Classification of precipitation. By appearance precipitation are divided into liquid, solid and terrestrial.
Liquid precipitation includes:
rain – precipitation in the form of drops of various sizes with a diameter of 0.5–7 mm;
drizzle - small droplets with a diameter of 0.05–0.5 mm, seemingly in suspension.
Solid sediments include:
snow – ice crystals that form various kinds of snowflakes (plates, needles, stars, columns) 4–5 mm in size. Sometimes snowflakes are combined into snow flakes, the size of which can reach 5 cm or more;
snow pellets - precipitation in the form of opaque spherical grains of white or matte white (milky) color with a diameter of 2 to 5 mm;
ice pellets are solid particles that are transparent on the surface and have an opaque, matte core in the center. The diameter of the grains is from 2 to 5 mm;
hail – more or less large pieces of ice (hailstones), having a spherical or irregular shape and a complex internal structure. The diameter of hailstones varies within a very wide range: from 5 mm to 5–8 cm. There are cases when hailstones weighing 500 g or more fell.
If precipitation does not fall from clouds, but is deposited from atmospheric air on the surface of the earth or on objects, then such precipitation is called ground precipitation. These include:
dew - tiny drops of water that condense on the horizontal surfaces of objects (decks, boat covers, etc.) due to radiation cooling them on clear cloudless nights. A slight wind (0.5–10 m/s) promotes the formation of dew. If the temperature of horizontal surfaces is below zero, then under similar conditions water vapor sublimates on them and frost forms - a thin layer of ice crystals;
liquid deposit – tiny drops of water or a continuous film of water, formed in cloudy and windy weather on the windward predominantly vertical surfaces of cold objects (walls of superstructures, protective devices of winches, cranes, etc.).
glaze is an ice crust that forms when the temperature of these surfaces is below 0 °C. In addition, a hard coating may form on the surfaces of the vessel - a layer of crystals densely or densely sitting on the surface or a thin continuous layer of smooth transparent ice.
Into the foggy frosty weather in low winds, granular or crystalline frost may form on the vessel's rigging, ledges, cornices, wires, etc. Unlike frost, rime does not form on horizontal surfaces. The loose structure of frost distinguishes it from solid plaque. Granular frost is formed at air temperatures from –2 to – 7 ° C due to freezing of supercooled fog droplets, and crystalline frost, which is white precipitate from crystals of a fine structure, is formed at night with a cloudless sky or thin clouds from particles of fog or haze at temperatures from –11 to –2 ° C and above.
According to the nature of precipitation, precipitation is divided into shower, heavy and drizzling.
Rainfall falls from cumulonimbus (thunderstorm) clouds. In summer it is large drops of rain (sometimes with hail), and in winter it is heavy snowfall with frequent changes in the shape of snowflakes, snow or ice grains. Precipitation occurs from nimbostratus (summer) and altostratus (winter) clouds. They are characterized by small fluctuations in intensity and long duration of fallout.
Drizzle falls from stratus and stratocumulus clouds in the form of small drops with a diameter of no more than 0.5 mm, descending at very low speeds.
Based on intensity, precipitation is divided into strong, moderate and light.
Clouds and precipitation.
Upper level clouds.
Cirrus (Ci)- Russian name feathery, individual tall, thin, fibrous, white, often silky clouds. Their fibrous and feathery appearance is due to the fact that they are composed of ice crystals.
Cirrus appear in the form of isolated bunches; long, thin lines; feathers like smoke torches, curved stripes. Cirrus clouds can appear in parallel bands that cross the sky and appear to converge on a single point on the horizon. This will be the direction to the area low pressure. Because of their height, they become illuminated earlier than other clouds in the morning and remain illuminated after the Sun has set. Cirrus generally associated with clear weather, but if they are followed by lower and denser clouds, then there may be rain or snow in the future.
Cirrocumulus (Cc) , the Russian name for cirrocumulus, are tall clouds made up of small white flakes. Usually they do not reduce illumination. They are placed in the sky in separate groups of parallel lines, often like ripples, similar to sand on the coast or waves on the sea. Cirrocumulus are composed of ice crystals and are associated with clear weather.
Cirrostratus (Cs), The Russian name is cirrostratus - thin, white, high clouds, sometimes covering the sky completely and giving it a milky tint, more or less distinct, reminiscent of a thin tangled network. The ice crystals they are made of refract light to form a halo with the Sun or Moon at the center. If the clouds subsequently thicken and lower, precipitation can be expected in about 24 hours. These are the clouds of a warm front system.
Upper level clouds do not produce precipitation.
Mid-level clouds. Precipitation.
Altocumulus (Ac), Russian name altocumulus,- middle-tier clouds, consisting of a layer of large individual spherical masses. Altocumulus (Ac) are similar to the upper level clouds of sirrocumulus. Since they lie lower, their density, water content and the size of individual structural elements are greater than those of sirrocumulus. Altocumulus (Ac) can vary in thickness. They can range from blinding white if they are illuminated by the Sun, to dark gray if they cover the entire sky. They are often mistaken for stratocumulus. Sometimes individual structural elements merge and form a series of large swells, like ocean waves, with stripes of blue sky between them. These parallel stripes differ from cirrocumulus in that they appear on the palate in large dense masses. Sometimes altocumulus appear before a thunderstorm. As a rule, they do not produce precipitation.
