Natural phenomena that hydrometeorology studies. Meteorology is the study of phenomena occurring in the earth's atmosphere.

A significant part of meteorologists is engaged in weather forecasting. They work in government and military organizations and private companies that provide forecasts to aviation, agriculture, construction and the navy, as well as broadcast them on radio and television. Other professionals monitor pollution levels, provide advice, teach or do research. In meteorological observations, weather forecasting and scientific research, electronic equipment is becoming increasingly important.

WEATHER STUDY PRINCIPLES

Temperature, atmospheric pressure, air density and humidity, wind speed and direction are the main indicators of the state of the atmosphere, and additional parameters include data on the content of gases such as ozone, carbon dioxide, etc.

A characteristic of the internal energy of a physical body is the temperature, which rises with an increase in the internal energy of the environment (for example, air, clouds, etc.), if the energy balance is positive. The main components of the energy balance are heating by absorbing ultraviolet, visible and infrared radiation; cooling due to the emission of infrared radiation; heat exchange with the earth's surface; the gain or loss of energy when water condenses or evaporates, or when air compresses or expands. Temperature can be measured in degrees Fahrenheit (F), Celsius (C) or Kelvin (K). The lowest possible temperature, 0° Kelvin, is called "absolute zero". Different temperature scales are interconnected by the relationships:

F = 9/5 C + 32; C \u003d 5/9 (F - 32) and K \u003d C + 273.16,

where F, C and K, respectively, denote the temperature in degrees Fahrenheit, Celsius and Kelvin. The Fahrenheit and Celsius scales coincide at the point -40 °, i.e. -40° F = -40° C, which can be verified using the formulas above. In all other cases, the temperature values ​​in degrees Fahrenheit and Celsius will differ. In scientific research, the Celsius and Kelvin scales are commonly used.

Atmospheric pressure at each point is determined by the mass of the overlying air column. It changes if the height of the air column above a given point changes. The air pressure at sea level is approx. 10.3 t/m2. This means that the weight of a column of air with a horizontal base of 1 square meter at sea level is 10.3 tons.

Air density is the ratio of the mass of air to the volume it occupies. The density of air increases when it is compressed and decreases when it expands.

Temperature, pressure and air density are interconnected by the equation of state. Air is largely like an "ideal gas" for which, according to the equation of state, temperature (expressed in the Kelvin scale) times density divided by pressure is a constant.

The basis of the modern international classification of clouds was laid in 1803 by the English amateur meteorologist Luke Howard. It uses Latin terms to describe the appearance of clouds: alto - high, cirrus - cirrus, cumulus - cumulus, nimbus - rain and stratus - layered. Various combinations of these terms are used to name the ten main cloud forms: cirrus - cirrus; cirrocumulus - cirrocumulus; cirrostratus - cirrostratus; altocumulus - Altocumulus; altostratus - high-layered; nimbostratus - nimbostratus; stratocumulus - stratocumulus; stratus - layered; cumulus - cumulus and cumulonimbus - cumulonimbus. Altocumulus and altostratus clouds are higher than cumulus and stratus.

The clouds of the lower tier (stratus, stratocumulus and stratocumulus) consist almost exclusively of water, their bases are located up to about a height of 2000 m. Clouds creeping along the earth's surface are called fog.

The bases of the mid-tier clouds (altocumulus and altostratus) are at altitudes from 2000 to 7000 m. These clouds have temperatures from 0°C to -25°C and are often a mixture of water droplets and ice crystals.

Clouds of the upper tier (cirrus, cirrocumulus and cirrostratus) usually have fuzzy outlines, as they consist of ice crystals. Their bases are located at altitudes of more than 7000 m, and the temperature is below -25 ° C.

Cumulus and cumulonimbus clouds are classified as clouds of vertical development and can go beyond the limits of one tier. This is especially true for cumulonimbus clouds, the bases of which are only a few hundred meters from the earth's surface, and the tops can reach heights of 15–18 km. At the bottom they are made of water droplets, and at the top they are made of ice crystals.

CLIMATE AND CLIMATE FORMING FACTORS

The inclination of the earth's axis to the plane of the earth's orbit causes changes not only in the angle of incidence of the sun's rays on the earth's surface, but also in the daily duration of sunshine. At the equinox, the duration of daylight hours on the entire Earth (with the exception of the poles) is 12 hours, in the period from March 21 to September 23 in the Northern Hemisphere it exceeds 12 hours, and from September 23 to March 21 it is less than 12 hours. .w (Arctic Circle) from December 21, the polar night lasts around the clock, and from June 21, daylight continues for 24 hours. At the North Pole, the polar night is observed from September 23 to March 21, and the polar day is observed from March 21 to September 23.

Thus, the cause of two distinct cycles of atmospheric phenomena - annual, lasting 365 1/4 days, and daily, 24 hours - is the rotation of the Earth around the Sun and the tilt of the earth's axis.

The amount of solar radiation per day entering the outer boundary of the atmosphere in the Northern Hemisphere is expressed in watts per square meter of horizontal surface (i.e. parallel to the earth's surface, not always perpendicular to the sun's rays) and depends on the solar constant, the angle of inclination of the sun's rays and the duration days (Table 1).

Table 1. Arrival of solar radiation at the upper boundary of the atmosphere

Table 1. INCOME OF SOLAR RADIATION TO THE UPPER BORDER OF THE ATMOSPHERE (W/m2 per day)
Latitude, °N	0	10	20	30	40	50	60	70	80	90
21st of June	375	414	443	461	470	467	463	479	501	510
21 December	399	346	286	218	151	83	23	0	0	0
Average annual value	403	397	380	352	317	273	222	192	175	167

It follows from the table that the contrast between the summer and winter periods is striking. June 21 in the Northern Hemisphere, the value of insolation is approximately the same. On December 21, there are significant differences between low and high latitudes, and this is the main reason that the climatic differentiation of these latitudes is much greater in winter than in summer. Atmospheric macrocirculation, which depends mainly on differences in the heating of the atmosphere, is better developed in winter.

The annual amplitude of the solar radiation flux at the equator is rather small, but increases sharply towards the north. Therefore, ceteris paribus, the annual temperature amplitude is determined mainly by the latitude of the area.

Rotation of the Earth around its axis.

The intensity of insolation anywhere in the world on any day of the year also depends on the time of day. This is due, of course, to the fact that in 24 hours the Earth rotates around its axis.

Albedo

- the fraction of solar radiation reflected by the object (usually expressed as a percentage or fractions of a unit). The albedo of freshly fallen snow can reach 0.81, the albedo of clouds, depending on the type and vertical thickness, ranges from 0.17 to 0.81. Albedo of dark dry sand - approx. 0.18, green forest - from 0.03 to 0.10. The albedo of large water areas depends on the height of the Sun above the horizon: the higher it is, the lower the albedo.

The albedo of the Earth, together with the atmosphere, varies depending on the cloud cover and the area of ​​snow cover. Of all the solar radiation entering our planet, approx. 0.34 is reflected into outer space and lost to the Earth-atmosphere system.

Atmospheric absorption.

About 19% of solar radiation entering the Earth is absorbed by the atmosphere (according to averaged estimates for all latitudes and all seasons). In the upper layers of the atmosphere, ultraviolet radiation is absorbed mainly by oxygen and ozone, and in the lower layers, red and infrared radiation (wavelength over 630 nm) is absorbed mainly by water vapor and, to a lesser extent, by carbon dioxide.

absorption by the earth's surface.

About 34% of the direct solar radiation arriving at the upper boundary of the atmosphere is reflected into outer space, and 47% passes through the atmosphere and is absorbed by the earth's surface.

The change in the amount of energy absorbed by the earth's surface depending on latitude is shown in Table. 2 and expressed through the average annual amount of energy (in watts) absorbed per day by a horizontal surface of 1 sq.m. The difference between the average annual arrival of solar radiation to the upper boundary of the atmosphere per day and the radiation that arrived on the earth's surface in the absence of cloudiness at different latitudes shows its loss under the influence of various atmospheric factors (except cloudiness). These losses generally amount to about one third of the incoming solar radiation.

Table 2. Average annual influx of solar radiation on a horizontal surface in the northern hemisphere

Table 2. AVERAGE ANNUAL INCOME OF SOLAR RADIATION ON A HORIZONTAL SURFACE IN THE NORTHERN HEMISPHERE (W/m2 per day)
Latitude, °N	0	10	20	30	40	50	60	70	80	90
The arrival of radiation at the outer boundary of the atmosphere	403	397	380	352	317	273	222	192	175	167
The arrival of radiation on the earth's surface in a clear sky	270	267	260	246	221	191	154	131	116	106
The arrival of radiation on the earth's surface with medium cloudiness	194	203	214	208	170	131	97	76	70	71
Radiation absorbed by the earth's surface	181	187	193	185	153	119	88	64	45	31

The difference between the amount of solar radiation arriving at the upper boundary of the atmosphere and the amount of its arrival on the earth's surface during medium cloudiness, due to radiation losses in the atmosphere, depends significantly on geographic latitude: 52% at the equator, 41% at 30°N. and 57% at 60°N. This is a direct consequence of the quantitative change in cloudiness with latitude. Due to the peculiarities of the atmospheric circulation in the Northern Hemisphere, the amount of clouds is minimal at a latitude of approx. 30°. The influence of clouds is so great that the maximum energy reaches the earth's surface not at the equator, but in subtropical latitudes.

The difference between the amount of radiation reaching the earth's surface and the amount of absorbed radiation is formed only due to the albedo, which is especially large at high latitudes and is due to the high reflectivity of the snow and ice cover.

Of all the solar energy used by the Earth-atmosphere system, less than one third is directly absorbed by the atmosphere, and most of the energy it receives is reflected from the earth's surface. Most solar energy comes to areas located at low latitudes.

Earth radiation.

Despite the continuous influx of solar energy into the atmosphere and onto the earth's surface, the average temperature of the earth and atmosphere is fairly constant. The reason for this is that almost the same amount of energy is emitted by the Earth and its atmosphere into outer space, mostly in the form of infrared radiation, since the Earth and its atmosphere are much colder than the Sun and only a small fraction is in the visible spectrum. The emitted infrared radiation is recorded by meteorological satellites equipped with special equipment. Many satellite synoptic maps shown on television are infrared images and reflect heat radiation from the earth's surface and clouds.

Thermal balance.

As a result of a complex energy exchange between the earth's surface, atmosphere and interplanetary space, each of these components receives on average as much energy from the other two as it loses itself. Consequently, neither the earth's surface nor the atmosphere experience any increase or decrease in energy.

GENERAL ATMOSPHERIC CIRCULATION

Due to the peculiarities of the mutual position of the Sun and the Earth, equatorial and polar regions of equal area receive completely different amounts of solar energy. The equatorial regions receive more energy than the polar regions, and their water areas and vegetation absorb more incoming energy. In the polar regions, the albedo of snow and ice covers is high. Although the warmer equatorial regions of temperature radiate more heat than the polar regions, the heat balance is such that the polar regions lose more energy than they gain, and the equatorial regions receive more energy than they lose. Since there is neither warming of the equatorial regions, nor cooling of the polar regions, it is obvious that in order to maintain the heat balance of the Earth, excess heat must move from the tropics to the poles. This movement is the main driving force of atmospheric circulation. The air in the tropics warms up, rising and expanding, and flows towards the poles at a height of approx. 19 km. Near the poles, it cools, becomes denser and sinks to the earth's surface, from where it spreads towards the equator.

The main features of the circulation.

Air rising near the equator and heading towards the poles is deflected by the Coriolis force. Let's consider this process on the example of the Northern Hemisphere (the same thing happens in the Southern Hemisphere). When moving towards the pole, the air deviates to the east, and it turns out that it comes from the west. This is how westerly winds are formed. Some of this air cools as it expands and radiates heat, sinks and flows in the opposite direction, towards the equator, deviating to the right and forming a northeast trade wind. Part of the air that moves towards the pole forms a westerly transport in temperate latitudes. The air descending in the polar region moves towards the equator and, deviating to the west, forms an easterly transport in the polar regions. This is just a schematic diagram of the circulation of the atmosphere, the constant component of which is the trade winds.

Wind belts.

