Typical atmospheric parts and weather in them - P2

2023-03-29

Table of contents

Tornadoes forward
Vortex tropics
Reverse vortex
Atmospheric circulation over different regions of the globe

Tornadoes forward

Knowledge of tornadoes

This section describes in more detail the many aspects of cyclones, their formation, and development at mid and high latitudes, commonly known as temperate cyclones, or simply cyclones, and at low latitudes – tropical cyclones. About tropical cyclones will be introduced in a separate section later.
Cyclone is a closed, low-pressure area with anti-clockwise air movement in the northern and clockwise in the southern hemispheres. On weather maps, it is represented as a secure homologous system with a barometric minimum in the center.

Thus, the horizontal barometric gradient is towards the center of the storm. Cyclones have the most significant atmospheric angle and excellent wind speed compared to other barometric systems. In deep, well-developed cyclones, wind speeds near the center can reach 60 – 70 m/s or higher.

This is especially common during tropical storms. At the storm’s center, the barometric gradient is zero, and the wind speed is negligible; this area is called the “eye of the storm.”
The pressure at the center of mid-latitude cyclones typically ranges from 990 to 1005 mb, but can drop as low as 930 mb… For example, the deepest North Atlantic cyclones are often found near the north coast. America on the coast of Grenlen and the islands.

In the Pacific Ocean – in the area near Japan’s coast- the islands of Kurin, Xakhalin, and Kamtraka. Lots of deep cyclones in the Gulf of Alaska and the Bering Sea southern hemisphere – areas near the coast of Antarctica where a large number of hurricanes are commonly observed, with pressures lower than 950 mb.
The width of mid- and high-latitude cyclones is usually in the range of 1000-2000 km. The longitudinal surface thickness is much smaller – several kilometers.

Occasionally, depending on the intensity and phase of the broadcast, they can reach heights of 12 – 20 km. In the early stages of development, tornadoes do not get 3 – 5 km.
The frequency of tornadoes and their depth depends on the time of year and the subsurface state. In the oceans of the northern and southern hemispheres at middle and high latitudes, they are usually found during the winter period. On the continent, on the contrary, there are more summers than winters.
In a cyclonic system, under the influence of a gradient force, the gas molecules gradually move toward its center. Still, under the action of the Coriolis force, they are deflected to the right – for the northern hemisphere, and when there is no magma close, they will move along the isobaric line.

In actual conditions, under friction force, the motion trajectory of gas molecules has the shape of a spiral, converging to the center. In a tornado, air near the ground moves into the center and is gradually lifted, i.e. airlift and water vapor condenses.

When there is enough moisture, clouds will form, and precipitation will decrease. Therefore, the central area of the cyclone is characterized by overcast weather and heavy rain.
In the middle and above the troposphere are clouds of tornadoes, the air escaping.
The line connecting points of minimum pressure at different levels is called the vertical axis of the cyclone. It inclines – due to the height of the hurricane’s center being deflected toward colder air.

Formation and evolution of a tornado.

In the earth’s atmosphere, cyclones’ formation, development, and loss are constantly occurring. Their lifespan ranges from a few hours to a few days.

The atmosphere always creates different conditions; some conditions allow tornadoes to develop, while others prevent development.
Cyclone – it is not only an area of low pressure but also a unique vortex of atmospheric circulation. Therefore, when considering the causes of its formation, it is necessary to view many processes occurring in the atmosphere.

At present, many theories about the appearance of vortices are proposed. Still, they cannot fully explain their development due to their complex magnetism, only one or a few just some of factors.
Depending on the characteristics of formation and development as well as different geographical areas, people are divided into extratropical cyclones and tropical cyclones. Extratropical cyclones are subdivided into frontal and non-frontal cyclones.
The vortex is not face-to-face, usually associated with uneven heating of the subsurface and also associated with the presence of a local decompression furnace. Heat cyclones typically occur in winter over the Black Sea – the warm waters and cold continents surrounding it.
We now consider the formation and development of front cyclones. This type usually forms in middle and high latitudes.
Assume that there are two adjacent groups of air, with the same travel speed, along a less moving facade (fig. 1). Due to the influence of several reasons, there is an uneven variation of the barometric pressure over the front band.

The airflow of the two air groups changes direction creating two forward and reverse circulations. The part of the front that didn’t move much started to break the waveform (fig. 1b).

When a large horizontal thermal gradient exists in the middle of the troposphere, the wave bending of the front will increase. The hot and cold parts of the front will appear wavy (fig. 1c).