Altostratus (As) , Russian name altostratified, - middle-tier clouds that look like a gray fibrous layer. The Sun or Moon, if visible, appears as if through frosted glass, often with crowns around the star. Halos do not form in these clouds. If these clouds thicken, lower, or turn into low ragged Nimbostratus, then precipitation begins to fall from them. Then you should expect prolonged rain or snow (for several hours). In the warm season, drops from altostratus, evaporating, do not reach the surface of the earth. IN winter time they can produce significant snowfalls.
Low level clouds. Precipitation.
Stratocumulus (Sc) Russian name stratocumulus– low clouds that look like soft, gray masses, like waves. They can be formed into long, parallel shafts similar to altocumulus. Sometimes precipitation falls from them.
Stratus (St), The Russian name is stratified - low, homogeneous clouds resembling fog. Often their lower boundary is at an altitude of no more than 300 m. The curtain of dense stratus gives the sky a hazy appearance. They can lie on the very surface of the earth and are then called fog. Stratus can be dense and transmit sunlight so poorly that the Sun is not visible at all. They cover the Earth like a blanket. If you look from above (having broken through the thickness of the clouds on an airplane), they are dazzlingly white illuminated by the sun. Strong wind sometimes tears the stratus into shreds, called stratus fractus.
Lungs can fall out of these clouds in winter ice needles, and in the summer - drizzle– very small droplets suspended in the air and gradually settling. Drizzle comes from continuous low stratus or from those lying on the surface of the Earth, that is, from fog. Fog is very dangerous in navigation. Freezing drizzle can cause icing on the boat.
Nimbostratus (Ns) , Russian name for stratostratus, - low, dark. Stratus, shapeless clouds, almost uniform, but sometimes with damp patches at the base. Nimbostratus usually cover vast territories measured in hundreds of kilometers. Throughout this vast territory there is simultaneously snow or rain. Precipitation falls for long hours (up to 10 hours or more), drops or snowflakes are small in size, the intensity is low, but during this time a significant amount of precipitation can fall. They are called cover. Similar precipitation may also fall from Altostratus, and sometimes from Stratocumulus.
Clouds of vertical development. Precipitation.
Cumulus (Cu) . Russian name cumulus, - dense clouds formed in vertically rising air. As the air rises, it cools adiabatically. When its temperature reaches the dew point, condensation begins and a cloud appears. Cumulus have a horizontal base, convex upper and lateral surfaces. Cumulus appear as separate flakes, and never cover the palate. When the vertical development is small, the clouds look like tufts of cotton wool or cauliflower. Cumulus are called "fair weather" clouds. They usually appear by midday and disappear by evening. However, Cu can merge with altocumulus, or grow and turn into thunderous cumulonimbus. Cumulus are distinguished by high contrast: the white, illuminated by the Sun, and the shadow side.
Cumulonimbus (Cb), Russian name cumulonimbus, - massive clouds of vertical development, rising in huge columns to great heights. These clouds start at the very lower tier and extend to the tropopause, and sometimes extend into the lower stratosphere. They are taller than the most high mountains on the ground. Their vertical thickness is especially great in equatorial and tropical latitudes. The upper part of Cumulonimbus is composed of ice crystals, often stretched by the wind in an anvil shape. At sea, the top of the cumulonimbus can be visible at a great distance, when the base of the cloud is still below the horizon.
Cumulus and cumulonimbus are called clouds of vertical development. They are formed as a result of thermal and dynamic convection. On cold fronts, cumulonimbus arise as a result of dynamic convection.
These clouds can appear in the cold air at the rear of the cyclone and at the front of the anticyclone. Here they are formed as a result of thermal convection and give, accordingly, intramass, local rainfall. Cumulonimbus and associated showers over the oceans occur more often at night, when the air above the water surface is thermally unstable.
Particularly powerful cumulonimbus develop in the intertropical convergence zone (near the equator) and in tropical cyclones. Associated with cumulonimbus are: atmospheric phenomena like rain showers, snow showers, snow pellets, thunderstorms, hail, rainbows. It is with cumulonimbus that tornadoes (tornadoes), the most intense and most often observed in tropical latitudes, are associated.
Shower rain (snow) characterized by large drops (snow flakes), sudden onset, sudden end, significant intensity and short duration (from 1-2 minutes to 2 hours). Rain showers in summer are often accompanied by thunderstorms.
Ice grains It is a hard, opaque piece of ice up to 3 mm in size, moist on top. Ice pellets fall with heavy rain in spring and autumn.
Snow pellets has the appearance of opaque soft grains of white branches from 2 to 5 mm in diameter. Snow pellets are observed when the wind is squally. Snow pellets are often observed simultaneously with heavy snow.
hail falls only in the warm season exclusively during showers and thunderstorms of their most powerful cumulonimbus and usually lasts no more than 5-10 minutes. These are pieces of ice with a layered structure, about the size of a pea, but there are also many larger sizes.