Under the influence of the Earth's rotation, several main wind belts are formed in the lower layers of the atmosphere ( see pic.).

equatorial calm zone,

located near the equator, it is characterized by weak winds associated with a zone of convergence (i.e., convergence of air flows) of stable southeast trade winds of the Southern Hemisphere and northeast trade winds of the Northern Hemisphere, which created unfavorable conditions for the movement of sailing ships. With converging air currents in the area, the air must either rise or fall. Since the surface of the land or ocean prevents its sinking, intense ascending air movements inevitably arise in the lower layers of the atmosphere, which is also facilitated by strong heating of the air from below. The rising air cools down and its moisture content decreases. Therefore, dense clouds and frequent precipitation are typical for this zone.

Horse latitudes

- areas with very weak winds, located between 30 and 35 ° N. latitude. and y.sh. This name probably goes back to the era of the sailing fleet, when ships crossing the Atlantic were often calm or delayed due to weak, variable winds. Meanwhile, the water supply was running out, and the crews of ships carrying horses to the West Indies were forced to throw them overboard.

The horse latitudes are located between the areas of the trade winds and the prevailing western transport (located closer to the poles) and are zones of divergence (i.e., divergence) of winds in the surface air layer. In general, descending air movements predominate within them. The descent of air masses is accompanied by heating of the air and an increase in its moisture capacity, therefore, these zones are characterized by low cloudiness and an insignificant amount of precipitation.

Subpolar zone of cyclones

located between 50 and 55°N. It is characterized by storm winds of variable directions associated with the passage of cyclones. This is a zone of convergence of western winds prevailing in temperate latitudes and eastern winds characteristic of the polar regions. As in the equatorial convergence zone, ascending air movements, dense clouds and precipitation over large areas prevail here.

IMPACT OF LAND AND SEA DISTRIBUTION

Solar radiation.

Under the influence of changes in the arrival of solar radiation, the land heats up and cools down much stronger and faster than the ocean. This is due to the different properties of soil and water. Water is more transparent to radiation than soil, so the energy is distributed in a larger volume of water and leads to less heating per unit volume. Turbulent mixing distributes heat in the upper ocean to about 100 m depth. Water has a greater heat capacity than soil, so for the same amount of heat absorbed by the same masses of water and soil, the temperature of the water rises less. Almost half of the heat that enters the water surface is spent on evaporation, and not on heating, and on land, the soil dries out. Therefore, the temperature of the ocean surface during the day and during the year varies much less than the temperature of the land surface. Since the atmosphere heats up and cools down mainly due to the thermal radiation of the underlying surface, the noted differences manifest themselves in air temperatures over land and oceans.

Air temperature.

Depending on whether the climate is formed mainly under the influence of the ocean or land, it is called maritime or continental. Maritime climates are characterized by significantly lower average annual temperature ranges (warmer winters and cooler summers) compared to continental ones.

Islands in the open ocean (for example, Hawaiian, Bermuda, Ascension) have a well-defined maritime climate. On the outskirts of the continents, climates of one type or another can form, depending on the nature of the prevailing winds. For example, in the zone of western transport predominance, the maritime climate dominates on the western coasts, and the continental climate dominates on the eastern ones. This is shown in Table. 3, which compares the temperatures at three US weather stations located at approximately the same latitude in the zone of western transport dominance.

On the west coast, in San Francisco, the climate is maritime, with warm winters, cool summers and low temperature ranges. In Chicago, in the interior of the mainland, the climate is sharply continental, with cold winters, warm summers, and a wide range of temperatures. The climate of the east coast, in Boston, is not very different from that of Chicago, although the Atlantic Ocean has a moderating effect on it due to winds sometimes blowing from the sea (sea breezes).

Monsoons.

The term "monsoon", derived from the Arabic "mausim" (season), means "seasonal wind". The name was first applied to the winds in the Arabian Sea blowing for six months from the northeast and for the next six months from the southwest. Monsoons reach their greatest strength in South and East Asia, as well as on tropical coasts, when the influence of the general circulation of the atmosphere is weak and does not suppress them. The Gulf Coast is characterized by weaker monsoons.

Monsoons are the large-scale seasonal analog of the breeze, a diurnal wind that blows in many coastal areas alternately from land to sea and from sea to land. During the summer monsoon, the land is warmer than the ocean, and warm air, rising above it, spreads to the sides in the upper atmosphere. As a result, low pressure is created near the surface, which contributes to the influx of moist air from the ocean. During the winter monsoon, the land is colder than the ocean, and so the cold air sinks over the land and flows towards the ocean. In areas of monsoon climate, breezes can also develop, but they cover only the surface layer of the atmosphere and appear only in the coastal strip.

The monsoon climate is characterized by a pronounced seasonal change in areas from which air masses come - continental in winter and maritime in summer; the predominance of winds blowing from the sea in summer and from land in winter; summer maximum precipitation, cloudiness and humidity.

The vicinity of Bombay on the western coast of India (about 20°N) is a classic example of a monsoonal climate. In February, about 90% of the time, winds from the northeast blow there, and in July - approx. 92% of the time - southwest rhumbs. The average amount of precipitation in February is 2.5 mm, and in July - 693 mm. The average number of days with precipitation in February is 0.1, and in July - 21. The average cloudiness in February is 13%, in July - 88%. The average relative humidity is 71% in February and 87% in July.

RELIEF INFLUENCE

The largest orographic obstacles (mountains) have a significant impact on the land climate.

thermal regime.

In the lower layers of the atmosphere, the temperature drops by about 0.65 ° C with an increase for every 100 m; in areas with long winters, the temperature is slightly slower, especially in the lower 300 m layer, and in areas with long summers, it is somewhat faster. The closest relationship between average temperatures and altitude is observed in the mountains. Therefore, isotherms of average temperatures, for example, in such regions as Colorado, in general terms, repeat the contour lines of topographic maps.

Cloudiness and precipitation.

When air meets a mountain range in its path, it is forced to rise. At the same time, the air cools, which leads to a decrease in its moisture capacity and condensation of water vapor (formation of clouds and precipitation) on the windward side of the mountains. When moisture condenses, the air heats up and, reaching the leeward side of the mountains, it becomes dry and warm. Thus, in the Rocky Mountains, the Chinook wind arises.

Table 4. Extreme temperatures of the continents and islands of Oceania

Table 4. EXTREME TEMPERATURES OF THE OCEAN CONTAINERS AND ISLANDS
Region	Maximum temperature, °С	Place	minimum temperature, °С	Place
North America	57	Death Valley, California, USA	–66	Nortis, Greenland 1
South America	49	Rivadavia, Argentina	–33	Sarmiento, Argentina
Europe	50	Seville, Spain	–55	Ust-Shchugor, Russia
Asia	54	Tirat Zevi, Israel	–68	Oymyakon, Russia
Africa	58	Al Azizia, Libya	–24	Ifrane, Morocco
Australia	53	Cloncurry, Australia	–22	Charlotte Pass, Australia
Antarctica	14	Esperanza, Antarctic Peninsula	–89	Vostok Station, Antarctica
Oceania	42	Tuguegarao, Philippines	–10	Haleakala, Hawaii, USA
1 In mainland North America, the minimum recorded temperature was -63° С (Snug, Yukon, Canada)

Table 5. Extreme values ​​of the average annual precipitation on the continents and islands of Oceania

Table 5. EXTREME VALUES OF ANNUAL AVERAGE PRECITATION ON THE MATERINS AND ISLANDS OF OCEANIA
Region	Maximum, mm	Place	Minimum, mm	Place
North America	6657	Henderson Lake, British Columbia, Canada	30	Batages, Mexico
South America	8989	Quibdo, Colombia		Arica, Chile
Europe	4643	Crkvice, Yugoslavia	163	Astrakhan, Russia
Asia	11430	Cherrapunji, India	46	Aden, Yemen
Africa	10277	Debunja, Cameroon		Wadi Halfa, Sudan
Australia	4554	Tully, Australia	104	Malka, Australia
Oceania	11684	Waialeale, Hawaii, USA	226	Puako, Hawaii, USA

SYNOPTIC OBJECTS

Air masses.

Air mass is a huge volume of air, the properties of which (mainly temperature and humidity) were formed under the influence of the underlying surface in a certain region and gradually change as it moves from the source of formation in a horizontal direction.

Air masses are distinguished primarily by the thermal characteristics of the areas of formation, for example, tropical and polar. The movement of air masses from one area to another, retaining many of their original characteristics, can be traced on synoptic maps. For example, cold and dry air from the Canadian Arctic, moving over the territory of the United States, slowly warms up, but remains dry. Similarly, warm, moist tropical air masses that form over the Gulf of Mexico remain moist, but can warm up or cool down depending on the properties of the underlying surface. Of course, such a transformation of air masses intensifies as the conditions encountered on their way change.

When air masses with different properties from distant formation centers come into contact, they retain their characteristics. Most of the time of their existence, they are separated by more or less clearly defined transition zones, where temperature, humidity and wind speed change dramatically. Then the air masses mix, disperse and, in the end, cease to exist as separate bodies. The transition zones between moving air masses are called "fronts".

Fronts

pass through the hollows of the baric field, i.e. along low pressure contours. When crossing a front, the direction of the wind usually changes dramatically. In polar air masses, the wind can be northwesterly, while in tropical air masses it can be southerly. The worst weather occurs along fronts and in the colder region near the front, where warm air slides up a wedge of dense cold air and cools. As a result, clouds form and precipitation falls. Extratropical cyclones sometimes form along the front. Fronts also form when cold northern and warm southern air masses in the central part of the cyclone (areas of low atmospheric pressure) come into contact.

There are four types of fronts. A stationary front forms on a more or less stable boundary between polar and tropical air masses. If cold air recedes in the surface layer and warm air advances, a warm front forms. Usually, ahead of an approaching warm front, the sky is overcast, it rains or snows, and the temperature gradually rises. When the front passes, the rain stops and the temperature remains high. When a cold front passes, cold air advances and warm air recedes. Rainy, windy weather is observed in a narrow band along the cold front. On the contrary, a warm front is preceded by a wide zone of cloudiness and rain. An occluded front combines features of both warm and cold fronts and is usually associated with an old cyclone.

Cyclones and anticyclones.

Cyclones are large-scale atmospheric disturbances in an area of ​​low pressure. In the Northern Hemisphere, winds blow counterclockwise from high to low pressure, and clockwise in the Southern Hemisphere. In cyclones of temperate latitudes, called extratropical, a cold front is usually expressed, and a warm front, if it exists, is not always clearly visible. Extratropical cyclones often form downwind of mountain ranges, such as over the eastern slopes of the Rocky Mountains and along the eastern coasts of North America and Asia. In temperate latitudes, most of the precipitation is associated with cyclones.

An anticyclone is an area of ​​high air pressure. It is usually associated with good weather with a clear or slightly cloudy sky. In the Northern Hemisphere, the winds blowing from the center of the anticyclone deviate clockwise, and in the Southern Hemisphere - counterclockwise. Anticyclones are usually larger than cyclones and move more slowly.

Since the air spreads from the center to the periphery in the anticyclone, higher layers of air descend, compensating for its outflow. In a cyclone, on the contrary, the air displaced by converging winds rises. Since it is the ascending air movements that lead to the formation of clouds, cloudiness and precipitation are mostly confined to cyclones, while clear or slightly cloudy weather prevails in anticyclones.

Tropical cyclones (hurricanes, typhoons)

Tropical cyclones (hurricanes, typhoons) is the general name for cyclones that form over the oceans in the tropics (with the exception of the cold waters of the South Atlantic and the southeast Pacific Ocean) and do not contain contrasting air masses. Tropical cyclones occur in different parts of the world, usually hitting the eastern and equatorial regions of the continents. They are found in the southern and southwestern North Atlantic (including the Caribbean Sea and the Gulf of Mexico), the North Pacific (west of the Mexican coast, the Philippine Islands and the China Sea), the Bay of Bengal and the Arabian Sea. , in the southern part of the Indian Ocean off the coast of Madagascar, off the northwestern coast of Australia and in the South Pacific Ocean - from the coast of Australia to 140 ° W.

By international agreement, tropical cyclones are classified according to wind strength. There are tropical depressions with wind speeds up to 63 km/h, tropical storms (wind speeds from 64 to 119 km/h) and tropical hurricanes or typhoons (wind speeds over 120 km/h).

