Climatic features. Earth's climates. Temperate maritime climate

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if you remove all the lies from history, this does not mean that only the truth will remain; as a result, there may be nothing left at all Stanislav Jerzy Lec Our recent video of 10 buried cities has gained a million views and, as promised, we will soon make a continuation. If you watched our previous video, give it a thumbs up if not. look at the link at the top today we will talk about the climate about which historians, as usual, do not tell us something, well, the work they have is such an operation on written sources before the 18th century, you need to be very careful because there is nothing easier than forging paper, it is much more difficult to forge buildings, for example and we will not rely on the evidence of which it is almost impossible to falsify and we must consider these facts not separately but in aggregate about the climate of the 18th century and earlier, a lot can be said from those buildings and structures that were built at that time, all the facts that we have accumulated indicate that that most of the palaces and mansions that were built before the nineteenth century were built for a different, warmer climate; in addition, we found other evidence of a sharp climate change; be sure to watch the video to the end; a very large area of ​​​​windows; the partition between the windows is equal to or even less than the width of the windows themselves; and the windows themselves very tall, stunning, huge building, but as we are assured, this is a summer palace; it was built supposedly to come here exclusively in the summer; the version is funny, considering that summer in St. Petersburg is quite cool and short-lived; if you look at the façade of the palace, you can clearly see a very large area of ​​windows, which is typical for southern hot regions, they are for the northern territories, if in doubt, make such windows in your house and then look at the heating bills and the questions will immediately disappear later, at the beginning of the 19th century, an extension was made to the palace where the famous lyceum is located where Alexander Sergeevich Pushkin studied, the extension differs not only architectural style, but also by the fact that it was already built for new climatic conditions, the area of ​​​​the windows is noticeably smaller; in many buildings, a heating system was not initially planned and was later built into the finished building; there is a lot of evidence for this; here, researchers Artem Vaidenkov clearly shows that initially there were no stoves in churches it was not provided for, well, the designers were apparently forgetful; the churches themselves were designed all over the country almost according to a standard design, but they forgot to provide for stoves; chimneys were hollowed out in the walls and rather carelessly and then sealed up, also clearly on a quick fix apparently the builders of the hollowed out chimneys had no time for beauty then, you can see the soot and soot the stoves themselves, of course, were stolen a long time ago, but there is no doubt that they were here, another example is what a cavalier looks like and a silver table stove was simply placed in a corner; wall decoration; presence of a stove in this corner ignores that is, it was done before she appeared there if you look at top part it is clear that it does not fit tightly to the wall because it is hampered by the figured gilded aril decoration of the top of the wall, and look at the size of the stove and the size of the rooms, the height of the ceilings in Catherine’s palace, do you believe that such stoves could somehow heat such a room, we are so accustomed to listening to opinions authorities that often, seeing obviously, we don’t believe our eyes, we’ll trust various experts who called themselves as such, but let’s try to abstract from the explanations of various historians, guides, local historians, that is, everything that is extremely easy to fake, distort, and just try to see someone’s fantasies and carefully look at what really is look at this photo, this is the building of the Kazan Kremlin, the building, as usual, is covered up to the windows on the horizon, there are no trees, but that’s not what we’re talking about now, pay attention to the building in the lower right corner, apparently this building has not yet been reconstructed for the new climatic conditions, the building on the left, as we can already see With chimneys and apparently they just haven’t gotten around to this building yet. If you find similar photos, share in the comments. The task of thermal vestibules is to prevent cold air from entering the main room with vestibules. The same story is that they are made from chimneys later than the buildings themselves; in these frames it is clearly visible that they don’t fit into the architectural ensemble of the buildings in any way; the vestibules are made of a different material; apparently it was very cold then; there’s no time for frills; somewhere the vestibules were made as elegantly as possible and matched to the style of the building; and somewhere else they didn’t bother at all and made a blunder; you can see in these frames that in old photographs of the temple there is no vestibule, but now there is one and the average person will never understand that something was once rebuilt here, here is another similar example; in the old photo there is no vestibule, but now there is one. Why are these thermal vestibules suddenly needed so much for beauty or maybe this was the fashion then for the vestibule, don’t rush to draw conclusions first, look at other facts further, what’s more interesting is the lack of waterproofing for those