The hot air begins to penetrate the cold air, and the cold air penetrates the hot air. The pressure drop continues, leading to the formation on the ground of the isoline being closed and forming a forward helical current.
Terrestrial cyclones are generated mainly on cold fronts that are less moving and near the confluence of storms as follows:

Figure 1 . Diagram of the development process of a temperate cyclone

1) Wavy phase. Bend formation is associated with fracture of the less mobile front face, with hot and cold segments on it. On a terrestrial weather map, a tornado takes the form of an isobaric Juvenile Cyclone Stage (see figure.1c).

2) Juvenile cyclonic phase (fig. 2a). The result is cold air behind the vortex and of pre-tropical thermal uplift and many other causes related to mid-tropospheric processes, causing waveform faulting to continue and descend pressure at the center of the cyclone.

On terrestrial weather maps, tornadoes often form several closed isobars. Spiral circulation is sometimes observed at an altitude of 3 – 4 km. (on the 700 mbar isobaric surfaces, there are closed curves).

At this stage, the hot and cold parts get closer together, and above the ground is a hot cyclonic phase.

3) The turbulent cyclonic phase (fig. 2b). At this stage, the cyclone reaches its highest development and begins to be perfected. The cold front moves faster than the hot front, overwhelming the hot air and approaching the hot front.

The hot (fan low) area gradually narrows and comes to a point when the confluence of the cold front and the hot front occurs, that is, the convergence of the cyclone. At this stage, many closed isobars are drawn on the weather map.

Closed circulation is discovered at an altitude of 3-5 km, sometimes even higher. The axis of a cyclone is usually tilted to the west – north, or west.

4) Cycle phase complete. The result of discharging kinetic energy in the vortex to win friction and reduced potential energy (decreased temperature contrast, weakening of vertical motion intensity …) leads to the completion and extinction of the vortex.

That process is started on the ground. The middle and upper cyclonic troposphere may still be undeveloped for some time.

Gradually cold air occupies the entire central part of the cyclone, and its axis becomes almost vertical. In this case, the hurricane is said to be a callous high-pressure formation. In this phase, there are primary fronts in the vortex, and secondary fronts are eroded.

Usually, the conditions created during the formation of cyclonic disturbances seem to be due to the emergence of some new disruption. So the same part of the main front (polar and subpolar fronts) branched into some perturbations and created a series of cyclones. The number of members of that cyclonic chain ranges from 2 to 6.

According to the depth of the hurricane, the cold front, on which the wave bending occurs, shifts southward. Therefore, each subsequent branch cyclone will move in a southerly and faster orbit than the previous one.

Figure 2. Cyclone stages: a) young cyclone; b) ancient cyclone

In a series of cases, the weakened tornado was restored – leading to its rebirth. Then at the center or periphery of the cyclone, the pressure drops.

The weather changed markedly: cloud systems formed, the wind increased, rain intensity increased, and visibility decreased; The direction of the tornado was altered, and the speed of movement increased. This is related to the appearance of excess energy in this area.

At sea, regeneration occurs more frequently when the cyclonic approach of the subpolar front confluences with the polar front.

The regeneration of cyclones can also occur at the confluence of young moving cyclones with less moving young storms. In that case, the confluent central vortex is filled and the new vortex side is rapidly branching. Typically, cyclone development occurs near confluence, when there is a filling of old fading cyclones.

Tornado reproduction is not always predictable. However, it is still found where the tornado dissipates if you pay attention to the weather map for the location and displacement.

The front is located north of the descending cyclone. In addition, if the front north of the weakening cyclone is observed to be strong, it demonstrates the possibility of a regenerative hurricane. In that case, bad weather conditions may arise, making navigation difficult: strong winds and storms, increased wave heights, and poor visibility…

Tornado reproduction is commonly found in the northwestern and northwestern regions of the Atlantic Ocean, near the North American coast in Grenlan, islands, in the Norwegian Sea, and the North Sea.

In the Pacific Ocean – in the vicinity of Japan, Kurin Island, and Aleut Island, near the shores of Kamtraka. Cyclone reconstruction is also seen in the Bering Sea and Alasca Bay.

Displacement of vortices

Since their appearance, tornadoes have moved in the direction of mid-troposphere currents. Because of the general displacement of air in the troposphere, which occurs from west to east, most tornadoes are displaced in that direction.

However, they rarely follow exactly along latitude because the troposphere is often systematically tilted away from the region. On average, tornadoes move from west to east, from lower latitudes to higher margins.
General statistics of all factors affecting certain circulation conditions to the movement of cyclones can only be done in specialized methods and calculations, often used in weather forecasting.
At first-order approximation, it can be assumed that the formation of all barometric fields in the next 6 hours is the same as yesterday. During this cyclonic phase, their displacement occurs along the isobaric line of the hot zone.

