Natural phenomena and weather conditions. Description of weather phenomena
The weather can be good or bad, but its anomalies always fascinate us. We have selected the most unusual natural phenomena that occur all over the globe and are observed extremely rarely.
(Total 19 photos and videos)
Brainicle (finger of death)
We are used to seeing icicles hanging from roofs. However, in the Arctic there are special icicles that hang under water and pose a mortal danger to the inhabitants of the ocean floor. This phenomenon was discovered almost 30 years ago, but the process of its birth was only filmed in 2011 by a BBC team.
The formation of this extraordinary icicle is easily explained by science. Salty sea water freezes a little differently and turns not into icy solids, but into something similar to a porous wet washcloth. Icebergs are literally riddled with small channels filled with salt water.
In northern latitudes, the surface air temperature can be -20 degrees Celsius, while the water temperature is much higher - about -2 degrees. The heat from the ocean water rises and melts the iceberg, forming new ice. The salt from this ice concentrates into a saturated brine and exits through shallow channels into the ocean. The density of the brine is higher and the temperature is lower, so it rushes to the bottom in a continuous stream and freezes the sea water around it. Within a few hours, the stream is covered with a thin ice crust that looks like a stalactite.
Having reached the bottom, the “finger of death” does not stop, but continues to spread along the bottom. In 15 minutes, such a structure is capable of destroying all leisurely living organisms over an area of several meters. It is for this reason that the fatal icicle was called the “icy finger of death.”
Tubular clouds
There are a large number of clouds that have a special shape and special reasons for their occurrence. Umbrella-shaped, or tubular, clouds look strange and unusual. They look either like sections of pipes, or like many suspended balls, the shade of which varies from white to blue-gray. The color depends on the thickness of the cloud.
How are they made? Clouds usually have a flat base. Warm, moist air cools and condenses into water droplets. This occurs at a certain temperature, and its decrease in the atmosphere is associated with altitude above sea level. The drops grow and form an opaque cloud.
However, under special conditions (humid air above and dry air below), cloud pockets begin to form in the atmosphere, filled with large droplets of water or even ice crystals, which literally fall into the clean air under their weight. This behavior of clouds is associated with the turbulent movement of air masses. And turbulent air movement indicates the proximity of a powerful thunderstorm front.
Like any relief surface, tubular clouds are especially impressive in low light conditions, during sunset or dawn. They are mainly observed in the tropics, but also appear in more northern latitudes.
Misty Rainbow
A hazy rainbow is another optical phenomenon in the atmosphere, similar to the well-known rainbow. The phenomenon appears as a wide, shiny white arc. However, this type of rainbow is neutral in color and can be seen not during rain, but during fog.
For a fog rainbow to occur, strict conditions are required. The water droplets from which the fog is formed must have a certain size - about 0.02 mm. However, due to diffraction of light, the split spectrum is mixed and a uniform white color is obtained.
Due to edge effects, the inner radius of the rainbow may be purple, while the outer radius may be orange.
Catatumbo Lightning
Lightning is a natural phenomenon that occurs in northwestern Venezuela, where the river of the same name flows into Lake Maracaibo. There is regular thunderstorm activity above the confluence: there is lightning in the clouds almost 200 days a year, continuous thunderstorm sessions last about 10 hours.
This is where warm, moist air from the Caribbean meets cold air coming down from the Andes, creating vortices. The decaying organic matter of numerous swamps releases methane gas into the atmosphere. It improves electrical conductivity in the cloud, resulting in lightning.
For a long time, this place served as a landmark for sailors - it can be seen from a distance of more than 400 km. The Venezuelan government wants to make the unique location a UNESCO World Heritage Site. It is believed to be the largest natural ozone generator.
Moon Rainbow
This phenomenon is much easier to see in a fantasy quest than in reality. Many factors are required: the full Moon must be low, the sky must be dark, and there must be a powerful waterfall opposite the luminary or it must be raining.
And still you will see a lunar rainbow completely white. The fact is that even under the best conditions its brightness is extremely low and human physiology allows you to see only a white rainbow.
This is where a modern camera that shoots at long exposures can come to the rescue. An exposure of 15-30 seconds will allow the sensor to collect enough light, and the rainbow can be seen in color, but only in the photograph.
Gloria is another phenomenon associated with the diffraction of light in cloud or fog droplets. This weather phenomenon can only be detected when the light source is behind you and the light reflected from the cloud returns directly to the observer. Gloria can be seen in the mountains as her own silhouette or during a flight as the shadow of an airplane on a cloud.
The rainbow halo around one's own shadow was interpreted by Buddhists as the degree of human enlightenment. The seemingly huge and living shadow disturbed the Germans who climbed the mountains.
Coastal cappuccino
The sea can turn to foam in any part of the planet, but it most often occurs in the southern hemisphere. In a few minutes, the entire coastline, houses and sun loungers disappear into suddenly appearing foam, which slowly dissolves on the sand.
For foam to appear in seawater there must be a large accumulation of algae, salt and some waste. These components act as surfactants (like shampoo in your bathroom) and reduce surface tension at the interface between water and air. Well, it doesn’t cost anything for strong currents and wind to whip all the ingredients into a rich foam and carry it out to the stunned swimmers.
So far, foaming occurs only occasionally. But with further ocean pollution it may become permanent.
Sprites, elves and blue jets
In addition to the lightning that we see from Earth, powerful flashes directed into space occur above thunderclouds. They are divided into red sprites, blue sprites and elves. The shape and color of the flashes depend on the altitude at which they occur.
Unlike lightning, these flashes are characterized by a distinct blue or red color and cover distances of up to 100 km in length and diameter. This makes them an element of space weather, since northern lights are born in these areas and meteors fly.
This phenomenon has been poorly studied for one reason: flares can be observed from Earth only at low altitudes. They are currently being studied from the ISS. According to some reports, strong surges of electricity can “drive” ozone out of the protective layer.
Waterspout
Waterspouts look like small tornadoes of water and typically occur under a cloud above the water's surface. Although from the outside it may appear that liquid is literally being sucked out of the water, the tornado is located above the surface and consists of water droplets formed by condensation.
Strong waterspouts occasionally occur, but most are weak and caused by the collision of atmospheric dynamics that form a vortex.