who don’t know what waterproofing is, this is protection of the underground part of the house from moisture, if you don’t waterproof it, the foundation will quickly become unusable from changes temperatures, since water tends to expand when it freezes, a brick that freezes then thaws, then heats up in the sun, then freezes again, this is what happens to the foundation if you don’t waterproof the building, it will quickly collapse. This situation is observed everywhere. The builders of the past certainly weren’t fools if they could build similar buildings. which we told you in one of our videos, look at the link at the top and in the description of the video, but why didn’t the designers provide waterproofing? They didn’t know that water expands when it freezes and this majestic building will collapse in a few years; I hardly believe it, but you can forget to do waterproofing in several buildings, but not everywhere, the change in the angle of inclination of the roof in these frames shows that the roof used to be of a different shape, why was it necessary to change the shape of the roof to a sharper one, if not so that snow would roll off it better and that the designers and builders did not know before that we have sometimes there is snow and the roof needs to be sharpened right away or they forgot again or maybe everything is simpler, maybe when the building was built there was no snow at all and when the snow appeared and there was a threat of the roof collapsing or the roof had already collapsed then and there was a need to change the angle of inclination then just about the snow absence of snow in engravings and paintings before the nineteenth century, the researcher analyzed the paintings and engravings did not find winter in them, a link to the study will be in the description, try to find on the Internet at least one engraving made before the nineteenth century that depicts snow, I emphasize made before the 19th century, look carefully at the date of birth artists and keep in mind that in history there is such a thing as chronological shifts, we talked about this in the video of antiquity to the Middle Ages, be sure to look at the link in the description, in order to replace the events of the past, just make a remake of some document and pass it off as antiquity, that is, do it retroactively, if you know lawyers, then ask how do they make a palm tree in the engravings of Astrakhan today in Astrakhan there are no palm trees except for the botanical garden and private greenhouses, but before the seventeenth century palm trees grew there everywhere, you don’t believe it, but take it yourself and google the engraving of Astrakhan 17th century and any search engine will give you these engravings, well that we will believe our own eyes or from the strokes of pundits who have hung regalia on themselves, the palm trees already in Peterhof the building looks abandoned, but what do we see around them from where in the northern capital of the palm trees and here is another photo of a palm tree growing, it would seem, on an abandoned building in an arboretum or greenhouse this obviously they don’t look like where the palm trees are from, maybe there used to be a greenhouse there and then it was dismantled, it also doesn’t look like it, in any case, if we consider this fact separately, you can argue something like it was dreamers who drew engravings and they planted a palm tree to make it beautiful photos or give another similar childish explanation, and if combined with all the previously given facts, then the presence of the field is quite easily explained by the mammoth in the 19th century on our channel there was a video clip, be sure to look at the link in the description for the word mammoths are tropical animals herbivores in winter they cannot survive because they there will simply be nothing to eat in our video we prove that mammoths lived back in the 19th century and how could they live if there was a climate like today in such a climate in the winter they simply would not have found food for themselves, but if we assume that the climate was different then the existence of mammoths in The 19th century does not seem such a seditious statement and is very consistent with all the previously listed facts. Well, just for a second, admit the thought, what if the historians really lied and you, based on their statement, are mistaken, and we are independent researchers whom no one funds, we really tell you the truth a year without a summer networks with a wealth of information about the so-called year without a summer the year without a summer nickname 1816 in which unusually cold weather reigned in Western Europe and North America today it remains the coldest year first documenting meteorological observations of the United States I also nicknamed it rating handle and frozen there which translates as 1800 frozen to death, this is another puzzle in the mosaic, and global cooling also has information that in central Russia back in the 18th and 19th centuries, pineapple and other tropical fruits were grown, but we have not found documentary evidence for this, if anyone has one, throw it in comments on the video in this way we, as investigators, collect information bit by bit and put together a general picture of events and it turns out to be a little shocking and indicates a catastrophic event that happened in the recent past which we have already talked about in one of our videos, the link is, as always, at the top if you want a continuation of this series, be sure to put your finger up, write comments and share this video with your friends on social networks, and of course, don’t forget to subscribe to us and put notifications so as not to miss new seditious videos, and we’ll see you soon for today

