During the pre-flight training, the Sun commander, the second pilot and the navigator should explore the meteorological situation and flight conditions on the route, at the airports of departure and landing, on the spare airfields, paying attention to the main atmospheric processes that cause the weather:
On the state of the air masses;
On the location of the barical formations;
In the situation atmospheric fronts Regarding the route of the flight.
2.1. Air masses and weather in them
Large air masses in the troposphere, possessing homogeneous weather conditions and physical propertiesCalled air masses (VM). The main thermodynamic characteristic of the VM is their temperature mode, moisture content and movement. In this regard, VM is divided:
Sustainable VM - warmer than the underlying surface. In Nege, there is no condition for the development of vertical air movements, since the cooling of the bottom reduces the vertical temperature gradient due to the decrease in the temperature contrast between the lower and the upper layers. Here form inversion and isothermia layers are formed. The most favorable time to acquire the resistance of VM over the continent is during the day - night, during the year - winter.
The weather in UMU in winter: low folding layered and layered cumulus clouds, moro, chimka, fog, ice, in clouds icing (Fig. 3).
Fig. 3. Weather in UMM in winter
Sophisticated conditions are only for take-off, planting and visual flights, from Earth to 1-2 km, above are clouded. In the summer, the ummus prevails with poor weather or cumulus clouds with a weak turbulence up to 500 m, visibility is somewhat deteriorated due to the smoke. Circulates of the URM and the warm sector of the cyclone in the path of the western periphery of anticyclones.
Unstable air mass (NVM) - this is the cold VM, in which are observed favorable conditions For the development of ascending air movements, mainly thermal convection. When moving over the warm underlying surface, the lower layer of the electron is heated, which leads to an increase in vertical temperature gradients to 0.8-1.5 / 100 m, as a result of this, to the intensive development of convective movements in the atmosphere. The most active NBM in the warm season. With sufficient moisture content of air, heap clouds are developing up to 8-12 km, shower, hail, intramassum thunderstorms, squalid wind gain. The daily course of all elements is well expressed. With sufficient humidity and subsequent night clarification, radiation fogs may occur in the morning. The flight in this mass is accompanied by a bolt (Fig. 4).
Fig. four Weather in NVM in summer
In the cold season in NVM complexity with flights is not observed. As a rule, it is clear, the gym, the lower snowstorm, with the winds of the northern and northeast, and with the north-western invasion of the KH, there are clouds with a lower boundary not lower than 200-300 m type of layered-cumulus or cumulating-rainy with snow charges.
Secondary cold fronts may occur in NBM. Circulates NVM in the rear part of the cyclone and on the eastern periphery of anticyclones.
2.2. Atmospheric fronts
To assess the actual and expected weather status on the route or in the flight area great importance It has an analysis of the position of atmospheric fronts relative to the flight route and their movement.
Fronts are zones of active interaction of warm and cold VM. Along the surface of the front, an ordered air rise occurs, accompanied by the condensation of water vapor containing in it.
This leads to the formation at the front of powerful cloud systems and precipitation, causing the most difficult weather conditions for aviation.
Before departure, it is necessary to estimate the activity of the front on the following features:
Fronts are located along the axis of the hollow, the sharp is expressed, the front is the front;
The wind undergoes when moving through the front, sharp changes in the direction, there is convergence of flow lines, as well as changes in speed;
The temperature on both sides of the front underwes sharp changes, the contrasts of the temperature are 6-10 0 or more;
The baric trend is not the same on both sides of the front, in front of the front falls, it grows behind the front, sometimes a change in pressure in 3 hours is 3-4 GPa and more;
Along the front line, the clouds and zones of precipitation are characteristic of each type. The wetter of the VM in the front zone, the more active the weather. On the high-altitude maps, the front is expressed in condensation of isohyps and isotherm, in the cutting of contrasts of temperature and wind.
Move Front It occurs in the direction and with the speed of the gradient wind observing in the cold air or its component, directed perpendicular to the front. If the wind is directed along the front line, then it remains sedimed.
Front offset is determined by airflow According to the AT 700 GPa card at a speed approximately equal to 0.7-0.8 wind speeds at the level of AT700, as well as extrapolation methods, i.e. Comparison of two surface weather cards for different times.
2.3 Warm Front
The weather and flight conditions in the warm front zone are determined, as a rule, the presence of an extensive zone of layered clouds located above the front surface in front of the front line, up to 700-1000 km width. Frontal cloud is formed due to adiabatic cooling warm air With its ordered climb on the wedge of retreating cold air. When flying towards the TF, the crew primarily meet the forelocks of the front - the clouds are perishes, then the peristo-layered, high-alone, layered-rain. From high-aluminous and layered raindrops drop down precipitation with a width of up to 300-400 km. Under layered raindrops, due to evaporation of drop-down precipitation, torn-rain, 50-150 m height, and sometimes go into fog. The most difficult conditions for the weather affecting the rise and landing of the aircraft and visual flights are noted at a distance of 300-400 km in the front area near the center of the cyclone. There are low clouds, precipitation, impairment of visibility due to front fog, in the clouds and sediments in winter icing, ice, common blizzards (Fig. 5).
Fig. 5 Warm Front in winter
The clouds have a sufficiently large vertical power and output from these clouds is usually carried out at the heights of 5-6 km, and above marks are cloudless layers, sufficiently stable time that can be used for flight.
In the summer, TF is weakly pronounced, but at night, it is sharply sharpened especially in cases where the TVM turns out to be a tropical air, in which there are significant moisture reserves and large vertical temperature gradients, then the tF is developing cumulating clouds with rains and thunderstorms disguised with layered clouds, which represents Danger for aircraft flights (Fig. 6.7).
Fig. 6 Warm Front in Summer Time
Fig. 7 Thunderstorm foci on the warm front
The bolt can only be observed in some casesWhen in the front zone, jet flows arranged in front of the front line at 400-500 km at an altitude of 7-9 km are noted.