Fire tornado
This natural phenomenon appears extremely rarely and under certain environmental conditions (temperature, air flows). It occurs when a column of hot, rising air interacts with or causes a fire on the ground. It is a vertical whirlpool of fire in the air.
Morning Glory
Morning glory is a rare meteorological phenomenon, a “thunderstorm collar” that forms at the border of an advancing cold front. The downdraft causes the warm, moist air to rise and cool - causing it to cool below its dew point and become a cloud.
This happens along the entire length of the front: the cloud is up to 1000 km long and also rotates around the longitudinal axis. The speed of cloud rolling can reach 60 km/h, which portends heavy winds and bad weather in the direction of the “collar” movement.
By the nature of its origin, morning gloria can be considered a tornado that lies on its side. It regularly appears in autumn in northern Australia, occasionally in other parts of the world.
Volcanic lightning
Volcanic activity provides a very fertile environment for spectacular discharges, in several ways. The incredible amount of volcanic dust and gas emitted creates a dense stream of charged particles.
This causes electrostatic ionization and, as a result, very powerful and very frequent lightning, which tries to neutralize the charge. Two types of such lightning are observed: 1) striking from the crater and associated with electrical processes in the magma, 2) occurring in the clouds and associated with the friction of volcanic ash.
However, the processes of thunderstorm formation at volcanoes are very complex and depend on many factors: temperature, eruption height, dust dispersion and its composition. Due to the large number of particulate volcanic ash particles, such thunderstorms are also called dirty thunderstorms.
Ecology
We live in an amazing world where many different forces collide. Electricity, wind, atmospheric pressure and plasma sometimes create an unreal combination that we often perceive as a strange phenomenon.
Here are some examples of what nature can do, although many examples of these phenomena remain unexplained.
1. Red sprites
Red sprites are faint but large red flashes in the sky that appear above active thunderstorms. Although people have reported seeing sprites in the past, the phenomenon remains relatively recent and the first accidental photograph of red sprites was taken in 1989. This is partly because the sprite lasts only a few milliseconds. The only thing that makes them easier for an observer to spot is the fact that sprites rarely appear individually, and usually appear as a cluster of three or more sprites.
Since the phenomenon is still quite new to science, there is no official explanation for the cause of these outbreaks. However, there is evidence that they appear when a thunderstorm fades and, one way or another, created by a discharge of positive energy from a large lightning bolt stretching from the clouds to the ground.
2. Blue jets
Blue sprites are closely related to red sprites and are often observed in the same thunderstorm conditions. This phenomenon consists of cone-shaped flashes of blue light that emerge from above a thundercloud. Like red sprites, blue sprites were discovered in 1989.
Blue sprites are not directly associated with lightning like red sprites, and they are less common. They are more often seen during thunderstorms with hail.. Scientists cannot yet explain why the blue jets appear, but they believe it is due to the accumulation or release of energy from a thunderstorm. The bright blue color is possibly due to the molecular release of nitrogen when it collides with oxygen at high speed.
3. St. Elmo's Fire
St. Elmo's Fire is an eerie but beautiful phenomenon where glowing blue plasma "shoots" from the edges of an object. This phenomenon was most often observed on ships and was named after Saint Erasmus (Elmo), the patron saint of sailors.
The lights occur when a grounded object is within an electrical field in the atmosphere, usually during a thunderstorm. What we see is plasma created by the discharge of energy at the tip.
4. Firestorm
Firestorms typically occur when two factors are present: either a tornado that spins too close to a wildfire, or a rotating vortex of flames caused by too much heat in the immediate area.
Fire tornadoes are very dangerous. In 1923, during the Great Kanto Earthquake in Japan, a firestorm was caused by massive fires and killed an estimated 38,000 people.
Firestorms occur when a warm updraft approaches wildfires. The height of such tornadoes can reach 10-60 meters in height and several meters in width.. Typically they last a few minutes, but there have been cases where they lasted 20 minutes.
5. Waterspout
Waterspouts look like small tornadoes of water and typically occur under a cloud above the water's surface. Although from the outside it may appear that liquid is literally being sucked out of the water, the tornado is located above the surface and consists of water droplets formed by condensation.
Strong waterspouts occasionally occur, but most are weak and caused by the collision of atmospheric dynamics that form a vortex.
6. Red Rain
In 2001, colored rain fell for a month in the state of Kerala in India. Most of the rain was red, but some were yellow, green and black.. There was also evidence that red showers had occurred before in 1896, but none lasted as long or as intense as the one in 2001.
A number of theories have emerged regarding what caused colored rain, including blood-colored rain. There were speculations that it had something to do with aliens, until the official report concluded that The unusual color of the rain was caused by algae spores, which were sucked into the atmosphere by a waterspout. Several species of these algae grow in this area.
7. Rain of Animals
Scientists believe waterspouts are responsible for one of the world's strangest weather phenomena - rain of animals. There is evidence that with various animals fell from the sky, including frogs, birds, bats and fish. Some animals survive, many die when they fall, while others freeze to death while in the clouds and fall icy.
Most Waterspouts are considered the likely cause of animal rain, since high-speed winds can lift animals into the air and transport them over long distances. The only thing that scientists cannot explain is why in each case only a certain type of animal falls out, while in a water storm different animals of approximately the same size are sucked in.
This phenomenon is quite rare in most places. In Honduras, they even celebrate the annual Rain of Fishes, although the fish that fall in the form of rain do not live in this area at all.
8. London fog
There were occasions when London was shrouded in thick black fog between 1813 and 1952. These fogs differed from ordinary ones in that they led to the death of people. The first occurrence of this fog lasted a week, and visibility was so poor that people had difficulty moving around the city. In 1873, a black fog caused the death rate in London to increase by 40 percent.
But the most deadly smog was on January 26, 1880. The fog contained a mixture of pollutants and coal smog with high levels of sulfur dioxide, which killed 12,000 people. In 1952, there was another toxic smog disaster that killed 4,000 people. After this, residents began to take action to combat the pollution that led to such merciless fogs.
