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What do we know about the Earth's blue atmosphere? Let's commit short trip into its depths.

When talking about the atmosphere as a whole, it is divided into four large areas, into four “floors”. The first is the lowest part of the atmosphere - the troposphere. The upper limit of this area is different places different. At the equator it extends to a height of 15-18 km, and at the poles - only to 7-9. Four-fifths of the air mass is found here, and it is here that weather is formed.

The second floor of the atmosphere is called the stratosphere. Interestingly, it does not lie immediately behind the troposphere, but is separated from it by an intermediate layer of air (1-3 km thick) - the tropopause, or substratosphere. It's like a small transition between floors. The position of this transition does not remain constant. It either goes down or goes up.

Special jet streams in the atmosphere are associated with the tropopause. With this mysterious phenomenon encountered, for example, during the American intervention in Korea. The soldiers of the People's Army observed a very strange picture from the ground. Some American bombers, flying at high altitude, suddenly stopped in the air, and sometimes even began to slowly back away! Scared unusual phenomenon, American pilots thought that the People's Army North Korea uses something new against them, secret weapon. It turned out that the planes fell into “rivers of air” - peculiar air currents flowing at very high speeds.

The study of these unusual flows showed that they are formed, as a rule, at the tropopause. Air currents really resemble in many ways big rivers. Their width is 100 kilometers or more, and their depth is several kilometers. The flow speed of the “rivers of air” is unusually high. It sometimes reaches -350-400 km per hour. To imagine this speed, it is enough to remember that at the strongest tropical hurricanes wind speed rarely exceeds 200-250 km per hour. Such a wind uproots mighty trees, destroys very strong buildings, and drives river water back. And the flow of “air rivers” is even faster!

It is not surprising that planes falling into this “river” cannot fly against the current. A terrible wind extinguishes almost all their speed. “Air rivers” arise in different areas and quickly mix. They are quite winding and stretch for hundreds and thousands of kilometers. Stratospheric jet currents are also known, occurring at an altitude of 25-30 km.

It has been noticed that in our temperate latitudes there are much more “rivers of air” than above the tropics and at the poles. When an airplane flies along the flow of such an “air river,” it sharply increases speed. There is a known case when a scheduled plane flying from the USA to England unexpectedly arrived at its destination 3 hours ahead of schedule. It turned out that he found himself in an “air river” and its rapid “waves” added several hundred kilometers of additional speed to him.

The stratospheric level rises to 80-90 km above earth's surface. The weather here is consistently clear, but strong winds often blow. Research recent years showed that the stratosphere has its own winter and its own high-altitude summer. Polar regions have been discovered here, temperate latitudes and the equator zone.

The speeds of air currents at heights depend mainly on the nature of the temperature field below the underlying layers of air. The greater the horizontal temperature gradients in the system of the high-altitude frontal zone, the stronger the jet current, indicating the presence strong winds in this zone. In other words, in the formation and evolution of jet streams main role plays the distribution of temperature in the atmosphere and the resulting horizontal temperature gradients.
Jet streams, causally associated with high-altitude frontal zones, arise, intensify or weaken due to the emergence and destruction of tropospheric fronts. In the first case, as a result of the convergence of cold and warm air masses horizontal gradients of temperature, pressure and wind speed increase. In the second case, when the cold and warm air temperature and pressure gradients decrease, winds weaken.
Jet streams occur in the troposphere and stratosphere. In the troposphere they are almost constantly observed in the subtropical zone of the northern and southern hemispheres: in winter between latitudes 25 and 35°, in summer between 35 and 45°. Jet currents in the troposphere very often arise and develop in extratropical latitudes, up to the Central Arctic and Antarctic. In accordance with the areas of their origin in the troposphere, subtropical and extratropical jet streams are distinguished.
The highest wind speeds in the troposphere are usually observed near the tropopause. Data on the distribution of wind at heights show that the highest speeds are most often observed below the tropopause and less often above the tropopause. In the stratosphere they are observed from time to time under certain circulation conditions in winter at altitudes of 25-30 km.
Tropospheric jet streams are observed over almost all parts globe, but not equally often everywhere. There are, for example, areas where at altitudes of 9-12 km the maximum speeds in the jet almost always exceed 200 km/h. In particular, such areas include the Pacific coast of Asia at a latitude of 30-40°. Here, especially over the southeastern part of China and the Japanese islands, for 6-8 months, air flow speeds (mainly from the west) exceeding 200 km/h at altitudes of 9-12 km are common.
Strong jet streams occur continuously near the eastern coast of the United States and often over Canada. Over Europe, jets most often form in the area of ​​the British Isles.
Areas of high frequency of jet streams coincide with areas of large horizontal temperature gradients. Therefore, the areas of greatest frequency of jet currents in winter lie at the junction of the cold continents of Asia, North America, and Greenland, on the one hand, and warm oceans, on the other. High frequency of subtropical jet currents is typical for northern Africa and southern Asia.
The low frequency of tropospheric jet currents occurs in areas with a more or less homogeneous underlying surface. These are oceans south of 30-40° N. w. and to the north 30-40° S. sh., the northern parts of the continents of Asia and America with the adjacent regions of the Arctic, and in the southern polar region - Central Antarctica.
Jet streams are usually depicted in horizontal and vertical planes. In this case, wind speeds are represented by isotachs, i.e., lines of equal wind speeds.
In Fig. 69 and 70 show maps of the absolute pressure topography of the 200 mb surface for various periods. The first map refers to the middle of winter, the second - to the middle of summer. A 200 mb surface pressure topography map (about 12 km altitude) shows the distribution of maximum wind speeds in the upper troposphere and lower stratosphere. It is easy to see that against the background of rare isohypses, a zone of their concentration clearly emerges, encircling the entire northern hemisphere. In these zones, the highest wind speeds are observed - jet streams. At the places where the jets merge, an increase in wind speeds is observed. Where the jets branch, the wind weakens.

