A short-term vortex that occurs in front of cold atmospheric fronts. What is a cyclone and anticyclone? Characteristics of atmospheric vortices

Control work on the topic "Climate of Russia" Option 1

Task 1. Finish the sentence:

A. Arrival on earth by radiation of solar heat and light ____________

B. Change in the properties of VMs when they move above the Earth's surface ___________

B. Vortex air movement associated with a low pressure area _____________

D. The ratio of annual precipitation to evaporation for the same period __________

A. FORM OVER MOST OF OUR COUNTRY?

B. IN THE WINTER PROMOTE A SHARP WARMING, IN THE SUMMER CAUSE CLOUDY WEATHER WITH INTERNATIONAL RAIN?

C. IN WINTER THEY BRING SNOWFALLS AND THAWS, AND IN THE SUMMER REDUCING THE HEAT, BRING PRECITATION?

Task 3. Test

1. The severity of the country's climate is growing in the direction

a)cnorth to south b) east to west c) west to east

2. This type of climate is typical for D.Vostok:

3. This type of climate is characterized by long cold winters and short cold summers, when the July temperature is not higher than +5C

A) arctic B) subarctic c) sharply continental d) monsoon

4. This type of climate is distinguished by severe winters, sunny and frosty; summers are sunny and warm, with little rainfall all year round.

A) Moderately continental b) continental C) sharply continental d) monsoon

5. Large volumes of troposphere air with homogeneous properties.

6. The state of the lower layer of the atmosphere in a given place at a given time.

A) atmospheric front b) circulation c) weather d) climate e) air masses f) solar radiation

7. The passage of a cold front is accompanied by weather.

8.WhirlwindsThey form over the Pacific and Atlantic Oceans, the movement of air from the outskirts to the center is counterclockwise, in the center there is an upward movement of air, the weather is changeable, windy, cloudy, with precipitation.

A) Cyclone b) Anticyclone

Task 4.

Find a match: climate type

- climatogram 1 2 3

A) sharply continental b) monsoon c) moderately continental

Task 5. Complete the list

drought, _________, dust storm, _________, frost, _________, black ice, __________

a) radish b) brown bread c) citrus fruits d) tea

Control work on the topic "Climate of Russia" Option 2

Task 1. Finish the sentence:

A. Transitional zone between dissimilar VMs hundreds of kilometers long and tens of kilometers wide.________

B. All varietyair movements ___________

B. Vortex air movement associated with a high pressure area ______________

D.Climate properties that provide agricultural production ____________________

Task 2. Determine the type of air masses (VM)

A. ARE FORMED OFF THE COASTS OF OUR COUNTRY OVER THE PACIFIC AND ATLANTIC OCEANS?

B. CONTRIBUTE TO THE FORMATION OF HOT, DRY WEATHER, DROUGHTS AND DRY WINDS?

Q. WHICH VM BRING FROST IN SPRING AND AUTUMN?

Task 3. Test

1. The presence of climatic regions within the belts is explained by the large length of the country

A) a)cnorth to south b)) from west to east

2. This type of climate is typical for Z. Siberia:

A) Moderately continental b) continental C) sharply continental d) monsoonal

3. This type of climate is distinguished by a rather cold winter with little snow; abundance of precipitation during the warm season.

A) arctic B) subarctic c) sharply continental d) monsoon

4. This type of climate is distinguished by mild snowy winters and warm summers:

A) Moderately continental b) continental C) sharply continental d) monsoon

5. The total amount of solar energy reaching the Earth's surface.

A) atmospheric front b) circulation c) weather d) climate e) air masses f) solar radiation

6. The average long-term weather regime characteristic of any territory

A) atmospheric front b) circulation c) weather d) climate e) air masses f) solar radiation

7. The passage of a warm front is accompanied by weather

A) quiet sunny weather. B) thunderstorms, squally winds, showers.

8. Atmospheric vortices form over Siberia,the movement of air from the center to the outskirts in a clockwise direction,in the center - downward movement of air; the weather is stable, windless, cloudless, without precipitation. warm in summer, cold in winter.

Task 4 .

Find a match climate type

- climatogram 1 2 3

A) arctic b) monsoon c) temperate continental

Task 5. Complete the list adverse climatic events.

Dry wind, _________, hurricane, ______________, hail, ____________, fog

Task 6. What crops are not grown in your area and why?

a) potatoes b) rice c) cabbage d) cotton

The main regularities of the formation of atmospheric vortices

An own, different from the generally accepted explanation of the formation of atmospheric vortices, according to which they are formed by oceanic Rossby waves, is given. The rise of water in waves forms the surface temperature of the oceans in the form of negative anomalies, in the center of which the water is colder than at the periphery. These water anomalies create negative air temperature anomalies, which turn into atmospheric vortices. The regularities of their formation are considered.

Formations are often formed in the atmosphere in which the air, and the moisture and solids contained in it, rotate cyclonically in the Northern Hemisphere and anticyclonically in the Southern Hemisphere, i.e. counterclockwise in the first case and along its movement - in the second. These are atmospheric vortices, which include tropical and mid-latitude cyclones, hurricanes, tornadoes, typhoons, trombos, orcans, wily-willies, begvis, tornadoes, etc.

The nature of these formations is largely common. Tropical cyclones are usually smaller in diameter than in middle latitudes and are 100-300 km, but the air speeds in them are high, reaching 50-100m/s. Vortices with high air speeds in the region of the tropical zone of the western part of the Atlantic Ocean near North and South America are called hurricanes, tornadoes, similar ones near Europe - thrombosis, near the southwestern part of the Pacific Ocean - typhoons, near the Philippines -begwiza, near the coast of Australia - vili-willi, in the Indian Ocean - orkans.

Tropical cyclones form in the equatorial part of the oceans at latitudes of 5-20° and spread westward up to the western borders of the oceans, and then move north in the northern hemisphere and south in the southern hemisphere. When moving north or south, they often intensify and are called typhoons, tornadoes, etc. Coming to the mainland, they quickly collapse, but manage to cause significant damage to nature and people.

Rice. 1. Tornado. The formations of the shape shown in the figure are often called the “tornado funnel”. The formation from the top of a tornado in the form of a cloud to the surface of the ocean is called the pipe or trunk of a tornado.

Similar rotational movements of smaller air over the sea or ocean are called tornadoes.

Accepted hypothesis of the formation of cyclonic formations. It is believed that the occurrence of cyclones and their replenishment with energy occurs as a result of the rise of large masses of warm air and the latent heat of condensation. It is believed that in areas where tropical cyclones form, the water is warmer than the atmosphere. In this case, the air is heated from the ocean and rises. As a result, moisture condenses and falls in the form of rain, the pressure in the center of the cyclone drops, which leads to the emergence of rotational movements of air, moisture, and solids contained in the cyclone [Gray, 1985, Ivanov, 1985, Nalivkin, 1969, Gray, 1975] . It is believed that the latent heat of evaporation plays an important role in the energy balance of tropical cyclones. At the same time, the temperature of the ocean in the region of the origin of the cyclone should be at least 26 ° C.