Changes constantly occur in nature and the weather, sometimes it snows, sometimes it rains, sometimes the sun shines, sometimes clouds appear. All these are called natural phenomena or natural phenomena. Natural phenomena are changes that occur in nature regardless of human will. Many natural phenomena are associated with the changing seasons (seasons), which is why they are called seasonal. Each season, and we have 4 of them - spring, summer, autumn, winter, is characterized by its own natural and weather phenomena. Nature is usually divided into living (animals and plants) and non-living. Therefore, phenomena are also divided into phenomena of living nature and phenomena of inanimate nature. Of course, these phenomena overlap, but some of them are especially characteristic of a particular season.
In the spring, after a long winter, the sun warms up more and more, ice begins to drift on the river, thawed patches appear on the ground, buds swell, and the first green grass grows. The days are getting longer and the nights are getting shorter. It is getting warmer. Migratory birds begin their journey to the region where they will raise their chicks.
What natural phenomena happen in spring?
Snowmelt.
Thawed patches.
They appear wherever the snow cover was thinner and where more sun fell on it. It is the appearance of thawed patches that indicates that winter has given up its rights and spring has begun. The first greenery quickly breaks through the thawed patches, and on them you can find the first spring flowers - snowdrops. The snow will lie in crevices and depressions for a long time, but on the hills and fields it melts quickly, exposing the islands of land to the warm sun.
Frost. It was warm and suddenly it froze - frost appeared on the branches and wires. These are frozen crystals of moisture.
Ice drift.
In spring it becomes warmer, the ice crust on rivers and lakes begins to crack, and the ice gradually melts. Moreover, there is more water in reservoirs, it carries ice floes downstream - this is ice drift. High water.
Streams of melted snow flow from everywhere to the rivers, they fill reservoirs, and the water overflows its banks.
Thermal winds.
The sun gradually warms the earth, and at night it begins to give off this heat, and winds are formed. They are still weak and unstable, but the warmer it gets around, the more the air masses move. Such winds are called thermal; they are characteristic of the spring season.
Rain. The first spring rain is cold, but not as cold as snow:)
Storm. The first thunderstorm may occur at the end of May. Not so strong yet, but bright. Thunderstorms are discharges of electricity in the atmosphere. Thunderstorms often occur when warm air is displaced and lifted by cold fronts.
Hail.
This is the fall of ice balls from a cloud. Hail can be anywhere from the size of a tiny pea to a chicken egg, and it can even break right through a car window!
Rain. While in the air, water vapor supercools, forming clouds consisting of millions of small ice crystals. Low temperatures in the air, below zero degrees, lead to the growth of crystals and the weighting of frozen drops, which melt in the lower part of the cloud and fall in the form of raindrops on the surface of the earth. In summer, the rain is usually warm, it helps to water the forests and fields. Summer rain is often accompanied by a thunderstorm. If it rains and the sun shines at the same time, it is said to be “Mushroom Rain.” This kind of rain happens when the cloud is small and does not cover the sun.
Heat. In summer, the sun's rays hit the Earth more vertically and heat its surface more intensely. At night, the surface of the earth releases heat into the atmosphere. Therefore, in summer it can be hot during the day and even sometimes at night.
Rainbow. Occurs in an atmosphere with high humidity, often after rain or thunderstorms. A rainbow is an optical phenomenon of nature; for the observer it appears in the form of a multi-colored arc. When the sun's rays are refracted in water droplets, an optical distortion occurs, which consists in the deviation of different colors, the white color is divided into a spectrum of colors in the form of a multi-colored rainbow.
Flowering begins in spring and continues throughout the summer.
In the fall you can no longer run outside in a T-shirt and shorts. It gets colder, the leaves turn yellow, fall off, migratory birds fly away, insects disappear from sight.
The following natural phenomena are typical for autumn:
Leaf fall.
Going through their year-round cycle, plants and trees shed their leaves in the fall, exposing bark and branches, preparing for hibernation. Why does a tree get rid of its leaves? So that the fallen snow does not break the branches. Even before the leaves fall, the leaves of the trees dry out, turn yellow or red and, gradually, the wind throws the leaves to the ground, forming leaf fall. This is an autumn phenomenon of wildlife.
Fogs.
The earth and water still heat up during the day, but in the evening it gets colder and fog appears. When air humidity is high, for example, after rain or in a damp, cool season, the cooled air turns into small droplets of water hovering above the ground - this is fog.
Dew. These are droplets of water from the air that fell on the grass and leaves in the morning. During the night, the air cools down, the water vapor that is in the air comes into contact with the surface of the earth, grass, tree leaves and settles in the form of water droplets. On cold nights, dew drops freeze, causing it to turn into frost.
Just like in spring, there is frost in autumn. This means there is a slight frost outside - frost.
Fog, dew, rain, wind, frost, frost - autumn phenomena of inanimate nature.
In winter it snows and it gets cold. Rivers and lakes are frozen. Winter has the longest nights and the shortest days; it gets dark early. The sun barely warms up.
Thus, the phenomena of inanimate nature characteristic of winter:
Snowfall is the fall of snow.
Blizzard. This is snowfall with wind. It is dangerous to be outside in a snowstorm; it increases the risk of hypothermia. A strong snowstorm can even knock you off your feet.
Freeze-up is the establishment of a crust of ice on the surface of the water. The ice will last all winter until spring, until the snow melts and the spring ice drifts.
Another natural phenomenon - clouds - occurs at any time of the year. Clouds are droplets of water collected in the atmosphere. Water, evaporating on the ground, turns into steam, then, together with warm air currents, rises above the ground. This way water is transported over long distances, ensuring the water cycle in nature.
Unusual natural phenomena
There are also very rare, unusual natural phenomena, such as the northern lights, ball lightning, tornadoes and even fish rain. One way or another, such examples of the manifestation of inanimate natural forces cause both surprise and, at times, anxiety, because many of them can harm humans.
Now you know a lot about natural phenomena and can accurately find those characteristic of a particular season :)
The materials were prepared for a lesson on the subject The World around us in 2nd grade, the Perspective and School of Russia (Pleshakov) programs, but will be useful to any primary school teacher, and to parents of preschoolers and primary schoolchildren in home schooling.
Thunderstorms
A thunderstorm is a discharge of atmospheric electricity in the form of lightning accompanied by thunder.
A thunderstorm is one of the most majestic phenomena in the atmosphere. It makes a particularly strong impression when it passes, as they say, “straight above your head.” Thunderclap follows strike simultaneously with flashes of lightning in hurricane-force winds and heavy rainfall.