In particular, on the evening of January 5, 1956 (Fig. 69), strong jet currents arose at the confluence of southwestern and northwestern air currents, between Iceland and Scandinavia. The same strong jets are easy to detect over the Southern and Southeast Asia, Alaska, etc. It should be noted that the thickening of the contours, i.e., high wind speeds, in winter months can almost always be found south of 40° N. w. (subtropical jets), while in temperate and high latitudes, especially over the USSR, jet streams weaken, break up and re-emerge due to the emergence and development of cyclones and anticyclones.
In summer south of 40° N. w. Jet streams are very rare. They are more often found in temperate and high latitudes. A typical distribution of jets in the northern hemisphere in summer is shown in Fig. 70. As can be seen, the zone of condensation of isohypses and strong winds on the isobaric surface of 200 mb on July 31, 1956 passed through the moderate latitudes of the northern hemisphere, and over low latitudes and the Arctic the winds were weak. However, on some days, jet streams can be intense at high latitudes.

The spatial structure of jet streams is also depicted in a vertical plane perpendicular to the direction of flow. These are ordinary vertical sections of the atmosphere with isotherms and isotachs, sections of fronts and tropopause. In Fig. 71 and 72 show two typical examples of vertical sections of jet streams for winter and summer. These sections represent the subtropical and extratropical jets. In the center of the jet streams, letters indicate the main directions of air currents.
On the average monthly vertical section of the atmosphere, constructed according to observational data for January 1957-1959. up to approximately 25 km between the equator and the North Pole (Fig. 71), two westerly jet streams are depicted with axes located at levels of 10 and 12 km. Average maximum wind speeds on the axis of the subtropical jet (left), reaching 180 km/h, were observed over Iraq. The second jet (on the right) was above Moscow at a level of about 9 km. Here the average maximum wind speeds were 100 km/h. Meanwhile, at the surface of the earth, average wind speeds did not exceed 10-20 km/h. In the summer (August 29, 1957), the subtropical jet was over Transcaucasia, and the extratropical jet was over Moscow. In the first jet the maximum speed reached 140 km/h, in the second - 120 km/h. Despite the typicality of the sections presented here, in certain periods the location of the jet streams may be different.
It should be noted that due to the significant discrepancy between the horizontal and vertical scales, the usual oblate shape of the jet is not expressed in the sections shown. However, if we consider that, for example, in the southern jet system in Fig. 71 the distance between the low and high positions of the isotach is 100 km/h, i.e. vertically, is approximately 10 km, and horizontally - more than 2000 km, then it will become obvious that the jet has the shape of a rather flattened ellipse. The relationships between vertical and horizontal extent are similar in other jet streams.

The characteristic structural features of high-altitude frontal zones and jet streams do not undergo noticeable seasonal changes. Seasonal differences are expressed mainly in the intensity and latitudinal position of the southern (subtropical) jets.
Due to the large temperature contrasts between low and high latitudes, wind speeds in the jet in the cold season are higher than in summer, with maximum speeds observed at more low levels. During the warm season, wind speeds are lower, and maximum speeds are observed at higher levels than in winter. Subtropical jet streams experience interseasonal shifts along the meridians. This can be seen in the sections shown (Fig. 71 and 72).

In addition, in a subtropical jet stream system, the tropopause is always broken, and the jet axis is located between the tropical and extratropical (polar) tropopause. On the contrary, in the zone of the extratropical jet stream, the tropopause is, as a rule, inclined, its rupture is observed in rare cases, and the axis of the jet is most often located under the tropopause. Therefore, in low latitudes the zone of maximum wind speeds is usually higher than in middle and high latitudes. The discontinuity and tilt of the tropopause are also expressed in the above vertical sections of the atmosphere.
Some data on the vertical and horizontal extent of tropospheric jet streams, as well as on the average maximum speeds in their system, can be found in Table. 27 and 28.