Study methods

To draw conclusions about climate features, long-term weather observation series are needed. In temperate latitudes they use 25-50-year trends, in tropical latitudes they are shorter. Climatic characteristics are derived from observations of meteorological elements, the most important of which are atmospheric pressure, wind speed and direction, air temperature and humidity, cloudiness and precipitation. In addition, they study the duration of solar radiation, the duration of the frost-free period, visibility range, temperature upper layers soil and water in reservoirs, evaporation of water from the earth's surface, height and condition of snow cover, all kinds of atmospheric phenomena, total solar radiation, radiation balance and much more.

Applied branches of climatology use the climate characteristics necessary for their purposes:

• in agroclimatology - the sum of temperatures during the growing season;
• in bioclimatology and technical climatology - effective temperatures;

Complex indicators are also used, determined by several basic meteorological elements, namely all kinds of coefficients (continentality, aridity, moisture), factors, indices.

Long-term average values ​​of meteorological elements and their complex indicators (annual, seasonal, monthly, daily, etc.), their sums, return periods are considered climatic norms. Discrepancies with them in specific periods are considered deviations from these norms.

Atmospheric general circulation models are used to assess future climate changes [ ] .

Climate-forming factors

The climate of the planet depends on a whole complex of astronomical and geographical factors that influence the total amount of solar radiation received by the planet, as well as its distribution across seasons, hemispheres and continents. With the beginning of the industrial revolution, human activity becomes a climate-forming factor.

Astronomical factors

Astronomical factors include the luminosity of the Sun, the position and movement of the planet Earth relative to the Sun, the angle of inclination of the Earth’s axis of rotation to the plane of its orbit, the speed of rotation of the Earth, and the density of matter in the surrounding outer space. The rotation of the Earth around its axis causes daily changes in weather, the movement of the Earth around the Sun and the inclination of the axis of rotation to the orbital plane cause seasonal and latitudinal differences weather conditions. The eccentricity of the Earth's orbit - affects the distribution of heat between the Northern and Southern Hemispheres, as well as the magnitude of seasonal changes. The speed of rotation of the Earth practically does not change and is a constantly acting factor. Due to the rotation of the Earth, trade winds and monsoons exist, and cyclones are also formed. [ ]

Geographical factors

TO geographical factors relate

Effect of solar radiation

The most important element of climate, influencing its other characteristics, primarily temperature, is the radiant energy of the Sun. The enormous energy released in the process of nuclear fusion on the Sun is radiated into outer space. Power solar radiation, received by the planet, depends on its size and distance from the Sun. The total flux of solar radiation passing per unit time through a unit area oriented perpendicular to the flux, at a distance of one astronomical unit from the Sun outside the earth’s atmosphere, is called the solar constant. At the top of the earth's atmosphere, every square meter, perpendicular to the sun's rays, receives 1,365 W ± 3.4% of solar energy. Energy varies throughout the year due to the ellipticity of the Earth's orbit; the greatest power is absorbed by the Earth in January. Although about 31% of the radiation received is reflected back into space, the remainder is sufficient to maintain atmospheric and ocean currents, and to provide energy for almost all biological processes on Earth.

The energy received by the earth's surface depends on the angle of incidence of the sun's rays, it is greatest if this angle is right, but most of the earth's surface is not perpendicular to the sun's rays. The inclination of the rays depends on the latitude of the area, time of year and day; it is greatest at noon on June 22 north of the Tropic of Cancer and on December 22 south of the Tropic of Capricorn; in the tropics the maximum (90°) is reached twice a year.

Another important factor determining latitudinal climate regime, is the length of daylight hours. Beyond the polar circles, that is, north of 66.5° N. w. and south of 66.5° S. w. The length of daylight hours varies from zero (in winter) to 24 hours in summer, at the equator all year round 12 hour day. Because seasonal changes in slope and day length are more pronounced at higher latitudes, the amplitude of temperature fluctuations throughout the year decreases from the poles to low latitudes.

The receipt and distribution of solar radiation over the surface of the globe without taking into account the climate-forming factors of a particular area is called solar climate.

The share of solar energy absorbed by the earth's surface varies markedly depending on cloud cover, surface type and terrain altitude, averaging 46% of that received in the upper atmosphere. Constantly present cloud cover, such as at the equator, helps to reflect most of the incoming energy. The water surface absorbs solar rays (except for very inclined ones) better than other surfaces, reflecting only 4-10%. The proportion of absorbed energy is higher than average in deserts located high above sea level due to the thinner atmosphere that scatters the sun's rays.

Atmospheric circulation

In the hottest places, the heated air has a lower density and rises, thus forming a zone of low atmospheric pressure. Similarly, a zone of high pressure is formed in colder places. Air movement occurs from an area of ​​high atmospheric pressure to an area of ​​low atmospheric pressure. Since the closer to the equator and further from the poles the area is located, the better it warms up, in the lower layers of the atmosphere there is a predominant movement of air from the poles to the equator.