In some regions of the world, tropical cyclones have local names: in the North Atlantic and the Gulf of Mexico - hurricanes (in Haiti - secretly); in the Pacific Ocean off the western coast of Mexico - cordonaso, in the western and most southern regions - typhoons, in the Philippines - baguyo, or baruyo; in Australia - willy-willy.

A tropical cyclone is a huge atmospheric vortex with a diameter of 100 to 1600 km, accompanied by strong destructive winds, heavy rains and high surges (rising sea levels caused by wind). Incipient tropical cyclones usually move to the west, deviating slightly to the north, with increasing speed of movement and increasing in size. After moving towards the pole, a tropical cyclone can “turn around”, merge into the western transfer of temperate latitudes and start moving east (however, such a change in direction of movement does not always occur).

The counterclockwise rotating cyclonic winds of the Northern Hemisphere have their maximum strength in a belt with a diameter of 30–45 km or more, starting from the “eye of the storm”. The wind speed near the earth's surface can reach 240 km/h. In the center of a tropical cyclone, there is usually a cloud-free area with a diameter of 8 to 30 km, which is called the "eye of the storm", since the sky here is often clear (or slightly cloudy), and the wind is usually very weak. The zone of destructive winds along the path of the typhoon has a width of 40–800 km. Developing and moving, cyclones cover distances of several thousand kilometers, for example, from the source of formation in the Caribbean Sea or in the tropical Atlantic to inland regions or the North Atlantic.

Although hurricane-force winds in the center of the cyclone reach tremendous speeds, the hurricane itself can move very slowly and even stop for some time, which is especially true for tropical cyclones, which usually move at a speed of no more than 24 km / h. As the cyclone moves away from the tropics, its speed usually increases and in some cases reaches 80 km/h or more.

Hurricane winds can cause great damage. Although they are weaker than in a tornado, they are nevertheless capable of felling trees, overturning houses, breaking power lines and even derailing trains. But the biggest loss of life is caused by floods associated with hurricanes. As the storm progresses, huge waves often form, and sea levels can rise by more than 2 m in a few minutes. Small ships are washed ashore. Giant waves destroy houses, roads, bridges and other buildings located on the shore and can wash away even long-standing sandy islands. Most hurricanes are accompanied by torrential rains that flood fields and damage crops, wash out roads and demolish bridges, and flood low-lying communities.

Improved forecasts, accompanied by operational storm warnings, have led to a significant reduction in the number of casualties. When a tropical cyclone forms, the frequency of forecast broadcasts increases. The most important source of information is reports from aircraft specially equipped for cyclone observations. Such aircraft patrol hundreds of kilometers from the coast, often penetrating into the center of a cyclone to obtain accurate information about its position and movement.

The coastal areas most prone to hurricanes are equipped with radar installations to detect them. As a result, the storm can be recorded and tracked at a distance of up to 400 km from the radar station.

Tornado (tornado)

A tornado (tornado) is a rotating funnel cloud that extends to the ground from the base of a thundercloud. Its color changes from gray to black. Approximately 80% of tornadoes in the United States have maximum wind speeds of 65–120 km/h, and only 1% of 320 km/h or more. An approaching tornado usually makes a noise similar to that of a moving freight train. Despite their relatively small size, tornadoes are among the most dangerous storm phenomena.

From 1961 to 1999, tornadoes killed an average of 82 people a year in the United States. However, the probability that a tornado will pass in this place is extremely low, since the average length of its run is quite short (about 25 km), and the swath is small (less than 400 m wide).

A tornado originates at altitudes up to 1000 m above the surface. Some of them never reach the ground, others may touch it and rise again. Tornadoes are usually associated with thunderclouds from which hail falls to the ground and may occur in groups of two or more. In this case, a more powerful tornado is formed first, and then one or more weaker vortices.

For the formation of a tornado in air masses, a sharp contrast in temperature, humidity, density and parameters of air flows is necessary. Cool and dry air from the west or northwest moves towards the warm and moist air in the surface layer. This is accompanied by strong winds in a narrow transition zone where complex energy transformations take place that can cause vortex formation. Probably, a tornado is formed only with a strictly defined combination of several fairly common factors that vary over a wide range.

Tornadoes are observed all over the globe, but the most favorable conditions for their formation are in the central regions of the United States. Tornado frequency typically rises in February in all eastern states adjacent to the Gulf of Mexico and peaks in March. In Iowa and Kansas, their highest frequency occurs in May–June. From July to December, the number of tornadoes in the whole country decreases rapidly. The average number of tornadoes in the US is approx. 800 per year, with half of them in April, May and June. This figure reaches the highest values ​​in Texas (120 per year), and the lowest - in the northeastern and western states (1 per year).

The destruction caused by tornadoes is terrible. They occur both because of the wind of huge force, and because of the large pressure drops in a limited area. A tornado is able to smash a building into pieces and scatter it through the air. Walls may collapse. The sharp decrease in pressure causes heavy objects, even those inside buildings, to rise into the air, as if sucked in by a giant pump, and sometimes are transported over considerable distances.

It is impossible to predict exactly where a tornado is formed. However, it is possible to define an area of ​​approx. 50 thousand sq. km, within which the probability of occurrence of tornadoes is quite high.

Thunderstorms

Thunderstorms, or thunderstorms, are local atmospheric disturbances associated with the development of cumulonimbus clouds. Such storms are always accompanied by thunder and lightning and usually strong gusts of wind and heavy rainfall. Sometimes hail falls. Most thunderstorms end quickly, and even the longest ones rarely last more than one or two hours.

Thunderstorms occur due to atmospheric instability and are associated mainly with the mixing of air layers, which tend to achieve a more stable density distribution. Powerful ascending air currents are a distinctive feature of the initial stage of a thunderstorm. Strong downward movements of air in the areas of heavy precipitation are characteristic of its final phase. Thunderclouds often reach heights of 12–15 km in temperate latitudes and even higher in the tropics. Their vertical growth is limited by the steady state of the lower stratosphere.

A unique property of thunderstorms is their electrical activity. Lightning can occur within a developing cumulus cloud, between two clouds, or between a cloud and the ground. In fact, a lightning discharge almost always consists of several discharges passing through the same channel, and they pass so quickly that they are perceived by the naked eye as one and the same discharge.

It is still not entirely clear how the separation of large charges of the opposite sign occurs in the atmosphere. Most researchers believe that this process is associated with differences in the size of liquid and frozen water droplets, as well as with vertical air currents. The electric charge of a thundercloud induces a charge on the earth's surface below it and charges of opposite sign around the base of the cloud. A huge potential difference arises between the oppositely charged parts of the cloud and the earth's surface. When it reaches a sufficient value, an electric discharge occurs - a flash of lightning.

The thunder that accompanies a lightning discharge is caused by the instantaneous expansion of air in the path of the discharge, which occurs when it is suddenly heated by lightning. Thunder is more often heard as continuous peals, and not as a single strike, since it occurs along the entire lightning discharge channel, and therefore the sound overcomes the distance from its source to the observer in several stages.

jet air currents

- meandering "rivers" of strong winds in temperate latitudes at altitudes of 9-12 km (which are usually confined to long-range flights of jet aircraft), blowing at speeds sometimes up to 320 km/h. An airplane flying in the direction of the jet stream saves a lot of fuel and time. Therefore, forecasting the propagation and strength of jet streams is essential for flight planning and air navigation in general.

Synoptic charts (Weather charts)

To characterize and study many atmospheric phenomena, as well as to predict the weather, it is necessary to simultaneously conduct various observations at many points and record the data obtained on maps. In meteorology, the so-called. synoptic method.

Surface synoptic maps.

On the territory of the United States every hour (in some countries - less often) weather observations are carried out. Cloudiness is characterized (density, height and type); readings of barometers are taken, to which corrections are introduced to bring the obtained values ​​to sea level; wind direction and speed are fixed; the amount of liquid or solid precipitation and the temperature of air and soil are measured (at the time of observation, maximum and minimum); air humidity is determined; visibility conditions and all other atmospheric phenomena (for example, thunderstorm, fog, haze, etc.) are carefully recorded.

Each observer then encodes and transmits the information using the International Meteorological Code. Because this procedure is standardized by the World Meteorological Organization, such data can be easily deciphered anywhere in the world. Encoding takes approx. 20 minutes, after which messages are transmitted to information collection centers and international data exchange takes place. Then the results of observations (in the form of numbers and symbols) are plotted on a contour map, on which meteorological stations are indicated by dots. In this way, the forecaster gets an idea of ​​the weather conditions within a large geographic region. The overall picture becomes even more clear after connecting the points at which the same pressure is recorded by smooth solid lines - isobars and drawing boundaries between different air masses (atmospheric fronts). Areas with high or low pressure are also distinguished. The map will become even more expressive if you paint over or shade the areas over which precipitation fell at the time of observations.

Synoptic maps of the surface layer of the atmosphere are one of the main tools for weather forecasting. The forecaster compares a series of synoptic maps at different times of observation and studies the dynamics of baric systems, noting changes in temperature and humidity within air masses as they move over various types of underlying surface.

Altitude synoptic maps.

Clouds are moved by air currents, usually at considerable heights above the earth's surface. Therefore, it is important for the meteorologist to have reliable data for many levels of the atmosphere. Based on the data obtained with the help of weather balloons, aircraft and satellites, weather maps are compiled for five altitude levels. These maps are transmitted to synoptic centers.

WEATHER FORECAST

The weather forecast is based on human knowledge and computer capabilities. A traditional component of forecasting is the analysis of maps showing the structure of the atmosphere horizontally and vertically. Based on them, a forecaster can evaluate the development and movement of synoptic objects. The use of computers in the meteorological network greatly facilitates the forecast of temperature, pressure, and other meteorological elements.

In addition to a powerful computer, weather forecasting requires a wide network of weather observations and a reliable mathematical apparatus. Direct observations provide mathematical models with the data necessary for their calibration.

An ideal forecast must be justified in all respects. It is difficult to determine the cause of errors in the forecast. Meteorologists consider a forecast to be justified if its error is less than forecasting the weather using one of two methods that do not require special knowledge in the field of meteorology. The first of them, called inertial, assumes that the nature of the weather will not change. The second method assumes that the weather characteristics will correspond to the average monthly for a given date.

The duration of the period during which the forecast is justified (i.e. gives a better result than one of the two approaches mentioned) depends not only on the quality of observations, mathematical apparatus, computer technology, but also on the scale of the predicted meteorological phenomenon. Generally speaking, the larger the weather event, the longer it can be predicted. For example, often the degree of development and the path of cyclones can be predicted for several days in advance, but the behavior of a particular cumulus cloud can be predicted for no more than the next hour. These limitations seem to be due to the characteristics of the atmosphere and cannot yet be overcome by more careful observations or more accurate equations.

Atmospheric processes develop chaotically. This means that different approaches are needed for forecasting various phenomena on different spatiotemporal scales, in particular, for predicting the behavior of large mid-latitude cyclones and local strong thunderstorms, as well as for long-term forecasts. For example, a forecast of air pressure for a day in the surface layer is almost as accurate as the measurements with the help of weather balloons, on which it was checked. And vice versa, it is difficult to give a detailed three-hour forecast of the movement of the squall line - a band of intense precipitation in front of the cold front and generally parallel to it, within which tornadoes can originate. Meteorologists can only preliminarily identify vast areas of possible occurrence of squall lines. When they are fixed on a satellite image or using radar, their progress can only be extrapolated by one to two hours, and therefore it is important to bring the weather report to the population in a timely manner. The prediction of unfavorable short-term meteorological phenomena (squalls, hail, tornadoes, etc.) is called an urgent forecast. Computer techniques are being developed to predict these hazardous weather phenomena.

On the other hand, there is the problem of long-term forecasts, i.e. more than a few days in advance, for which observations of the weather within the entire globe are absolutely necessary, but even this is not enough. Since the turbulent nature of the atmosphere limits the ability to predict the weather over a large area to about two weeks, forecasts over longer periods must be based on factors that affect the atmosphere in a predictable way and will themselves be known more than two weeks in advance. One such factor is ocean surface temperature, which changes slowly over weeks and months, influences synoptic processes, and can be used to identify areas of abnormal temperatures and precipitation.