2.4 Cold fronts
Depending on the speed of the front, the characteristic of the rising movements of the TV, and those from the location of the zones of cloudiness and precipitation relative to the front surface, the cold fronts are divided:
Cold front 1 kind - slowly moving (15-30 km / h)
Cold front 2 kind - fast moving front (30 km / h or more).
Cold fronts are most pronounced in warm and exacerbated in the middle of the day.
Cold Front 1 kind More often formed in the cold half year. In the upstream warm air, the condensation process is not a rapid nature and its cloud system is similar to TF, but the front width is 300-400 km, the precipitation is covered with a width of 150-200 km, a cloud system of 4-5 km. In the XF zone 1, flights are significantly complicated at low altitudes due to limited visibility and the formation of low sub-terminal torn-rain clouds, which sometimes goes into frontal fog (Fig. 8).
Fig. 8 Cold Front 1 kind in winter time
In the summer in front of the front due to the development of convection, sch with thunderstorms, storm sediments and a squally wind enhancement are formed.
Convective cloudiness on HF 1 kind is the zone-limited zone in the form of individual foci.
Over the front of SV transition to layered rain, and then in high-alone. Storm sediments are replaced by chain, the flight is accompanied by a boltan (Fig. 9).
Fig. 9 Cold Front 1 kind in summer
Cold Front 2 presents the greatest danger For flights. It is characteristic of a young developing cyclone. This front is associated with a narrow zone of powerful cumulating raininess and intense storm sediments, which is located mainly on the front line of 50-100 km width. Ahead of the front, under a heap-rain, is often formed by the shaft of low torn-rain clouds rotating around the horizontal axis, a squall collar, which is very dangerous when trying to cross the front. In the summer, accompanied by strong squalls, thunderstorms, intensive hail loss and the occurrence of dust storms, wind shifts, intense bolting, which sharply complicates the conditions of flights for all types of aircraft (Fig. 10).
Fig. 10 Cold Front 2 kind and summer time
Kuchvo-rain clouds usually on the locator are a continuous chain of lights with small lumets. When flying to meet the front, close to it, as a rule, the ridge of cumulating rains will be observed with strips of storm sediments and thunderstorm foci. The harbingers of HF 2 kinds are high-tech lentilscence clouds that appear ahead of the front for 200-300 km. Winter HF 2 kinds causes sharp cooling, wind strengthening, snow charges, blizzards (Fig. 11).
Fig. 11 Cold Front 2 kind in winter
2.5 Fronts occlusion
The cold front, as more active, has a greater speed than a warm front, resulting in a merger. A new challenging front is formed - the front of the occlusion. With the process of fusion of the fronts, warm air is supplanted upwards, and in the surface layer there are cold masses. If the rear HF turns out to be colder, the front occlusion is formed by the type of HF (Fig. 12, 13).
Fig. 12 Cold front occlusion in winter
Fig. 13 Cold front occlusion in summer
If the HF is the warmer of the retreating, it is formed occlusion by TF type (Fig. 14, 15).
Fig. 14 Warm front occlusion in winter
Fig. 15 Warm occlusion front in summer
Weather conditions are typical on the fronts of occlusion by TF or HF type. The most difficult conditions for weather and flights at the point of occlusion.
Here in the winter is low clouds, layered-rain and torn-rain clouds, precipitation, icing, ice, fog. In the summer, Kuchevo-rain clouds, thunderstorms, shower, boltanka. Weather conditions on occlusions depend on the degree of sustainability of VM, their moisture content, terrain, season and day. For the cloud system of fronts, occlusion is characterized by significant stratification, up to 5-7 layers. The thickness of the layers and the interlayers between them reaches 1 km, which makes it possible to cross these sections, as well as flights in their zone, but however, the existence on the fronts occlusion of cumulating raindrops requires increased attention of flight composition during flights in the clouds.
2.6 secondary cold front
The secondary cold front is a section between different portions of the same air mass. There are in unstable cold air masses due to inhomogeneous heating from the underlying surface in the rear part of the cyclone. Contrasts of temperature in the EO zone of about 3-5 0 S. should not be underestimated the importance of these fronts for the production of flights. With the origin of the secondary front in the summer, heap-rain clouds are observed with an upper boundary of 7-9 km, storm sediments, thunderstorms, squalid wind gain. The width of the zone of the influence of this front is 50-70 km. In the cold season, there is a low cloudiness on this front, poor visibility due to snow charges, blizzards. They usually pass for the main cold fronts.
2.7 Stationary fronts
Front, which does not experience a noticeable displacement in the direction of the TVM, nor in the direction of the WDM, is called stationary. Such fronts occur in baric saddles, on the periphery of the region high pressure and are located parallel to the windflow. The width of the front zone is 50-100 km. In winter, flights are complicated due to low layered, layered-cumulus, layered rain clouds with drinkers and chained rain, fogs, ice. In the summer, on the front, separate foci of cucco-rain clouds with thunderstorms and shoes are formed.
2.8 High-rise frontal zones (VFZ)
The VFZ is a transition zone between the warm anticyclone and a cold cyclone in the middle or upper troposphere, which is detected by thickening isoips on the cards of absolute topography. The VFZ has an entrance and a delta, characterized by large values \u200b\u200bof horizontal temperature gradients and pressure. The high-altitude front zone is associated with atmospheric fronts, which are expressed up to the tropopause, the width of the transition zone between the VM increases. The transition is smoother. Frontal cloudiness and other phenomena characteristic of fronts near the surface of the Earth may not be here. In the upper troposphere, the thickening isohyps and the wind gain can be observed and without communication with atmospheric fronts. The atmosphere sections are connected with VFZ big speeds The wind is more than 100 km / h - jet flows that cause a dangerous battle of aircraft dangerous for flights.
All types of fronts when approaching the mountain ranges and in their reassurance are sharpened, the configuration and the vertical structure of the fronts change, the speed of their movement slows down, the power of the clouds is slowed down, the power of precipitation increases, which must be taken into account when flying along mountain routes.