However, the Earth also rotates on its axis, so the Coriolis force acts on the moving air and deflects this movement to the west. IN upper layers the troposphere is formed reverse movement air masses: from the equator to the poles. Its Coriolis force constantly deflects to the east, and the further, the more. And in areas around 30 degrees north and south latitude, the movement becomes directed from west to east, parallel to the equator. As a result, the air that reaches these latitudes has nowhere to go at such a height, and it sinks down to the ground. This is where the area of ​​highest pressure forms. In this way, trade winds are formed - constant winds blowing towards the equator and to the west, and since the turning force acts constantly, when approaching the equator, the trade winds blow almost parallel to it. Air currents in the upper layers, directed from the equator to the tropics, are called anti-trade winds. Trade winds and anti-trade winds, as it were, form an air wheel through which a continuous air circulation is maintained between the equator and the tropics. Between the trade winds of the Northern and Southern Hemispheres lies the Intertropical Convergence Zone.

During the year, this zone shifts from the equator to the warmer summer hemisphere. As a result, in some places, especially in the Indian Ocean basin, where the main direction of air transport in winter is from west to east, it is replaced by the opposite direction in summer. Such air transfers are called tropical monsoons. Cyclonic activity connects the tropical circulation zone with the circulation in temperate latitudes and an exchange of warm and cold air occurs between them. As a result of inter-latitudinal air exchange, heat is transferred from low latitudes to high latitudes and cold from high latitudes to low latitudes, which leads to the preservation of thermal equilibrium on Earth.

In fact, atmospheric circulation is constantly changing, both due to seasonal changes in the distribution of heat on the earth's surface and in the atmosphere, and due to the formation and movement of cyclones and anticyclones in the atmosphere. Cyclones and anticyclones move generally towards the east, with cyclones deflecting towards the poles and anticyclones deflecting away from the poles.

Climate types

The classification of Earth's climates can be done either directly climatic characteristics(classification by W. Keppen), and based on the characteristics of the general circulation of the atmosphere (classification by B. P. Alisov), or on the nature of geographical landscapes (classification by L. S. Berg). The climatic conditions of the area are determined primarily by the so-called. solar climate - the influx of solar radiation to the upper boundary of the atmosphere, depending on latitude and varying at different times and seasons. Nevertheless, the boundaries of climate zones not only do not coincide with parallels, but do not even always circle the globe, while there are zones isolated from each other with the same type of climate. Also important influences are the proximity of the sea, the atmospheric circulation system and altitude.

The classification of climates proposed by the Russian scientist W. Koeppen (1846-1940) is widespread in the world. It is based on the temperature regime and the degree of humidification. The classification was repeatedly improved, and as amended by G. T. Trevart (English) Russian There are six classes with sixteen climate types. Many types of climates according to the Köppen climate classification are known by names associated with the vegetation characteristic of the type. Each type has precise parameters for temperature values, amounts of winter and summer precipitation, this makes it easier to classify a certain place as a certain type of climate, which is why the Köppen classification has become widespread.

On both sides of the low pressure band along the equator there are zones of high atmospheric pressure. The oceans are dominated here trade wind climate with constant easterly winds, the so-called. trade winds The weather here is relatively dry (about 500 mm of precipitation per year), with moderate cloudiness, in summer the average temperature is 20-27 °C, in winter - 10-15 °C. Precipitation increases sharply on the windward slopes of mountainous islands. Tropical cyclones are relatively rare.

These oceanic areas correspond to tropical desert zones on land with dry tropical climate. The average temperature of the warmest month in the Northern Hemisphere is about 40 °C, in Australia up to 34 °C. In northern Africa and inland California, the highest temperatures on Earth are observed - 57-58 ° C, in Australia - up to 55 ° C. In winter, temperatures drop to 10 - 15 °C. Temperature changes during the day are very large and can exceed 40 °C. There is little precipitation - less than 250 mm, often no more than 100 mm per year.

In many tropical regions - Equatorial Africa, South and Southeast Asia, northern Australia - the dominance of trade winds is changing subequatorial, or tropical monsoon climate. Here, in the summer, the intertropical convergence zone moves further north of the equator. As a result, the eastern trade wind transport of air masses is replaced by the western monsoon, which is responsible for the bulk of the precipitation that falls here. Predominant types of vegetation - monsoon forests, forest savannas and tall grass savannas

In the subtropics

In the zones of 25-40° northern latitude and southern latitude, subtropical climate types prevail, formed under conditions of alternating prevailing air masses - tropical in summer, moderate in winter. The average monthly air temperature in summer exceeds 20 °C, in winter - 4 °C. On land, the amount and regime of atmospheric precipitation strongly depend on the distance from the oceans, resulting in very different landscapes and natural areas. On each of the continents, three main climatic zones are clearly expressed.