This generally accepted hypothesis of the formation of cyclones arose without analyzing natural information, by way of logical conclusions and ideas of its authors about the physics of the development of such processes. It is natural to assume that if the air in the formation rises, which happens in cyclones, then it must be lighter than the air at its periphery.

Rice. 2. Top view of a tornado cloud. Partially it is located above the peninsula of Florida. http://www.oceanology.ru/wp-content/uploads/2009/08/bondarenko-pic3.jpg

So it is considered: light warm air rises, moisture condenses, pressure drops, rotational movements of the cyclone occur.

Some researchers see weaknesses in this, albeit generally accepted, hypothesis. So, they believe that local temperature and pressure drops in the tropics are not so great that only these factors could play a decisive role in the occurrence of a cyclone, i.e. so significantly accelerate the air currents [Yusupaliev, et al., 2001]. Until now, it remains unclear what physical processes occur at the initial stages of tropical cyclone development, how the initial disturbance intensifies, how a large-scale vertical circulation system arises, supplying energy to the cyclone dynamic system [Moiseev et al., 1983]. Adherents of this hypothesis do not explain in any way the patterns of heat fluxes from the ocean to the atmosphere, but simply assume their presence.

We see an obvious shortcoming of this hypothesis. So that the air is heated by the ocean, it is not enough that the ocean is warmer than the air. A flow of heat from the depth to the surface of the ocean is required, and, consequently, the rise of water. At the same time, in the tropical zone of the ocean, water at depth is always colder than near the surface, and such a warm flow does not exist. In the accepted hypothesis, as noted, the cyclone is formed at a water temperature of more than 26°C. However, in reality we observe otherwise. Thus, in the equatorial zone of the Pacific Ocean, where tropical cyclones are actively formed, the average water temperature is ~ 25°C. However, cyclones form more often during La Niña, when the ocean surface temperature drops to 20°C, and rarely during El Niño, when the ocean surface temperature rises to 30°C. Therefore, we can assume that the accepted hypothesis of cyclone formation cannot be realized, at least in tropical conditions.

We analyzed these phenomena and propose a different hypothesis for the formation and development of cyclonic formations, which, in our opinion, more correctly explains their nature. Oceanic Rossby waves play an active role in the formation and replenishment of energy of eddy formations.

Rossby waves of the oceans. They form part of an interconnected field of free, progressive waves of the World Ocean propagating in space, and have the property of propagating in the open part of the ocean in a westerly direction. Rossby waves are present throughout the oceans, but in the equatorial zone they are large. The movement of water particles in waves and wave transfer (Stokes, Lagrange) are, in fact, wave flows. Their speeds (energy equivalent) change in time and space. According to the results of studies [Bondarenko, 2008], the current velocity is equal to the amplitude of fluctuations in the wave current velocity, in fact, the maximum velocity in the wave. Therefore, the highest speeds of wave currents are observed in areas of strong large-scale currents: western boundary, equatorial and circumpolar currents (Fig. 3a, b).

Rice. 3a, b. Vectors of the currents of the Northern (a) and Southern (b) hemispheres of the Atlantic Ocean averaged over the ensemble of drifter observations. Currents: 1 - Gulf Stream, 2 - Guiana, 3 - Brazilian, 4 - Labrador, 5 - Falkland, 6 - Canary, 7 - Benguela.

In accordance with the studies [Bondarenko, 2008], the streamlines of Rossby wave currents in a narrow equatorial zone (2° - 3° from the Equator to the north and south) and its surroundings can be schematically represented as dipole current lines, (Fig. 5a, b) . Recall that the streamlines indicate the instantaneous direction of the current vectors, or, which is the same thing, the direction of the force that creates the currents, the speed of which is proportional to the density of the streamlines.

Rice. 4. Paths of all tropical cyclones for 1985-2005. The color indicates their strength on the Saffir-Simpson scale.

It can be seen that near the surface of the ocean in the equatorial zone, the density of current lines is much greater than outside it, therefore, the speed of the currents is also greater. The vertical velocities of the currents in the waves are small, they are approximately one thousandth of the horizontal current velocity. If we take into account that the horizontal speed at the Equator reaches 1 m/s, then the vertical speed is approximately 1 mm/s. In this case, if the wavelength is 1 thousand km, then the area of ​​rise and fall of the wave will be 500 km.

Rice. 5 a, b. Streamlines of Rossby waves in a narrow equatorial zone (2° - 3° from the Equator to the north and south) in the form of ellipses with arrows (wave current vector) and its environment. Above - a view along the vertical section along the Equator (A), below - a top view of the current. Light blue and blue highlight the area of ​​rise to the surface of cold deep waters, yellow – the area of ​​sinking to the depth of warm surface waters (Bondarenko, Zhmur, 2007).

The sequence of waves, both in time and in space, is a continuous series of small - large - small, etc. formed in modulation (groups, trains, beats). waves. The parameters of the Rossby waves in the equatorial zone of the Pacific Ocean are determined from current measurements, a sample of which is shown in Fig. 6a and temperature fields, a sample of which is shown in fig. 7a, b, c. The wave period is easily determined graphically from fig. 6a, it is approximately equal to 17-19 days.

With a constant phase, approximately 18 waves fit in the modulations, which corresponds in time to one year. On fig. 6a such modulations are clearly expressed, there are three of them: in 1995, 1996 and 1998. In the equatorial zone of the Pacific Ocean, ten waves fit, i.e. almost half of the modulation. Sometimes modulations have a harmonious quasi-harmonic character. This state can be considered as typical for the equatorial zone of the Pacific Ocean. Sometime they are expressed indistinctly, and sometimes the waves collapse and turn into formations with alternation of large and small waves, or the waves as a whole become small. This was observed, for example, from the beginning of 1997 until the middle of 1998 during a strong El Niño, the water temperature reached 30°C. After that came a strong La Niña: the water temperature dropped to 20°C, sometimes up to 18°C.

Rice. 6 a, b. The meridional component of the current velocity, V (a) and the water temperature (b) at a point on the Equator (140°W) on a 10 m horizon for the period 1995-1998. Fluctuations in the current velocity with a period of about 17–19 days, formed by Rossby waves, are noticeably distinguished in the currents. Temperature fluctuations with a similar period are also traced in the measurements.

Rossby waves create fluctuations in the temperature of the water surface (the mechanism is described above). Large waves observed during La Niña correspond to large fluctuations in water temperature, and small waves observed during El Niño correspond to small ones. During La Niña, waves form noticeable temperature anomalies. On fig. 7c, zones of cold water rise (blue and light blue) and in the intervals between them zones of warm water sink (light blue and white) are distinguished. During El Niño, these anomalies are small and not noticeable (Fig. 7b).