From the table 27 it follows that subtropical jet streams are relatively powerful. Subtropical jets of large vertical and horizontal extent (within wind speeds of more than 100 km/h) are more common than the same extratropical jets.
In particular, subtropical jets with a width of more than 2000 km and a height of more than 12 km are much more common than extratropical ones. However, in some cases, extratropical jets can be powerful; wind speeds in the center of the jet sometimes reach 400 km/h or more.
Most often, the average maximum speeds in the extratropical jet stream system are 150-250 km/h, and in the subtropical ones - 200-300 km/h. In other words, even in terms of maximum velocities in the center, subtropical jets are on average more intense than extratropical ones (Table 28).

Air currents can trigger destructive weather anomalies

There are weather anomalies that cannot be predicted in advance, for example, due to a lack of knowledge about certain phenomena in the Earth's atmosphere. The European heat wave in 2003, the drought in California in 2014, Superstorm Sandy in 2012 - all these catastrophic events that claimed a lot human lives, were triggered by the phenomenon of jet stream blocking. But until now, scientists have not been able to find a convincing way to explain what is happening.

Jet streams were first discovered by University of Chicago meteorologist Carl Rossby in the first half of the twentieth century. This term refers to narrow streams of strong wind (on average 45-50 meters per second) in the upper troposphere and lower stratosphere, which have a rather complex structure in the horizontal and vertical directions. Almost simultaneously with the discovery of jet streams, it became known that they can “slow down” quite sharply.

And finally, geophysicist Noboru Nakamura and his graduate student Clare Huang connected the events into a single whole. Interestingly, the solution to the problem was a mathematical model that describes a kind of traffic jam formation on a high-speed multi-lane highway.

One of the problems in describing the “braking” process was the selection of parameters that would most accurately characterize the movement of air masses. To the authors new job we had to add several previously unused parameters, in particular, the meander, that is, the degree of tortuosity of the jet stream. (A similar characteristic is usually used when describing a river bed.)

Returning to the traffic analogy, researchers found that the jet stream throughput air masses Obviously, when the threshold value of this indicator is exceeded, the flow rate decreases. A similar effect occurs when several airways merge.

In a press release from the university, the scientists note that their unexpectedly simple model not only explains the blocking of jet streams, but also provides a long-awaited opportunity to predict it. Moreover, we are talking about both short-term weather forecasting and models of long-term behavior of air masses in regions that are subject to frequent droughts or floods.

“This is one of the most unexpected moments of enlightenment in my career as a scientist - truly a gift from God,” says Nakamura. “It is very difficult to predict something until you understand why it happens. That is why our model should be extremely useful.”

It is important that new model, unlike most modern climate calculations, turned out to be simple from a computational point of view. At the same time, the authors note that when using it, it is worth paying maximum attention to the meteorological features of a particular region. In particular, in Pacific Ocean“air jams” can take decades to resolve.

You can learn more about the achievements of Chicago geophysicists by reading their article published in Science.

A description of other important discoveries and research in the field of meteorology and other climate sciences can be found in the corresponding section of the Vesti.Science project (nauka.vesti.ru).

I wonder why domestic climatologists and meteorologists avoid mentioning Rossby waves and Jet Stream in every possible way as one of the determining factors of the weather!?

As you can see, spring warmth in Central Russia was accompanied by abnormally cold stormy weather in Europe. And the explanation for this is the uncharacteristic position of the high-altitude jet currents for the season. But later the atmospheric situation changed to reverse side, warmth came to Europe, but an influx of Arctic air entered Central Russia, bringing precipitation and reduced temperature. This is what it looked like:

Temperature map of the end of May.

Jet stream in high layers of the atmosphere. You see how its waves correspond to the influx of Arctic masses.

Jet streams in the middle layers of the atmosphere. The origin of cyclones and anticyclones in the bends of the jet stream is clearly visible - depending on their direction, clockwise or counterclockwise.

Let's hope that the reform announced by the new head of the Ministry of Natural Resources will improve the quality of forecasts and lead to more modern methods.

The Ministry of Natural Resources proposed to liquidate Roshydromet

The Ministry of Natural Resources took the initiative to dissolve Federal service on hydrometeorology and monitoring environment(Roshydromet). It is planned to create a separate state-owned company on its basis. This was announced by the head of the department, Sergei Donskoy, Interfax reports.

“We consider as a priority the task of reforming the Roshydromet system and creating a corresponding state company on its basis,” he said.

Earlier, the head of Roshydromet, Maxim Yakovenko, told the agency that the service had submitted to the Russian government a proposal to merge the Russian meteorological services into a single state corporation.

He recalled that Roshydromet manages an extensive structure of subordinate institutions, of which the agency has about 50 throughout Russia, explaining that in a number of regions their work brings losses, but in some it can bring profit.

Of course, the formally stated reasons for optimization do exist, but we remember what scandal with the subsequent retirement of the head of Roshydromet followed the deadly storm in Moscow, which meteorologists missed in the saddest way.

The climate is changing across the planet, and its monitoring service is receiving the same important, like the Ministry of Emergency Situations, in preventing the consequences of weather anomalies. The government cannot afford to maintain an ineffective agency that uses ancient methods of weather forecasting, which negatively affects national economy and leads to serious destruction and death among Russian residents.