Other precipitation.
Precipitation in the form of drops, crystals or ice on the surface of the Earth or objects is often observed, not falling from clouds, but precipitating from the air under a cloudless sky. This is dew, frost, frost.
Dew drops that appear on the deck at night in summer. At negative temperatures it forms frost. Frost - ice crystals on wires, ship equipment, racks, yards, masts. Frost forms at night, more often when there is fog or haze, at air temperatures below -11°C.
Ice an extremely dangerous phenomenon. It is an ice crust that results from the freezing of supercooled fog, drizzle, raindrops or droplets on supercooled objects, especially on windward surfaces. A similar phenomenon occurs from splashing or flooding of the deck. sea water at negative air temperatures.
Determining cloud height.
At sea, cloud heights are often determined approximately. This is a difficult task, especially at night. The height of the lower base of clouds of vertical development (any variety of cumulus), if they were formed as a result of thermal convection, can be determined from psychrometer readings. The height to which the air must rise before condensation begins is proportional to the difference between the air temperature t and the dew point td. At sea, this difference is multiplied by 126.3 to obtain the height of the lower boundary of the cumulus clouds N in meters. This empirical formula looks like:
H = 126.3 ( t – t d ). (4)
The height of the base of lower layer stratus clouds ( St, Sc, Ns) can be determined using empirical formulas:
H = 215 (t – t d ) (5)
H = 25 (102 - f); (6)
Where f – relative humidity.
Visibility. Fogs.
Visibility it's called maximum distance horizontally, in which an object can be clearly visible and recognized in daylight. In the absence of any impurities in the air, it is up to 50 km (27 nautical miles).
Visibility is reduced due to the presence of liquid and solid particles in the air. Visibility is impaired by smoke, dust, sand, and volcanic ash. This occurs when there is fog, smog, haze, or precipitation. The visibility range decreases due to splashes in the sea in stormy weather with a wind force of 9 or more (40 knots, about 20 m/s). Visibility becomes worse during low, continuous clouds and at dusk.
Haze
Haze is a clouding of the atmosphere due to solid particles suspended in it, such as dust, as well as smoke, burning, etc. With severe haze, visibility decreases to hundreds, and sometimes to tens of meters, as in thick fog. Haze is usually a consequence of dust (sand) storms. Even relatively large particles are lifted into the air by strong winds. This is a typical phenomenon of deserts and plowed steppes. Large particles spread in the lowest layer and settle near their source. Small particles are carried over long distances by air currents, and due to air turbulence they penetrate upward to a considerable height. Fine dust remains in the air for a long time, often in the complete absence of wind. The color of the Sun becomes brownish. The relative humidity during these events is low.
Dust can be transported over long distances. It was celebrated in the Greater and Lesser Antilles. Dust from the Arabian deserts is carried by air currents into the Red Sea and the Persian Gulf.
However, during haze, visibility is never as bad as during fog.
Fogs. General characteristics.
Fogs pose one of the greatest dangers to navigation. They are responsible for many accidents, human lives, and sunken ships.
Fog is said to occur when horizontal visibility, due to the presence of droplets or water crystals in the air, becomes less than 1 km. If visibility is more than 1 km, but not more than 10 km, then such a decrease in visibility is called haze. Relative humidity during fog is usually more than 90%. Water vapor itself does not reduce visibility. Visibility is reduced by water droplets and crystals, i.e. water vapor condensation products.
Condensation occurs when the air is oversaturated with water vapor and the presence of condensation nuclei. Above the sea it is mainly small particles of sea salt. Supersaturation of air with water vapor occurs when the air is cooled or in cases of additional supply of water vapor, and sometimes as a result of mixing of two air masses. In accordance with this, fogs are distinguished cooling, evaporation and mixing.
Based on intensity (based on the visual range D n), fogs are divided into:
strong D n 50 m;
moderate 50 m<Д n <500 м;
weak 500 m<Д n < 1000 м;
heavy haze 1000 m<Д n <2000 м;
light haze 2000 m<Д n <10 000 м.
Based on their state of aggregation, fogs are divided into droplet-liquid, icy (crystalline) and mixed. Visibility conditions are worst in icy fogs.
Cooling mists
Water vapor condenses as the air cools to its dew point. This is how cooling fogs are formed - the largest group of fogs. They can be radiative, advective and orographic.
Radiation mists. The Earth's surface emits long-wave radiation. During the day, energy losses are offset by the arrival of solar radiation. At night, radiation causes the Earth's surface temperature to drop. On clear nights, the cooling of the underlying surface occurs more intensely than in cloudy weather. The air adjacent to the surface also cools. If the cooling is to the dew point and below, then dew will form in calm weather. A weak wind is required for fog to form. In this case, as a result of turbulent mixing, a certain volume (layer) of air is cooled and condensation forms in this layer, i.e. fog. Strong wind leads to mixing of large volumes of air, dispersion of condensate and its evaporation, i.e. to the disappearance of the fog.