2.9. Baric systems
In the formation of weather and in total circulation Atmospheric, cyclones and anticyclones are playing a big role, which are giant aerial vortices that involve huge air masses with colossal reserves. kinetic energy. Meteorological conditions that can meet a pilot when flying in a particular baric system depends on many factors: the stage of development of this Bar system, the time of year and day, the position of the flight route relative to the center of the Baric Education. However, despite big variety Weather conditions, you can still specify characteristics in different parts Baric formations.
Cyclones.
In its development, cyclones pass four stages: a wave, a young cyclone, an occluded cyclone, which achieves maximum development, and the filling cyclone (Fig. 16).
Fig. 16 stages of cyclone
Cyclone is formed from several VM, separated by atmospheric fronts, so the weather in it is very diverse. Cyclone is conditionally divided into four weather areas, where flight conditions will be different (Fig. 17).
Fig. 17 Weather in Cyclone
1. central part covers the territory within a radius of 300-500 km, is characterized by the most unfavorable conditions Weather for flights. In the center of the developing cyclone (stage of the wave and young cyclone), as a rule, a well-developed cloudy cloudy is observed up to 6-9 km and above without layer-rain-raindrops, cue-rain, with torn-rain with a height of 50-100 m, Intensive precipitation, impairment of visibility up to 1-2 km and less, ice, in precipitation and clouds intensive icing of aircraft, in the summer of thunderstorms, shower, the plane rolls are possible. In the center of the filling cyclone, cloudy is gradually blurred, stratified and the precipitation is stopped.
2. The front part is characterized by continuous cloudiness and weather of this part depends on the activity of TF. Cutter clouds, peristo-layered, high-alone, layered-rain, lower edge drops to cyclone center, chained precipitation, worsening visibility, frontal fogs, ice.
The winds are dominated by YUV and V. Flights on all echelons below 6-8 km, as a rule, in clouds with icing. Sometimes there are disguised foci of cucco-rain clouds in summer.
3. Rear part of the cyclone. The weather is determined by the circulation of cold unstable VM, partly cloudy, cumulative, cumulating-rain with short-term precipitation, in summer Intramass thunderstorms, the wind is strong, gusty of the northern and northwestern direction. Flight is always accompanied by a bump.
4. The warm sector - it circulates warm sustainable VM. In the cold half of the year there is a solid low cloudiness (layered-cumulus, layered) with frosting precipitation and aduteactive fogs. All this weather is observed in surface layers up to 500-1500 m, above clearly.
Visual flights are complicated, as well as take off and landing Sun, on the echelons of complexity in the flights is not observed. In the summer - clouded.
When flying in the field of cyclones, it should be remembered that the most active fronts and the speed of ascending movements are most active and the weather is harder - it is closer to the cloon center, and the most favorable flight conditions on the periphery.
Slabin - this is a narrow elongated strip reduced pressuredirected from the center of the cyclone. The weather in its area has a cyclonic character and is determined by the type of front with which it is connected. In the surface layer, there is a convergence of air flows, which creates conditions for the emergence of the axis of ascending air movements. The latter are carried out to the formation of clouds and precipitate, to the boltan of aircraft with the intersection of the hollow (Fig. 18).
Fig. 18 Slabin
Anticyclones - flight conditions in anticyclone in general are much better than in cyclone. This applies, first of all, to the warmth time of the year, when there is substantial weather over the entire area. In the center of the anticyclone in the morning hours, with sufficient moisture content of air, the radiation fogs are formed in places. If the anticyclone is formed in the masses of unstable wet air, then in the second half of the day, powerful-cumulus and cumulus-rain clouds can develop with thunderstorms, especially on its eastern periphery. In the cold season for flights at low altitudes, complexity represents aduteactive fogs, low computers, dense haze, drinking precipitations, ice, special such conditions are observed on the Western and South-Western periphery of anticyclones, where the removal of warm stable VM is observed (Fig. 19) .
Fig. 19 Weather in Anticyclone
Crest - This is an elongated area increased pressure, oriented from the center of Anticyclone and located between two regions low pressure. In the ridge there is a divergence of air flows from its axis, so the wind axis the winds are weak, the wind gain occurs on its periphery. The weather is clouded, but in the morning clouds can occur the enabling low clouds (layered) and radiation fogs.
Fig. 20 Comb
Saddle - This is a baric system concluded between the two areas of high pressure and two areas of low pressure, located crosswise. The weather of the saddle is determined by the moisture content of the VM, if it is formed by dry VM, the weather is clouded. In the saddle, with sufficient moisture content in the summer, powerful-cumulus and cumulus-rain clouds are developing with thunderstorms and shoes, in winter radiation-advective fogs, low layered cloudiness with drizzling precipitation, ice (Fig. 21).
Fig. 21 saddles
2.10 Moving and evolution of Baric systems
To determine the direction and speed of displacement of the baric systems, methods are used:
1. Method of extrapolation, i.e. By comparing sightseeing cards for different times.
2. The cyclone moves towards the isobar of its warm sector, leaving the sector on the right (Fig. 22a).
3. The cyclone center moves parallel to the line connecting the foci of falling and pressure growth towards the pressure drop (Fig. 22b).
4. Two cyclones having common closed isobaras make a rotational movement relative to each other counterclockwise (Fig. 22B).
5. The flavor moves along with the cyclone with which it is connected and rotates around it counterclockwise.
6. The anticyclone moves parallel to the line connecting the height and fall foci in the direction of the pressure growth center (Fig. 22g).
7. The comb moves together with the anticyclone, with which it is connected, and rotates around it clockwise.
8. The surface centers of barical systems are shifted in the direction of air flow (drive flow), observed in these centers at altitudes 3-6 km, i.e. In the direction of isogeps on the AT 700 card at a speed of 0.8 at this level and on the map AT 500 at a rate of 0.5 at this level (Fig. 22d).
9. High cyclones And anticyclones with a vertical spatial axis remain low-lifted (Fig. 22e). A large slope of the spatial axis indicates the rapid movement of the barytic education.
10. The cyclone is deepened if the pressure drop captures the center and its warm sector, the pressure growth indicates its filling. Cyclone and Nuzbin are deepened if on the maps of AT 700 and AT 500, AT 400 is observed the divergence of streams and is filled, if the convergence of flows.