In the west of the continents it dominates Mediterranean climate(semi-dry subtropics) with summer anticyclones and winter cyclones. Summer here is hot (20-25 °C), partly cloudy and dry, in winter it rains and is relatively cold (5-10 °C). The average annual precipitation is about 400-600 mm. In addition to the Mediterranean itself, such a climate prevails on the southern coast of Crimea, western California, southern Africa, and southwestern Australia. The predominant type of vegetation is Mediterranean forests and shrubs.

In the east of the continents it dominates monsoon subtropical climate. The temperature conditions of the western and eastern edges of the continents differ little. Heavy rainfall brought by the oceanic monsoon falls here mainly in summer.

Temperate zone

In the belt of year-round predominance of moderate air masses, intense cyclonic activity causes frequent and significant changes in air pressure and temperature. Predominance western winds most noticeable over the oceans and in the Southern Hemisphere. In addition to the main seasons - winter and summer, there are noticeable and fairly long transitional seasons - autumn and spring. Due to large differences in temperature and humidity, many researchers classify the climate of the northern part of the temperate zone as subarctic (Köppen classification), or classify it as an independent climate zone - boreal.

Subpolar

There is intense cyclonic activity over the subpolar oceans, the weather is windy and cloudy, and there is a lot of precipitation. Subarctic climate dominates in the north of Eurasia and North America, characterized by dry (precipitation no more than 300 mm per year), long and cold winters, and cold summers. Despite the small amount of precipitation, low temperatures and permafrost contribute to swamping of the area. Similar climate Southern Hemisphere - Subantarctic climate invades land only on the subantarctic islands and Graham's Land. In Köppen's classification, subpolar or boreal climate refers to the climate of the taiga growing zone.

Polar

Polar climate characterized by year-round negative air temperatures and scanty precipitation (100-200 mm per year). It dominates in the Arctic Ocean and Antarctica. It is mildest in the Atlantic sector of the Arctic, the most severe is on the plateau of East Antarctica. In Köppen's classification, the polar climate includes not only ice climate zones, but also the climate of the tundra zone.

Climate and people

Climate has a decisive impact on the water regime, soil, flora and fauna, and on the possibility of cultivating crops. Accordingly, the possibilities of human settlement, the development of agriculture, industry, energy and transport, living conditions and public health depend on the climate. Heat loss by the human body occurs through radiation, thermal conductivity, convection and evaporation of moisture from the surface of the body. With a certain increase in these heat losses, a person experiences discomfort and the possibility of illness appears. In cold weather, these losses increase; dampness and strong winds enhance the cooling effect. During weather changes, stress increases, appetite worsens, biorhythms are disrupted and resistance to diseases decreases. Climate determines the association of diseases with certain seasons and regions, for example, pneumonia and influenza are suffered mainly in winter in temperate latitudes, malaria is found in the humid tropics and subtropics, where climatic conditions favor the breeding of malaria mosquitoes. Climate is also taken into account in healthcare (resorts, epidemic control, public hygiene), and influences the development of tourism and sports. According to information from human history (famine, floods, abandoned settlements, migrations of people), it may be possible to restore some climate change of the past .

Anthropogenic changes in the operating environment of climate-forming processes change the nature of their occurrence. Human activities have a significant impact on the local climate. Heat influx due to fuel combustion, pollution from industrial activities and carbon dioxide, changing the absorption of solar energy, cause an increase in air temperature, noticeable in large cities. Among the anthropogenic processes that have taken global character, are

see also

Notes

1. (undefined) . Archived from the original on April 4, 2013.
2. , p. 5.
3. Local climate //: [in 30 volumes] / ch. ed. A. M. Prokhorov
4. Microclimate // Great Soviet encyclopedia: [in 30 volumes] / ch. ed. A. M. Prokhorov. - 3rd ed. - M.: Soviet Encyclopedia, 1969-1978.

Climatic conditions can change and transform, but general outline they remain the same, making some regions attractive for tourism and others difficult to survive. Understand existing types worth it for better understanding geographical features of the planet and a responsible attitude towards the environment - humanity may lose some zones during global warming and other catastrophic processes.

What is climate?

This definition refers to the established weather regime that distinguishes a particular area. It is reflected in the complex of all changes observed in the territory. Types of climate influence nature, determine the state of water bodies and soils, lead to the appearance of specific plants and animals, and influence the development of sectors of the economy and agriculture. Formation occurs as a result of exposure to solar radiation and winds in combination with the variety of surface. All these factors directly depend on geographical latitude, which determines the angle of incidence of the rays, and therefore the volume of heat received.