Radiation fog can extend up to a height of 150 m. It reaches its maximum intensity before or shortly after sunrise, when the minimum air temperature occurs. Conditions necessary for the formation of radiation fog:
High air humidity in the lower layers of the atmosphere;
Stable stratification of the atmosphere;
Partly cloudy or clear weather;
Light wind.
The fog disappears as the earth's surface warms up after sunrise. The air temperature rises and the droplets evaporate.
Radiation mists above the water surface are not formed. Daily fluctuations in the temperature of the water surface, and therefore the air, are very small. The temperature at night is almost the same as during the day. Radiative cooling does not occur, and there is no condensation of water vapor. However, radiation fogs can cause problems in navigation. In coastal areas, fog, as a single whole, flows with cold, and therefore heavy, air onto the water surface. This can also be amplified by the night breeze from land. Even clouds formed at night over elevated coasts can be carried by the night breeze to the surface of the water, as is observed on many coasts of temperate latitudes. The cloud cap from the hill often flows down, covering the approaches to the shore. More than once this led to a collision between ships (port of Gibraltar).
Advection fogs. Advective fogs result from the advection (horizontal transfer) of warm, moist air onto a cold underlying surface.
Advective fogs can simultaneously cover vast horizontal spaces (many hundreds of kilometers), and vertically extend up to 2 kilometers. They do not have a daily cycle and can exist for a long time. Over land at night they intensify due to radiation factors. In this case, they are called advective-radiative. Advective fogs also occur with significant winds, provided that the air stratification is stable.
These fogs are observed over land in the cold season when relatively warm and humid air enters it from the water surface. This phenomenon occurs in Foggy Albion, Western Europe, and coastal areas. In the latter case, if fogs cover relatively small areas, they are called coastal.
Advective fogs are the most common fogs in the ocean, occurring near the coasts and in the depths of the oceans. They always stand above cold currents. In the open sea, they can also be found in warm sectors of cyclones, in which air is transported from warmer areas of the ocean.
They can be found off the coast at any time of the year. In winter, they form over land and can partially slide to the water surface. In summer, advective fogs occur off the coast in cases where warm, moist air from the continent, in the process of circulation, passes to a relatively cold water surface.
Signs of the imminent disappearance of advective fog:
- change in wind direction;
- disappearance of the warm sector of the cyclone;
- it started to rain.
Orographic fogs. Orographic fogs or slope fogs are formed in mountainous areas with a low-gradient baric field. They are associated with the valley wind and are observed only during the day. The air rises up the slope with the valley wind and is cooled adiabatically. Once the temperature reaches the dew point, condensation begins and a cloud forms. For residents of the slope it will be fog. Sailors can encounter such fogs off the mountainous coasts of islands and continents. Fogs can obscure important landmarks on the slopes.
Mists of evaporation
Condensation of water vapor can occur not only as a result of cooling, but also when the air is oversaturated with water vapor due to evaporation of water. The evaporating water should be warm and the air cold, the temperature difference should be at least 10 °C. Cold air stratification is stable. In this case, an unstable stratification is established in the lowest driving layer. This causes a large amount of water vapor to flow into the atmosphere. It will immediately condense in the cold air. A fog of evaporation appears. Often it is small vertically, but its density is very high and, accordingly, visibility is very poor. Sometimes only the masts of the ship stick out from the fog. Such fogs are observed over warm currents. They are characteristic of the Newfoundland region, at the junction of the warm Gulf Stream and the cold Labrador Current. This is an area of heavy shipping.
In the Gulf of St. Lawrence, fog sometimes extends vertically up to 1500m. At the same time, the air temperature can be below 9°C below zero and the wind is almost gale force. The fog in such conditions consists of ice crystals and is dense with very poor visibility. Such dense sea fogs are called frost smoke or arctic frost smoke and pose a serious danger.
At the same time, with unstable air stratification, there is a slight local hovering of the sea, which does not pose a danger to navigation. The water seems to be boiling, streams of “steam” rise above it and immediately dissipate. Such phenomena occur in the Mediterranean Sea, off Hong Kong, in the Gulf of Mexico (with the relatively cold north wind “Norther”) and in other places.
Mixing mists
Fog can also form when two air masses mix, each of which has high relative humidity. The reservoir may be oversaturated with water vapor. For example, if cold air meets warm and humid air, the latter will cool at the mixing boundary and fog may appear there. Fog ahead of a warm front or occluded front is common in temperate and high latitudes. This mixing fog is known as frontal fog. However, it can also be considered as evaporation fog, since it occurs when warm droplets evaporate in cold air.
Mixing fogs form at the edge of ice and above cold currents. An iceberg in the ocean can be surrounded by fog if there is enough water vapor in the air.
Geography of fogs
The type and shape of clouds depend on the nature of the prevailing processes in the atmosphere, the season of the year and the time of day. Therefore, much attention is paid to observations of the development of clouds over the sea when sailing.
There are no fogs in the equatorial and tropical regions of the oceans. It’s warm there, there are no differences in temperature and air humidity day and night, i.e. There is almost no daily variation of these meteorological quantities.