Rice. 7 a, b, c. The average water temperature (°C) of the equatorial region of the Pacific Ocean at a depth of 15 m for the period 01/01/1993 - 12/31/2009 (a) and temperature anomalies during El Niño December 1997 (b) and La Niña December 1998 . (in) .

Formation of atmospheric vortices (author's hypothesis). Tropical cyclones and tornadoes, tsunamis, etc. move along the equatorial and zones of the western boundary currents, in which the Rossby waves have the highest vertical velocities of water movement (Fig. 3, 4). As noted, in these waves, the rise of deep water to the ocean surface in tropical and subtropical zones leads to the creation on the ocean surface of significant negative anomalies of oval-shaped water, with a temperature in the center below the temperature of the waters surrounding them, “temperature spots” (Fig. 7c) . In the equatorial zone of the Pacific Ocean, temperature anomalies have the following parameters: ~ 2–3 °C, diameter ~ 500 km.

The very fact of the movement of tropical cyclones and tornadoes along the zones of equatorial and western boundary currents, as well as an analysis of the development of such processes as upwelling - downwelling, El Niño - La Niña, and trade winds led us to the idea that atmospheric vortices somehow must be physically connected with the activity of Rossby waves, or rather, they must be generated by them, which we later found an explanation for.

Cold water anomalies cool atmospheric air, creating negative anomalies of an oval shape, close to circular, of cold air in the center and warmer on the periphery. As a result, the pressure inside the anomaly is lower than on its periphery. As a result of this, efforts arise due to the pressure gradient that move the masses of air and the moisture and solids contained in it to the center of the anomaly - F d. The Coriolis force acts on the air masses - F k , which deflects them to the right in the Northern Hemisphere and to the left in the Southern . Thus, the masses will move into the center of the anomaly in a spiral. For cyclonic motion to occur, the Coriolis force must be non-zero. Since F k \u003d 2mw u Sinf, where m is the body mass, w is the angular frequency of the Earth's rotation, f is the latitude of the place, u is the modulus of the speed of the body (air, moisture, solids). At the equator, Fk = 0, so cyclonic formations do not occur there. In connection with the movement of masses along the circumference, a centrifugal force is formed - F c, which tends to push the masses away from the center of the anomaly. In general, a force will act on the masses, tending to shift them along the radius - F r \u003d F d - F c. and the Coriolis force. The speed of rotation of the masses of air, moisture and solids in the formation and their supply to the center of the cyclone will depend on the force gradient F r . Most often in the anomaly F d > F c. The force F c reaches a significant value at high angular velocities of rotation of the masses. This distribution of forces leads to the fact that the air with the moisture and solid particles contained in it rushes to the center of the anomaly and is pushed up there. It is pushed out, but does not rise, as it is considered in the accepted hypotheses of the formation of cyclones. In this case, the heat flux is directed from the atmosphere, and not from the ocean, as in the accepted hypotheses. The rise of air causes condensation of moisture and, accordingly, a drop in pressure in the center of the anomaly, the formation of clouds above it, and precipitation. This leads to a decrease in the air temperature of the anomaly and an even greater drop in pressure in its center. There is a kind of connection between processes that mutually reinforce each other: the pressure drop in the center of the anomaly increases the air supply to it and, accordingly, its rise, which in turn leads to an even greater pressure drop and, accordingly, an increase in the supply of air masses, moisture and solids. particles into an anomaly. In turn, this leads to a strong increase in the speed of air (wind) movement in the anomaly, forming a cyclone.

So, we are dealing with a connection of processes that mutually reinforce each other. If the process proceeds without amplification, in a forced mode, then, as a rule, the wind speed is small - 5-10 m/s, but in some cases it can reach 25 m/s. Thus, the speed of the winds - trade winds is 5 - 10 m / s with differences in the temperature of the surface ocean waters of 3-4 ° C for 300 - 500 km. In the coastal upwellings of the Caspian Sea and in the open part of the Black Sea, winds can reach 25 m/s with water temperature differences of ~ 15°C per 50–100 km. During the “work” of the connection of processes mutually reinforcing each other in tropical cyclones, tornadoes, tornadoes, the wind speed in them can reach significant values ​​- over 100-200 m/s.

Feeding the cyclone with energy. We have already noted that Rossby waves propagate westward along the Equator. They form on the surface of the ocean water anomalies with a negative temperature of ~500 km in diameter, which are supported by a negative heat flux and a mass of water coming from the depth of the ocean. The distance between the centers of anomalies is equal to the wavelength, ~ 1000 km. When the cyclone is above the anomaly, it is fueled by energy. But when the cyclone is between the anomalies, it is practically not fed with energy, since in this case there are no vertical negative heat fluxes. He skips this zone by inertia, perhaps with a small loss of energy. Further, in the next anomaly, it receives an additional portion of energy, and this continues throughout the entire path of the cyclone, often turning into a tornado. Of course, conditions may arise when the cyclone will not encounter anomalies or they will be small, and it may eventually collapse.

Formation of a tornado. After a tropical cyclone reaches the western borders of the ocean, it moves north. Due to the increase in the Coriolis force, the angular and linear velocities of air movement in the cyclone increase, and the pressure in it decreases. The pressure drops inside and outside the cyclonic formation reach values ​​of more than 300 mb, while in mid-latitude cyclones this value is ~30 mb. Wind speeds exceed 100 m/s. The area of ​​rise of air and solid particles and moisture contained in it narrows. She received the name of the trunk or pipe of the vortex formation. Masses of air, moisture and solids come from the periphery of the cyclonic formation to its center, into the pipe. Such formations with a pipe are called tornadoes, blood clots, typhoons, tornadoes (see Fig. 1, 2).

At high angular speeds of air rotation in the center of the tornado, the following conditions arise: F d ~ F c. Under these conditions, moisture and solids are absent in the pipe and the air is transparent. Such a state of tornado, tsunami, etc. was called the “eye of the storm”. On the walls of the pipe, the resulting force acting on the particles is practically zero, while inside the pipe it is small. The angular and linear velocities of air rotation in the center of the tornado are also small. This explains the absence of wind inside the pipe. But such a state of a tornado, with an “eye of the storm”, is not observed in all cases, but only when the angular velocity of rotation of substances reaches a significant value, i.e. in strong tornadoes.

A tornado, like a tropical cyclone, is fueled by the energy of water temperature anomalies created by Rossby waves along the entire route over the ocean. On land, there is no such mechanism for pumping energy, and therefore the tornado is destroyed relatively quickly.

It is clear that in order to predict the state of a tornado along its path over the ocean, it is necessary to know the thermodynamic state of surface and deep waters. Such information is provided by shooting from space.