PROBLEMS OF THE CURRENT STATE OF WEATHER AND CLIMATE

Air pollution.

Global warming.

The carbon dioxide content of the Earth's atmosphere has increased by about 15% since 1850 and is projected to increase by almost the same amount by 2015, in all likelihood due to the burning of fossil fuels: coal, oil and gas. It is assumed that as a result of this process, the average annual temperature on the globe will increase by approximately 0.5 ° C, and later, in the 21st century, will become even higher. The consequences of global warming are difficult to predict, but they are unlikely to be favorable.

Ozone,

the molecule of which consists of three oxygen atoms, is found mainly in the atmosphere. Observations carried out from the mid-1970s to the mid-1990s showed that the ozone concentration over Antarctica changed significantly: it decreased in spring (in October), when the so-called ozone was formed. "ozone hole", and then again increased to a normal value in the summer (in January). During the period under review, there is a clear trend towards a decrease in the spring minimum ozone content in this region. Global satellite observations indicate a somewhat smaller but noticeable decrease in ozone concentrations occurring everywhere, with the exception of the equatorial zone. It is assumed that this happened due to the widespread use of fluorochlorine-containing freons (freons) in refrigeration units and for other purposes.

El Nino.

Once every few years, an extremely strong warming occurs in the east of the equatorial region of the Pacific Ocean. It usually starts in December and lasts for several months. Due to the closeness of time to Christmas, this phenomenon was called "El Niño", which in Spanish means "baby (Christ)". The accompanying atmospheric phenomena have been called the Southern Oscillation because they were first observed in the Southern Hemisphere. Due to the warm water surface, convective air rise is observed in the eastern part of the Pacific Ocean, and not in the western part, as usual. As a result, the area of ​​heavy rains is shifting from the western regions of the Pacific Ocean to the eastern ones.

Droughts in Africa.

The mention of drought in Africa goes back to biblical history. More recently, in the late 1960s and early 1970s, a drought in the Sahel, on the southern edge of the Sahara, killed 100,000 people. The drought of the 1980s took a similar toll in East Africa. The unfavorable climatic conditions of these regions were exacerbated by overgrazing, deforestation, and military action (as in Somalia in the 1990s).

METEOROLOGICAL INSTRUMENTS

Meteorological instruments are designed both for immediate urgent measurements (thermometer or barometer for measuring temperature or pressure), and for continuous recording of the same elements over time, usually in the form of a graph or curve (thermograph, barograph). Only devices for urgent measurements are described below, but almost all of them also exist in the form of recorders. In fact, these are the same measuring instruments, but with a pen that draws a line on a moving paper tape.

Thermometers.

Liquid glass thermometers.

In meteorological thermometers, the ability of a liquid enclosed in a glass bulb to expand and contract is most often used. Typically, a glass capillary tube ends in a spherical expansion that serves as a reservoir for liquid. The sensitivity of such a thermometer is inversely related to the cross-sectional area of ​​the capillary and in direct proportion to the volume of the reservoir and the difference in the coefficients of expansion of a given liquid and glass. Therefore, sensitive meteorological thermometers have large reservoirs and thin tubes, and the liquids used in them expand much faster with increasing temperature than glass.

The choice of liquid for a thermometer depends mainly on the range of measured temperatures. Mercury is used to measure temperatures above -39°C, its freezing point. For lower temperatures, liquid organic compounds, such as ethyl alcohol, are used.

The accuracy of the tested standard meteorological glass thermometer is ± 0.05°C. The main reason for the error of a mercury thermometer is associated with gradual irreversible changes in the elastic properties of glass. They lead to a decrease in the volume of the glass and an increase in the reference point. In addition, errors can occur as a result of incorrect readings or due to placing the thermometer in a place where the temperature does not correspond to the true air temperature in the vicinity of the weather station.

The errors of alcohol and mercury thermometers are similar. Additional errors can occur due to cohesive forces between the alcohol and the glass walls of the tube, so that when the temperature drops rapidly, some of the liquid is retained on the walls. In addition, alcohol in the light reduces its volume.

Minimum thermometer

is designed to determine the lowest temperature for a given day. For these purposes, a glass alcohol thermometer is usually used. A glass pointer with bulges at the ends is immersed in alcohol. The thermometer works in a horizontal position. When the temperature drops, the alcohol column recedes, dragging the pin with it, and when the temperature rises, the alcohol flows around it without moving it, and therefore the pin fixes the minimum temperature. Return the thermometer to working condition by tilting the tank up so that the pin comes into contact with alcohol again.

Maximum thermometer

used to determine the highest temperature for a given day. Usually this is a glass mercury thermometer, similar to a medical one. There is a constriction in the glass tube near the tank. Mercury is squeezed out through this constriction during a rise in temperature, and when it is lowered, the constriction prevents its outflow into the reservoir. Such a thermometer is again prepared for operation on a special rotating installation.

Bimetal thermometer

consists of two thin strips of metal, such as copper and iron, which expand to varying degrees when heated. Their flat surfaces fit snugly against each other. Such a bimetallic tape is twisted into a spiral, one end of which is rigidly fixed. When the coil is heated or cooled, the two metals expand or contract differently, and the coil either unwinds or twists tighter. According to the pointer attached to the free end of the spiral, the magnitude of these changes is judged. Examples of bimetal thermometers are room thermometers with a round dial.

Electrical thermometers.

Such thermometers include a device with a semiconductor thermoelement - a thermistor, or thermistor. The thermocouple is characterized by a large negative resistance coefficient (i.e. its resistance decreases rapidly with increasing temperature). The advantages of the thermistor are high sensitivity and quick response to temperature changes. Thermistor calibration changes over time. Thermistors are used on meteorological satellites, balloons, and most digital room thermometers.

Barometers.

mercury barometer

is a glass tube approx. 90 cm, filled with mercury, sealed at one end and tipped into a cup of mercury. Under the influence of gravity, part of the mercury pours out of the tube into the cup, and due to air pressure on the surface of the cup, the mercury rises through the tube. When equilibrium is established between these two opposing forces, the height of the mercury in the tube above the surface of the liquid in the tank corresponds to atmospheric pressure. If the air pressure increases, the level of mercury in the tube rises. The average height of the mercury column in a barometer at sea level is approx. 760 mm.

Aneroid barometer

consists of a sealed box from which the air is partially evacuated. One of its surface is an elastic membrane. If atmospheric pressure increases, the membrane flexes inward; if it decreases, it flexes outward. A pointer attached to it captures these changes. Aneroid barometers are compact and relatively inexpensive and are used both indoors and on standard meteorological radiosondes. see also BAROMETER.

Instruments for measuring humidity.

Psychrometer

consists of two adjacent thermometers: dry, measuring the temperature of the air, and wetted, the tank of which is wrapped in a cloth (cambric) moistened with distilled water. Air flows around both thermometers. Due to the evaporation of water from the fabric, the wet bulb temperature usually reads lower than the dry bulb. The lower the relative humidity, the greater the difference in thermometer readings. Based on these readings, relative humidity is determined using special tables.

Hair hygrometer

measures relative humidity based on changes in the length of a human hair. To remove natural fats, the hair is first soaked in ethyl alcohol and then washed in distilled water. The length of the hair thus prepared has an almost logarithmic dependence on relative humidity in the range of 20 to 100%. The time required for the hair to react to a change in humidity depends on the air temperature (the lower the temperature, the longer it is). In a hair hygrometer, with an increase or decrease in the length of the hair, a special mechanism moves the pointer along the scale. Such hygrometers are usually used to measure the relative humidity in rooms.

Electrolytic hygrometers.

The sensitive element of these hygrometers is a glass or plastic plate coated with carbon or lithium chloride, the resistance of which varies with relative humidity. Such elements are commonly used in meteorological balloon instrument kits. When the probe passes through the cloud, the device is moistened, and its readings are distorted for quite a long time (until the probe is outside the cloud and the sensitive element dries out).

Instruments for measuring wind speed.

Cup anemometers.

Wind speed is usually measured using a cup anemometer. This device consists of three or more cone-shaped cups, vertically attached to the ends of metal rods, which extend radially symmetrically from a vertical axis. The wind acts with the greatest force on the concave surfaces of the cups and causes the axle to turn. In some types of cup anemometers, the free rotation of the cups is prevented by a system of springs, the magnitude of the deformation of which determines the wind speed.

In freely rotating cup anemometers, the rate of rotation, roughly proportional to the wind speed, is measured by an electrical meter that signals when a certain volume of air has flowed around the anemometer. The electrical signal includes a light signal and a recording device at the weather station. Often a cup anemometer is mechanically coupled to a magneto and the voltage or frequency of the electrical current generated is related to the wind speed.

Anemometer

with a mill turntable consists of a three-four-blade plastic screw mounted on a magneto axis. The screw with the help of a weather vane, inside of which a magneto is placed, is constantly directed against the wind. Information about the direction of the wind is sent via telemetry channels to the observation station. The electric current generated by the magneto varies in direct proportion to the wind speed.

Beaufort scale.

Wind speed is estimated visually by its impact on objects surrounding the observer. In 1805, Francis Beaufort, a sailor in the British Navy, developed a 12-point scale to characterize the strength of the wind at sea. In 1926, estimates of wind speed on land were added to it. In 1955, to distinguish between hurricane winds of varying strengths, the scale was extended to 17. The modern version of the Beaufort scale (Table 6) makes it possible to estimate the wind speed without the use of any instruments.

Table 6. Beaufort scale for determining wind strength

Table 6. BEAUFORT SCALE FOR DETERMINING WIND FORCE
Points	Visual signs on land	Wind speed, km/h	Terms that define the strength of the wind
0	Calmly; smoke rises vertically	Less than 1.6	Calm
1	The direction of the wind is noticeable by the deviation of the smoke, but not by the weather vane	1,6–4,8	Quiet
2	The wind is felt by the skin of the face; leaves rustle; turning ordinary weathervanes	6,4–11,2	Light
3	Leaves and small twigs are in constant motion; waving light flags	12,8–19,2	Weak
4	The wind raises dust and papers; thin branches sway	20,8–28,8	Moderate
5	The leafy trees sway; ripples appear on land	30,4–38,4	Fresh
6	Thick branches sway; the whistle of the wind is heard in the electric wires; hard to hold an umbrella	40,0–49,6	Strong
7	Tree trunks sway; hard to go against the wind	51,2–60,8	Strong
8	Tree branches break; almost impossible to go against the wind	62,4–73,6	Very strong
9	Minor damage; the wind rips smoke hoods and tiles off the roofs	75,2–86,4	Storm
10	Rarely on dry land. Trees are uprooted. Significant damage to buildings	88,0–100,8	Heavy storm
11	It is very rare on dry land. Accompanied by destruction over a large area	102,4–115,2	Violent storm
12	Strong destruction (Scores 13-17 were added by the US Weather Bureau in 1955 and are used in the US and UK scales)	116,8–131,2	Hurricane
13		132,8–147,2
14		148,8–164,8
15		166,4–182,4
16		184,0–200,0
17		201,6–217,6

Instruments for measuring precipitation.

Precipitation consists of water particles, both in liquid and solid form, that come from the atmosphere to the earth's surface. In standard non-recording rain gauges, the receiving funnel is inserted into the measuring cylinder. The ratio of the area of ​​the upper part of the funnel and the cross section of the measuring cylinder is 10:1, i.e. 25 mm of precipitation will correspond to a mark of 250 mm in the cylinder.

Recording rain gauges - pluviographs - automatically weigh collected water or count how many times a small measuring vessel is filled with rainwater and automatically emptied.

If precipitation in the form of snow is expected, the funnel and measuring cup are removed and the snow is collected in a precipitation bucket. When snow is accompanied by moderate or strong winds, the amount of snow entering the vessel does not correspond to the actual amount of precipitation. The height of the snow cover is determined by measuring the thickness of the snow layer within the area typical for the given area, and the average value of at least three measurements is taken. To establish the water equivalent in areas where the impact of blizzard transport is minimal, a cylinder is immersed in the snow mass and a column of snow is cut out, which is melted or weighed. The amount of precipitation measured by a rain gauge depends on its location. Air turbulence, whether caused by the instrument itself or by obstructions around it, results in an underestimation of the amount of precipitation entering the measuring cup. Therefore, the rain gauge is installed on a flat surface as far as possible from trees and other obstacles. A protective screen is used to reduce the effect of vortices created by the instrument itself.