11. If positive trends are observed in the center of the anticyclone (pressure growth), this indicates an increase in it, the pressure in the center falls - the anticyclone is destroyed.
Anticyclones and ridges are enhanced if Pa AT 700, AT 500 and AT 400 observes the convergence of streams, and destroys if there is divergence of streams.
High-rise frontal zones
Zones relative to elevated horizontal temperature gradients (and pressure), traced on the cards of baric topography, are called high-altitude front zones (VFZ).
The passage of VFZ causes significant local changes Meteorological values \u200b\u200bnot only in the lower and middle troposphere, but also in the upper troposphere and the lower part of the stratosphere.
Tropopausis in WFZ or strongly inclined, or torn. The stratosphere in cold air begins at a lesser height than in warmth. Thus, when in the cold side of the VFZ, a decrease in temperature with a height ceases, the temperature on the opposite side continues to drop. Due to this above the level of the cold air tropopause, the horizontal temperature gradient is rapidly reduced. Then, its direction changes to the opposite, and the value gradually increases and reaches the maximum in most cases at the level of heat-air tropopause. Above this level, horizontal temperature gradients are usually reduced again.
As a result, with a large difference, the heights of the tropopause from different sides of the tropospheric front zone at the bottom of the stratosphere also arises the front zone. It is tilted in the opposite direction compared with the inclination of the front zone in the troposphere and is separated from it with low horizontal temperature gradients. In the stratosphere, zones of large horizontal temperature gradients may occur, obviously not associated with tropospheric front areas. Radiation factors play a major role.
In WFZ, the direction of isotherm with a height varies small; The wind seeks to take the direction parallel to isotherms average temperature The underlying layer of air, and enhances, turning into the upper part of the troposphere in jet flows. Thus, the front zones are characterized by both large horizontal temperature gradients and considerable wind speeds. There is no unambiguous communication between frontal zones at altitudes and atmospheric fronts. Often, two approximately parallel front of the front, well-pronounced below, merge in the upper layers in. One wide front zone. At the same time, in the presence of the front zone at altitudes, there is a front at the surface of the Earth. The front in the lower layers is noted, as a rule, where the surface convergence of friction is observed. In the divergence of the wind, the signs of the existence of the front are usually absent.
Thus, the front zone, continuous on a high distance at altitudes, in the lower layer of the troposphere is often divided into separate sections - exists in cyclones and is absent in anticyclones. In the middle and upper troposphere, high-rise front zones are often encircling all the hemispheres of the Earth. Such front zones are called planetary.
The change in the contrast of the temperature in the field of the front zone is primarily determined by the character of the horizontal transfer of air with different temperatures. Vertical movements and transformation of air play a significant role. In extensive mountainous areas with high mountain chains, relief strongly affects the change in temperature contrast.
In the frontal zones, large energy reserves are concentrated, therefore, in them, as a rule, the pressure is strongly changed and the processes of cyclo- and anticyclicogenesis occur. Intense vertical movements are developing here. Insecularly linked jet flows with planetary frontal zones.
Spatial Structure of Atmospheric Fronts
The atmospheric front is not a geometric surface that does not have thickness, but represents some transition layer in which the change in the main meteorological quantities (temperature, wind, humidity, pressure) is essential for the dynamics of the atmosphere.
Fig. one
At any level, the front represents not a line, but some transition zoneAnd the front line of the front is in the middle of this zone.
The transition zone at the surface of the Earth has a width of several tens of kilometers, and the thickness of the transition layer in the vertical plane is several hundred meters. The horizontal length of the front line is hundreds and thousands of kilometers. When analyzing the synoptic cards, the front is carried out in the form of one line. Only on vertical cuts of a large-scale atmosphere sometimes it is possible to divide the lower and upper borders transition layer. The angle of inclination of the front surface to the horizon is approximately 1 °. It has been established that the tangent of the front of the front of the front has an order of 0.01--0.03, and for the cataphronts - about 0.001.
The known theoretical formulas of the front surface are not applicable to the boundary layer of the atmosphere, as they did not take into account the features of the wind distribution in this layer: here, with other things being equal in the cold fronts, the profile is sharper than in warm fronts.
For strong winds The front surface near the surface front line due to turbulent stirring is unmatched and its definition is difficult.
An even more important consequence of the deviation of the surface wind from the geostrophy is the convergence of the wind along the front line. Due to the convergence, the movement of the front slows down and the upward movement of warm air along the front surface increases. For the same reason, absolutely stationary fronts are in reality. If the front line is parallel to the edges, then it still happens at least a small movement of the front line. For the presence of ascending movements along the surfaces of sedentary fronts, in particular, indicate the zones of cloudiness and precipitation observers.
Atmospheric fronts
Fragment from the leadership of short-term weather forecasts edited by the editorial office of Dr. Fiz.mat. Sciences N. F. Veltishcheva
Front classification. Atmospheric fronts - transition zones or surfaces of the section between different by the properties of air masses, as a rule, characterized by relatively increased values \u200b\u200bof horizontal air temperature and pressure gradients, as well as features in wind fields and air humidity. The most difficult weather conditions, dangerous and especially dangerous phenomena are associated with atmospheric fronts.
Atmospheric fronts are divided into groups depending on various conditions and features:
a) by their movement relative to the arrangement of the air masses separated by the fronts;
b) in spatial (vertical and horizontal) length and circulation significance;
c) by geographical features.
According to relative movement, the fronts are divided into warm, cold, low-modular, occlusion fronts (warm, cold and neutral).
According to the spatial length and circulation significance, the fronts are divided into basic (tropospheric, high), secondary (surface, low) and upper.
According to geographical features, the fronts are divided into arctic and polar (fronts moderate breadth). The intrachetic convergence zone (BRK) is also distinguished, called the previously tropical front.