Tropical cyclones and tornadoes usually form during the summer and fall, when La Niña forms in the Pacific Ocean. Why? In the equatorial zone of the oceans, it is precisely at this time that the Rossby waves reach their maximum amplitude and create significant temperature anomalies, the energy of which feeds the cyclone (Bondarenko, 2006). We do not know how the amplitudes of the Rossby waves behave in the subtropical part of the oceans, so it cannot be argued that the same thing happens there. But it is well known that deep negative anomalies in this zone appear in summer, when surface waters are heated more than in winter. Under these conditions, temperature anomalies of water and air occur with large temperature drops, which explains the formation of strong tornadoes mainly in summer and autumn.

Mid-latitude cyclones. These are formations without a pipe. In middle latitudes, a cyclone, as a rule, does not turn into a tornado, since the conditions Fr ~ Fk are satisfied, i.e. the movement of masses is geostrophic.

Rice. Fig. 8. Temperature field of surface waters of the Black Sea at 19:00 on September 29, 2005.

Under these conditions, the velocity vector of the masses of air, moisture and solid particles is directed along the circumference of the cyclone, and all these masses only weakly enter its center. Therefore, the cyclone does not shrink and does not turn into a tornado. We managed to trace the formation of a cyclone over the Black Sea. Rossby waves often create negative temperature anomalies of surface waters in the central regions of its western and eastern parts. They form cyclones over the sea, sometimes with high wind speeds. Often the temperature in the anomalies reaches ~ 10 - 15 °C, while over the rest of the sea the water temperature is ~ 230C. Figure 8 shows the distribution of water temperature in the Black Sea. Against the background of a relatively warm sea with surface water temperatures up to ~ 23°C, a water anomaly up to ~ 10°C stands out in its western part. The differences are very significant, which formed the cyclone (Fig. 9). This example indicates the possibility of implementing our hypothesis of the formation of cyclonic formations.

Rice. 9. Scheme of the atmospheric pressure field over the Black Sea and near it, corresponding to the time: 19h. September 29, 2005 Pressure in mb. There is a cyclone in the western part of the sea. The average wind speed in the area of ​​the cyclone is 7 m/s and is directed cyclonically along the isobars.

Often, a cyclone comes to the Black Sea from the Mediterranean side, which is significantly intensified over the Black Sea. So, most likely, in November 1854. the famous Balaklava storm formed, which sank the English fleet. Water temperature anomalies similar to those shown in Fig. 8 are also formed in other closed or semi-enclosed seas. For example, tornadoes moving towards the United States often intensify significantly when passing over the Caribbean Sea or the Gulf of Mexico. To substantiate our conclusions, we quote verbatim an excerpt from the Internet site “Atmospheric processes in the Caribbean Sea”: “The resource presents a dynamic image of the tropical hurricane Dean (tornado), one of the most powerful in 2007. The hurricane gains the greatest strength over the water surface, and when passing over land, it is “washed out” and weakened.

Tornadoes. These are small vortex formations. Like tornadoes, they have a pipe, they form over the ocean or sea, on the surface of which temperature anomalies of small sizes occur. The author of the article had to repeatedly observe tornadoes in the eastern part of the Black Sea, where the high activity of Rossby waves against the background of a very warm sea leads to the formation of numerous and deep temperature anomalies in surface waters. The development of tornadoes in this part of the sea is also facilitated by very humid air.

Conclusions. Atmospheric eddies (cyclones, tornadoes, typhoons, etc.) are formed by temperature anomalies of surface waters with a negative temperature; in the center of the anomaly, the water temperature is lower, and at the periphery - higher. These anomalies are formed by the Rossby waves of the World Ocean, in which cold water rises from the depth of the ocean to its surface. In this case, the air temperature in the episodes under consideration is usually higher than the water temperature. However, the fulfillment of this condition is not necessary; atmospheric vortices can be formed when the air temperature over the ocean or sea is lower than the water temperature. The main condition for the formation of a vortex is the presence of a negative anomaly of water and a temperature difference between water and air. Under these conditions, a negative air anomaly is created. The greater the temperature difference between the atmosphere and ocean water, the more actively the vortex develops. If the water temperature of the anomaly is equal to the air temperature, then the vortex is not formed, and the vortex that exists under these conditions does not develop. Further, everything happens as described.

Literature:
Bondarenko A.L. El Niño – La Niña: formation mechanism // Nature. No. 5. 2006. S. 39 - 47.
Bondarenko A.L., Zhmur V.V. The Present and Future of the Gulf Stream // Nature. 2007. No. 7. S. 29 - 37.
Bondarenko A.L., Borisov E.V., Zhmur V.V. On the long-wave nature of sea and ocean currents// Meteorology and hydrology. 2008. No. 1. pp. 72 - 79.
Bondarenko A.L. New ideas about the patterns of formation of cyclones, tornadoes, typhoons, tornadoes. 17.02.2009 http://www.oceanographers.ru/index.php?option=com_content&task=view&id=1534&Itemid=52
Gray W.M. Genesis and intensification of tropical cyclones // Sat. Intense atmospheric vortices. 1985. M.: Mir.
Ivanov V.N. Origin and development of tropical cyclones// C.: Tropical meteorology. Proceedings of the III International Symposium. 1985. L. Gidrometeoizdat.
Kamenkovich V.M., Koshlyakov M.M., Monin A.S. Synoptic eddies in the ocean. Leningrad: Gidrometeoizdat. 1982. 264p.
Moiseev S.S., Sagdeev R.Z., Tur A.V., Khomenko G.A., Shukurov A.V. Physical mechanism of amplification of vortex disturbances in the atmosphere// Reports of the Academy of Sciences of the USSR. 1983. T.273. Number 3.
Nalivkin D.V. Hurricanes, storms, tornadoes. 1969. L .: Science.
Yusupaliev U., Anisimov E.P., Maslov A.K., Shuteev S.A. On the question of the formation of the geometric characteristics of a tornado. Part II // Applied Physics. 2001. No. 1.
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Albert Leonidovich Bondarenko, oceanologist, doctor of geographical sciences, leading researcher at the Institute of Water Problems of the Russian Academy of Sciences. Area of ​​scientific interests: the dynamics of the waters of the World Ocean, the interaction of the ocean and the atmosphere. Achievements: proof of the significant influence of oceanic Rossby waves on the formation of the thermodynamics of the ocean and atmosphere, weather and climate of the Earth.
[email protected]

The concept of an atmospheric front is commonly understood as a transition zone in which adjacent air masses with different characteristics meet. Fronts are formed when warm and cold air masses collide. They can stretch for tens of kilometers.

Air masses and atmospheric fronts

The circulation of the atmosphere occurs due to the formation of various air currents. Air masses located in the lower layers of the atmosphere are able to combine with each other. The reason for this is the common properties of these masses or identical origin.

Changes in weather conditions occur precisely because of the movement of air masses. Warm temperatures cause warming, and cold temperatures cause cooling.

There are several types of air masses. They are distinguished by the origin. Such masses are: arctic, polar, tropical and equatorial air masses.

Atmospheric fronts occur when various air masses collide. Collision areas are called frontal or transitional. These zones instantly appear and also quickly collapse - it all depends on the temperature of the colliding masses.