Thunder is a kind of explosion of air when, under the influence of the high temperature of lightning (about 20,000°), it instantly expands and then contracts due to cooling.
Linear lightning is a huge electrical spark several kilometers long. Its appearance is accompanied by a deafening crash (thunder). Photo: Jens Rost
Scientists have long carefully observed and tried to study lightning. Its electrical nature was discovered by the American physicist V. Franklin and M. V. Lomonosov.
When a powerful cloud with large raindrops forms, strong and uneven updrafts of air begin to crush the raindrops in its lower part. The separated outer particles of the droplets carry a negative charge, and the remaining core turns out to be positively charged. Small drops are easily carried upward by the air flow and charge the upper layers of the cloud with negative electricity; large drops collect at the bottom of the cloud and become positively charged. The strength of a lightning discharge depends on the strength of the air flow. This is the scheme for electrifying a cloud. In reality, this process is much more complicated.
Lightning strikes often cause fires, destroy buildings, damage power lines, and disrupt the movement of electric trains. To combat the harmful effects of lightning, it is necessary to “catch” it and carefully study it in the laboratory. This is not easy to do: after all, lightning penetrates the strongest insulation and experiments with it are dangerous. And yet scientists cope brilliantly with this task. To catch lightning, in mountain lightning laboratories they install an antenna up to 1 km between the ledges of mountains or between the mountain and the masts of the laboratory. Lightning strikes such antennas. We have organized one of these laboratories in the Caucasus - in Bakuriani, where thunderstorms are observed most often.
Having struck the pantograph, lightning travels along a cable into the laboratory, passes through automatic recording devices and immediately goes into the ground. The machines force lightning to “sign” on paper. This makes it possible to measure the voltage and current of lightning, the duration of an electric discharge, and much more.
It turned out that lightning has a voltage of 100 million volts or more, and the current reaches 200 thousand amperes. For comparison, we point out that electrical energy transmission lines use voltages of tens and hundreds of thousands of volts, and the current strength is expressed in hundreds and thousands of amperes. But in one lightning the amount of electricity is small, since its duration is usually calculated in small fractions of a second. One lightning bolt would be enough to power only a 100-candle light bulb for 24 hours.
However, the use of “catchers” forces scientists to wait for lightning strikes, and they are not that frequent. For research, it is much more convenient to create artificial lightning in laboratories. Using special equipment, scientists managed to obtain an electrical voltage of up to 5 million volts for a short time. A discharge of electricity produced sparks up to 15 m long and was accompanied by a deafening crash.
Photography helps study lightning. On a dark night, point the camera lens at a thundercloud and leave the camera open for a while. After the lightning flash, the camera lens is closed and the photo is ready. But such photography does not provide a picture of the development of individual parts of lightning, so special rotating cameras are used. It is necessary that the mechanism of the device rotates quickly enough when shooting (1000-
1500 rpm), then individual parts of the lightning will appear in the picture. They will show in which direction and at what speed the discharge developed.
There are several types of lightning.
Flat lightning looks like an electrical flash on the surface of clouds.
Linear lightning is a giant electrical spark, very tortuous and with numerous branches. The length of such a zipper is 2-3 km, but it happens before 10 km and more. Linear lightning is very powerful. It splits tall trees, sometimes infects people, and when it hits wooden buildings, it often causes fires.
Beaded lightning is a luminous dotted lightning bolt running against a background of clouds. This is a very rare form of lightning.
Rocket-shaped lightning develops very slowly, its discharge lasts 1-1.5 seconds.
The rarest form of lightning is ball lightning. It is a round luminous mass.
Beaded lightning is similar to the trajectory of a tracer bullet. The movement of lightning beads can be seen with the naked eye.
In a closed room, ball lightning the size of a fist and even a head was observed, and in a free atmosphere with a diameter of up to 20 m. Usually ball lightning disappears without a trace, but sometimes it explodes with a terrible crash. When ball lightning appears, a whistling or buzzing sound is heard, it seems to be boiling, scattering sparks; After it disappears, a haze often remains in the air. The duration of ball lightning is from a second to several minutes. Its movement is associated with air currents, but in some cases it moves independently. Ball lightning occurs during severe thunderstorms.
An explanation for ball lightning has been found only in recent years. Ball lightning occurs under the influence of a linear lightning discharge, when ionization 1 and dissociation 2 of a volume of ordinary air occur in the air. Both of these processes are accompanied by the absorption of huge amounts of energy. Ball lightning essentially has no right to be called lightning: it is simply hot air charged with electrical energy. A bunch of charged air gradually gives up its energy to free electrons of the surrounding layers of air. If the ball gives up its energy to glow, then it simply disappears: it turns back into ordinary air. When on its way the ball encounters any substances that act as pathogens, it explodes. Such pathogens can be oxides of nitrogen and carbon in the form of fumes, dust, soot, etc.
The temperature of ball lightning is about 5000°. It is also calculated that the energy of the explosion of ball lightning is 50-60 times higher than the energy of the explosion of smokeless gunpowder.
During severe thunderstorms there is a lot of lightning. So, during one thunderstorm, an observer counted 1 thousand lightning strikes in 15 minutes. During one thunderstorm in Africa, 7 thousand lightning strikes were recorded in an hour.
To protect buildings and other structures from lightning, a lightning rod, or, as it is now correctly called, a lightning rod, is used. This is a metal rod connected to a securely grounded wire.
To protect yourself from lightning, do not stand under tall trees, especially those standing alone, as lightning often strikes them. Oak is very dangerous in this regard, because its roots go deep into the ground. You should never take refuge in haystacks and sheaves.
In an open field, especially in elevated places, during a strong thunderstorm, a walking person is at great risk of being struck by lightning. In such cases, it is recommended to sit on the ground and wait out the thunderstorm.
Lightning rod for protection against lightning strikes. A metal rod is installed on the roof of the building and connected to a thick wire that goes into the ground. To better dissipate electricity, the wire in the ground is securely connected to a metal sheet.