The turbulent eddy moves perpendicular to the direction of the maximum horizontal barometric gradient and deviates to the right. The velocity of a cyclone depends on the airflow rate in the middle troposphere.
The average speed in the Northern Hemisphere is about 30-40 km/h, while in the Southern Hemisphere, it is 42-45 km/h.

Weather in tornado

Weather characteristics in a cyclone are very diverse and depend on its development processes. At the same time, the evolution of the weather is also determined by the part passing through the monitoring point.

In a cyclone, children can be divided into 3 regions with different weather conditions (fig. 3).

The front and center part of the tornado distributed in cold air. Stable weather characteristics are determined by the neighboring conditions of the hot front: with the existence of a cloud system: Ci, Cs, as, Ns and a lot of rainfall over a large area, the wind strengthens with the opposite direction clockwise in the northern hemisphere or clockwise in the southern hemisphere; Visibility is reduced to 2 knots.
The hot zone lies between the hot front and the cold front. The weather conditions are different from the above area. The burning front cloud system disappeared, the rainfall stopped falling, and the wind weakened.

Cloudy, overcast weather can be observed in the hot seas in summer. Winter is cloudy with Switzerland and Scotland, cloudy showers, and cold. Visibility is reduced in blind conditions not less than 200 m. The front road is hard, often with showers, thunderstorms, and strong winds.
Post-cyclonic close to a cold front. The cold front determines weather characteristics: there exists the order of clouds Ns, as, Cs, Ci. In front of the front can see each type of cloud, Cc, Ac, and separately, when the front comes – Ns clouds, below it, in the front area with moderate rain.

After the cloud system, a marked decrease in cloud patterns can be observed. It is possible to develop accumulation clouds such as Cb and Sc with a precipitation barrier in the cold air group located quite far from the cold front.

In the forward area, unlike intensification, gusts often occur along the very front. Visibility is good, in average water from 200 to 400 m.In a cyclonic confluence, a cloud system of hot and cold fronts combines, accompanied by many precipitations, lousy visibility, and robust winds.

Weather conditions at the center and front of the confluence may differ slightly from those of the latter, depending on the magnitude of the difference, like the air forces on either side of the front prison neck.

Before the storm front, the cloud system of the hot show is still preserved, and there is average rain after the storm front – showers related to cumulus clouds.During a complete tornado, frontal erosion occurs, clouds disperse, precipitation is possible only in some places, visibility is improved, winds are weak, and weather conditions in all areas parts of the tornado are almost the same.

In the barometric trench, weather conditions are determined by the characteristics of the front, its distribution, and depth. For example, if the barometric trough represents a hot zone, the weather conditions would be characterized by a Ci, Cs, as a cloud system.

NS, there is a lecture on regular water, stronger wind, there is blind. The further away from the cyclone and the less visible the barometric trough, the less visible the hot front: small water shape, slight increase in wind, and variable cloud characteristics.

Cloud system Ci, Cs, as, Ns is gradually broken butt, Sc appeared, and Ns clouds disappeared. The part of the hot front in the barometric trough is poorly represented, often firmly erased, followed by stratospheric clouds near the front, easily confused with Ac clouds. In that case, it can only be distinguished by slight rising winds and weak glare.

In slow-moving barometric troughs, along with cold fronts, mainly Cs, as, Ns clouds are formed with precipitation in the posterior part of the trench. However, there is also the possibility of clouds and rain on both sides of the cold air.

Usually, in the front part of the trench, due to active convection, cumulus clouds appear, while the as, Ns cloud system is absent. In fast-moving troughs, clouds are usually formed in their front part, directly in front of the cold front.

After the cold front, there are often showers. Winds in trenches with cold fronts are usually solid and intermittent.

The change in meteorological factors during the passage of the cyclone.

We consider three variants of the passage of the cyclone from the point of view of the northern hemisphere: the southern part, the central region, and the north.

When crossing the viewpoint by the southern part of the cyclone – the weather changes in proportion to the passage of the warm front, the warm zone, and the cold front, which have been represented above, if the cross-section of the cyclone is located at a considerable distance from the center, the characteristic cloud system and the de-precipitation of the warm front may not be the case.

This is related to cloud formation and precipitation. Passing further south, variable cloudy or cloudy weather can be observed, with no rain and no fog.
The passage of the observation point of the middle part of the cyclone, with the peak of the hot zone. In this case, the approach of the hurricane will initially be characterized by a slight decrease, followed by a substantial reduction in pressure.