The wind generated during such a collision can reach speeds of 200 km/k at an altitude of 10 km from the earth's surface. Cyclones and anticyclones are the result of collisions of air masses.

Warm and cold fronts

Warm fronts are fronts moving in the direction of cold air. The warm air mass moves along with them.

As warm fronts approach, pressure decreases, clouds thicken, and heavy precipitation falls. After the front has passed, the direction of the wind changes, its speed decreases, the pressure begins to gradually rise, and the precipitation stops.

A warm front is characterized by the flow of warm air masses onto cold ones, which causes them to cool.

It is also often accompanied by heavy rainfall and thunderstorms. But when there is not enough moisture in the air, precipitation does not fall.

Cold fronts are air masses that move and displace warm air. A cold front of the first kind and a cold front of the second kind are distinguished.

The first genus is characterized by the slow penetration of its air masses under warm air. This process forms clouds both behind the front line and within it.

The upper part of the frontal surface consists of a uniform cover of stratus clouds. The duration of the formation and decay of a cold front is about 10 hours.

The second kind is cold fronts moving at high speed. Warm air is instantly displaced by cold air. This leads to the formation of a cumulonimbus region.

The first signals of the approach of such a front are high clouds, visually resembling lentils. Their education takes place long before his arrival. The cold front is located two hundred kilometers from the place where these clouds appeared.

The cold front of the 2nd kind in the summer is accompanied by heavy precipitation in the form of rain, hail and squally winds. Such weather can spread for tens of kilometers.

In winter, a cold front of the 2nd kind causes a snow blizzard, strong winds, and turbulence.

Atmospheric fronts of Russia

The climate of Russia is mainly influenced by the Arctic Ocean, the Atlantic and the Pacific.

In summer, Antarctic air masses pass through Russia, affecting the climate of Ciscaucasia.

The entire territory of Russia is prone to cyclones. Most often they form over the Kara, Barents and Okhotsk Seas.

Most often in our country there are two fronts - the Arctic and the Polar. They move south or north during different climatic periods.

The southern part of the Far East is subject to the influence of the tropical front. Abundant precipitation in central Russia is caused by the influence of the polar front, which operates in July.

Whirlwinds in the air. A number of methods for creating vortex motions are experimentally known. The method described above for obtaining smoke rings from a box makes it possible to obtain vortices, the radius and speed of which are of the order of 10-20 cm and 10 m/s, respectively, depending on the diameter of the hole and the force of impact. Such eddies travel distances of 15-20 m.

Vortices of a much larger size (with a radius of up to 2 m) and a higher speed (up to 100 m/s) are obtained using explosives. In a pipe closed at one end and filled with smoke, an explosive charge located near the bottom is detonated. A vortex obtained from a cylinder with a radius of 2 m with a charge weighing about 1 kg travels a distance of about 500 m. For most of the way, the vortices obtained in this way are of a turbulent nature and are well described by the law of motion, which is set forth in § 35.

The mechanism of formation of such vortices is qualitatively clear. When the air moves in the cylinder caused by the explosion, a boundary layer is formed on the walls. At the edge of the cylinder, the boundary layer is torn off,

resulting in a thin layer of air with significant vorticity. Then this layer is collapsed. A qualitative picture of successive stages is shown in fig. 127, which shows one edge of the cylinder and a vortex layer shedding from it. Other schemes for the formation of vortices are also possible.

At low Reynolds numbers, the helical structure of the vortex is retained for quite a long time. At high Reynolds numbers, as a result of instability, the spiral structure is destroyed immediately and turbulent mixing of the layers occurs. As a result, a vortex core is formed, in which the vorticity distribution can be found by solving the problem posed in § 35, described by the system of equations (16).

However, at the moment there is no calculation scheme that would allow one to determine the initial parameters of the formed turbulent vortex (i.e., its initial radius and speed) from the given parameters of the pipe and the weight of the explosive. The experiment shows that for a pipe with given parameters, there is the largest and smallest charge weights at which a vortex is formed; its formation is strongly influenced by the location of the charge.

Whirlwinds in the water. We have already said that vortices in water can be obtained in a similar way by pushing a certain volume of ink-colored liquid out of the cylinder with a piston.

Unlike air vortices, the initial speed of which can reach 100 m/s or more, in water at an initial speed of 10-15 m/s, due to the strong rotation of the liquid moving along with the vortex, a cavitation ring appears. It arises at the moment of formation of a vortex when the boundary layer is torn off from the edge of the Cylinder. If trying to get whirlwinds with speed

more than 20 m/sec, then the cavitation cavity becomes so large that instability occurs and the vortex is destroyed. The foregoing applies to cylinder diameters of the order of 10 cm, it is possible that with an increase in diameter it will be possible to obtain stable vortices moving at high speed.

An interesting phenomenon occurs when a vortex moves vertically upwards in water towards a free surface. Part of the liquid, forming the so-called vortex body, flies up above the surface, at first almost without changing shape - the water ring jumps out of the water. Sometimes the speed of the ejected mass in the air increases. This can be explained by the ejection of air that occurs at the boundary of the rotating fluid. Subsequently, the escaping vortex is destroyed under the action of centrifugal forces.

Falling drops. It is easy to observe the vortices formed when ink drops fall into the water. When an ink drop hits the water, a ring of ink is formed and moves down. A certain volume of liquid moves along with the ring, forming a vortex body, which is also colored with ink, but much weaker. The nature of the movement strongly depends on the ratio of the densities of water and ink. In this case, density differences of tenths of a percent turn out to be significant.

The density of pure water is less than that of ink. Therefore, when a vortex moves, a downward force acts on it along the vortex. The action of this force leads to an increase in the momentum of the vortex. Vortex momentum

where Г is the circulation or intensity of the vortex, and R is the radius of the vortex ring, and the velocity of the vortex

If the circulation change is neglected, then a paradoxical conclusion can be drawn from these formulas: the action of a force in the direction of the vortex motion leads to a decrease in its speed. Indeed, from (1) it follows that with increasing momentum at a constant

circulation, the radius R of the vortex should increase, but from (2) it can be seen that with constant circulation, with increasing R, the velocity decreases.

At the end of the vortex movement, the ink ring breaks up into 4-6 separate clots, which in turn turn into vortices with small spiral rings inside. In some cases, these secondary rings break apart again.

The mechanism of this phenomenon is not very clear, and there are several explanations for it. In one scheme, the main role is played by the force of gravity and the instability of the so-called Taylor type, which occurs when a denser fluid is above a less dense one in a gravitational field, both fluids being initially at rest. A flat boundary separating two such liquids is unstable - it deforms, and individual clots of a denser liquid penetrate into a less dense one.

When the ink ring moves, the circulation actually decreases, and this causes the vortex to stop completely. But the force of gravity continues to act on the ring, and, in principle, it should descend further as a whole. However, Taylor instability occurs, and as a result, the ring breaks up into separate clumps, which fall under the action of gravity and in turn form small vortex rings.