1 When ionized, neutral atoms acquire an electrical charge.
2 Dissociation is the process by which molecules break apart into individual atoms.
Before a thunderstorm begins, it is necessary to eliminate drafts in the room and close all chimneys. In rural areas, you should not talk on the phone, especially during severe thunderstorms. Usually our rural telephone exchanges stop connecting at this time. Radio antennas must always be grounded during thunderstorms.
If an accident happens - someone is shell-shocked by lightning - it is necessary to immediately provide first aid to the victim (artificial respiration, special infusions, etc.). In some places there is a harmful superstition that someone struck by lightning can be helped by burying his body in the ground. This should never be done: a person injured by lightning especially needs increased air flow to the body.
Showers
Thunderstorms are usually accompanied by showers. But there are showers without thunderstorms. A downpour is a rain of such force that more than 1 minute falls in one minute. mm precipitation.
Rainfall can in some cases cause real disasters. In July 1882, at the Kukuevka station of the Kursk railway. d. a downpour broke out with a strong thunderstorm. For several hours the rain poured down in buckets. The result was 158 mm precipitation, or 140 thousand buckets of water per hectare. The railway embankment was washed away by streams of water. As a result, a mail train crashed. There were many casualties.
The intensity of showers increases from high latitudes to the equator. In the northern regions of the European part of the USSR, the greatest intensity of showers does not exceed 1.5 mm/min, in the middle zone - 2.5 mm. Showers with an intensity of 5-6 were observed in the Caucasus Mountains mm/min. Tropical downpours are even more intense. Sometimes more than 1000 fall in a day mm precipitation! This is almost twice as much precipitation as Moscow receives in a whole year.
Heavy rains cause unusual rises in rivers and severe flooding. Heavy rains in the mountains bring many misfortunes. Everyone knows the terrible force of the flow of mountain rivers, especially after rainstorms. Huge rocks fall from the mountains into the valleys, entire villages are demolished, fertile valleys are filled with stones.
Rainfall in the mountains can cause mud or mud-stone flows - the so-called mudflows.
To protect against flooding, huge dams are usually built on the banks of large rivers.
In our country, protective forest belts are being created to protect fields from the destructive effects of wastewater, dams and colossal reservoirs are being built that help regulate the flow of rain and flood waters.
How does hail form?
Hail is pieces of ice (usually irregularly shaped) that fall from the atmosphere with or without rain (dry hail). Hail falls primarily in summer from very powerful cumulonimbus clouds and is usually accompanied by thunderstorms. In hot weather, hailstones can reach the size of a pigeon or even a chicken egg.
The strongest hailstorms have been known since ancient times from chronicles. It happened that not only individual areas, but even entire countries were subject to hail damage. Such phenomena still happen today.
On June 29, 1904, large hail fell in Moscow. The weight of hailstones reached 400 G and more. They had a layered structure (like an onion) and external spines. The hail fell vertically and with such force that the glass of greenhouses and conservatories seemed to be shot through with cannonballs: the edges of the holes formed in the glass turned out to be completely smooth, without cracks. Hailstones made holes in the soil up to 6 cm.
On May 11, 1929, heavy hail fell in India. There were hailstones 13 cm in diameter and weighing a kilogram! This is the largest hail ever recorded by meteorology. On the ground, hailstones can freeze into large pieces, which explains the amazing stories about the size of hailstones the size of a horse's head.
The history of the hailstone is reflected in its structure. In a round hailstone cut in half, you can see the alternation of transparent layers with opaque ones. The degree of transparency depends on the speed of freezing: the faster it goes, the less transparent the ice. In the very center of a hailstone, the core is always visible: it looks like a grain of “cereal” that often falls in winter.
The rate at which hailstones freeze depends on the water temperature. Water usually freezes at 0°, but in the atmosphere the situation is different. In the ocean of air, raindrops can remain in a supercooled state at very low temperatures: minus 15-20° and below. But as soon as a supercooled drop collides with an ice crystal, it instantly freezes. This is already the embryo of a future hailstone. It occurs at altitudes above 5 km, where in summer the temperature is below zero. Further growth of hailstones occurs under different conditions. The temperature of a hailstone falling under the influence of its own gravity from the high layers of the cloud is lower than the temperature of the surrounding air, so droplets of water and water vapor from which the cloud consists are deposited on the hailstone. The hailstone will begin to get larger. But for now it is small, and even a moderate rising air flow picks it up and carries it to the upper parts of the cloud, where it is colder. There it cools and when the wind weakens it begins to fall again. The speed of the upward flow either increases or decreases. Therefore, a hailstone, having made a “journey” several times up and down into powerful clouds, can grow to significant sizes. When it becomes so heavy that the updraft can no longer support it, the hailstone will fall to the ground. Sometimes “dry” hail (without rain) falls from the edge of a cloud, where the updrafts have weakened significantly.
So, for the formation of large hail, very strong upward air currents are needed. To maintain hailstones with a diameter of 1 cm vertical flow required at speed 10 m/sec, for hailstones with a diameter of 5 cm- 20 m/sec etc. Such turbulent flows were discovered in hail clouds by our pilots. Even higher speeds - hurricane speeds - were recorded by movie cameras that filmed the growing cloud tops from the ground.
Scientists have long tried to find means to disperse hail clouds. In the last century, cannons were built to shoot at clouds. They threw out a swirling smoke ring into the heights. It was assumed that vortex movements in the ring could prevent the formation of hail in the cloud. It turned out, however, that, despite the frequent shooting, hail continued to fall from the hail cloud with the same force, since the energy of the vortex rings was negligible. Nowadays, this problem has been fundamentally solved, and mainly through the efforts of Soviet scientists.
Storms, hurricanes, typhoons
Light or moderate winds sometimes increase to a gale (storm) or hurricane. A storm (storm) is a long-lasting strong wind whose speed exceeds 15 m/sec according to the wind scale adopted in navigation and meteorology.
On land, such winds are relatively rare: the wind encounters unevenness of the earth's surface and many other obstacles and cannot reach such strength as on the open sea. The stronger the wind, the more gusty it is. During a storm, wind gusts are sometimes one and a half to two times higher than average speeds and can cause destruction.
Since strong storms occur relatively rarely on land, but more often occur on the seas and oceans, they are given marine names. A force 8 wind is called a gale, a force 10 wind is a severe storm, and a force 11 wind is a severe storm.
A hurricane is a storm when the wind speed exceeds 24 m/sec(12 or more points).