The vertical length of the fronts is determined by the temperature field using for this, first of all, the Map vertical length of the fronts is determined by the temperature field using for this, first of all, the map from 5001000. If the frontal zone is clearly visible on the map from 5001000, corresponding to the front at the ground surface, which front is called the main (tropospheric, high). At the main fronts, the temperature jump during the transition through the front line at the surface of the earth usually exceeds 5 ° C. In the high-altitude front zone associated with the main front, the temperature contrasts in the middle troposphere usually exceed 8 ° C / 1000 km (the relative geopotential gradient from 5001000 more than 16 GP. Ladies / 1000 km). Fronts defined by geographical feature (arctic, polar, as well as BC) are the main.
The fronts that exist at the surface of the Earth, but in the temperature field at altitudes are either not at all detected, or are traced to a small height (often not visible on the surface 850 GPa) belong to the secondary (surface, low). Cold secondary fronts are most often formed in the rear of cyclones in the occurrence of flow convergence in the lower layers of the atmosphere.
The tops are called fronts that are missing at the surface of the Earth, but quite well pronounced at altitudes. They can be detected only by the nature of the cloudiness and precipitation or at the same time in the temperature field at any level. The reasons for the formation of the upper fronts are different. For example, they can be formed due to the frontogenesis, which occurred only in the upper layers of the troposphere, or due to the erosion of the front at the surface of the Earth, but still preserved at altitudes. The upper front also occurs during occlusion as one of the components of the occlusion front. Finally, the front can be masked in the surface of the earth the front, moving above the thin surface layer of highly stretched air. Such a layer for a long time can persist above the same area without participating in general movement air. In some cases, according to data on synoptic maps of a large scale, narrow zones of convective clouds are found on satellite and radar observations, often with thunderstorms and squalls (stagnation lines, shkvalov line), as well as other circulation sections (partitions along the coast of the sea, edges arctic ice etc.), for a number of signs similar to atmospheric fronts, but not them. The lines of instability somewhat will be mentioned below.
High-rise front zones. Zones relative to elevated horizontal temperature gradients (and pressure), traced on the cards of baric topography, are called high-altitude front zones (VFZ).
The passage of the WFZ causes significant local changes in meteorological values \u200b\u200bnot only in the lower and middle troposphere, but also in the upper troposphere and the lower part of the stratosphere.
Tropopausis in WFZ or strongly inclined, or torn. The stratosphere in cold air begins at a lesser height than in warmth. Thus, when in the cold side of the VFZ, a decrease in temperature with a height ceases, the temperature on the opposite side continues to drop. Due to this above the level of the cold air tropopause, the horizontal temperature gradient is rapidly reduced. Then, its direction changes to the opposite, and the value gradually increases and reaches the maximum in most cases at the level of heat-air tropopause. Above this level, horizontal temperature gradients are usually reduced again.
As a result, with a large difference, the heights of the tropopause from different sides of the tropospheric front zone at the bottom of the stratosphere also arises the front zone. It is tilted in the opposite direction compared with the inclination of the front zone in the troposphere and is separated from it with low horizontal temperature gradients. In the stratosphere, zones of large horizontal temperature gradients may occur, obviously not associated with tropospheric front areas. Radiation factors play a major role.
In WFZ, the direction of isotherm with a height varies small; The wind tends to take the direction parallel to the isotherm of the average temperature of the underlying layer of air, and is enhanced by turning in the upper part of the troposphere in jet flows. Thus, the front zones are characterized by both large horizontal temperature gradients and considerable wind speeds. There is no unambiguous communication between frontal zones at altitudes and atmospheric fronts. Often, two approximately parallel front of the front, well-pronounced below, merge in the upper layers in. one wide front zone. At the same time, in the presence of the front zone at altitudes, there is a front at the surface of the Earth. The front in the lower layers is noted, as a rule, where the surface convergence of friction is observed. In the divergence of the wind, the signs of the existence of the front are usually absent.
Thus, the front zone, continuous on a high distance at altitudes, in the lower layer of the troposphere is often divided into separate sections - exists in cyclones and is absent in anticyclones. In the middle and upper troposphere, high-rise front zones are often encircling all the hemispheres of the Earth. Such front zones are called planetary.
The change in the contrast of the temperature in the field of the front zone is primarily determined by the character of the horizontal transfer of air with different temperatures. Vertical movements and transformation of air play a significant role. In extensive mountainous areas with high mountain chains, relief strongly affects the change in temperature contrast.
In the frontal zones, large energy reserves are concentrated, therefore, in them, as a rule, the pressure is strongly changed and the processes of cyclo- and anticyclicogenesis occur. Intense vertical movements are developing here. Insecularly linked jet flows with planetary frontal zones.
Spatial structure Atmospheric fronts. The atmospheric front is not a geometric surface that does not have thickness, but represents some transition layer in which the change in the main meteorological quantities (temperature, wind, humidity, pressure) is essential for the dynamics of the atmosphere.
The vertical section of the front transition layer (the scale vertically and the horizontal is different). L is the width of the transition zone, H is the thickness of the transition layer.
At any level, the front is not a line, but some transition zone, and the front line of the front is in the middle of this zone.
The transition zone at the surface of the Earth has a width of several tens of kilometers, and the thickness of the transition layer in the vertical plane is several hundred meters. The horizontal length of the front line is hundreds and thousands of kilometers. When analyzing the synoptic cards, the front is carried out in the form of one line. Only on vertical cuts of a large-scale atmosphere can sometimes be divided by the lower and upper boundaries of the transition layer. The angle of inclination of the front surface to the horizon is approximately 1 °. It has been established that the tangent of the front angle of the front has an order of 0.01-0.03, and for the cataphronts - about 0.001.
The known theoretical formulas of the front surface are not applicable to the boundary layer of the atmosphere, as they did not take into account the features of the wind distribution in this layer: here, with other things being equal in the cold fronts, the profile is sharper than in warm fronts.
With strong winds, the front surface near the surface of the surface front due to turbulent stirring is expressed fuzzy and its definition is difficult.
An even more important consequence of the deviation of the surface wind from the geostrophy is the convergence of the wind along the front line. Due to the convergence, the movement of the front slows down and the upward movement of warm air along the front surface increases. For the same reason, absolutely stationary fronts are in reality. If the front line is parallel to the edges, then it still happens at least a small movement of the front line. For the presence of ascending movements along the surfaces of sedentary fronts, in particular, indicate the zones of cloudiness and precipitation observers.