There is another possible explanation for this phenomenon. An increase in the radius of the ink ring leads to the fact that the part of the liquid moving along with the vortex takes the form shown in Fig. 127 (p. 352). As a result of the action on a rotating torus, consisting of streamlines, of forces similar to the Magnus force, the elements of the ring acquire a speed directed perpendicular to the speed of the ring as a whole. Such a motion is unstable, and disintegration into separate clumps occurs, which again turn into small vortex rings.

The mechanism of formation of a vortex when drops fall into water can have a different character. If a drop falls from a height of 1-3 cm, then its entry into the water is not accompanied by a splash and the free surface is slightly deformed. On the border between a drop and water

a vortex layer is formed, the folding of which leads to the formation of an ink ring surrounded by water trapped by the vortex. The successive stages of vortex formation in this case are qualitatively depicted in Fig. 128.

When drops fall from a great height, the mechanism of vortex formation is different. Here the falling drop, being deformed, spreads on the surface of the water, imparting, over an area much larger than its diameter, an impulse with maximum intensity in the center. As a result, a depression is formed on the surface of the water, it expands by inertia, and then a collapse occurs and a cumulative splash occurs - a plume (see Chapter VII).

The mass of this sultan is several times greater than the mass of the drop. Falling under the action of gravity into the water, the sultan forms a vortex according to the already disassembled scheme (Fig. 128); in fig. 129 shows the first stage of the fall of the drop, leading to the formation of the plume.

According to this scheme, vortices are formed when a rare rain with large drops falls on the water - then the surface of the water is covered with a grid of small plumes. Due to the formation of such sultans, each

the drop significantly increases its mass, and therefore the vortices caused by its fall penetrate to a fairly large depth.

Apparently, this circumstance can be used as the basis for explaining the well-known effect of damping surface waves in water bodies by rain. It is known that in the presence of waves, the horizontal components of the particle velocity on the surface and at some depth have opposite directions. During rain, a significant amount of liquid penetrating to the depth dampens the wave velocity, and currents ascending from the depth dampen the velocity at the surface. It would be interesting to develop this effect in more detail and build its mathematical model.

Vortex cloud of atomic explosion. A phenomenon very similar to the formation of a vortex cloud during an atomic explosion can be observed during explosions of conventional explosives, for example, when a flat round plate of explosives is blown up, located on dense soil or on a steel plate. It is also possible to place explosives in the form of a spherical layer or glass, as shown in Fig. 130.

A ground-based atomic explosion differs from a conventional explosion primarily in a significantly higher concentration of energy (kinetic and thermal) with a very small mass of gas thrown upwards. In such explosions, the formation of a vortex cloud occurs due to the buoyancy force, which appears due to the fact that the mass of hot air formed during the explosion is lighter than the environment. The buoyant force also plays a significant role in the further motion of the vortex cloud. In the same way as during the movement of an ink vortex in water, the action of this force leads to an increase in the radius of the vortex cloud and a decrease in speed. The phenomenon is complicated by the fact that air density changes with height. A scheme for an approximate calculation of this phenomenon is available in the work.

Vortex model of turbulence. Let the flow of liquid or gas flow around the surface, which is a plane with dents bounded by spherical segments (Fig. 131, a). In ch. V, we have shown that zones with constant vorticity naturally arise in the region of dents.

Let us now assume that the vortex zone separates from the surface and begins to move in the main flow (Fig.

131.6). Due to swirling, this zone, in addition to the velocity V of the main flow, will also have a velocity component perpendicular to V. As a result, such a moving vortex zone will cause turbulent mixing in the liquid layer, the size of which is tens of times larger than the dimensions of the dent.

This phenomenon, apparently, can be used to explain and calculate the movement of large masses of water in the oceans, as well as the movement of air masses in mountainous regions during strong winds.

Reduced resistance. At the beginning of the chapter, we said that air or water masses without shells that move along with the vortex, despite their poorly streamlined shape, experience significantly less resistance than the same masses in shells. We also indicated the reason for such a decrease in resistance - it is explained by the continuity of the velocity field.

A natural question arises as to whether it is possible to give a streamlined body such a shape (with a movable boundary) and impart to it such a movement that the flow that arises in this case is similar to the flow during the movement of a vortex, and thereby try to reduce the resistance?

We give here an example belonging to B. A. Lugovtsov, which shows that such a formulation of the question makes sense. Let us consider a plane potential flow of an incompressible inviscid fluid symmetric with respect to the x axis, the upper half of which is shown in Fig. 132. At infinity, the flow has a velocity directed along the x axis, in fig. 132 hatching marks a cavity in which such pressure is maintained that at its boundary the velocity is constant and equal to

It is easy to see that if, instead of a cavity, a solid body with a moving boundary is placed in the flow, the speed of which is also equal, then our flow can also be considered as an exact solution to the problem of a viscous fluid flow around this body. Indeed, the potential flow satisfies the Navier-Stokes equation, and the no-slip condition on the boundary of the body is satisfied due to the fact that the velocities of the fluid and the boundary coincide. Thus, due to the moving boundary, the flow will remain potential, despite the viscosity, the wake will not appear and the total force acting on the body will be equal to zero.

In principle, such a construction of a body with a moving boundary can also be implemented in practice. To maintain the described motion, a constant supply of energy is required, which must compensate for the energy dissipation due to viscosity. Below we calculate the power required for this.

The nature of the flow under consideration is such that its complex potential must be a multivalued function. To isolate its single-valued branch, we

we will make a cut along the segment in the flow area (Fig. 132). It is clear that the complex potential maps this region with a cut to the region shown in Fig. 133, a (the corresponding points are marked with the same letters), it also shows the images of streamlines (the corresponding points are marked with the same numbers). The discontinuity of the potential on the line does not violate the continuity of the velocity field, because the derivative of the complex potential remains continuous on this line.

On fig. 133b shows the image of the flow area when displayed, it is a circle of radius with a cut along the real axis from the point to the point of flow branching B, in which the velocity is zero, goes to the center of the circle

Thus, in the plane the image of the flow region and the position of the points are completely determined. In the opposite plane, you can arbitrarily set the dimensions of the rectangle. By setting them, you can find by

Riemann's theorem (Chapter I) the only conformal mapping of the left half of the region in fig. 133, and on the lower semicircle of fig. 133b, at which the points in both figures correspond to each other. Due to symmetry, then the entire area of ​​Fig. 133, but will be displayed on a circle with a cut fig. 133b. If at the same time we choose the position of point B in Fig. 133, a (i.e., the length of the cut), then it will go to the center of the circle and the display will be completely determined.

It is convenient to express this mapping in terms of the parameter changing in the upper half-plane (Fig. 133, c). The conformal mapping of this half-plane onto a circle with a cut in Fig. 133, b with the desired correspondence of points is written elementarily.