AEROLOGICAL OBSERVATIONS

Instruments for measuring the height of clouds.

The simplest way to determine the height of a cloud is to measure the time it takes for a small balloon released from the earth's surface to reach the base of the cloud. Its height is equal to the product of the average speed of ascent of the balloon by the time of flight.

Another way is to observe a spot of light formed at the base of the cloud with a projector beam directed vertically upwards. From a distance of approx. 300 m from the searchlight, the angle between the direction to this spot and the searchlight beam is measured. Cloud height is calculated by triangulation, similar to how distances are measured in topographic surveys. The proposed system can operate automatically day and night. A photocell is used to observe the spot of light at the bases of the clouds.

Cloud height is also measured using radio waves - 0.86 cm long pulses sent by the radar. Cloud height is determined by the time it takes for a radio pulse to reach the cloud and return back. Since clouds are partially transparent to radio waves, this method is used to determine the height of layers in multi-layer clouds.

Meteorological balloons.

The simplest type of meteorological balloon - the so-called. A balloon is a small rubber balloon filled with hydrogen or helium. By optically observing changes in the azimuth and altitude of the balloon, and assuming that its rate of rise is constant, it is possible to calculate the wind speed and direction as a function of the height above the earth's surface. For nighttime observations, a small battery-operated flashlight is attached to the ball.

A weather radiosonde is a rubber balloon carrying a radio transmitter, a thermistor thermometer, an aneroid barometer, and an electrolytic hygrometer. The radiosonde rises at a speed of approx. 300 m/min up to a height of approx. 30 km. As you ascend, measurement data is continuously transmitted to the launch station. A directional receiving antenna on Earth tracks the azimuth and altitude of the radiosonde, from which the wind speed and direction are calculated at various heights in the same way as with pilot balloon observations. Radiosondes and balloons are launched from hundreds of locations around the world twice a day, at noon and midnight GMT.

Satellites.

For daytime photography of cloud cover, illumination is provided by sunlight, while infrared radiation emitted by all bodies allows shooting both day and night with a special infrared camera. Using photographs in different ranges of infrared radiation, you can even calculate the temperature of individual layers of the atmosphere. Satellite observations have a high planned resolution, but their vertical resolution is much lower than that provided by radiosondes.

Some satellites, such as the American TIROS, are launched into a circular polar orbit at an altitude of approx. 1000 km. Since the Earth rotates around its axis, from such a satellite each point of the earth's surface is usually visible twice a day.

Even more important are the so-called. geostationary satellites that orbit the equator at an altitude of approx. 36 thousand km. Such a satellite takes 24 hours to make a complete revolution. Since this time is equal to the length of the day, the satellite remains above the same point on the equator, and it offers a constant view of the earth's surface. Thus, a geostationary satellite can repeatedly photograph the same area, recording changes in the weather. In addition, wind speeds can be calculated from the movement of clouds.

Weather radars.

The signal sent by the radar is reflected by rain, snow or temperature inversion, and this reflected signal arrives at the receiving device. Clouds are usually not visible on a radar screen because the droplets that form them are too small to effectively reflect the radio signal.

By the mid-1990s, the US National Weather Service was re-equipped with Doppler effect radars ( see also DOPPLER EFFECT ; RADAR). In installations of this type, to measure the speed of approach of reflecting particles to the radar or away from it, the so-called principle is used. Doppler shift. Therefore, these radars can be used to measure wind speed. They are especially useful for detecting tornadoes, since the wind on one side of the tornado quickly rushes towards the radar, and on the other side it rapidly moves away from it. Modern radars can detect meteorological objects at a distance of up to 225 km.



Dictionary of Efremova

Meteorology

and.
A scientific discipline that studies the earth's atmosphere and the processes occurring in it.

Dictionary Ushakov

Naval Dictionary

Meteorology

a science that studies the composition and structure of the atmosphere, as well as the phenomena occurring in it (thermal regimes, air movement, acoustic and electrical). Military meteorology studies the influence of meteorological conditions on the actions of troops (Navy), on the use of weapons and military equipment.

Ozhegov's dictionary

METEOROL O GIA, and, and. The science of the physical state of the earth's atmosphere and the processes occurring in it. Synoptic m. (study of atmospheric processes in connection with weather forecasting).

| adj. meteorological, oh, oh.

encyclopedic Dictionary

Meteorology

(from the Greek meteora - atmospheric phenomena and ... logic), the science of the earth's atmosphere and the processes occurring in it. The main branch of meteorology is atmospheric physics. Meteorology studies the composition and structure of the atmosphere; heat circulation and thermal regime in the atmosphere and on the earth's surface; moisture circulation and phase transformations of water in the atmosphere, the movement of air masses; electrical, optical and acoustic phenomena in the atmosphere. Meteorology includes actinometry, dynamic and synoptic meteorology, atmospheric optics, atmospheric electricity, aerology, and other applied meteorological disciplines.

Encyclopedia of Brockhaus and Efron

Meteorology

The science that studies the phenomena occurring in the earth's atmosphere, such as: pressure, temperature, air humidity, cloudiness, precipitation, rain, snow, etc. In contrast to the closest science to it - physics, experimental science - M. science observant. The phenomena that take place in the earth's atmosphere are extremely complex and are mutually dependent on one another, and generalizations are possible only if extensive, possibly accurate material obtained by observations is available (see Meteorological Observations). Since the air is thermally transparent, i.e., it passes a significant amount of heat, only slightly warming up from the sun's rays, a significant amount of solar heat reaches the surface of the land and waters of the globe. Since, moreover, both land and water have a much higher heat capacity than air (with the same volume, the first is more than 1500 times, the second is more than 3000 times), it is clear what effect the temperature of the surface of the land and waters of the globe has on the temperature of the lower layer of air, and the lower layers of the air are the most studied. Therefore, the study of the upper layers of land and water, especially their temperature, is included in the area of ​​M. As material accumulated and its scientific development, M. began to be divided into parts or departments. Until relatively recently, M. decisively dominated method of averages (see Meteorological observations), at present it is of particular importance for climatology (see Climates), that is, parts of meteorology, but even here more and more attention is paid to the differences and fluctuations of meteorological elements, depicting them not only figures, but also more clearly, on graphic tables and maps. The smaller the fluctuations, the more constant the climate and the more important the average values ​​become. If the fluctuations are very large and frequent, then the average values ​​characterize climates much less than where the fluctuations are smaller. Modern meteorology also pays great attention to the extreme magnitudes of various meteorological elements, and the study of them is of importance both for pure science and in application to practice, for example, in agriculture. All meteorological phenomena directly or indirectly depend on the influence of solar heat and light on the Earth; In view of this, two periods are of particular importance: daily, depending on the rotation of the Earth around its axis, and annual, depending on the revolution of the Earth around the Sun. The lower the latitude, the greater the relative value of the daily period, especially temperature (but also of other phenomena), and the smaller the value of the annual period. At the equator, the length of the day is the same throughout the year, i.e., 12 hours 7 minutes, and the angle of incidence of the sun's rays at noon changes only within the boundaries from 66 ° 32 "to 90 °, so at the equator for a whole year around noon it turns out a lot heat from the sun, and during the long night a lot is lost by radiation, hence the conditions are favorable for a large daily amplitude the temperature of the soil surface and the lower layer of air, i.e., a large difference between the daily temperature of the lowest and highest. On the contrary, the temperature of the day at different times of the year should differ very little. At the poles, the diurnal period completely disappears, the sun rises on the day of the vernal equinox and then remains above the horizon until the day of the autumnal equinox, and for more than 2 months its rays constantly fall at an angle of more than 20 °, and for about half a year the sun is not visible at all. Obviously, these conditions should contribute to a very large annual temperature amplitude at the poles , which differs sharply from the small amplitude observed in the tropics. The daily and annual periods of meteorological phenomena are indisputable periods, but next to them, meteorologists have been looking and are looking for other periods, some shorter than the annual, some longer. Of the first, special attention was drawn to the 26-day period of the Sun's revolution around its axis, which, according to other meteorologists, corresponds to the same period of thunderstorm frequency. Of the longer periods, especially many calculations have been made to clarify the question whether more or less sunspots affect the earth's atmosphere. Their period is approximately 11 years, i.e., periods of an especially large and especially small number of spots are repeated after such an interval. In recent years, much has been written about a 35-year period during which supposedly cold and wet years alternate with warm and dry ones, but such a period does not coincide with any known phenomena on the Sun. Studies of this kind have yielded results that are far from consistent with each other, and therefore the influence on our atmosphere of any periods other than daily and annual can be considered doubtful.

In the last 30 years, M. is less and less content with averages and empirical research in general, and is increasingly trying to penetrate into the essence of phenomena, applying to them the laws of physics (especially the theory of heat) and mechanics. Thus, the whole modern theory of temperature changes in ascending and descending air movements is based on the application of the laws of thermodynamics, and it turned out that, despite the extreme complexity of the phenomena, in some cases results are obtained that are very similar to theoretical ones. Particularly great in this matter are the merits of Hann (Hann, see). The whole modern theory of air movement is based on the application of the teachings of mechanics, and meteorologists had to independently develop the laws of mechanics as applied to the conditions of the globe. Ferrel did the most in this area (see). In the same way, a lot has been done in recent years in questions of the emission of radiation from the sun, earth, and air, especially in the first one, and if the most important work has been done by physicists and astrophysicists (we will especially mention Langle, see), then these scientists were familiar with modern requirements of M., very clearly expressed by many meteorologists, and the latter, in addition, tried to quickly take advantage of the results achieved, while developing simple methods of observation accessible to a large circle of people, so that now actinometry is becoming more and more a necessary part of M. It was mentioned above that meteorology has so far studied mainly the lower layers of the air because the phenomena here are more easily accessible for study and, moreover, are of great importance for practical life. But meteorologists have long sought to explore layers of air distant from the mass of the earth's surface. On high, distant mountains, the air comes into contact with a very small part of the earth's surface, and, moreover, it is usually in such a rapid movement that the purpose is to some extent achieved by the device of mountain meteorological observatories. They exist in several countries of Europe and America (France is ahead of other countries in this matter) and undoubtedly have rendered and will continue to render great services to M. Soon after the invention of balloons, scientists set themselves the goal of using them to explore layers of air that are very remote from the earth's surface and very rarefied , and already at the beginning of the 19th century, Gay-Lussac undertook flights for scientific purposes. But for a long time, the shortcomings of aeronautics and the insufficient sensitivity of meteorological instruments hindered the success of the case, and only from 1893, almost simultaneously in France and Germany, balloons were launched to a great height (up to 18,000 m) without people, with self-writing instruments. In Russia, this business has also made great progress, and now in France, Germany and Russia, simultaneous flights are being undertaken, which are very important in this business. For a long time, after mathematics became a science, when correct observations and generalizations began, the connection between science and practice was extremely weak for a long time, or even did not exist at all. In the last 35 years, this has changed significantly, and synoptic or practical M. has received great development. It aims not only to study weather phenomena, but also to foresee or predict the weather (see). The case began with simpler phenomena, that is, predictions storms, for the purposes of navigation, in which significant progress has already been made. At present, M. is striving for the same in the interests of agriculture, but this task is undoubtedly more difficult, both in terms of the nature of the phenomena, the prediction of which is especially desirable, that is, precipitation (see), and in the scattered farms, it is difficult to warn them of the likely onset one weather or another. However, the tasks of agricultural meteorology are far from being limited to predicting the weather in the interests of agriculture; a detailed climatological study of all meteorological elements important for agriculture is in the foreground. Agricultural mechanization is just emerging and has gained particular importance in two vast agricultural states, Russia and the United States. Above it was pointed out the differences in the methods of the two sciences, as close to each other as physics and M. By the predominance of observation, M. approaches astronomy. Nevertheless, the difference is very great, not only in the object of study, but also in something else. All the observations necessary for astronomy can be made at a few dozen points expediently located on the globe; these observations require only people with great knowledge and who have fully mastered the rather complex technique of the case. Meteorology is another matter. A few dozen observatories, located in the most expedient way around the globe, with the best observers and instruments, will still be far from being sufficient for the study of very many meteorological phenomena. The latter are so complex, so variable in space and time, that they certainly require a very large number of observation points. Since it would be unthinkable to supply tens and hundreds of thousands of stations with complex and expensive instruments, and even less possible to find such a number of observers who are at the height of science and technology, then M. has to be content with less perfect observations, and resort to the assistance of a wide range of people, those who have not received special education, but who are interested in climate and weather phenomena, and to develop for them the simplest and cheapest possible instruments and methods of observation. In many cases, even observations are made without instruments. Therefore, no science so needs talented popular books and articles as M.