All storms, no matter what they are called, arise for the same reason - due to the large difference in atmospheric pressure at close distances. Most often, storms are associated with atmospheric cyclones. If the pressure in the center of a cyclone is very low compared to its outskirts, then a large pressure difference arises, causing stormy winds. Storm cyclones (up to 12 points) are rare in mid-latitudes: once every 8-10 years.
The usual speed of cyclones is 30-40 km/h; but sometimes more than 80 km/h. A severe hurricane with wind speeds of up to 60 m/sec (220 km/h) swept over the southern coast of the United States in early September 1961. The city of Galveston (northwest Gulf Coast) was particularly affected. It was almost completely destroyed. The wind blew wooden houses, barns, and sheds out to sea. The hurricane destroyed the power plant. The courthouse collapsed, in which more than 100 city residents were sheltering from the elements. Most of the windows in the buildings were broken. The downpour flooded some areas of the city with water levels exceeding 1 m. The disaster was further aggravated by the fact that masses of deadly rattlesnakes and water moths filled the roads that were used to rescue the victims. There were many casualties. The city was deserted: out of 75 thousand inhabitants, only 15 thousand remained in it.
Cyclones that form in tropical latitudes are especially dangerous. Tropical cyclones are caused by the same reasons as the cyclones of our latitudes, but they are smaller in size and reach only 200-300 in diameter. km.
Beaufort points | Verbal definition of wind force | Average wind speed, m/s (km/h) | Average wind speed, knots | Wind action | |
---|---|---|---|---|---|
on the land | on the sea | ||||
0 | Calm | 0-0,2 (< 1) | 0-1 | Calm. Smoke rises vertically, tree leaves are motionless | Mirror smooth sea |
1 | Quiet | 0,3-1,5 (1-5) | 1-3 | The direction of the wind is noticeable from the drift of the smoke, but not from the weather vane. | There are no ripples, no foam on the crests of the waves. Wave height up to 0.1 m |
2 | Easy | 1,6-3,3 (6-11) | 3,5-6,4 | The movement of the wind is felt by the face, the leaves rustle, the weather vane is set in motion | Short waves with a maximum height of up to 0.3 m, the crests do not overturn and appear glassy |
3 | Weak | 3,4-5,4 (12-19) | 6,6-10,1 | The leaves and thin branches of the trees sway all the time, the wind flutters light flags | Short, well defined waves. The ridges, overturning, form glassy foam. Occasionally small lambs are formed. Average wave height 0.6 m |
4 | Moderate | 5,5-7,9 (20-28) | 10,3-14,4 | The wind raises dust and debris and moves thin tree branches | The waves are elongated, whitecaps are visible in many places. Maximum wave height up to 1.5 m |
5 | Fresh | 8,0-10,7 (29-38) | 14,6-19,0 | Thin tree trunks sway, the movement of the wind is felt by the hand | Well-developed in length, but not large waves, maximum wave height 2.5 m, average - 2 m. Whitecaps are visible everywhere (in some cases splashes are formed) |
6 | Strong | 10,8-13,8 (39-49) | 19,2-24,1 | Thick tree branches sway, telegraph wires hum | Large waves begin to form. White foamy ridges occupy large areas and splashes are likely. Maximum wave height - up to 4 m, average - 3 m |
mb by 100 km. Therefore, the wind speed reaches the strength of a hurricane. Cyclones are accompanied by powerful thunderclouds, heavy rainfall and huge ocean waves. These cyclones occur relatively rarely - from 5 to 15 times a year. Tropical cyclones usually originate between 6 and 20° N. and Yu. w. Over the Pacific Ocean, they most often occur east of the Philippine Islands. Over the Atlantic Ocean, cyclones appear most often in the area of the Cape Verde and Antilles islands. The first signs of an approaching tropical cyclone appear in the sky. Even the day before, at sunrise or sunset, the sky is bright red. It is the high and light cirrus clouds moving ahead of the advancing cyclone that are colored by the sun. Gradually, as the cyclone approaches, the sky turns copper-red. A dark streak appears on the horizon. The wind calms down. There is an ominous silence in the stuffy, hot air. Seabirds quickly gather in flocks and fly into the interior of the continent. The barometer begins to drop 24 hours or even 48 hours before the storm arrives. The faster the pressure drops, the sooner and the stronger the storm will be. In the center of a tropical cyclone there is always a calm area with a diameter of 20-30 km. The sky is clearing, the sun is shining, the wind is dying down, but the waves of the raging ocean are still moving. Sailors called this area the “eye of the storm.” In this small zone, the air is compressed on all sides by hurricane winds rushing towards the center of the cyclone. Downdrafts of air in the center of the cyclone dissipate cloudiness. The destruction caused by a tropical cyclone depends not only on the direct action of the wind, but also on the roughness of the sea: huge waves, rushing onto low shores, also destroy buildings, wash away villages and even entire cities. The hurricane washes large ships ashore. In September 1961, a terrible typhoon (as tropical cyclones in Southeast and East Asia are called) called Nancy swept over the Pacific Ocean. It originated in the Marshall Islands. At first, the typhoon moved rapidly to the west. Very low pressure was observed at the center of the cyclone. On September 13, for example, it dropped to 888.5 mb, below the lowest pressure ever recorded by meteorologists. The wind speed in the typhoon exceeded 80 m/sec(up to 300 km/hour). On September 15, "Nancy" approached the shores of Japan - the island of Kyushu. Over the following days, the typhoon passed along the Japanese islands to the northeast. It caused great disaster: about 150 people died and more than 2 thousand were injured. 450 thousand houses were flooded and destroyed, dams were broken and bridges were destroyed. Heavy rainfall and ocean waves caused floods, landslides and landslides. The cyclone crossed the island of Hokkaido, entered the Sea of Okhotsk and covered the southern part of Sakhalin. Here, the roofs of many houses were torn off, chimneys were destroyed, and windows were broken. On its path, the typhoon broke trees, knocked down telegraph poles, and tore wires. There was a strong storm at sea. However, ships in the threatened area were warned in advance by the Weather Service and took shelter. Squally windA squall is a sudden increase in wind before a storm with a sharp change in direction. A squall wind is often compared to a wind blow: the destruction that a squall produces in a few minutes is so great. In terms of strength, a squall wind is not only not inferior to storms, but even surpasses them. Particular attention was paid to the study of the nature of squalls at the end of the last century, after the disaster in 1878 with the English military frigate Eurydice. The ship was returning from a long voyage. The pier was crowded with greeters. "Eurydice" appeared on the horizon, emerging more and more clearly every minute. When there were only 2-3 left to the shore km, suddenly there was a squall. People on the pier were knocked off their feet by the wind. A mass of wet snow covered the entire horizon, turning day into night. The