After passing through the center of the vortex, the pressure drops a little, then gradually rises. The thick cloud zone of the Ci, Cs, as, Ns system is wider than the passage of the region of hot air, so there is a lot of precipitation and a long time.

The selection of a cyclone is accompanied by a decrease in the wind, sometimes a calm, then a sharp increase in the wind. The air temperature drops slightly. Visibility is relatively poor at 2-4 knots, in rainfall less than 2 knots.
When passing the belvedere, the northern part of the cyclone is shown on line CC figure 3. In this case, the weather change is almost the same as in the central region. However, the head loss is lower, and the precipitation area is smaller. The wind direction changes counterclockwise.

Figure 3. Distribution of some meteorological elements and weather phenomena in young cyclones

Vortex tropics

General concepts

Cyclonic activity is not only observed at mid and high latitudes. Usually, there are many cyclonic disturbances at low margins, but they are less pronounced.

The pressure in the center is only 1-2 mbar lower than the surrounding area, the wind is weak, and they are moving slowly from east to west. But these disturbances develop into deep tropical cyclones, with significant pressure gradients and stormy winds.
What is a tropical cyclone? It is a region of small-scale but deep spirals, generating significant kinetic energy; the barometric gradient developed in tropical cyclones is the largest compared to other barometric systems. According to him, the wind speed is also the strongest.
In our country, tropical cyclones are also called tropical storms. In many other countries, they are called by many different local names. For example, in China, it is called “Typhoon”; in Australia, Willy – Willy, in the Caribbean Sea-Hurricane.

These names are united under a common designation “tropical depression.” The term “tropical cyclone” refers to all cyclone’s winds with the lowest pressure in the center.

Formation of tropical cyclones

To date, the cause of the formation of tropical cyclones is not entirely understood, but through ongoing studies and certain suitable conditions known, it is demonstrated that tropical storms form and development are necessary:

– The sea surface temperature is above 26-27°C, causing intense water evaporation, creating a low-pressure area. This can only happen at low latitudes and during the year’s hot season.

– Must create a vortex necessary to form a cyclonic circulation. That is, there must be an intersection of two air masses with significantly different temperatures, creating conditions for convection to develop.

– There must be a deviation of the air currents due to the earth’s rotation. The force must be large enough to create a cyclone. For tropical cyclones, the pressure at the center is usually as low as 980-950 mb in some cases – below 930 mb. The storm’s diameter is around 100 to 300 nautical miles, sometimes larger.

The barometric gradient near the cyclone’s center can reach 20-25 mb/1° of longitude. This leads to windstorms’ appearance, getting t 60-80 m/s, sometimes more than 100 m/s. Typhoon “Ida” measured wind speeds of up to 113 m/s.

Zone of generation of tropical cyclones

Tropical cyclones form in both hemispheres, in latitude belts between 5° and 20° north latitude, mainly over seas and oceans; where the surface water temperature is high, evaporation is intense, creating a zone of low-pressure turbulence. Sometimes tropical cyclones form on the mainland.

As per observational data from artificial satellites, there is a vortex-generating tropical climate in Africa.

But to develop into a strong storm only on the surface of the sea.

Most tropical cyclones form during the year’s hot season, from April to November; tropical cyclones are still seen during the cold season but are generally less intense. Here are some of the seas regularly seen by tropical storms each year and their local names.

Table 1. The seas are subject to tropical cyclones and their names.

Waters	Nameplate	Main season	The most month
West – North Pacific	Typhoon	June-November	July, August, and September
Northeast Pacific Ocean	Hurricane	June-November	September
South Indian Ocean	Xiclon	November – April	January and February
West – North Australia	Willy-Willy	December-April	January and February
North Atlantic	Hurricane	June-November	September
Arabian Sea and the Bay of Bengal	Xiclon	April-November	June, July, October, and November

The main track and mean displacement of tropical cyclones.

Tropical cyclones generally move west, then northwest, at low speed. This direction is dominated by a constant flow of tropical air from the east. Later, at higher latitudes, tropical cyclones’ movement rate increases to 30-40 km/g and more than.

In the latitude belt of about 15-30°, tropical cyclones change direction, moving north and even northeast in the northern hemisphere or south and then east-south in the southern hemisphere. Figure 4 shows the main principle of the tropical cyclone’s center in the north and southern hemispheres.

This is only a general diagram of the direction of the tropical cyclone’s center. This is not always the case, but very erratic. The complex diversion of tropical cyclones depends on the general distribution of barometric pressure, which persists during this period.

This direction of travel generally tends to curve around a subtropical anticyclone.