There are a few exceptions. These are vast areas off the coast of Peru (South America), Namibia (South Africa) and off Cape Guardafui in Somalia. In all these places it is observed upwelling(rising of cold deep waters). Warm, moist air from the tropics flows over cold water and forms advective fog.
Fogs in the tropics can occur near continents. Thus, the port of Gibraltar has already been mentioned; fog is possible in the port of Singapore (8 days a year); in Abidjan there are up to 48 days of fog. Their greatest number is in the Bay of Rio de Janeiro - 164 days a year.
In temperate latitudes, fogs are a very common phenomenon. Here they are observed off the coast and in the depths of the oceans. They occupy vast territories and occur in all seasons of the year, but are especially frequent in winter.
They are also typical for polar regions near the boundaries of ice fields. In the North Atlantic and the Arctic Ocean, where the warm waters of the Gulf Stream penetrate, there is constant fog during the cold season. They are often found at the ice edge in summer.
Fogs most often occur at the junction of warm and cold currents and in places where deep water rises. The frequency of fogs is also high along the coasts. In winter, they occur when warm, moist air advects from the ocean onto land, or when cold continental air flows down onto relatively warm water. In the summer, air from the continent hitting the relatively cold water surface also produces fog.
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 contained in the atmosphere condenses and falls to the surface of the earth in the form of rain or snow. Forecasters call this precipitation.
Scientific definition of precipitation
Atmospheric precipitation in the scientific community is usually called ordinary water, which in liquid (rain) or solid (snow, frost, hail) form falls from the atmosphere onto 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 flows with different temperatures collide.
The amount of precipitation determines the climatic characteristics of the area and also serves as the basis for agricultural productivity. Therefore, meteorologists constantly measure how much precipitation fell in a particular area over a certain period. This information forms the basis of productivity, etc.
Precipitation is measured in millimeters of the layer of water that would cover the surface of the earth if the water were not absorbed or evaporated. On average, 1000 millimeters of precipitation falls per year, but some areas receive more, while others receive less.
Thus, 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 accumulates per year.
Types of precipitation
Meteorologists distinguish between three main types of precipitation: rain, snow and hail. Rain consists of drops of water in a liquid state, hail and in a solid state. However, there are also transitional forms of precipitation:
— rain and snow are a common occurrence in autumn, when snowflakes and drops of water alternately fall from the sky;
— freezing rain is a rather rare type of precipitation, consisting of ice balls filled with water. Falling to the ground, they break, water flows out and immediately freezes, covering asphalt, trees, roofs of houses, wires, etc. with a layer of ice;
- snow pellets - small white balls, reminiscent of cereals, falling from the sky at air temperatures close to zero. The balls consist of ice crystals weakly frozen together and are easily crushed in the fingers.
Precipitation can be torrential, continuous and drizzling.
— Heavy precipitation usually occurs suddenly and is characterized by high intensity. They can last from several minutes to several days (in tropical climates), and are often accompanied by thunderstorms and sharp gusts of wind.
— Heavy precipitation occurs over a long period of time, several hours or even days in a row. They begin with low intensity, gradually increase and then continue, without changing intensity, all the time until the end.
— Drizzle precipitation differs from regular precipitation in the very small size of the droplets and in that it falls not only from clouds, but also from fog. Drizzling precipitation is often observed at the beginning and end of rainfall, 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 lowest layer of the atmosphere in contact with the earth's surface. They occupy a small percentage of the total precipitation, but are also taken into account by meteorologists.
— Frost is ice crystals that freeze in the early morning on protruding objects and the surface of the ground if the night temperature drops below zero.
— Dew is drops of water that condense in the warm season as a result of night cooling of the air. Dew falls on plants, protruding objects, stones, walls of houses, etc.
— Frost is ice crystals that form in winter at temperatures from – 10 to – 15 degrees on tree branches and wires in the form of a fluffy fringe. Appears at night and disappears during the day.
— Ice and glaze - freezing of an ice layer on the surface of the earth, trees, walls of buildings, etc. resulting from the rapid cooling of air during or after sleet and freezing rain. 
All types of precipitation are formed as a result of the condensation of water that has evaporated from the surface of the planet. The most powerful “source” of precipitation is the surface of the seas and oceans; land provides no more than 14% of all atmospheric moisture.
Rain is liquid precipitation in the form of droplets with a diameter of 0.5 to 5 mm. Individual drops of rain leave a mark on the surface of water in the form of a diverging circle, and on the surface of dry objects - in the form of a wet spot.
Supercooled rain is liquid precipitation in the form of drops with a diameter of 0.5 to 5 mm, falling at negative air temperatures (most often 0...−10°, sometimes up to −15°) - falling on objects, the drops freeze and ice forms.
Freezing rain is solid precipitation that falls at negative air temperatures (most often 0...−10°, sometimes up to −15°) in the form of solid transparent ice balls with a diameter of 1-3 mm. There is unfrozen water inside the balls - when falling on objects, the balls break into shells, the water flows out and ice forms.