sea boiled and became covered with huge waves. This lasted no more than five minutes. Then the hurricane wind suddenly died down, the snow stopped falling, and the sky cleared. But there was no trace left of the frigate. People peered into the sea in vain. It was empty. The frigate "Eurydice" was overturned by a wind blow and instantly sank with its entire crew. Only a few days after the squall, divers found the ship at the bottom of the sea at the entrance to the bay. When information was collected from different places about the hurricane, it turned out that it was moving at enormous speed - 90 km/hour- very narrow (2-3 km width) stripe. Its length exceeded 700 km. It is now well known what causes such a sudden hurricane wind. A squall occurs when cold air masses invade warm ones. When cold air enters, it displaces warm air, causing it to rise quickly. When warm air cools above, cumulonimbus clouds form, bursting into showers, hail, and squalls, which always come in a long narrow stripe, usually from 1 to 6 km width. The wind suddenly changes its direction, sometimes even to the opposite, and intensifies. A squall cloud has a very characteristic appearance: it is black, with ragged edges, like claws going down, and a white curtain of rain in the depths of the cloud. This cloud comes low to the ground; its lower edge changes shape all the time. Just by the appearance of the cloud, an observer can guess about the upcoming squall. To anticipate squalls, you need to monitor daily weather maps for cold fronts. By determining their movement, it is possible to promptly warn areas threatened by squalls. A tornado - a whirlwind with a diameter of 100-300 m, sometimes more than a kilometer - moves along with the cloud at a speed of 40 - 50 km/h. Tornadoes (tornadoes, blood clots) In nature, sometimes it happens that everything calms down, but this is the calm before the storm. A huge dark cloud is approaching. The thunder is getting louder and louder. And suddenly, from behind a curtain of rain, a rotating shaft begins to emerge from the right side of the cloud. Wriggling like a snake, he approaches the edge of the cloud, bends and heads down to the ground. So he sinks lower and lower. A spinning column of dust rises from the ground towards him, forming a figure similar to the trunk of a giant elephant. Inside the “trunk” the air rotates at tremendous speed and at the same time quickly rises upward in a spiral. The “trunk” does not stand in one place, it moves all the time. When the “trunk” approaches the observation site, the hurricane speed of air rotation can be judged by the flying branches, twigs, and sometimes logs. In 1-2 minutes the whirlwind will move away and a regular thunderstorm will begin with heavy rain. Such a vortex is called a tornado. It is almost always associated with a thunderstorm. The wind speed inside a tornado reaches 100 meters per second or more, far exceeding the speed of severe hurricanes. The whirlwind can lift logs that ram buildings. The diameter of a tornado on the water surface ranges from 25 to 100 m, on land more - from 100 to 1000 m, and sometimes up to 1.5-2 km. The visible height of the “trunk” reaches 800-1500 m. In the USA and Mexico, a tornado is called a tornado, and in Western Europe - a blood clot. In rural areas of the United States, where tornadoes are frequent, residents build special cellars where they hide to escape from them. In our country, tornadoes are rarely observed. When a tornado passes, the wind, even at a close distance from it, has the same speed as it was before the tornado appeared. Sometimes, while a tornado sweeps through some area, destroying everything in its path, at a distance of several tens of meters from it there is almost complete calm. The strong rarefaction of air inside a tornado causes a significant drop in temperature, which leads to condensation of water vapor in the air: therefore, the “trunk” looks like a cloud column. A decrease in pressure also causes the suction action of a tornado: it, like a giant vacuum cleaner, grabs various objects and carries them over long distances. Waterspouts can suck up fish and wash them ashore. “Fish rains” are a phenomenon that used to terrify people. If a tornado passes over a swamp that is “blooming” and has “rusty water”, then it will throw out “bloody rain” in the neighboring area. The mystery of the origin of tornadoes has not yet been completely resolved. It is believed that the tornado originates in the central part of a powerful thundercloud at a height of 3-4 km, where the strongest updrafts are observed and sharp jumps in wind occur both in direction and in strength. Here is the “axis” of vertical flows. If these strongest updrafts are “overturned” by an even more powerful horizontal air flow, then a vortex with a horizontal axis is formed. Carried away by a horizontal current, it will seem to roll forward and begin to emerge from the clouds. According to the laws of mechanics, such a vortex should become ring-shaped. And indeed, the vortex begins to bend on both sides of the cloud and descend to the ground. Quite often a two-sided tornado is observed, which simultaneously lowers its “trunks” on the left and right sides of the cloud. Halo When the sky becomes covered with a thin layer of cirrus clouds made of ice crystals, circles, crowns and pillars called halos form around the sun and moon. A rainbow circle with the sun or moon in the center and the inside is colored red and bluish on the outside. The appearance of the rainbow circle is explained by the fact that ice crystals in the shape of a hexagonal prism float in the air. Rays of light, passing through these prisms, are decomposed into red, green, blue and others: they give the rainbow color to the circle. Circles around the sun or moon can serve as an important local sign of changing weather, since cirrus clouds producing a halo usually precede the appearance of a cyclone. The colored rings around the luminaries are called crowns. The color of the crowns is different from the color of the circles: the inside is bluish and the outside is red. Since observation in the blinding rays of the sun is impossible without special devices, the crowns are visible to the naked eye only around the moon. They occur when light rays pass through tight gaps between the ice crystals or water droplets that make up the cloud. It turned out that the larger the cloud particles, the smaller the diameter of the crown. From this we can conclude that when very small crowns (in the form of a halo) appear, large quantities of large particles (ice crystals or water droplets) float in the air and therefore precipitation should be expected. In some cases, during sunrise or sunset, white vertical pillars above the luminaries are visible. They are obtained by reflecting rays from the faces of horizontal prisms of ice crystals that make up cirrus clouds. When ice crystals slowly fall in the air, not just one bright spot appears, but a pillar of light. In severe frosts, two pillars are sometimes observed on either side of the sun. At this time, ice needles are hovering in the air below, glistening in the rays of the sun (“diamond dust”). The pillars indicate the continuation of severe frosts. Rainbow Everyone knows the phenomenon of rainbows. When the sun is at the horizon, we see a full semicircle; when the sun is high, only part of the rainbow is at the horizon. If the sun is above the horizon above 45° (during the day and summer), then the rainbow is not visible, since it goes below the horizon, but it can be detected from an airplane: it is projected onto the earth’s surface. Sometimes even double rainbows are observed. You can also see a rainbow under the moon, but it appears white to us, since the light from the moon is very weak and our eyes are not able to distinguish the colors of the rainbow. 