Zones relative to elevated horizontal temperature gradients (and pressure), traced on the cards of baric topography, are called high-altitude front zones (VFZ).
The passage of the WFZ causes significant local changes in meteorological values \u200b\u200bnot only in the lower and middle troposphere, but also in the upper troposphere and the lower part of the stratosphere. TV program Canal Friday at http://www.awtv.ru/pyatniza/.
Tropopausis in WFZ or strongly inclined, or torn. The stratosphere in cold air begins at a lesser height than in warmth. Thus, when in the cold side of the VFZ, a decrease in temperature with a height ceases, the temperature on the opposite side continues to drop. Due to this above the level of the cold air tropopause, the horizontal temperature gradient is rapidly reduced. Then, its direction changes to the opposite, and the value gradually increases and reaches the maximum in most cases at the level of heat-air tropopause. Above this level, horizontal temperature gradients are usually reduced again.
As a result, with a large difference, the heights of the tropopause from different sides of the tropospheric front zone at the bottom of the stratosphere also arises the front zone. It is tilted in the opposite direction compared with the inclination of the front zone in the troposphere and is separated from it with low horizontal temperature gradients. In the stratosphere, zones of large horizontal temperature gradients may occur, obviously not associated with tropospheric front areas. Radiation factors play a major role.
In WFZ, the direction of isotherm with a height varies small; The wind tends to take the direction parallel to the isotherm of the average temperature of the underlying layer of air, and is enhanced by turning in the upper part of the troposphere in jet flows. Thus, the front zones are characterized by both large horizontal temperature gradients and considerable wind speeds. There is no unambiguous communication between frontal zones at altitudes and atmospheric fronts. Often, two approximately parallel front of the front, well-pronounced below, merge in the upper layers in. One wide front zone. At the same time, in the presence of the front zone at altitudes, there is a front at the surface of the Earth. The front in the lower layers is noted, as a rule, where the surface convergence of friction is observed. In the divergence of the wind, the signs of the existence of the front are usually absent.
Thus, the front zone, continuous on a high distance at altitudes, in the lower layer of the troposphere is often divided into separate sections - exists in cyclones and is absent in anticyclones. In the middle and upper troposphere, high-rise front zones are often encircling all the hemispheres of the Earth. Such front zones are called planetary.
The change in the contrast of the temperature in the field of the front zone is primarily determined by the character of the horizontal transfer of air with different temperatures. Vertical movements and transformation of air play a significant role. In extensive mountainous areas with high mountain chains, relief strongly affects the change in temperature contrast.
In the frontal zones, large energy reserves are concentrated, therefore, in them, as a rule, the pressure is strongly changed and the processes of cyclo- and anticyclicogenesis occur. Intense vertical movements are developing here. Insecularly linked jet flows with planetary frontal zones.
Human potential of the Republic of Udmurtia
The population of the population by 2010 was 1,526,304. Udmurtia ranks 29th in terms of population. Population density - 36.3 people / km², specific gravity Urban population - 67.8%. The national composition in the republic will live representatives of more than a hundred nationalities. For border RA ...
Demographic situation in Russia
In terms of population (142.2 million people as of January 1, 2007), the Russian Federation takes the seventh place in the world after China, India, the USA, Indonesia, Brazil and Pakistan. Table 1.1. The population of the years is the entire population, million people including in the total population, interest ...
Coliseum
The amphitheater was built at three emperors. Emperor Vespasian began construction in 72 AD. Forces of the prisoners of Jews, from conquered by his son, Jerusalem. For the construction of Amphitheater Vespasian chose the territory of the artificial lake, once in the gardens of the Golden House, Grande ...
S. V. Morozova. On VlpianPP of the Planetary High-altitude Frontal Zone
the height difference is on the area and the viewing distance, you can calculate the resulting image depth and vertical scale of stereo-del. Depth of the image (A1), Pararallax (P1) and the distance view (D) are associated with the relation:
A1 / (g-a1) \u003d p1 / b,
where in the eye basis. By simple transformations, we get:
A1 \u003d P1I / (B + P1).
In our case, parallax frames in the stereo pair was 4 mm (910-0.04 / 9). When viewing a viewing of 2000 mm and the eye frame 65 mm we obtain the depth of the image relative to the stereoocane equal to 115 mm. Taking into account the central position of the stereo glass, the height difference on the ground was (250-15) / 2 \u003d 117.5 m. Thus, we obtain a vertical scale of the model approximately 1: 1 000. It should be noted that such calculations are approximate since the perception of stereo mode depends largely on individual features viewer.
The developed technique can be used to create and visualize stereoscopy
clear locality models in order to:
Visual evaluation contemporary state and use of the territory;
Preliminary assessment of the territory in design;
Representations of the design project. In addition, created models can be
used as a visual manual in educational institutions.
Bibliographic list
1. Akkermann F. Modern machinery and university Education // Izv. universities. Geodesy and aerial photography. 2011. No. 2. P. 8-13.
2. Tiffin Yu. S. Information technology using photogrammetry // Geodesy and cartography. 2002. No. 2. P. 39-45
3. Tufflines Yu. S. Photoogrametry - yesterday, today and tomorrow // Izvestia universities. Geodesy and aerial photography. 2011. No. 2. P. 3-8.
4. Digital stereoscopic locality model: Experimental studies / Yu. F. Kravnikov, V. I. Kravtsova, E. A. Baldin [and others]. M.: Scientific world, 2004. 244 p.
5. Foreign exchange N. A. Steameoscopy. M.: Academy of Sciences of the USSR, 1962. 380 p.
On the influence of the planetary high-altitude front zone on the change in some characteristics of the climatic regime on the northern hemisphere
S. V. Morozova
Saratovsky state University E-mail: [Email Protected]
this article discusses the influence of the planetary high-altitude front zone (PVFZ) on climatic regime Northern Hemisphere. The dynamics of the PVFZ places relative to the natural climatic periods of the state of the earthly climate system (ZKS) is shown. Found the connection of the dynamics of PVFZ areas with change wind regime On a hemisphere.