What influences the climate?

Various conditions (in addition to geographic latitude) can determine what the weather will be like. For example, proximity to the ocean has a strong impact. The further the territory is from big waters, the less precipitation it receives, and the more uneven it is. Closer to the ocean, the amplitude of fluctuations is small, and all types of climate in such lands are much milder than continental ones. Sea currents are no less significant. For example, they warm the coast of the Scandinavian Peninsula, which promotes the growth of forests there. At the same time, Greenland, which has a similar location, is covered with ice all year round. Strongly influences climate formation and relief. The higher the terrain, the lower the temperature, so the mountains can be cold even if they are in the tropics. In addition, the ridges can hold back, causing a lot of precipitation to fall on the windward slopes, while further on the continent there is noticeably less rainfall. Finally, it is worth noting the impact of winds, which can also seriously transform climate types. Monsoons, hurricanes and typhoons carry moisture and significantly influence the weather.

All existing types

Before studying each type separately, it is worth understanding the general classification. What are the main types of climate? The easiest way to understand this is to use the example of a specific country. The Russian Federation occupies a large area, and the weather varies greatly throughout the country. The table will help you study everything. The types of climates and the places where they prevail are distributed in it according to each other.

Continental climate

This weather prevails in regions located further beyond the maritime climate zone. What are its features? The continental type of climate is characterized by sunny weather with anticyclones and an impressive range of both annual and daily temperatures. Here summer quickly gives way to winter. Continental climate type can be further divided into moderate, harsh and normal. The most best example can be called the central part of the territory of Russia.

Monsoon climate

This type of weather is characterized by a sharp difference in winter and summer temperatures. In the warm season, the weather is formed under the influence of winds blowing onto land from the sea. Therefore, in summer the monsoon type of climate resembles a maritime one, with heavy rains, high clouds, humid air and strong winds. In winter, the direction of air masses changes. The monsoon type of climate begins to resemble the continental one - with clear and frosty weather and minimal precipitation throughout the season. Such options natural conditions characteristic of several Asian countries - found in Japan, the Far East and northern India.

Chapter III

Climatic characteristics of the seasons

Seasons of the year

Under the natural climate season. should be understood as a period of time of year, characterized by a similar code of meteorological elements and a certain thermal regime. The calendar boundaries of such seasons generally do not coincide with the calendar boundaries of the months and are to a certain extent arbitrary. The end of this season and the beginning of the next one can hardly be fixed by a specific date. This is a certain period of time on the order of several days, during which a sharp change occurs atmospheric processes, radiation regime, physical properties of the underlying surface and weather conditions.

Average long-term boundaries of seasons can hardly be tied to average long-term dates of transition of the average daily temperature through certain limits, for example, summer is counted from the day the average daily temperature exceeds 10° during the period of its increase, and the end of summer - from the date of the onset of the average daily temperature below 10 ° during the period of its decrease, as proposed by A. N. Lebedev and G. P. Pisareva.

In the conditions of Murmansk, located between a vast continent and the Barents Sea, when dividing the year into seasons, it is advisable to be guided by differences in temperature regimes over land and sea, which depend on the conditions of transformation of air masses over the underlying surface. These differences are most significant between November and March, when above Barents Sea air masses warm up and cool over the mainland, and from June to August, when the transformation of air masses over the mainland and the sea area is opposite to winter. In April and May, as well as in September and October, temperature differences between sea and continental air masses are smoothed out to a certain extent. Differences in the temperature regime of the lower layer of air over land and sea form in the Murmansk region significant meridional temperature gradients in absolute value during the coldest and warmest periods of the year. In the period from November to March, the average value of the meridional component of the horizontal temperature gradient reaches 5.7°/100 km when the gradient is directed south, towards the mainland; from June to August - 4.2°/100 km when directed north, towards seas. In intermediate periods, the absolute value of the meridional component of the horizontal temperature gradient decreases to 0.8°/100 km from April to May and to 0.7°/100 km from September to October.

Temperature differences in the lower layer of air above the sea and the mainland also form other temperature characteristics. Such characteristics include the average monthly variability of the average daily air temperature, depending on the direction of advection of air masses and partly the change in the conditions of transformation from one day to another of the surface layer of air when cloudiness clears or increases, wind increases, etc. We present the annual variation of the average between - daily variability of air temperature in the conditions of Murmansk:

From November to March in any month the average monthly value of day-to-day temperature variability is greater than the annual average; from June to August it is approximately equal to 2.3°, i.e. close to the annual average, and in other months it is below the annual average. Consequently, the seasonal values ​​of this temperature characteristic confirm the given division of the year into seasons.