At present, there is no complete course in meteorology corresponding to the current state of science; the only two complete courses are K ä mtz, "Lehrbuch d. M." (1833) and Schmid, "Lehrbuch der M." (1860) are already considerably outdated in many parts. Of the less complete manuals covering all parts of science, we point to von Bebber, "Lehrbuch der M."; Lachinov, "Fundamentals of M.". Much shorter and more popular is the well-known course Mohn, "Grundz ü ge der M."; here the main attention is paid to weather phenomena, there is a Russian translation from the 1st German edition: "M., or the Science of the Weather." A completely independent book about the weather: Abercromby, "Weather" (there is a German translation); systematic guide to the study of the weather: von Bebber, "Handbuch der aus ü benden Witterungskunde". Pomortsev's book, "Synoptic M.", by its nature is in the middle of the above. According to dynamic M.: Sprung, "Lehrbuch der M.". For climatology: Hann, "Handbuch der Klimatologie"; Voeikov, "Climates of the globe". According to agricultural M.: Houdaille, "Meteorologie agricole"; according to forest M.: Hornberger, "Grundriss der M.". Quite popular, very short courses "Houzeau et Lancaster Meteorologie"; Scott, "Elementary M.". Collections of observations and periodicals - see Meteorological publications.

This is the science of the atmosphere, studying its composition, properties and the physical and chemical processes occurring in it. Meteorology is briefly and succinctly called atmospheric physics. Meteorology is part of a more general science - geophysics, which studies the phenomena and processes occurring in the atmosphere, on the land surface and in the thickness of the soil (Figure 1).

Figure 1. Block diagram of science - geophysics.

The main tasks of meteorology:

• the study of all physical and chemical processes and phenomena occurring in the atmosphere;
• the study of the patterns by which these processes and phenomena occur;
• forecasting the onset and development of atmospheric processes and phenomena;
• organization of an observation system for atmospheric phenomena and processes;
• development of methods for managing processes occurring in the atmosphere;
• use of the results of meteorological information in sectors of the national economy: primarily in aviation, for sea, rail and road transport, in the design and construction of various critical structures (power lines, buildings, reservoirs, gas pipelines and power plants).

Agricultural production is directly and directly dependent on meteorological information.

Solving problems in ecology and environmental protection is also associated with meteorological observations of the processes of pollution of the atmosphere and water bodies.

The listed main tasks of meteorology are based on the solution of the following specific, individual tasks or subtasks:

• study of the main characteristics of the atmosphere: composition, vertical stratification, horizontal heterogeneity, atmospheric pressure, etc.;
• study of solar, terrestrial and atmospheric radiation: fluxes of solar energy in the atmosphere, spectrum of solar radiation, arrival and consumption of solar energy;
• thermal regime of soil and water bodies: heating and cooling of soil, daily and annual variation of soil surface temperature, change in soil temperature with depth, temperature regime of water bodies;
• thermal regime of the atmosphere: heating and cooling of air, daily and annual temperature fluctuations, the influence of vegetation, the geographical distribution of the temperature of the surface layer of the atmosphere, temperature changes with height, adiabatic processes in the atmosphere;
• water vapor in the atmosphere: evaporation, humidity, condensation of water vapor, the formation of various types and varieties of clouds;
• the formation of atmospheric precipitation: the type of precipitation and their characteristics, the distribution of precipitation over the earth's surface;
• air currents in the atmosphere: change in wind speed and direction, influence of obstacles on the wind, change in wind speed and direction in height;
• optical phenomena and electrical processes in the atmosphere: scattering and absorption of light, visibility range, refraction and reflection of light in the atmosphere, electric field and electrical conductivity of the atmosphere, lightning electricity;
• sound phenomena in the atmosphere: speed of sound, refraction and reflection of sound, attenuation of sound in the atmosphere.

Since meteorology solves a very wide range of problems, it is divided into several individual directions.

synoptic meteorology- the direction of meteorology, which studies the patterns of development of atmospheric processes that determine weather conditions, and methods for its forecast are being developed.

weather called the state of the atmosphere and the totality of phenomena observed in it at a given moment.

Climatology- the direction of meteorology, which studies the conditions and patterns of climate formation, distribution over the globe and climate change over time.

climate A given locality is called the weather regime characteristic of this locality in a long-term context and due to solar radiation, the nature of the underlying surface (the surface on which solar radiation is directed) and the circulation of the atmosphere.

The heterogeneity of the underlying surface determines the different climate. The study of climate features associated with the heterogeneity of the underlying surface is microclimatology.

Actinometry- the direction of meteorology, which studies solar, terrestrial and atmospheric radiation in atmospheric conditions.

Atmospheric physics- the direction of meteorology, which studies the physical laws of processes and phenomena occurring in the surface, that is, the lower layers of the atmosphere, in the free atmosphere (aerology) and in the upper atmosphere.

Actinometry is sometimes referred to as atmospheric physics. Atmospheric physics is subdivided into atmospheric optics, atmospheric electricity and atmospheric acoustics.

Dynamic meteorology- a branch of meteorology that studies the dynamics of the atmosphere (movement) and related energy transformations based on the laws of hydromechanics and thermodynamics.

One of the important tasks in this area is the development of mathematical models of atmospheric processes for the preparation of weather forecasts, the study of environmental ecology, and changes in climatic phenomena.

Applied meteorology- the direction of meteorology, which studies the influence of various meteorological processes on the functioning of various sectors of the national economy.

There are agricultural meteorology (agrometeorology), medical meteorology (biometeorology), aviation meteorology, etc.

Meteorology (from the Greek μετέωρος, metéōros, atmospheric and celestial phenomena and -λογία, -logy) is the science of the structure and properties of the earth's atmosphere and the physical processes taking place in it. In many countries, meteorology is called atmospheric physics, which is more in line with its current meaning.

Main objects of research

• physical, chemical processes in the atmosphere
• atmospheric composition
• structure of the atmosphere
• thermal regime of the atmosphere
• moisture exchange in the atmosphere
• general atmospheric circulation
• electric fields
• optical and acoustic phenomena
• cyclones
• anticyclones
• wind
• fronts
• climate
• weather
• clouds

History of science

The first studies in the field of meteorology date back to ancient times (Aristotle). The development of meteorology accelerated from the first half of the 17th century, when the Italian scientists G. Galilei and E. Torricelli developed the first meteorological instruments, the barometer and thermometer.

In the 17-18 centuries. the first steps were taken in the study of the regularities of atmospheric processes. Of the works of this time, one should single out the meteorological studies of M. V. Lomonosov and B. Franklin, who paid special attention to the study of atmospheric electricity. In the same period, instruments for measuring wind speed, precipitation, air humidity, and other meteorological quantities were invented and improved. This made it possible to begin systematic observations of the state of the atmosphere with the help of instruments, first at individual points, and later (from the end of the 18th century) at a network of meteorological stations. A world network of meteorological stations conducting ground-based observations on the main part of the surface of the continents took shape in the middle of the 19th century.

Observations of the state of the atmosphere at various altitudes began in the mountains, and soon after the invention of the balloon (late 18th century) in the free atmosphere. From the end of the 19th century to observe meteorological values ​​at various heights, pilot balloons and balloons with self-recording instruments are widely used. In 1930, the Soviet scientist P. A. Molchanov invented the radiosonde, a device that transmits information about the state of the free atmosphere by radio. Subsequently, observations with the help of radiosondes became the main method for studying the atmosphere at a network of aerological stations. In the middle of the 20th century a world actinometric network has been formed, at the stations of which observations are made of solar radiation and its transformations on the earth's surface; methods were developed for observing the ozone content in the atmosphere, for the elements of atmospheric electricity, for the chemical composition of atmospheric air, etc. In parallel with the expansion of meteorological observations, climatology developed, based on the statistical generalization of observational materials. A. I. Voeikov, who studied a number of atmospheric phenomena: the general circulation of the atmosphere, moisture circulation, snow cover, and others, made a great contribution to the construction of the foundations of climatology.

In the 19th century empirical studies of atmospheric circulation were developed in order to substantiate the methods of weather forecasts. The work of W. Ferrel in the USA and H. Helmholtz in Germany marked the beginning of research in the field of the dynamics of atmospheric motions, which were continued at the beginning of the 20th century. Norwegian scientist V. Bjerknes and his students. Further progress in dynamic meteorology was marked by the creation of the first method of numerical hydrodynamic weather forecasting, developed by the Soviet scientist I. A. Kibel, and the subsequent rapid development of this method.

In the middle of the 20th century The methods of dynamic meteorology have been greatly developed in the study of the general circulation of the atmosphere. With their help, American meteorologists J. Smagorinsky and S. Manabe built world maps of air temperature, precipitation, and other meteorological quantities. Similar studies are being carried out in many countries, they are closely related to the International Program for the Study of Global Atmospheric Processes (GARP). Considerable attention in modern meteorology is given to the study of physical processes in the surface air layer. In the 20-30s. these studies were started by R. Geiger (Germany) and other scientists with the aim of studying the microclimate; later they led to the creation of a new branch of meteorology - the physics of the boundary layer of air. A large place is occupied by research on climate change, in particular the study of the increasingly noticeable influence of human activities on climate.

Meteorology in Russia reached a high level already in the 19th century. In 1849, the Main Physical (now Geophysical) Observatory, one of the world's first scientific meteorological institutions, was founded in St. Petersburg. G. I. Vild, who directed the observatory for many years in the second half of the 19th century, created in Russia an exemplary system of meteorological observations and a weather service. He was one of the founders of the International Meteorological Organization (1871) and chairman of the international commission for the 1st International Polar Year (1882-83). During the years of Soviet power, a number of new scientific meteorological institutions were created, including the Hydrometeorological Center of the USSR (formerly the Central Institute of Forecasts), the Central Aerological Observatory, the Institute of Atmospheric Physics of the USSR Academy of Sciences, and others.

A. A. Fridman was the founder of the modern school of dynamic meteorology. In his studies, as well as in later works by N. E. Kochin, P. Ya. Kochina, E. N. Blinova, G. I. Marchuk, A. M. Obukhov, A. S. Monin, M. I. Yudina et al. studied the regularities of atmospheric movements of various scales, proposed the first models of climate theory, and developed a theory of atmospheric turbulence. K. Ya. Kondratiev's works were devoted to the regularities of radiation processes in the atmosphere.

In the works of A. A. Kaminsky, E. S. Rubinshtein, B. P. Alisov, O. A. Drozdov, and other Soviet climatologists, the climate of our country was studied in detail and the atmospheric processes that determine climatic conditions were investigated. In the studies carried out at the Main Geophysical Observatory, the heat balance of the globe was studied and atlases were prepared containing world maps of the balance components. Works in the field of synoptic meteorology (V. A. Bugaev, S. P. Khromov, A. S. Zverev and others) contributed to a significant increase in the level of success of meteorological forecasts. In the studies of agrometeorologists (G. T. Selyaninov, F. F. Davitaia, and others), a justification was given for the optimal placement of agricultural crops. cultures in our country.

Significant results have been obtained in the Soviet Union in work on active influences on atmospheric processes. Experiments on influencing clouds and precipitation, begun by V. N. Obolensky, were widely developed in the postwar years. As a result of research conducted under the guidance of E.K. Fedorov, the first system was created that allows weakening hail damage over a large area.

Meteorology today

A characteristic feature of modern meteorology is the application in it of the latest achievements of physics and technology. Thus, meteorological satellites are used to observe the state of the atmosphere, which make it possible to obtain information on many meteorological quantities for the entire globe. For ground-based observations of clouds and precipitation, radar methods are used. The automation of meteorological observations and the processing of their data is finding increasing application. In research in theoretical meteorology, computers are widely used, the use of which was of tremendous importance for the development and improvement of numerical methods for weather forecasts. The use of quantitative physical methods of research is expanding in such areas of meteorology as climatology, agrometeorology, and human biometeorology, where previously they were almost never used.