An area of high pressure, which can impede the movement of a tropical cyclone when its intensity is large enough, can cause a change of direction. The seasonal migration of subtropical high-pressure areas causes the inflection point to move appropriately north or south relative to its mid-latitude.

Figure 5 shows typical tracks of tropical cyclones, according to which it is possible to identify the seas that often generate them. As it reaches mid-latitudes, the hurricane gradually fills up and slows down.

However, in an encounter with colder air, it is revived, leading to its deepening, the acceleration of its movement, and the widening of the cyclonic zone… And like extratropical cyclones, they can move to higher latitudes. When it reaches dry land, it quickly weakens and fades.

Figure 4. Diagram of the main direction of the center of tropical cyclone

Weather in tropical cyclones

The activity time of a tropical cyclone is calculated from the moment it formed, i.e. the beginning of the convergence of cumulus clouds, cirrus clouds, and a slight decrease in pressure over a large surface until it disintegrates completely.

Depending on the stage of development of tropical cyclones, the weather conditions are also very different. Depending on the wind speed in the near center, people divide tropical cyclones into 4 main categories:

Tropical depression with wind speeds below 17 m/s (below 33 knots) or subgrade 7
The moderate tropical storm, with wind speed from 17: 24 m/s (from 33: 47 knots) or from level 8-9.
A strong tropical storm with a wind speed of 25: 32 m/s, or level 10: 11.
Storm extremely strong tropical with wind speed above 32 m/s, level 12 above. Here are the meteorological manifestations in the stages of development of tropical cyclones:

- Phase of tropical depression; denser clouds, cumulus clouds, and Ti clouds. On the weather map on the ground, several closed isobars are displayed. The eastern area has local showers; the wind speed here reaches 17 m/s, while the wind speed is lower west of the low pressure.

– During the tropical storm period, a very dense system of accumulators existed. The thick cloud system begins with a spiral, followed by spiral bands converging at the center along currents, on the weather map – some concentric closed isobars and large barometric gradients.

Appearing showers, with great intensity in the east and northeast-north of the cyclone, with thunderstorms, strong winds, and extended storm winds.

– Strong and powerful storm phase – there is a dense disc-shaped convergent cloud system with a sharp outer edge; cumulus spirals are scattered away from the central mass in the center.

Usually, a dark area can be seen in the center of the cloud mass, called the “eye of the storm” – the sky is clear and cloudy. On a weather map – a system of double concentric closed isobars; many barometric gradients of up to 15-20 mb over 1° meridians.

The wind speed is raised to the maximum value. The waves are very violent and messy. Storm characteristics can last up to 5-7 days.

– The disintegration phase of tropical cyclones – gradually loses the characteristic features of the distribution of clouds, rain, and wind. The thickness of the Ti cloud decreases and partially disappears, the central disc-shaped cloud mass disintegrates, and there is no clear outline on the outer edge.

On the weather map, the number of closed isobars decreases, the barometric gradient becomes weak, and the wind is soft.

Signs of approaching tropical cyclones

Ship operators operating in sea areas where tropical cyclones are likely to encounter should take care to monitor changing weather conditions to detect their approach early and anticipate possible consequences.

Signs of approaching tropical cyclones can be the following phenomena:

The appearance of surge waves coming from a direction does not coincide with the actual movement of the wind. Large waves move faster than tropical cyclones; when this wave is observed, the hurricane’s center is 400-500 nautical miles away.

Off the ocean, the direction of wave propagation approaches the direction of the cyclone’s center. However, when there are islands near the shore, the wave direction no longer points to the tropical cyclone’s location. The closer the typhoon, the more intense the sea surface becomes.
The initial barometric pressure decreases slightly, then decreases more sharply.
The appearance of Ti, Ti clouds clustered at one point on the horizon indicates that a tropical cyclone is about to come from there. After the Ti clouds – rain clouds – thick cumulus clouds appear. The intensity of the wind increases gradually.
The intense atmospheric discharge causes significant interference in radio receivers. The most vigorous discharge intensity is observed in the direction of the cyclonic position.
The color of the sky sparkles at dawn and dusk.

However, it should be remembered that the above signs cannot accurately determine the proximity of a tropical cyclone. For example, the direction is the wind speed resulting from convective processes, which can often differ from the distribution of demand and wind speed in the canonical diagram of a cyclone.

Therefore, it is necessary to monitor and observe weather changes; marine weather forecasts and storm forecasts are broadcast from ship weather service facilities by radio receivers, using radio receivers’ fax machines,s and other radio receivers.

It is also necessary, even when the tropical cyclone is still very far from the ship, and must consider the possibility of changing its direction and speed of movement.