Snow is solid precipitation that falls (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 snow 1-3 km, with heavy snow - less than 1000 m (in this case, snowfall increases gradually, so 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 may fall from a partly cloudy sky. Separately, the phenomenon of wet snow is noted - mixed precipitation that falls at positive air temperatures in the form of flakes of melting snow.
Rain and snow are mixed precipitation that falls (most often at positive air temperatures) in the form of a mixture of drops and snowflakes. If rain and snow fall at subzero air temperatures, precipitation particles freeze onto objects and ice forms.
Drizzle
Characterized by low intensity, monotonous loss without changing intensity; start and stop gradually. The duration of continuous loss is usually several hours (and sometimes 1-2 days). Fall out of stratus clouds or fog; Moreover, in most cases the cloudiness is continuous (10 points) and only occasionally significant (7-9 points, usually at the beginning or end of the precipitation period). Often accompanied by decreased visibility (haze, fog).
Drizzle is 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 becomes wet slowly and evenly. When deposited on the surface of the water, it 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 at negative air temperatures (most often 0...−10°, sometimes up to −15°) - settling on objects, The drops freeze and ice forms.
Rainfall
They are characterized by the suddenness of the beginning and end of the loss, and a sharp change in intensity. The duration of continuous loss usually ranges from several minutes to 1-2 hours (sometimes several hours, in the tropics - up to 1-2 days). Often accompanied by a thunderstorm and a short-term increase in wind (squall). They fall from cumulonimbus clouds, and the amount of clouds can be both significant (7-10 points) and small (4-6 points, and in some cases even 2-3 points). The main feature of precipitation of a torrential nature is not its high intensity (storm precipitation can be weak), but the very fact of precipitation from convective (most often cumulonimbus) clouds, which determines fluctuations in the intensity of precipitation. In hot weather, light showers may fall from powerful cumulus clouds, and sometimes (very light showers) even from mid-cumulus clouds.
Shower rain is rain of a torrential nature.
Shower snow is snow of a torrential nature. 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”).
Shower rain with snow - mixed precipitation of a torrential nature, falling (most often at positive air temperatures) in the form of a mixture of drops and snowflakes. If heavy rain with snow falls at sub-zero air temperatures, precipitation particles freeze onto objects and ice forms.
Snow pellets are solid rainfall precipitation that falls at an air temperature of about zero degrees and has the appearance of opaque white grains with a diameter of 2-5 mm; The grains are fragile and easily crushed by fingers. Often falls before or simultaneously with heavy snow.
Hail is solid precipitation that falls in the warm season (at air temperatures above +10°) in the form of pieces of ice of various shapes and sizes: usually the diameter of hailstones is 2-5 mm, but in some cases individual hailstones reach the size of a pigeon or even a chicken egg (then hail causes significant damage to vegetation, car surfaces, breaks window glass, etc.). The duration of hail is usually short - from 1-2 to 10-20 minutes. In most cases, hail is accompanied by rain showers and thunderstorms.
Precipitation
Long-term, average monthly, seasonal, annual precipitation, its distribution over the earth's surface, annual and daily variations, frequency, intensity are the defining characteristics of climate, which are of significant importance for agriculture and many other sectors of the national economy.
Classification of precipitation
Precipitation falling on the earth's surface
Cover precipitation
They are characterized by monotony of loss without significant fluctuations in intensity. They start and stop gradually. The duration of continuous precipitation is usually several hours (and sometimes 1-2 days), but in some cases light precipitation can last half an hour to an hour. Usually fall from nimbostratus or altostratus clouds; Moreover, in most cases the cloudiness is continuous (10 points) and only occasionally significant (7-9 points, usually at the beginning or end of the precipitation period). Sometimes weak short-term (half an hour to an hour) precipitation is observed from stratus, stratocumulus, altocumulus clouds, with the number of clouds being 7-10 points. In frosty weather (air temperature below −10...-15°), light snow may fall from a partly cloudy sky.
Rain- liquid precipitation in the form of droplets with a diameter of 0.5 to 5 mm. Individual drops of rain leave a mark on the surface of water in the form of a diverging circle, and on the surface of dry objects - in the form of a wet spot.
Freezing rain- liquid precipitation in the form of drops with a diameter of 0.5 to 5 mm, falling at negative air temperatures (most often 0...-10°, sometimes up to −15°) - falling on objects, the drops freeze and ice forms.
freezing rain- solid precipitation that falls at negative air temperatures (most often 0...-10°, sometimes up to −15°) in the form of solid transparent ice balls with a diameter of 1-3 mm. There is unfrozen water inside the balls - when falling on objects, the balls break into shells, the water flows out and ice forms.
Snow- solid precipitation that falls (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 snow 1-3 km, with heavy snow - less than 1000 m (in this case, snowfall increases gradually, so 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 may fall from a partly cloudy sky. Separately, the phenomenon of wet snow is noted - mixed precipitation that falls at positive air temperatures in the form of flakes of melting snow.
Rain with snow- mixed precipitation that falls (most often at positive air temperatures) in the form of a mixture of drops and snowflakes. If rain and snow fall at subzero air temperatures, precipitation particles freeze onto objects and ice forms.