The struggle of warm and cold currents, seeking to equalize the temperature difference between north and south, occurs with varying degrees of success. Then the warm masses take over and penetrate in the form of a warm tongue far to the north, sometimes to Greenland, Novaya Zemlya and even to Franz Josef Land; then the masses of Arctic air in the form of a giant “drop” break through to the south and, sweeping away warm air on their way, fall on the Crimea and the republics of Central Asia. This struggle is especially pronounced in winter, when the temperature difference between north and south increases. On synoptic maps of the northern hemisphere, one can always see several tongues of warm and cold air penetrating to different depths to the north and south.
The arena, in which the struggle of air currents unfolds, falls precisely on the very insects ...

Introduction. 2
1. Formation of atmospheric vortices. four
1.1 Atmospheric fronts. Cyclone and anticyclone 4
1.2 Approach and passage of cyclone 10
2. The study of atmospheric vortices at school 13
2.1 The study of atmospheric vortices in geography lessons 14
2.2 The study of the atmosphere and atmospheric phenomena from grade 6 28
Conclusion.35
Bibliography.

Introduction

Introduction

Atmospheric whirlwinds - tropical cyclones, tornadoes, storms, squalls and hurricanes.
Tropical cyclones are eddies with low pressure at the center; they come in summer and winter. Tropical cyclones occur only at low latitudes near the equator. In terms of destruction, cyclones can be compared with earthquakes or volcanoes.
The speed of cyclones exceeds 120 m / s, while powerful clouds appear, there are showers, thunderstorms and hail. A hurricane can destroy entire villages. The amount of rainfall seems incredible compared to the intensity of rainfall during the strongest cyclones in temperate latitudes.
A tornado is a destructive atmospheric phenomenon. This is a huge vertical whirlwind several tens of meters high.
Humans cannot yet actively fight tropical cyclones, but it is important to prepare in time, whether on land or at sea. For this, meteorological satellites are on duty around the clock, which are of great help in forecasting the paths of tropical cyclones. They photograph whirlwinds, and from the photograph one can quite accurately determine the position of the center of the cyclone and trace its movement. Therefore, in recent times it has been possible to warn the population about the approach of typhoons that could not be detected by ordinary meteorological observations.
Despite the fact that the tornado has a destructive effect, at the same time it is a spectacular atmospheric phenomenon. It is concentrated on a small area and all, as it were, before our eyes. On the shore you can see how a funnel extends from the center of a powerful cloud, and another funnel rises towards it from the surface of the sea. After closing, a huge, moving column is formed, which rotates counterclockwise. Tornadoes

They form when the air in the lower layers is very warm, and in the upper layers it is cold. A very intensive air exchange begins, which
accompanied by a vortex with a high speed - several tens of meters per second. The diameter of a tornado can reach several hundred meters, and the speed is 150-200 km/h. Low pressure is formed inside, so the tornado draws in everything that it meets on the way. Known, for example, "fish"
rains, when a tornado from a pond or lake, along with the water, drew in the fish located there.
A storm is a strong wind, with the help of which great excitement can begin at sea. A storm can be observed during the passage of a cyclone, a tornado.
The wind speed of the storm exceeds 20 m/s and can reach 100 m/s, and when the wind speed is more than 30 m/s, a hurricane begins, and wind intensifications up to speeds of 20-30 m/s are called squalls.
If in geography lessons only the phenomena of atmospheric vortices are studied, then during the lessons of life safety they learn how to protect themselves from these phenomena, and this is very important, because knowing the methods of protection today's students will be able to protect not only themselves but also friends and relatives from atmospheric vortices.

Fragment of the work for review

19
Areas of high pressure are forming in the Arctic Ocean and in Siberia. From there, cold and dry air masses are sent to the territory of Russia. From the side of Siberia, continental moderate masses come, bringing frosty clear weather. Marine air masses in winter come from the Atlantic Ocean, which at this time is warmer than the mainland. Consequently, this air mass brings precipitation in the form of snow, thaws and snowfalls are possible.
III. Fixing new material
What air masses contribute to the formation of droughts and dry winds?
What air masses bring warming, snowfalls, and soften the heat in summer, often bring cloudy weather and precipitation?
Why does it rain in the Far East in summer?
Why is an easterly or southeasterly wind in the East European Plain often much colder in winter than a northerly one?
More snow falls on the East European Plain. Why, then, at the end of winter, the thickness of the snow cover is greater in Western Siberia?
Homework
Answer the question: “How would you explain the type of weather today? Where did he come from, by what signs did you determine this?
atmospheric fronts. Atmospheric vortices: cyclones and anticyclones
Objectives: to form an idea of ​​atmospheric vortices, fronts; show the relationship between weather changes and processes in the atmosphere; Explain the reasons for the formation of cyclones and anticyclones.
20
Equipment: maps of Russia (physical, climatic), demonstration tables "Atmospheric fronts" and "Atmospheric vortices", cards with points.
During the classes
I. Organizational moment
II. Checking homework
1. Frontal survey
What are air masses? (Large volumes of air that differ in their properties: temperature, humidity and transparency.)
Air masses are divided into types. Name them, how are they different? (Approximate answer. Arctic air is formed over the Arctic - it is always cold and dry, transparent, because there is no dust in the Arctic. A moderate air mass is formed over most of Russia in temperate latitudes - cold in winter and warm in summer. Tropical air comes to Russia in summer masses that form over the deserts of Central Asia and bring hot and dry weather with air temperatures up to 40 ° C.)
What is air mass transformation? (Approximate answer. Change in the properties of air masses as they move over the territory of Russia. For example, temperate sea air coming from the Atlantic Ocean loses moisture, warms up in summer and becomes continental - warm and dry. In winter, temperate sea air loses moisture, but cools and becomes dry and cold.)
Which ocean and why has a greater influence on the climate of Russia? (An approximate answer. Atlantic. Firstly, most of Russia
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is located in the prevailing western wind transfer, and secondly, there are practically no obstacles for the penetration of western winds from the Atlantic, since there are plains in the west of Russia. The low Ural Mountains are not an obstacle.)
2. Test
1. The total amount of radiation reaching the Earth's surface is called:
a) solar radiation;
b) radiation balance;
c) total radiation.
2. The largest indicator of reflected radiation has:
a) sand c) black soil;
b) forest; d) snow.
3.Move over Russia in winter:
a) arctic air masses;
b) moderate air masses;
c) tropical air masses;
d) equatorial air masses.
4. The role of the western transport of air masses is increasing in most of Russia:
in the summer; c) autumn.
b) in winter;
5. The largest indicator of total radiation in Russia has:
a) south of Siberia; c) south of the Far East.
b) North Caucasus;
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6. The difference between total radiation and reflected radiation and thermal radiation is called:
a) absorbed radiation;
b) radiation balance.
7. When moving towards the equator, the amount of total radiation:
a) is decreasing c) does not change.
b) increases;
Answers: 1 - in; 3 - g; 3 - a, b; 4 - a; 5 B; 6 - b; 7 - b.
3. Work on cards
- Determine what type of weather is described.
1. At dawn, the frost is below 35 ° C, and the snow is barely visible through the fog. The creak can be heard for several kilometers. The smoke rises vertically from the chimneys. The sun is red like hot metal. During the day, the sun and snow sparkle. The fog has already cleared. The sky is blue, permeated with light, if you look up, it seems like summer. And it’s cold outside, severe frost, the air is dry, there is no wind.
The frost is getting stronger. A rumble is heard from the sounds of cracking trees in the taiga. In Yakutsk, the average January temperature is -43 °C, and from December to March, an average of 18 mm of precipitation falls. (Continental temperate.)
2. The summer of 1915 was very rainy. It rained all the time with great constancy. One day it rained heavily for two days in a row. He did not allow people to leave their houses. Fearing that the boats would be carried away by water, they pulled them further ashore. Several times in one day
23
overturned them and poured out the water. By the end of the second day, water suddenly came from above in a shaft and immediately flooded all the banks. (Monsoon temperate.)
III. Learning new material
Comments. The teacher offers to listen to a lecture, during which students define terms, fill in tables, make diagrams in a notebook. Then the teacher, with the help of consultants, checks the work. Each student receives three score cards. If within
lesson, the student gave the score card to the consultant, which means that he still needs to work with a teacher or consultant.
You already know that three types of air masses move in our country: arctic, temperate and tropical. They are quite different from each other in terms of the main indicators: temperature, humidity, pressure, etc. When air masses approach each other, having
different characteristics, in the zone between them the difference in air temperature, humidity, pressure increases, the wind speed increases. Transitional zones in the troposphere, in which the convergence of air masses with different characteristics occurs, are called fronts.
In the horizontal direction, the length of the fronts, as well as air masses, is thousands of kilometers, along the vertical - about 5 km, the width of the frontal zone near the Earth's surface is about a hundred kilometers, at altitudes - several hundred kilometers.
The time of existence of atmospheric fronts is more than two days.
Fronts, together with air masses, move at an average speed of 30-50 km/h, and the speed of cold fronts often reaches 60-70 km/h (and sometimes 80-90 km/h).
24
Classification of fronts according to the features of movement
1. Warm fronts are those moving towards colder air. A warm air mass moves into the region behind a warm front.
2. Cold fronts are those that move towards a warmer air mass. A cold air mass moves into the region behind a cold front.