Meteorology is most closely connected with oceanology and land hydrology. These three sciences study different links of the same processes of heat exchange and moisture exchange developing in the geographic envelope of the Earth. The connection of meteorology with geology and geochemistry is based on the common tasks of these sciences in the study of the evolution of the atmosphere and changes in the Earth's climates in the geological past. Modern meteorology makes extensive use of the methods of theoretical mechanics, as well as the materials and methods of many other physical, chemical, and technical disciplines.

One of the main tasks of Meteorology is weather forecasting for various periods. Short-range forecasts are especially necessary for aviation operations; long-term - are of great importance for agriculture. Since meteorological factors have a significant impact on many aspects of economic activity, materials on the climatic regime are needed to meet the demands of the national economy. The practical importance of active influences on atmospheric processes, including influences on cloudiness and precipitation, protection of plants from frost, etc., is rapidly growing.

Scientific and practical work in the field of meteorology is directed by the Hydrometeorological Service of the USSR, established in 1929.

The activities of the meteorological services of various countries are united by the World Meteorological Organization and other international meteorological organizations. International scientific conferences on various problems of meteorology are also held by the Association of Meteorology and Atmospheric Physics, which is part of the Geodetic and Geophysical Union. The largest meetings on meteorology in the Russian Federation were the All-Union Meteorological Congresses. Meteorological congresses have been held in Russia since 1900. The last congress was held in the USSR in 1971. The 6th All-Russian Meteorological Congress is intended to be the largest event in the new Russian history in the field of hydrometeorology and environmental monitoring, and it took place on October 14-16, 2009 Russia, St. Petersburg.

Works carried out in the field of Meteorology are published in meteorological journals.

The most important historical dates:

• end of the 17th century (under Peter I) - constant observations of the weather began.
• 1715 - the first water measuring post in Russia, by order of Peter I on the Neva near the Peter and Paul Fortress.
• On April 10, 1722, by decree of Peter the Great, systematic observations of the weather began in St. Petersburg. The records were kept by Vice Admiral Cornelius Kruys. At first, the entries were rather stingy with interesting information and looked something like this: “April, 22, Sunday. In the morning the wind is northwest; water is the same as mentioned above. Cloudy and chilly… in the afternoon a small northwest wind and rain in the afternoon. Quiet and red day until evening. Later observations took on a more scientific character.
• In 1724, the first meteorological station in Russia was formed, and from December 1725, observations were made at the Academy of Sciences using a barometer and a thermometer.
• 30s of the XVIII century. - a network of 20 meteorological stations was created (“Great Northern Expedition”).
• April 1, 1849 - the "Main Physical Observatory" (GFO) was established in St. Petersburg. (Now the "Main Geophysical Observatory" named after A. I. Voeikov (GGO)).
• 70s of the XIX century. - massive development of a network of hydrological observation points on large rivers and lakes.
• January 1, 1872 - The HFO began to create daily synoptic maps of Europe and Siberia and to issue a meteorological bulletin (the date is considered to be the birthday of the weather service in Russia).
• 1892 - The Meteorological Monthly began to appear.
• June 21, 1921 - V. I. Lenin signed a decree "On the organization of a meteorological service in the RSFSR."
• August 1929 - Decree of the Council of People's Commissars of the USSR on the organization of a unified Hydrometeorological Service. The creator and leader is A.F. Vangengeim, chairman of the Hydrometeorological Committee under the Council of People's Commissars of the USSR.
• January 1, 1930 - The "Central Weather Bureau" began operations.

Where do meteorologists work

• Bodies of the Russian Federal Service for Hydrometeorology and Environmental Monitoring (departments of weather forecasting, climatology, agricultural meteorology).
• Prognostic divisions of civil and military aviation.
• Regional centers for collection, control and analysis of information on the state of the air environment.
• Network of meteorological, aerological and actinometric stations.
• Research institutions that study climate patterns and develop forecasts of climate change.

What do meteorologists do

A significant part of meteorologists is engaged in weather forecasting. They work in government and military organizations and private companies that provide forecasts for aviation, navigation, agriculture, construction, and also broadcast them on radio and television.

Other professionals monitor pollution levels, provide advice, teach or do research. In meteorological observations, weather forecasting and scientific research, electronic equipment is becoming increasingly important.

Professional practice consists in:

• research: participation in the development of physical and mathematical models of the general circulation of the atmosphere and climate, including the interaction of the atmosphere and the ocean, in their comparison with observations, analysis of sensitivity to various natural factors; the study of physical and chemical processes occurring in the atmosphere and during its interaction with the earth's surface and the biosphere; implementation of the geographical and physical analysis of atmospheric processes and phenomena, their classification, the establishment of empirical dependencies and patterns; study of the transfer, transformation and removal of industrial and other pollutants emitted into the atmosphere;
• operational and production: assessment of the impact of meteorological factors on the state of the environment and development of recommendations for their rational consideration for the purposes of nature protection; meteorological substantiation of the designed structures of airports, location of construction, etc.; participation in the environmental impact assessment of projects;
• design and production: organization and conduct of special meteorological observations; conducting operational weather forecasts of various lead times and collecting the necessary information; assessment of the impact of existing and expected meteorological conditions on agriculture, fisheries and production activities of all types of transport;
• pedagogical (subject to the development of a pedagogical training program): teaching meteorological disciplines in universities and secondary specialized educational institutions; educational and auxiliary work in universities.

A meteorologist who has mastered the basic educational program of higher professional education can continue his education in graduate school in the specialties "Meteorology, climatology and agrometeorology", "Geoecology", and other related specialties, as well as in the master's program in the direction of "Hydrometeorology".

The weather is constantly changing, its changes are subject to complex laws, not yet fully known by people. No matter how calm she is, at any moment you can expect surprises from her. A meteorologist, especially a weather forecaster, never has to deal with the same situation, with the same weather: the variety of meteorological conditions in nature is so great that no one has ever seen two identical weather maps. The analysis of any situation reflected by the weather map of any day is always a new task that has not been encountered before. You really can't get bored with the weather!

Another attractive feature of the work of a meteorologist deserves to be noted: he has colleagues almost anywhere in the world. One can note the amazing ease of communication between colleagues meteorologists who have never seen each other before, wherever they meet - in a taiga village in Eastern Siberia or on the passes of the Gissar Range in Central Asia, in the Western Caucasus nature reserve or in the villages of the Alazani Valley, in Georgia, in the Romanian port of Constanta, in Bulgarian cities in the Danube valley, in Serbian and Hungarian villages, at American scientific stations in Antarctica, in tropical Australia in subtropical New Zealand, in the Brazilian jungle, the Argentinean savannah, in the Swiss Alps and the French Jura ...

One cannot discount the awareness of the importance of the work of a meteorologist, the results of which are needed by all branches of the national economy. The constant interest of all sections of the country's population in meteorological information makes the work of meteorologists doubly interesting.

The profession of a meteorologist is one of the relatively rare, non-mass and to some extent romantic professions: meteorologists are indispensable participants in various expeditions, they spend the winter at polar stations, work in sparsely populated areas, on high mountain plateaus and passes, on board ocean ships, on airfields, they fly in planes and balloons, etc., etc. All this is true, indeed meteorologists are ubiquitous, they have to go to places where people of other professions cannot hope to go under any circumstances. But still, this is not the main distinguishing feature of the work of a meteorologist, which is far from always as romantic as it might seem at first glance, and almost always requires punctuality, perseverance and perseverance in the performance of everyday, everyday duties. The main requirement for the work of a meteorologist of any qualification is objectivity. Objectivity in the performance of observations, a significant part of which are made visually and the results of which are documented by only one meteorological observer and can neither be verified nor corrected if inaccuracy or error is made. Objectivity in processing the results of observations, the accuracy of their recording in international code numbers, making them available to the whole world. The objectivity of the analysis of the entire amount of observational data, the minimization of subjectivity in their assessment - this is the key to the success of all types of providing consumers with meteorological information, including the success of weather forecasts compiled on the basis of this analysis ... The second feature of the work of a meteorologist is constant attention to the object observations, study and analysis, the inability to be distracted, at least for a while, to do something else. A meteorologist at work - hourly weather, he is on watch that cannot be left for a minute. He is obliged to monitor all changes in the weather, no matter how insignificant they may be, to record all these changes and to read. A meteorologist monitors the sky constantly, even when not at work. Wherever he is and whatever happens, he mentally evaluates everything that happens in the atmosphere before his eyes. However, there is no profession that is more international than that of a meteorologist. The very idea of ​​performing weather observations, collecting, processing and disseminating meteorological information provides for international cooperation, without which it is not feasible. Indeed: weather phenomena develop over the earth's surface, regardless of state borders; the exchange of meteorological information is necessary on a global scale, and it is possible only if there is an international language that is generally accessible to all meteorological specialists, such as digital meteorological codes and standard symbols; the results of weather observations and all meteorological measurements should be comparable and comparable with each other, which requires a unified system of measures for the whole world, a unified methodology for making observations, standardizing instruments, observing the accuracy and timing of measurements of meteorological quantities. Meteorologists are people with special education. Among them are weather observers, weather radar operators, technicians, engineers and scientists. In the meteorological service, together with meteorologists, people of other specialties work - radio engineers, signalmen, mechanics, telemetry, electronics engineers, programmers and computer operators, and many others. Without their help, it is impossible to imagine the work of meteorologists, who today guard the weather.

Sections of meteorology

The main branch of Meteorology is atmospheric physics, which studies physical phenomena and processes in the atmosphere.

Chemical processes in the atmosphere are studied by atmospheric chemistry - a new, rapidly developing branch of meteorology.

The study of atmospheric processes by theoretical methods of hydroaeromechanics is a task of dynamic meteorology, one of the important problems of which is the development of numerical methods for weather forecasts.

Other sections of Meteorology are: the science of the weather and methods of its prediction - synoptic meteorology and the science of the Earth's climates - climatology, which has become an independent discipline. In these disciplines, both physical and geographical methods of research are used, but recently the physical directions in them have become leading. The influence of atmospheric factors on biological processes is studied by biometeorology, including agricultural meteorology and human biometeorology.

Atmospheric physics includes: physics of the surface layer of air, which studies processes in the lower layers of the atmosphere; aerology, devoted to processes in the free atmosphere, where the influence of the earth's surface is less significant; physics of the upper layers of the atmosphere, considering the atmosphere at altitudes of hundreds of kilometers, where the density of atmospheric gases is very low. Aeronomy is the study of the physics and chemistry of the upper layers of the atmosphere. The physics of the atmosphere also includes actinometry, which studies solar radiation in the atmosphere and its transformations, atmospheric optics - the science of optical phenomena in the atmosphere, atmospheric electricity and atmospheric acoustics.

Specialty and profile "Meteorology" at ISU

Today, no one needs to be convinced that high-quality higher education is the key to a successful, secure future. It is necessary for every person in the modern world in order to succeed and realize themselves. Irkutsk State University (ISU) provides an opportunity to get a full-fledged higher education in the field of hydrometeorology that meets international norms and standards.

There are three main specialties in which meteorologists are trained: meteorological proper, climatological and agrometeorological. There are several specializations within the meteorological specialty: weather forecasting, aerology, marine meteorology, aviation meteorology, radio meteorology, meteorological instrumentation and weather prediction (solution of forecasting problems by numerical methods using a computer). Forecasters are engaged in compiling weather forecasts, aerologists - in the study of the state of the atmosphere at altitudes, marine meteorologists - in providing meteorological information for maritime transport, and aviation meteorologists - in air transport. Radio meteorologists are working on the use of various radio technical means for studying the atmosphere. In recent years, there has been a trend towards the development of another specialization - satellite meteorology, which is dictated by the ever-increasing need for the use of information from meteorological satellites for the needs of the national economy.

During the training of meteorologists at the Department of Meteorology and Atmosphere Protection, both the most advanced technologies for analyzing meteorological information and time-tested methods are studied. The former include modeling of climatic processes, weather prediction using neural networks, the latter - the usual statistical analysis, but with the involvement of modern software and computer equipment.