Keywords: global climate, planetary high-altitude front zone, climatic changes, wind mode.
oN INFLUENCE OF THE PLANETARY FRONT HIGH-RISE ZONE TO CHANGE SOME CHARACTERISTICS OF THE CLIMATIC REGIME IN THE NORTHERN HEMISPHERE
This article Considers The Questions of Influence of the Planetary High-Rise Frontal Zones (PVFS) on the climatic regime of the Northern Hemisphere. SHOWS THE DYNAMICS OF THE AREAS PVFS RELATIVELY NATURAL CLIMATIC PERIODS STATE THE EARTH "S CLIMATE SYSTEM. THE CONNECTION OF THE
speakers Areas Pvfs with the Wind Regime Change in the Hemisphere. Key Words: Global Climate, Planetary High-Rise Frontal Zone, Climatic Changes, Wind Regime.
It is known that regional climatic changes are primarily caused by anomalies of the general circulation regime of the atmosphere (OCC). Climatic crests and hopes migrate for decades, participating in the formation of circulating eras. However, the controversial still remains about the effect of circulation on the global climate. The author of this article published some results of research on the influence of the general circulation of the atmosphere on the global climate. This article is a continuation of research on the possibility of the influence of global circulation objects on climatic processes across the hemisphere.
As the studied characteristics of the global circulation object - the planetary high-altitude front zone - its area is selected,
© Morozova S. V., 2014
limited axial line. The source materials were the values \u200b\u200bof the average monthly PVFZ spaces published in the reference monograph. Based on these data, the average perennial values \u200b\u200bof the area in various natural climatic periods of the CX state are calculated.
The dynamics of the PVFZ spices relative to the natural climatic periods of the state of the ZKS - the stabilization period (1949-1974) and the second wave of global warming (19752010) - presented in Table. one.
Based on the analysis of Table. 1 Note that the most powerful variability of PVFZ spaces manifested itself during the stabilization period (1949-1974). Against the background of the second wave of global warming
we observe a decrease in the variability of the area. It deserves attention that from the first period to the second, an increase in the PVFZ Square has occurred, which involves the expansion of the region of negative temperature anomalies.
Since the study of the dynamics of the PVFZ is carried out by statistical methods, it seems necessary to assess the statistical significance of the results obtained, which can be done using standard procedures of mathematical statistics. For each time segment, confidence intervals are calculated using the Satuden-Ta criterion at a 95% level of significance. Trust intervals for each period are shown in Table. 2.
Table 1
Dynamics of the area of \u200b\u200bthe planetary high-altitude front zone relative to the natural climatic periods of the state of the ZKS
The period is the value of the PVFZ Square, Million CM2 A2, MIL2 CM2 A, MILI CM2 CV
1st, 1949-1974. (stabilization) 56.97 13.32 3.65 0.06
2nd, 1975-2010 (The second wave of global warming) 57.77 (increase. by 1.5%) 2.82 1.68 0.03
table 2
Evaluation of the statistical significance of the dynamics of PVFZ
Period of confidence intervals
1st, 1949-1974. (stabilization)
2nd, 1975-2010 (Second Wave of Global Warming)
We see that the boundaries of the intervals overlap, and the second interval is even included in the first, which indicates the statistical insignificance of changes detected. Thus, the change in areas by 1.5% is unlikely to lead to any climate meaningful changes in zx. However, to make unambiguous conclusions about the absence of the influence of the planetary high-altitude front zone on the global climate, as the use of statistical methods to natural processes It has a well-known share of conventionality. Sometimes very small initial perturbations of any component in the earth's climate system can get a large resonance and cause rather noticeable changes in it. In this regard, it is interesting to know in what limits of changing the area of \u200b\u200bPVFZ are meaningful. To do this, the inverse problem was solved, the condition of which was the lack of overlapping intervals at the very most extreme possible provisions of the mathematical expectation on a numerical direct. Required calculations Persecuted according to formula (1), which made it possible to obtain the average latitude of the position of the PVFZ under the condition of the interval impaired:
S \u003d 2NR2 (1 - SIN FS. "), (1)
where n \u003d 3,14159;
R \u003d 6378.245 km - Earth's radius at the equator;
FS.I is the average latitude of the axial isogenesis of the PVFZ on the northern hemisphere.
It turned out that in order to achieve the statistical significance of changes, the localization area of \u200b\u200bthe PVFS should be within 30-35 ° of northern latitude. Currently, the planetary altitude front zone is located in the field of the fifties latitudes of the northern hemisphere. Thus, it was revealed that in order to achieve the statistical significance of changes in the area, the planetary high-altitude front zone should be shifted by 15-20 ° south, respectively, the cyclone trajectories, respectively, will be shifted, which, in turn, will lead to a change in the position of arid and humid regions, and Consequently, I. natural zones. Thus, the statistically significant dynamics of PVFZ corresponds to climatic changes across large geological eras. Climatic reconstructions made by geological sources and historical materials show that exclusively wet conditionswho dominated in dry now tropical belt, took place in the destruction of the Quaternary glaciation and in early period Epoch of Golocene. Consequently, the cyclone trajectories and the localization area of \u200b\u200bthe PVFZ were located much south, which contributed to good moistening of these currently arid areas. In this way,
With V. Morozova. On the effect of the planetary high-altitude front zone
with existing climatic changes, statistical significance cannot be detected, but noticeable climatic changes in the earth's climate system, which manifested during global temperatures, take place.
It is important to note that the seen growth of the average PVFZ area, which implies the promotion of the PVFZ to more southern latitudes and expanding the zone of negative temperature anomalies, took place when switching from a colder period to a more warm, which is not entirely logical. One of the possible explanations of such unusual behavior of the PVFZ may be that its displacement to the south leads not so much to a decrease in the average half-coar temperature, how much to change any other characteristics of the climatic mode, one of which may be wind regime. Then the influence of the PVFZ on the global climate can manifest itself in changing the activity and intensity of one of the components of the ZKS - the total circulation of the atmosphere. One explanation of the inconsistency of the dynamics of the PVFZ area and the movement of global temperature in natural climatic periods can be the change in any individual parameters of the PVFZ (sizes, intensity, torture, etc.), which, of course, affects the activity and intensity of circulation and is reflected in wind mode. So, the promotion of the PVFZ in more southern or more northern latitudes It can lead to a narrowing or expansion of the Localization zone of the PVFZ, which, in turn, leads to the exacerbation or weakening of gradients, increase or decrease in circulation activity and, consequently, strengthening or weakening wind velocities.