IV. Fixing new material
1. Working with the map
1. Determine where the arctic and polar fronts are located over the territory of Russia in summer. (Example answer). Arctic fronts in summer are located in the northern part of the Barents Sea, over the northern part of Eastern Siberia and the Laptev Sea, and over the Chukchi Peninsula. Polar fronts: the first in summer stretches from the Black Sea coast over the Central Russian Upland to the Cis-Urals, the second is located in the south
Eastern Siberia, the third - over the southern part of the Far East and the fourth - over the Sea of ​​Japan.)
2. Determine where the Arctic fronts are located in winter. (In winter, the Arctic fronts shift south, but the front remains over the central part of the Barents Sea and over the Sea of ​​Okhotsk and the Koryak Highlands.)
3. Determine in which direction the fronts shift in winter.
25
(Example answer). In winter, the fronts move south, because all air masses, winds, pressure belts move south following the visible movement
Sun.
The Sun on December 22 is at its zenith in the Southern Hemisphere over the Tropic of the South.)
2. Independent work
Filling tables.
atmospheric fronts
26
Cyclones and anticyclones
signs
Cyclone
Anticyclone
What's this?
Atmospheric vortices that carry air masses
How are they shown on the maps?
Concentric isobars
atmospheres
pressure
Vortex with low pressure in the center
High pressure in the center
air movement
From the periphery to the center
From the center to the outskirts
Phenomena
Air cooling, condensation, cloud formation, precipitation
Heating and drying air
Dimensions
2-3 thousand km across
Transfer speed
displacement
30-40 km/h, mobile
sedentary
direction
movement
West to East
Place of birth
North Atlantic, Barents Sea, Sea of ​​Okhotsk
In winter - Siberian anticyclone
Weather
Cloudy, with precipitation
Partly cloudy, warm in summer, frosty in winter
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3. Working with synoptic maps (weather maps)
Thanks to synoptic maps, one can judge the progress of cyclones, fronts, clouds, make a forecast for the next hours, days. Synoptic maps have their own symbols, by which you can find out about the weather in any area. Isolines connecting points with the same atmospheric pressure (they are called isobars) show cyclones and anticyclones. In the center of the concentric isobars is the letter H (low pressure, cyclone) or B (high pressure, anticyclone). The isobars also indicate the air pressure in hectopascals (1000 hPa = 750 mm Hg). The arrows show the direction of motion of the cyclone or anticyclone.
The teacher shows how various information is reflected on the synoptic map: air pressure, atmospheric fronts, anticyclones and cyclones and their pressure, areas with precipitation, the nature of precipitation, wind speed and direction, air temperature.)
- From the proposed signs, select what is typical for
cyclone, anticyclone, atmospheric front:
1) atmospheric vortex with high pressure in the center;
2) atmospheric vortex with low pressure in the center;
3) brings cloudy weather;
4) stable, inactive;
5) is installed over Eastern Siberia;
6) zone of collision of warm and cold air masses;
28
7) ascending air currents in the center;
8) downward movement of air in the center;
9) movement from the center to the periphery;
10) movement counterclockwise to the center;
11) is hot and cold.
(Cyclone - 2, 3, 1, 10; anticyclone - 1, 4, 5, 8, 9; atmospheric front - 3.6, 11.)
Homework

Bibliography

Bibliography

1. Theoretical foundations of the methodology for teaching geography. Ed. A. E. Bibik and
etc., M., "Enlightenment", 1968
2. Geography. Nature and people. 6th class_ Alekseev A.I. and others_2010 -192s
3. Geography. Initial course. 6th grade. Gerasimova T.P., Neklyukova
N.P. (2010, 176s.)
4. Geography. 7th grade At 2 o'clock Ch.1._Domogatskikh, Alekseevsky_2012 -280s
5. Geography. 7th grade At 2 o'clock Part 2._Domogatskikh E.M_2011 -256s
6. Geography. 8th grade_Domogatskikh, Alekseevsky_2012 -336s
7. Geography. 8th grade. textbook. Rakovskaya E.M.
8. Geography. 8 cells Lesson plans based on the textbook by Rakovskaya and Barinov_2011
348s
9. Geography of Russia. economy and geographical areas. Tutorial for 9
class. Under. ed. Alekseeva A.I. (2011, 288s.)
10. Climate change. Handbook for high school teachers. Kokorin
A.O., Smirnova E.V. (2010, 52s.)

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