Drizzle
Characterized by low intensity, monotonous loss without changing intensity; start and stop gradually. The duration of continuous loss is usually several hours (and sometimes 1-2 days). Fall out of stratus clouds or fog; Moreover, in most cases the cloudiness is continuous (10 points) and only occasionally significant (7-9 points, usually at the beginning or end of the precipitation period). Often accompanied by decreased visibility (haze, fog).
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 becomes wet slowly and evenly. When deposited on the surface of the water, it does not form diverging circles on it.
Freezing drizzle- liquid precipitation in the form of very small drops (less than 0.5 mm in diameter), as if floating in the air, falling at negative air temperatures (most often 0...-10°, sometimes up to −15°) - settling on objects, the drops freeze and ice forms.
Snow grains- solid precipitation in the form of small opaque white particles (sticks, grains, grains) with a diameter of less than 2 mm, falling at negative air temperatures.
Rainfall
They are characterized by the suddenness of the beginning and end of the loss, and a sharp change in intensity. The duration of continuous loss usually ranges from several minutes to 1-2 hours (sometimes several hours, in the tropics - up to 1-2 days). Often accompanied by a thunderstorm and a short-term increase in wind (squall). They fall from cumulonimbus clouds, and the amount of clouds can be both significant (7-10 points) and small (4-6 points, and in some cases even 2-3 points). The main feature of precipitation of a torrential nature is not its high intensity (storm precipitation can be weak), but the very fact of precipitation from convective (most often cumulonimbus) clouds, which determines fluctuations in the intensity of precipitation. In hot weather, light showers may fall from powerful cumulus clouds, and sometimes (very light showers) even from mid-cumulus clouds.
Rain shower- torrential rain.
Shower snow- shower 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”).
Shower rain with snow- mixed rainfall precipitation, falling (most often at positive air temperatures) in the form of a mixture of drops and snowflakes. If heavy rain with snow falls at sub-zero air temperatures, precipitation particles freeze onto objects and ice forms.
Snow pellets- solid rainfall precipitation that falls at an air temperature of about zero degrees and has the appearance of opaque white grains with a diameter of 2-5 mm; The grains are fragile and easily crushed by fingers. Often falls before or simultaneously with heavy snow.
Ice grains- solid rainfall precipitation that falls at air temperatures from −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 there is an opaque core. The grains are quite hard (they can be crushed with your fingers with some effort), and when they fall on a hard surface they bounce off. In some cases, the grains may be covered with a film of water (or fall out along with droplets of water), 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 air temperatures above +10°) in the form of pieces of ice of various shapes and sizes: usually the diameter of 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 glass, etc.). The duration of hail is usually short - from 1-2 to 10-20 minutes. In most cases, hail is accompanied by rain showers and thunderstorms.
Unclassified precipitation
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 sun's rays, at night - in the rays of the moon or in the light of lanterns. Quite often, ice needles form beautiful glowing “pillars” at night, extending from the lanterns upward into the sky. They are most often observed in clear or partly cloudy skies, sometimes falling from cirrostratus or cirrus clouds.
Insulation- precipitation in the form of rare and large (up to 3 cm) water bubbles. A rare phenomenon that occurs during light thunderstorms.
Precipitation formed on the surface of the earth and on objects
Dew- water droplets formed on the surface of the earth, plants, objects, roofs of buildings and cars as a result of condensation of water vapor contained in the air at positive air and soil temperatures, partly cloudy skies and weak winds. Most often observed at night and early morning hours, and may be accompanied by haze or fog. Heavy dew can cause measurable amounts of precipitation (up to 0.5 mm per night), running off water from roofs onto the ground.
Frost- a white crystalline sediment formed on the surface of the earth, grass, objects, roofs of buildings and cars, snow cover as a result of desublimation of water vapor contained in the air at negative soil temperatures, partly cloudy skies and weak winds. It is observed in the evening, night and morning hours, and may be accompanied by haze or fog. In fact, it is an analogue of dew, formed at negative temperatures. On tree branches and wires, frost is deposited weakly (unlike frost) - on the wire of an ice machine (diameter 5 mm), the thickness of frost deposits does not exceed 3 mm.
Crystal frost- a white crystalline sediment consisting of small, fine-structured shiny particles of ice, formed as a result of desublimation of water vapor contained in the air on tree branches and wires in the form of fluffy garlands (easily crumbling when shaken). It is observed in lightly cloudy (clear, or clouds of the upper and middle tier, or broken-stratified) frosty weather (air temperature below −10...-15°), with haze or fog (and sometimes without them) with weak wind or calm. Frost deposits usually occur over several hours at night; during the day, it gradually crumbles under the influence of sunlight, but in cloudy weather and in the shade it can persist throughout the day. On the surface of objects, roofs of buildings and cars, frost is deposited very weakly (unlike frost). However, frost is often accompanied by frost.
Grainy frost- white loose snow-like sediment formed as a result of the settling of small droplets of supercooled fog on tree branches and wires in cloudy, foggy weather (at any time of the day) at air temperatures from zero to −10° and moderate or strong wind. When fog droplets become larger, it can turn into ice, and when the air temperature drops in combination with weakening winds and a decrease in the amount of clouds at night, it can turn into crystalline frost. The growth of grainy frost continues as long as the fog and wind last (usually several hours, and sometimes several days). The deposited granular frost may persist for several days.