The captain’s action

When there are signs of approaching a tropical cyclone, the sailors’ goal is not to let the ship come to the tropical cyclone’s center. By natural signals, such as cloud conditions, high waves, sky color, barometer readings, marine weather reports, and storm forecasts, the captain can know where am I on the ship, to the position of the center of the vortex?

Before deciding on an action to avoid a cyclone, the captain must know: the azimuth and, if possible, the distance to its center, the semicircle in which the ship is located, and the potential trajectory of the tropical cyclone.

For safety reasons, the stormy area is divided into semi-circles: the “dangerous semi-circle” and the “maritime semi-circle.” The “dangerous semi-circle” is also divided into two districts: the “most dangerous district” and the “dangerous district.”

Figure 6. Hazardous quadrants in hurricanes (in the northern hemisphere). Circle – the boundary of the affected area of storm weather.

Quadrant I – The most dangerous quadrant.

Quadrant II – Dangerous quadrant.

Quadrant III + IV – Low-Risk Semicircle

The most dangerous quadrant is located in the right and left front corner because ships are pushed into the center of the storm by waves and winds. This is also where the heart of the battery will come from.

Located to the left of the northern hemisphere and the right of the southern hemisphere concerning the direction of the storm center is called a semicircle because here, the position of the storm center tends to move away from the part of the ship.

When the ship is away from the storm, the area with the center of the battery can be determined according to the Buy Ballot rule.

The content of this rule is as follows: if you stand with your back to the wind, the area with the center of the storm is on the left for the northern hemisphere, and the right front, for the southern hemisphere.

Also, it is necessary to observe the wind and measure the barometric pressure to determine the semi-circle in which the ship is moving. The monitoring results show that the vessel is in one of the following cases:

If the barometric pressure decreases, the wind increases, and the wind direction gradually deviates to the right, the ship approaches and to the right of the path of the storm’s center (Figure 7, a, b position I).
The same conditions, but the wind direction is shifted to the left, indicating that the vessel is approaching and to the left of the storm center track (Figure 45 a, b, position II).
If the wind direction remains constant while the pressure decreases and the speed increases, the ship will approach and be on the correct course toward the center of the storm (Figure 7, a, b, position III).

It should be remembered that the direction of the wind is inclined concerning the tangent of the outer circular isobar at an angle of approximately 45° and the closer to the center of the storm, the smaller the angle of inclination at the innermost isobar, the direction of the wind approximately coincides with its tangent.

When it is known that the ship is in one of the three situations above, the following general rule can be applied to maneuver the boat away from the center of the storm (see figure 7).

Figure 7. Diagram to avoid the storm when it is detected early. a) For the northern hemisphere, b) For the southern hemisphere

The dashed line indicates the direction the train needs to go.

a. For the Northern Hemisphere: in case the train is located to the left or right of the center of the storm: positions II and III, it is necessary to change the train’s running direction so that the wind blows to the right.

And when the ship goes to starboard, the boat must be guided so that the wind blows to the right.

b. For the Southern Hemisphere: If the ship is located on the right or right side of the storm center, it is necessary to change direction so that the wind blows to the left.

And when the train is moving to the left, the train must be guided so that the wind blows to the left.

In all of the above cases, sail until the pressure no longer increases. For each specific case, a ship located in an area strongly affected by storm winds can use the following ship maneuvering diagram.

Figure 8. Cases of ship maneuvering under the influence of tropical storm weather

Scenario A: Vessels near the most dangerous quadrant that can confidently pass before the center of the storm need to keep the wind to the right and keep the ship’s direction perpendicular to the center of the battery to overcome the cargo vortex sea completely.

In the case of B, if it is challenging to pass before the storm, it is necessary to change the ship’s direction so that the wind blows to the left and gradually retreats away from the storm’s center.
In the case of C, it is impossible to go far from the storm’s center, and the ship must be kept in the opposite direction by operating the engine at full power.

Case D. When the ship is in quadrant II, it is advisable to turn left and let the wind blow to the right.
Case E. The ship is located in part IV; let the boat go straight to gradually move away from the center of the storm; at this time, the wind blows to the right.

Case F. The ship is on the left before IV but near the center of the storm and cannot keep the direction perpendicular to the storm’s path, so keep the ship’s direction so that the wind blows to the right and keep that direction until the center of the storm passes.

Case G. The ship is in the third quarter, changing direction to the right, so the wind blows to the left.
Case H. The ship is pushed behind the center of the storm, in a floating state, letting the wind blow to the left and keep it like that until the storm’s center goes away.