1) spherical drop 2) internal reflection 3) primary rainbow 4) refraction 5) secondary rainbow 6) incoming light beam 7) the course of rays during the formation of the primary rainbow 8) the course of rays during the formation of a secondary rainbow 9) observer 10) area of formation of the primary rainbow 11) area of secondary rainbow formation 12) cloud of droplets A rainbow arises from the refraction and decomposition of light rays in raindrops. It is customary to talk about “all the colors of the rainbow,” but in reality we see only three colors - red, green, purple, and sometimes two more colors - yellow and orange, but they are very weakly expressed. The brightness of the rainbow and the clearly defined red color indicate large drops of rain in which light rays are refracted. It should be borne in mind that each observer sees not a rainbow in general, but “his” rainbow, “his” circle and crown, because these phenomena in the atmosphere depend on the position of the sun or moon in relation to the observer’s eye. Reasons for the formation of mirage in deserts Sometimes in the desert, a wavy surface of water suddenly appears on the horizon in front of exhausted travelers. The long-awaited oasis! The travelers rush to the water, but it keeps moving away from them and finally disappears. This is a mirage. Because of him, entire caravans perished in the deserts, losing their way in a fruitless search for an oasis. Mirage is an optical phenomenon. It occurs when a ray of light from an object passes to the observer’s eye through layers of air of varying density and deviates from its original straight direction. There are inferior and superior mirages. An inferior mirage usually occurs in deserts, where the air in the lower layers of the atmosphere overheats due to the strong heat of sand or soil, while colder air is located above. In this case, the air density increases sharply with height. Moving from less heated layers to more heated ones, i.e. from more dense to less dense, the light beam deviates more and more from the straight path. There may come a time when the beam deflection angle reaches 90°. In this case, the curved beam gives an inverse image of objects and the area of the sky located behind it. The image of the sky gives the impression of a shiny water surface, especially since the color of the sky and the water surface are very similar. When the color of the sky changes (haze, clouds), the color of the mirage also changes. For example, it resembles snow when the sky is a dull, whitish color. In some cases, the inferior mirage also occurs in temperate latitudes. When driving along a sun-baked asphalt highway, a water surface suddenly appears in front of the observer, causing amazement in the first minutes - where does the water come from? The water stays ahead all the time and just as suddenly disappears. The superior mirage occurs when air density decreases sharply with altitude. This happens early in the morning, when the layer of atmosphere adjacent to the earth's surface is still cold, and the layers of air located above are warm. The upper mirage is especially often observed in polar countries, where the lower layers of air are greatly cooled by contact with ice or snow. With an upper mirage above an object located near the horizon, its image appears in a highly distorted form. One day, an image of a ship appeared in the air, which was at that time over the horizon. Through the telescope, various parts of the ship were visible. Mirages are formed under one mandatory condition - the absence of strong wind, which mixes the upper and lower air layers. Copyright BioFile 2007-2016 |
What is weather? This is everything that is currently happening outside the window: whether it is raining, whether the sun is shining, whether it is warm or cold outside. The weather can be very changeable even within one day. In the morning you can be chilled by the morning coolness, suffer from the heat during the day, and in the evening you can get wet to the skin in the pouring rain.
Weather detection
In scientific terms, weather is the state of the atmosphere in a specific area during a certain period of time. The atmosphere is the air envelope of the globe.
The weather is characterized by such indicators as:
- air temperature and humidity;
- Atmosphere pressure;
- wind strength and direction;
- precipitation.
One of the rare and very dangerous weather phenomena is a tornado. This is a powerful whirlwind that looks like a huge column descending to the ground from thunderclouds. Most often it forms during a severe thunderstorm. A tornado sweeps away everything in its path, and it is impossible to hide from it.
Rice. 1. Tornado
The weather directly depends not only on the time of year and day, but also on what part of the planet a given place is located on, on the movement of air masses and many other indicators.
The weather is not stable and can change not only seasonally, but also over short periods of time.
TOP 4 articleswho are reading along with this
Basic weather indicators
Since weather is a combination of several basic indicators, it is necessary to consider each of them.
- Temperature
The sun heats the air and thus affects temperature readings. It can be positive (above 0 degrees Celsius) and negative (below 0 degrees). Its readings are greatly influenced by air masses that move endlessly. The coldest point on the planet is Antarctica, and the hottest is the Libyan Desert in Africa.
- Atmospheric pressure and wind
The air envelope exerts pressure on the Earth's surface, and this is called atmospheric pressure. This value is not constant, and due to the difference in pressure, wind is formed - a rapid flow of air.
- Precipitation
Water evaporates under the influence of the sun's heat, and a lot of moisture enters the air. It cools, forming droplets of moisture that collect in rain clouds. In this way, precipitation is formed, which can fall to the ground in the form of hail, rain, snow, dew, frost or fog.
Rice. 2. Rain
Why study weather?
The science that studies weather is called meteorology. Thanks to modern research, humanity has the opportunity to know in advance what to expect from the weather in the coming days.
All the information necessary for this is collected from meteorological stations, aircraft, ships, and space satellites. Based on the data obtained, synoptic maps are created.
Rice. 3. Meteorological station
The weather forecast is compiled not only to find out how to dress for the street and whether to take an umbrella with you. It is of great importance for the movement of transport, agricultural work and some types of industry. And thanks to the timely prediction of tornadoes, floods and other natural disasters, many human lives can be saved.