Ice- a layer of dense glassy ice (smooth or slightly lumpy), formed on plants, wires, objects, the surface of the earth as a result of freezing of precipitation particles (supercooled drizzle, freezing rain, freezing rain, ice pellets, sometimes rain with snow) in contact with the surface, having a negative temperature. It is observed at air temperatures most often from zero to −10° (sometimes up to −15°), and during sudden warming (when the earth and objects still maintain a negative temperature) - at an air temperature of 0…+3°. It greatly impedes the movement of people, animals, and vehicles, and can lead to broken wires and breaking off tree branches (and sometimes to massive falls of trees and power line masts). The growth of ice continues as long as the supercooled precipitation lasts (usually several hours, and sometimes with drizzle and fog - several days). The deposited ice may persist for several days.
Black ice- a layer of lumpy ice or icy snow that forms on the surface of the earth due to the freezing of melt water when, after a thaw, the air and soil temperatures decrease (transition to negative temperature values). Unlike ice, black ice is observed only on the earth's surface, most often on roads, sidewalks and paths. The resulting ice can persist for many days in a row until it is covered with freshly fallen snow or melts completely as a result of an intense increase in air and soil temperatures.
Links
- // Encyclopedic Dictionary of Brockhaus and Efron: In 86 volumes (82 volumes and 4 additional ones). - St. Petersburg. , 1890-1907.
The answer is frost. The only thing that makes me happy is late autumn, when the first cold weather sets in. In the morning, leaves that have not yet withered, late flowers, leaves on the ground are covered with frost, acquiring a special charm, and you just want to take a camera and take pictures, take pictures... At such moments you forget about physics.
The answer is actually simple and everyone knows it, it is Frost.
It forms on surfaces at low temperatures. Many of us have already seen the frozen beauty, and some of us have yet to see it.
Frost can be observed not only in winter, but also in autumn and spring. Everything depends, of course, on the air temperature.
When answering, it is worth paying attention to the fact that the question is about precipitation, which does not fall from the sky, but forms on the surface if the temperature is low.
Therefore, it is worth focusing on FROST, there are very intricate patterns.
When you read this question, you immediately remember the song about the blue-blue frost that lay on the wires and the like. However, frost is not blue at all, rather it doesn’t even have a color, since it is essentially frozen water - ice, in its own way, or has a color closer to white.
The phenomenon appears very beautiful and fascinating, especially on plants, but it actually forms in calm conditions and when the soil is frozen.
So the correct answer would be FROST.
We can often observe such solid precipitation in winter, when the temperature is negative, on various surfaces, tree branches, grass, on windows, forming beautiful patterns, or simply on the ground. This is of course FROST, which is ice crystals.
Since in the question of solid atmospheric precipitation there is a clarification about the location of the formed substance, it is possible to easily determine what exactly we are talking about - of course, this FROST, which draws fancy patterns on the glass of windows and creates a unique sparkling coating for leaves, berries, branches and even flowers.
Such a complex phenomenon, described as solid precipitation, is simply called frost in real life. Frost covers almost the entire surrounding nature with small ice crystals. It can be seen on trees, flowers, soil - everywhere.
Everything fits, so the answer is frost.
We're talking about frost here. It is he who considers everything we see to be solid atmospheric precipitation, which occurs directly on surfaces. Other types of precipitation include hail and snow. But they fall from the sky, and do not appear right in front of us.
Solid precipitation usually occurs in winter, but sometimes it also falls in summer - it is snow or hail. These types of precipitation are well known to all residents of our country. But there is another type of solid precipitation that does not fall from the sky on your head and does not fill a cone, but forms directly on trees, on windows, on cars and the ground. This is Frost. Frost, like snow or hail, consists of ice crystals, but it tends to grow, forming unusually beautiful patterns on surfaces.
I answered this question without anyone's help. It seems to me that schoolchildren should not have questions with answers. Many people probably like to look at beautiful trees that are shrouded in winter Frost.
The correct answer is frost.
Solid atmospheric precipitation that forms on the surface of the earth or plants is called - FROST. In the summer, after sunset, the impact of radiation on the soil ceases. In case the soil is covered with dense vegetation or underground water is close to the surface. In this case, fog is formed. If the soil temperature drops to 0 degrees, water molecules begin to crystallize. Cooling occurs faster on uneven, rough surfaces.
MAGAZINE. A white crystalline precipitate formed on the surface of the earth, grass, objects, roofs of buildings and cars, and snow cover as a result of sublimation of water vapor contained in the air at negative soil temperatures, partly cloudy skies and weak winds. It is observed in the evening, night and morning hours, and may be accompanied by haze or fog. In fact, it is an analogue of dew, formed at negative temperatures.
On tree branches and wires, frost is deposited weakly (unlike frost) - on the wire of a cold machine (diameter 5 mm), the thickness of frost deposits does not exceed 3 mm.
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