We will try to find out how the identified dynamics of the PVFZ Square is associated with a change in its activity. To do this, consider the intensity of the planetary high-altitude front zone according to the reference monograph from 1949 to 2010. The autings of the reference monograph intensity of the high-altitude front zone was determined as the difference in latitude (DF) of the two isogeps on the south of the south and north And southern isogeps took the same - 8 GP. Ladies. If the intensity is to consider the difference in latitude, it turns out that the average intensity in July (8 ° latitude) turns out to be greater than in January (5 ° latitude). Therefore, the author of the present study to assess the intensity of the PVFZ departed from back proportional dependence The activity of the OCC and the difference of latitudes, adopting to estimate the intensity of circulation the value of the geostatic wind (y ^) at the average level of the troposphere, calculating it by formula (2):
geopotential gradient,
Yu I dp, where I is a Coriolis parameter (i \u003d 2nd SINF),
yu - angular speed of rotation of the Earth;
f - the latitude of the location of the axial isogeps.
However, before switching to the analysis of OCC intensity against the background of the natural climatic periods of the state of the ZKS, we will pay attention to interesting Facts Dynamics of PVFZ spaces and changes in the difference in the latitude, between which the planetary high-altitude front zone is located.
It is known that the intensity of the planetary high-altitude front zone is determined by the temperature gradient equator - pole. The greater the gradient, the more actively processes in the area of \u200b\u200bits localization. In winter, when the contrast of temperatures of the equator-pole is much larger than in summer, circulating processes proceed much more active. In addition, in winter, the PVFZ shifts to the south, in the summer rises to the north, then it is quite logical to assume that the southern shift of the PVFS should lead to an increase in its activity, while its localization should be narrowed, and the North, on the contrary, to the weakening of the ACC and the expansion PVFZ localization zones.
For confirmation or refutation of such an assumption, graphs of changes in the average annual difference of the localization of the planetary high-altitude front zone were built for the period from 1949 to 2010. Along the way, we note that the linear filtering curve is added to all these graphs, and in order to extinguish high-frequency oscillations, a sliding averaging procedure is applied to the initial row.
The average annual differences of the Location of the PVFZ are shown in Fig. 1, a. The non-periodicity of the change is visible, however, an increase in the difference in the latitude of the latitude is striking during the transition from the period of stabilization to the beginning of the second wave of global warming, after which the direction of change disappears. It is much more clearly manifested in Fig. 1, B, where it can be seen that in a colder period, the localization zone of the PVFZ is already, and this indicates the aggravation of gradients in the field of PVFZ, and therefore, to increase its activity. In the next warmer period, the difference is larger than larger, and therefore the activity of the PVFZ is reduced. All this is visually visible in fig. 2, where the calculated average annual values \u200b\u200bare presented. mid speed Geostrofic winds, statistical procedures of linear filtering were carried out and low-frequency fluctuations were isolated by the method of sliding averaging.
Thus, we have that when moving from a colder to a warm period (from stabilization to the second wave of global warming), the PVFZ area is expanded, the promotion of the PVFZ itself to the south and reducing its activity. Revealed peculiarity of speakers
Izv. Sarat. un-ta. New. Ser. Ser. Earth science. 2014. T. 14, Vol. 2.
Fig. 1. Changing the difference in the larch of the localization of PVFZ on the hemisphere: A -Linear filtration; b - sliding averaging
14,0 13,0 -12,0 11,0 ■ 10.0
13,0 -> 12,5 -12,0 -11,5 -11,0 ■ 10,5 -10,0
1969 1973 1 989 1 999 2009
Fig. 2. Changing the average for the hemispheres of the geostrofic wind speed: A - linear filtering; b - sliding averaging
With V. Morozova. On VlpianPP of the Planetary High-altitude Frontal Zone
PVFZ reflects indirectly well-known fact The climate theory that when moving from cold periods, the activity of the OCC is reduced to the lapel.
Comparing the features of the dynamics of the planetary high-altitude front zone in natural climatic periods with its seasonal dynamics, one can detect the similarity of the change, manifested in the fact that during the transition from cold periods to warm (from winter to fly and from stabilization to warming) there is a decrease in the activity of the total circulation of the atmosphere . But should also be specified on significant differenceThe fact that, with a climate transition of the ZKS, the PVFZ Square is growing from a colder period, while during seasonal climatic changes from the cold period to a warm (from winter by summer) its area is reduced.
Thus, with a climatically significant consequence, it may be that when the climate system transitions from one qualitative state to another, there are changes not only to global temperatures, but also a wind regime, and the role of global circulation objects in the formation of climate variability is amended climatic characteristicsAs planetary wind mode.
According to data, the wind speed has occurred on the territory of Russia, the reason for which is associated with the change in the regimen of the general circulation of the atmosphere. However, finding out the reasons for the weakening of the speeds is far from unambiguous. So, in the studies of Bardin, Meshcherskaya and co-authors shown that lately (Two - three decades) There is an increase in the number of days with cyclonic circulation, the consequence of increasing wind speeds due to frequent passage of atmospheric fronts. However, the same authors conclude the contradiction of the facts of increasing the repeatability of cyclonicity and reducing wind velocities. Reducing the wind speed in Russia is sometimes explained by a decrease in the repeatability of the form ^-cycling. Nevertheless, from the 70s. There is an increase in the repeatability of zonal processes, which also does not allow to explain the reduction of wind speed by this factor. It is possible that the reason for the weakening of the wind is the change in the qualitative state of the global circulation object - the planetary high-altitude front zone. As shown above, its dynamics are directly related to the intensity of the general circulation of the atmosphere.
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