temperatures in areas where air experiences uplifts (above the equator, in cyclones, on the windward slopes of mountain ranges), an environment favorable for precipitation is created, and all other factors become subordinate. In those places where descending air movements predominate (in subtropical maxima, in anticyclones in general, in the area of ​​the trade winds, on the leeward slopes of mountains, etc.), precipitation is much less.

It is generally accepted that the amount of precipitation in a given area is highly dependent on its proximity to the sea or its distance from the sea. In fact, many examples are known when very dry regions of the Earth are located on the ocean coasts and, conversely, far from the sea, inland (as, for example, on the eastern slope of the Andes in the upper reaches of the Amazon), a huge amount of precipitation falls. The point here is not so much in the distance from the sea, but in the nature of the circulation of the atmosphere and the structure of the surface, that is, in the absence or presence of mountain ranges that interfere with the movement of air masses carrying moisture. During the southwestern monsoon in India, air masses pass over the Thar Desert without irrigating it with rain, since the flat relief does not impede the movement of air, and the heated desert has a rather drying effect on the air masses.

Types of precipitation.

But the same monsoon on the windward slope of the Western Ghats, not to mention the southern slopes of the Himalayas, leaves a huge amount of moisture.

The need to single out orographic precipitation as a special type testifies to the exceptionally large role of the structure of the earth's surface in the distribution of precipitation. True, in this case, as in all others, the relief is important not only in itself, as a mechanical obstacle, but in combination with absolute height and atmospheric circulation.

The penetration of warm sea currents into high latitudes contributes to the formation of precipitation due to the fact that cyclonic circulation of the atmosphere is associated with warm currents. Cold currents have the opposite effect, since spurs of high pressure usually develop above them.

Of course, none of these factors affects the distribution of precipitation independently of the others. In each case, the precipitation of atmospheric moisture is regulated by a complex and sometimes contradictory interaction of both general and local agents. However, leaving aside the details, the main conditions that determine the distribution of precipitation in the landscape envelope still include temperature, general atmospheric circulation, and topography.

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