At the initial stages, students receive basic information from statistics and acquire skills in working on personal computers. Further training is based on deepening the received data and teaching other skills. So, for the statistical analysis of numerical series, which are the series of measurements of meteorological characteristics, the packages of StatSoft STATISTICA and Goldern SoftWare Grapher are used. The first one has the potential for the most complete analysis of numerical series using most of the known statistical approaches, and the second one presents these series in the form of a graph so that the trends in the behavior of one or another meteorological characteristic become clear.

In the senior years, students are taught the technologies that are being introduced into modern weather services. These include, first of all, geographic information systems (GIS). Based on data received twice a day from the World Data Centers in Moscow and Washington, students build and process meteorological maps. These maps show isotherms, isobars, and atmospheric fronts. Prognostic maps of various lead times are built and much more.

Promising areas are paleoclimatology (the ancient climates of the Earth), biometeorology (the impact of climatic conditions on living organisms, Chizhevsky's solar activity cycles), medical climatology (life and economic activity of people in different climatic zones of the Earth), weather forecast based on satellite meteorology, military meteorology ( development of the so-called climate weapons), planetary meteorology (the study of the atmospheres of Venus, Mars, Jupiter, Saturn and their satellites), the problems of global warming and ozone holes on Earth, computer modeling of meteorological and climatic processes.

Specialists need to know physics, mathematics and computer science well, therefore, at the Department of Meteorology and Atmospheric Protection, physics and mathematics are given no less attention than geography itself!

Meteorology (from the Greek metéōros - raised up, heavenly, metéōra - atmospheric and celestial phenomena and ... Logia

the science of the atmosphere and the processes occurring in it. The main section of M. - Atmospheric physics , investigating physical phenomena and processes in the atmosphere. Chemical processes in the atmosphere are studied by atmospheric chemistry - a new, rapidly developing section of M. The study of atmospheric processes by theoretical methods of hydroaeromechanics (See Hydroaeromechanics) - the problem of dynamic meteorology (See Dynamic meteorology) , one of the important problems of which is the development of numerical methods for weather forecasts (See weather forecast). Dr. The sections of meteorology are: the science of the weather and the methods of its prediction - Synoptic meteorology and the science of the Earth's climates - Climatology , developed into an independent discipline. In these disciplines, both physical and geographical methods of research are used, but recently the physical directions in them have become leading. The influence of atmospheric factors on biological processes is studied by biometeorology, including page - x. M. and human biometeorology.

Atmospheric physics includes: physics of the surface layer of air, which studies processes in the lower layers of the atmosphere; Aerology , devoted to processes in the free atmosphere, where the influence of the earth's surface is less significant; physics of the upper atmosphere, considering the atmosphere at altitudes of hundreds and thousands km, where the density of atmospheric gases is very low. Aeronomy deals with the study of the physics and chemistry of the upper layers of the atmosphere. Atmospheric physics also includes Actinometry , studying solar radiation in the atmosphere and its transformations, Atmospheric optics - the science of optical phenomena in the atmosphere, Atmospheric electricity and Atmospheric acoustics.

The first researches in the field of M. belong to antique time (Aristotle). The development of meteorology accelerated from the first half of the 17th century, when the Italian scientists G. Galilei and E. Torricelli developed the first meteorological instruments, the barometer and thermometer.

In the 17-18 centuries. the first steps were taken in the study of the regularities of atmospheric processes. Of the works of this time, one should single out the meteorological studies of M. V. Lomonosov and B. Franklin, who paid special attention to the study of atmospheric electricity. In the same period, instruments for measuring wind speed, precipitation, air humidity, and other meteorological elements were invented and improved. This made it possible to begin systematic observations of the state of the atmosphere with the help of instruments, first at individual points, and later (from the end of the 18th century) at a network of meteorological stations. A world network of meteorological stations conducting ground-based observations on the main part of the surface of the continents took shape in the middle of the 19th century.

Observations of the state of the atmosphere at various altitudes began in the mountains, and soon after the invention of the balloon (late 18th century) in the free atmosphere. From the end of the 19th century Pilot balloons and sounding balloons with self-recording instruments are widely used to observe meteorological elements at various heights. In 1930, the Soviet scientist P. A. Molchanov invented the Radiosonde, a device that transmits information about the state of the free atmosphere by radio. Subsequently, observations with the help of radiosondes became the main method for studying the atmosphere at a network of aerological stations. In the middle of the 20th century a world actinometric network has been formed, at the stations of which observations are made of solar radiation and its transformations on the earth's surface; methods were developed for observing the ozone content in the atmosphere, for the elements of atmospheric electricity, for the chemical composition of atmospheric air, etc. In parallel with the expansion of meteorological observations, climatology developed, based on the statistical generalization of observational materials. A great contribution to the foundations of climatology was made by A. I. Voeikov, who studied a number of atmospheric phenomena: the general circulation of the atmosphere (see Atmospheric circulation), Moisture circulation , snow cover, etc.

In the 19th century empirical studies of atmospheric circulation were developed in order to substantiate the methods of weather forecasts. The work of W. Ferrel in the USA and H. Helmholtz in Germany marked the beginning of research in the field of the dynamics of atmospheric motions, which were continued at the beginning of the 20th century. Norwegian scientist V. Bjerknes and his students. Further progress in dynamic weather was marked by the creation of the first method for numerical hydrodynamic weather forecasting, developed by the Soviet scientist I. A. Kibel, and the subsequent rapid development of this method.

In the middle of the 20th century methods of dynamic meteorology have been greatly developed in the study of the general circulation of the atmosphere. With their help, the American meteorologists J. Smagorinsky and S. Manabe built world maps of air temperature, precipitation, and other meteorological elements. Similar research is underway in many countries and is closely linked to the International Global Atmospheric Research Program (GAPAP). Considerable attention in modern mathematics is given to the study of physical processes in the surface layer of air. In the 20-30s. these studies were started by R. Geiger (Germany) and other scientists with the aim of studying the microclimate; later they led to the creation of a new section of mathematics - the physics of the boundary layer of air. A large place is occupied by research on climate change, in particular the study of the increasingly noticeable influence of human activities on climate.

M. in Russia reached a high level already in the 19th century. In 1849, the Main Physical (now Geophysical) Observatory, one of the world's first scientific meteorological institutions, was founded in St. Petersburg. G. I. Wild , who directed the observatory for many years in the second half of the 19th century, created in Russia an exemplary system of meteorological observations and a weather service. He was one of the founders of the International Meteorological Organization (1871) and chairman of the international commission for the 1st International Polar Year (1882-83). Over the years of the Soviet The authorities created a number of new scientific meteorological institutions, including the Hydrometeorological Center of the USSR (formerly the Central Institute of Forecasts), the Central Aerological Observatory, the Institute of Atmospheric Physics of the Academy of Sciences of the USSR, etc.

The founder of the owls school of dynamic M. was A. A. Fridman. In his studies, as well as in later works by N. E. Kochin, P. Ya. Kochina, E. N. Blinova, G. I. Marchuk, A. M. Obukhov, A. S. Monin, M. I. Yudina et al. studied the regularities of atmospheric movements of various scales, proposed the first models of climate theory, and developed a theory of atmospheric turbulence. K. Ya. Kondratiev's works were devoted to the regularities of radiation processes in the atmosphere.

In the works of A. A. Kaminsky, E. S. Rubinshtein, B. P. Alisov, O. A. Drozdov, and other Soviet climatologists, the climate of our country was studied in detail and the atmospheric processes that determine climatic conditions were investigated. In the studies carried out at the Main Geophysical Observatory, the heat balance of the globe was studied and atlases were prepared containing world maps of the balance components. Work in the field of synoptic weather (V. A. Bugaev, S. P. Khromov, and others) contributed to a significant increase in the level of success in meteorological forecasts. In the studies of owls. agrometeorologists (G. T. Selyaninov, F. F. Davitaia, and others) substantiated the optimal placement of agricultural crops. cultures in our country.

Significant results have been obtained in the Soviet Union in work on active influences on atmospheric processes. Experiments on influencing clouds and precipitation, begun by VN Obolenskii, were widely developed in the postwar years. As a result of research conducted under the guidance of E.K. Fedorov, the first system was created that allows weakening hail damage over a large area.

A characteristic feature of modern mathematics is the use in it of the latest achievements in physics and technology. Thus, for observing the state of the atmosphere, meteorological satellites are used, which make it possible to obtain information on many meteorological elements for the entire globe. For ground-based observations of clouds and precipitation, radar methods are used (see Radar in meteorology). The automation of meteorological observations and the processing of their data is finding increasing application. In research on theoretical weather, computers are widely used, the use of which was of great importance for improving the numerical methods of weather forecasting. The use of quantitative physical methods of research is expanding in such areas of mathematics as climatology, agrometeorology (see Agricultural meteorology), and human biometeorology (see Medical climatology), where previously they were almost never used.

Hydrology is most closely associated with oceanology and land hydrology. These three sciences study different links of the same processes of heat exchange and moisture exchange developing in the geographic envelope of the Earth. M.'s connection with geology and geochemistry is based on the general tasks of these sciences in the study of the evolution of the atmosphere and changes in the Earth's climates in the geological past. Modern mechanics makes extensive use of the methods of theoretical mechanics, as well as the materials and methods of many other physical, chemical, and technical disciplines.

One of the main tasks of M. is the weather forecast for various periods. Short-range forecasts are especially necessary for aviation operations; long-term - are of great importance for agriculture. Since meteorological factors have a significant impact on many aspects of economic activity, materials on the climatic regime are needed to meet the demands of the national economy. The practical importance of active influences on atmospheric processes, including influences on cloudiness and precipitation, protection of plants from frost, etc., is rapidly growing.

The activities of the meteorological services of various countries are united by the World Meteorological Organization and other international meteorological organizations. International scientific conferences on various problems of meteorology are also held by the Association of Meteorology and Atmospheric Physics, which is part of the Geodetic and Geophysical Union. The largest conferences on meteorology in the USSR are the All-Union Meteorological Congresses; the last (5th) congress took place in June 1971 in Leningrad. Work carried out in the area of ​​meteorology is published in meteorological journals (see Meteorological journals).

Lit.: Khrgian A. Kh., Essays on the development of meteorology, 2nd ed., vol. 1, L., 1959; Meteorology and hydrology for 50 years of Soviet power, ed. Edited by E. K. Fedorova. Leningrad, 1967. Khromov S.P., Meteorology and climatology for geographical faculties, L., 1964; Tverskoy P. N., Course of meteorology, L., 1962; Matveev L. T., Fundamentals of General Meteorology, Atmospheric Physics, L., 1965; Fedorov E.K., Hourly weather, [L.], 1970.

M. I. Budyko.

Great Soviet Encyclopedia. - M.: Soviet Encyclopedia. 1969-1978 .

Synonyms:

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Meteorology… Spelling Dictionary

- (Greek meteorologia, from meteoros meteor, and I say lego). The science of air phenomena, meteors; studies the phenomena occurring in the atmosphere. Dictionary of foreign words included in the Russian language. Chudinov A.N., 1910. METEOROLOGY Greek ... ... Dictionary of foreign words of the Russian language

Meteorology- Meteorology: the science of the atmosphere about its structure, properties and physical processes occurring in it, one of the geophysical sciences (the term atmospheric sciences is also used). Note The main disciplines of meteorology are dynamic, ... ... Official terminology

meteorology- and, well. meteorologie, c. meteorology. The science that studies the physical state of the earth's atmosphere and the processes occurring in it. BAS 1. Meteorology is the science of phenomena in the air. Corypheus 1 24. Not a single science has represented until now ... ... Historical Dictionary of Gallicisms of the Russian Language

- (from the Greek. meteora atmospheric phenomena and ... logic) the science of the earth's atmosphere and the processes occurring in it. The main branch of meteorology is atmospheric physics. Meteorology studies the composition and structure of the atmosphere; heat transfer and thermal regime in the atmosphere and ... Big Encyclopedic Dictionary

- (Meteorology) department of geophysics, which studies all phenomena occurring in the gaseous shell of the globe, i.e. in the atmosphere. Samoilov K.I. Marine Dictionary. M. L .: State Naval Publishing House of the NKVMF of the USSR, 1941 ... ... Marine Dictionary