Classical storm maneuvering schemes should not be trusted blindly, as outlined in marine manuals. Maneuvering ships to avoid storms must be done based on a combination of specific meteorological conditions with current maritime circumstances.

After the maneuver is complete, it is still necessary to continue closely observing the weather changes in the area of the ship’s operation to promptly correct and change the maneuvering method.

Reverse vortex

General awareness of anticyclones

Anticyclone is an area of high pressure with closed isobars. Air in a cyclone moves clockwise in the northern hemisphere and counter-clockwise in the southern hemisphere.

The barometric gradient in the vortex is directed outward from the center. Winds in the center of the cyclone are weak, sometimes intense, and in the periphery – stronger. The most robust wind speeds usually occur in front of anticyclones.

The pressure at the cyclone’s center varies between 1010 and 1040 mb. The barometric pressure for the Siberian winter storm is as high as 1080 mb.

Retrograde vortices can cover a huge area, often commensurate with the continent’s size.

The frequency and intensity of cyclones depend on the year’s season and the subsurface’s state. On continents, storms are more potent in winter, in mid- and high-latitude oceans in summer, and subtropical regions of both the northern and southern oceans. Hemisphere – in August and September.

In the anticyclonic system introduced, under the effect of a gradient, the gas flows move in the form of a spiral radiating from the center to the outside.

So, in its central part, the downward flow of air from the upper layers of the troposphere is observed. The “deposition” of thick gas layers leads to dynamic heating and the creation of thermal inversion.

Therefore, in the central area of the cyclone, the weather is often cloudy, dry, and windy.

The formation and displacement of cyclonic countercurrents

The formation of cyclones is also due to causes such as the formation of cyclones. For their formation, factors that lead to an increase in atmospheric pressure and the formation of vortices of the barometric field near the ground and the troposphere are required.
The formation and development of the cyclonic circulation are closely related to the development of the vortex. But if in the process of building and development of cyclones, the dominant role of atmospheric fronts, then in the anticyclones, they do not bring the action.

Reverse eddies are created in homogeneous air groups. They usually occur in cold air, not far from the front lines on the ground.
The retrograde and cyclonic vortices, commensurately shifting, are in the same direction as the mid-troposphere flow.

The order of movement of young cyclones mainly coincides with the direction of air currents at an altitude of 3-5 km. As they grow, the speed of movement of anti-vortexes slows down, and they often become less moving objects.
The average travel speed is 25-35 km/h. Retrograde vortices mainly move from west to east, roughly south, concerning the northern hemisphere and north to south, i.e. their orbits tend towards lower latitudes.

The polar vortex has a distinct direction from west-north to east-south in the northern hemisphere called a retrograde vortex. The erosion of cyclones from the north, or from east-north to south or east-southeast, is called polar cavitation.

The weather is in a tornado

For the central part of the cyclone, the weather is characterized as dry and cloudy with fairly straightforward day-to-day heat variations.

Depending on the characteristics of the air group, during the generation of the cyclone, and the features of the underlying surface, the anticyclone may contain the following conditions: different weather.

For example, under the inversion layer, thick St and Sc clouds and even drizzle can be observed during the cold season of the year. Radiation blindness often occurs, making it difficult for ships to navigate.
In the periphery of the circulation, the weather conditions differ from the central region. They are usually determined by the weather characteristics of the area approaching the surrounding tornadoes.
The eastern part of the circulation, bordering the back of the cyclone, can see the formation of Cu, Cb clouds, and showers. Sc clouds also often appear, created from the fragmentation of Cb clouds.
In the western part of the retrograde, a Ci cloud may appear, which is a precursor to the approach of the hot front. Here we can see bad weather, with moderate rainfall over a large area and clouds of the secondary hot front.
The western periphery of the anticyclone, especially the low-moving type, is characterized by winds of magnitude 6-7, sometimes even more significant.
For the northern part, there exist thick or relatively thick St and Sc clouds. It is not uncommon to have fog.
In the southern part of the anticyclone, clouds of Ci, Cs, and as are visible. Strong winds often appear.

For example, in winter, due to the sizeable barometric gradient on the southern periphery of the cyclone, strong storm winds are observed in the northern part of the Black Sea.
In the barometric vanes, weather conditions vary widely, but there is almost no wind, no rain, and occasional radiation haze.

Atmospheric circulation over different regions of the globe

The concept of the general circulation of the atmosphere

The general atmospheric circulation is a collection of air currents that cover large areas of the earth and are relatively stable.

These currents make it possible to exchange air masses between separate parts of the earth. Even the details are very far apart.