According to L.N. Vodovozova, cases with sharp fluctuations in temperature values ​​from one day to the next (>10°) are most likely in winter (November-March) - 74 cases, somewhat less likely in summer (June-August) - 43 cases and least probable in transition seasons: spring (April-May) - 9 and autumn (September-October) - only 2 cases in 10 years. This division also confirms the fact that sharp temperature fluctuations are largely associated with changes in the direction of advection, and, consequently, with temperature differences between land and sea. No less indicative of dividing the year into seasons is the average monthly temperature for a given wind direction. This value, obtained over a limited observation period of only 20 years, with a possible error of the order of 1°, which in this case can be neglected, for two wind directions (southern quarter from the mainland and northern quarter from the sea), is given in Table. 36.

The average difference in air temperature, according to table. 36, changes sign in April and October: from November to March it reaches -5°. from April to May and from September to October - only 1.5°, and from June to August it increases to 7°. A number of other characteristics can be cited that are directly or indirectly related to temperature differences over the continent and the sea, but it can already be considered obvious that the period from November to March should be classified as the winter season, from June to August - to the summer season, April and May - to spring, and September and October - to autumn.

The definition of the winter season coincides closely in time with the average length of the period with persistent frost, which begins on November 12 and ends on April 5. The beginning of the spring season coincides with the beginning of radiation thaws. The average maximum temperature in April passes through 0°. The average maximum temperature in all summer months is >10°, and the minimum is >5°. The beginning of the autumn season coincides with the earliest date of the onset of frost, and the end - with the onset of stable frost. During spring, the average daily temperature increases by 11°, and during autumn it decreases by 9°, i.e., the increase in temperature during the spring and its decrease during the fall reaches 93% of the annual amplitude.

Winter

The beginning of the winter season coincides with the average date of formation of stable snow cover (November 10) and the beginning of the period with persistent frost (November 12). The formation of snow cover causes a significant change in the physical properties of the underlying surface, the thermal and radiation regime of the surface air layer. The average air temperature passes through 0° somewhat earlier, in the fall (October 17), and in the first half of the season its further decrease continues: crossing -5° on November 22 and -10° on January 22. January and February are the cold months of winter. From the second half of February, the average temperature begins to rise and on February 23 it passes through -10°, and at the end of the season, on March 27 - through -5°. Possible on clear nights in winter very coldy. Absolute minimums reach -32° in November, -36° in December and January, -38° in February and -35° in March. However, such low temperatures are unlikely. The minimum temperature below -30° is observed in 52% of years. It is most rarely observed in November (2% of years) and March (4%)< з наиболее часто - в феврале (26%). Минимальная температура ниже -25° наблюдается в 92% лет. Наименее вероятна она в ноябре (8% лет) и марте (18%), а наиболее вероятна в феврале (58%) и январе (56%). Минимальная температура ниже -20° наблюдается в каждом сезоне, но ежегодно только в январе. Минимальная температура ниже -15° наблюдается в течение всего сезона и в январе ежегодно, а в декабре, феврале и марте больше чем в 90% лет и только в ноябре в 6% лет. Минимальная температура ниже -10° возможна ежегодно в любом из зимних месяцев, кроме ноября, в котором она наблюдается в 92% лет. В любом из зимних месяцев возможны оттепели. Максимальные температуры при оттепели могут достигать в ноябре и марте 11°, в декабре 6° и в январе и феврале 7°. Однако такие высокие температуры наблюдаются очень редко. Ежегодно оттепель бывает в ноябре. В декабре ее вероятность составляет 90%, в январе 84%, в феврале 78% и в марте 92%. Всего за зиму наблюдается в среднем 33 дня с оттепелью, или 22% общего числа дней в сезоне, из них 13,5 дня приходится на ноябрь, 6,7 на декабрь, 3,6 на январь, 2,3 на февраль и 6,7 на март. Зимние оттепели в основном зависят от адвекции теплых масс воздуха из северных районов, реже из центральных районов Атлантики и наблюдаются обычно при большой скорости ветра. В любом из зимних месяцев средняя скорость ветра в период оттепелей больше среднего значения за весь месяц. Наиболее вероятны оттепели при western directions wind. As the clouds decrease and the wind weakens, the thaw usually stops.