The general atmospheric circulation is formed mainly under the influence of the following factors:

The uneven distribution of solar radiation over different latitudes.
The day-night movement of the earth generates the coriolis force.
The heterogeneity of the buffer layer, i.e. the division of the earth’s surface into continents and oceans.

Along with the above 3 main factors, it can be added that the topographic factor also significantly determines the air flows, which are part of the general atmospheric circulation.

A simple diagram of the general atmospheric circulation.

To consider a proper cycle of the earth, we must first assume that the earth’s surface is homogeneous.

Thus the absorption of solar radiation by the buffer and by the air will be the same over the same latitude, and assume that the earth is not rotating but stationary!

At low latitudes, most of the year, where the sun’s rays are vertical, the surface receives the most solar energy, and according to it, the air temperature here is highest compared to above middle and high latitudes.

That leads to a surface depression on either side of the equator. Hot air here will rise to compensate for this equatorial belt; from the regions near the poles, there will be air currents close to the ground, moving towards the equator, in the direction of meridians, making gas pressure decreases from the poles towards the equator.

In the upper layers, air currents move from the equatorial belt, toward the poles, in the direction of meridians. Thus: the most superficial atmospheric circulation has a meridian direction.

Figure 9.a) The sun’s rays reach the ground with different inclinations along the parallels, creating three different climates. Figure 9.b) The simplest diagram of the atmospheric circulation, assuming that the earth is at rest and the buffer is uniform.

As the earth rotates on its axis, a deflection force is produced, which affects the direction of displacement of the air currents; in addition, the quantity of the deflection force is proportional to the sine of the geographic latitude.

At about 30-35 degrees north or south latitude, the deflection force is large enough that the direction of movement of the upper air current, which is gradually deviating to the right, has wholly turned to the east.

These airflows are called anti-winds. Above latitudes more significant than 35°, the direction of air movement is west-east.

In the equatorial belt, there is a solid upward flow of air from the ground to an altitude of over 4000 m. At latitudes 30-35°, the downward movement of air forms a belt of high pressure above the ground.

From this high-pressure belt, the gas flows move towards the equator in the direction NE – SW for the Northern Hemisphere and SW – NW for the Southern Hemisphere. These air currents are called nebulae.

Thus, wind and anti-wind form a closed vertical cycle. The high-pressure belt at 30-35° north or south is called the subtropical maximum.

From the subtropical maximum (30-35° north or south), the air moves to the lower pressure area (60-65° north or south) in the direction SW – NE, northern hemisphere, and NW – SE, southern hemisphere, (see figure 48 b).

The cause of the minimum barometric belt at mid-latitudes 60-65° north and south is explained by cyclonic solid activity on it.

At high latitudes, greater than 65° north and south, air currents will shift from the bipolar barometric maximum, where the year-round temperature is slow, to the barometric minimum at the mid-latitudes direction NE – SW, for the northern hemisphere and SE – NW, for the southern hemisphere.

Air currents close to the ground.

Figure 10.a) High air currents (the anti-leprosy). Figure 10.b) Near-ground air currents (winds).

Realistic atmospheric circulation

The actual atmospheric circulation is much more complicated. Because the land surface is divided into continents and oceans, faults of high-pressure zones are formed; due to the strong warming of summer on the continents, low pressure prevails. In the high-pressure seas, it divides itself into a series of closed anticyclones, and only in circulating oceans does the tropical wind manifest clearly, with the year-round wind direction being NE and E in the northern hemisphere but in the southern hemisphere, in the sea – SE and E.

At middle and high latitudes, atmospheric circulation is much more complicated. The wind direction on the diagram is simply the most common in those regions, where many different and alternating cyclonic and anticyclonic circulations form. There are the following prevailing winds over the oceans:

– In the middle latitudes of the Atlantic Ocean and the west coast of Europe, in winter, there are southwesterly winds.

Also, in the western Atlantic Ocean, near the east coast of North America and Canada – the prevailing northwesterly winds. These wind directions are closely related to Assorian anticyclones and inversions.

– In the Far East and North Pacific, relative to the seasonal Pacific subtropical maximum in summer, the winds are in the SE and S direction. Far East wind direction NW, Japan direction, East Sea wind direction N and NE.

– In the Southern Hemisphere, the underside is relatively more even since it’s oceanic primarily. In the South Atlantic, Southern Indian Ocean, and South Pacific Ocean, three subtropical anticyclones are present almost all year round.

Therefore, the easterly direction of each of these anticyclones will be in the opposite direction.

At medium and high latitudes, there is a barometric minimum, and the main wind direction is W and WNW. The formation of westerly air currents creates a cyclonic cycle around Antarctica.