24-hour thaws are rare, only about 5 days per season: 4 days in November and one in December. In January and February, round-the-clock thaws are possible no more than 5 days in 100 years. Winter advective thaws are possible at any time of the day. But in March, daytime thaws already predominate and the first radiation thaws are possible. However, the latter are observed only against the background of a relatively high average daily temperature. Depending on the prevailing development of atmospheric processes in any month, significant anomalies in the average monthly air temperature are possible. So, for example, with the average long-term air temperature in February equal to -10.1°, the average temperature in February in 1959 reached -3.6°, i.e. was 6.5° higher than normal, and in 1966 dropped to -20.6°, i.e. it was 10.5° below normal. Similar significant air temperature anomalies are possible in other months.

Abnormally high average monthly air temperatures in winter are observed during intense cyclonic activity in the north of the Norwegian and Barents seas with stable anticyclones over Western Europe and the European territory of the USSR. Cyclones from Iceland in abnormally warm months move northeast through the Norwegian Sea to the north of the Barents Sea, and from there southeast to the Kara Sea. In the warm sectors of these cyclones, very warm masses of Atlantic air are carried to the Kola Peninsula. Episodic intrusions of Arctic air do not cause significant cooling, since, passing over the Barents or Norwegian Sea, the Arctic air warms up from below and does not have time to cool down on the mainland during short clearings in rapidly moving ridges between individual cyclones.

The winter of 1958-59 can be classified as abnormally warm, which was almost 3° warmer than normal. This winter there were three very warm months: November, February and March, only December was cold and January was close to normal. February 1959 was especially warm. Such a warm February has not been observed over the years of observations not only in Murmansk since 1918, but also at the station. Cola since 1878, i.e. for 92 years. This February, the average temperature exceeded the norm by more than 6°, there were 13 days with a thaw, i.e. more than 5 times more than the long-term average values. The trajectories of cyclones and anticyclones are shown in Fig. 19, from which it is clear that throughout the month the cyclones moved from Iceland through the Norwegian and Barents Seas, carrying them to the north European territory USSR warm Atlantic air, anticyclones - from west to east along more southern trajectories than in normal years. February 1959 was anomalous not only in temperature, but also in a number of other meteorological elements. Deep cyclones passing over the Barents Sea caused frequent storms this month. Number of days with strong wind ≥ 15 m/sec. reached 13, i.e., exceeded the norm by almost three times, and the average monthly wind speed exceeded the norm by 2 m/sec. Due to the frequent passage of fronts, cloudiness also exceeded normal. For the entire month there was only one clear day with lower clouds, with the norm being 5 days, and 8 cloudy days, with the norm being 6 days. Similar anomalies of other meteorological elements were observed in the abnormally warm March of 1969, the average temperature of which exceeded the norm by more than 5°. In December 1958 and January 1959 there was a lot of snow. However, by the end of winter it had almost completely melted. In table 37 presents observational data in the second half of the winter of 1958-59, from which it is clear that the transition of the average temperature through -10° during the period of its increase occurred 37 days earlier than usual, and after -5° - 47 days.

Of the exceptionally cold winters during the observation period in Murmansk since 1918 and at the Kola station since 1888, we can indicate the winter of 1965-66. In that winter, the average seasonal temperature was almost 6° below the long-term average for this season. The coldest months were February and March. Months as cold as February and March 1966 have not been observed in the last 92 years. In February 1966, as can be seen from Fig. 20, the trajectories of the cyclones were located south of the Kola Peninsula, and the anticyclones were located over the extreme north-west of the European territory of the USSR. There were occasional inflows of continental Arctic air from the Kara Sea, which also caused significant and persistent cold snaps.

An anomaly in the development of atmospheric processes in February 1966 caused an anomaly not only in air temperature, but also in other meteorological elements. The predominance of anticyclonic weather caused a decrease in cloud cover and wind speed. Thus, the average wind speed reached 4.2 m/sec, or was 2.5 m/sec below normal. This month there were 8 clear days based on lower cloudiness, with the norm being 6, and only one cloudy day with the same norm. During December, January, and February there was not a single day with a thaw. The first thaw was observed only on March 31. In normal years, there are about 19 thaw days between December and March. The Kola Bay is covered with ice very rarely and only in exceptionally cold winters. In the winter of 1965-66, a long-term continuous ice cover was established in the Kola Bay in the Murmansk region: once in February and once in March*, and non-continuous, sparse ice with patches was observed in most of February and March and at times even in April.

The transition of the average temperature through -5 and -10° during the cooling period in the winter of 1965-66 occurred earlier than usual by 11 and 36 days, and during the warming period through the same limits with a delay against the norm by 18 and 19 days. The stable transition of the average temperature through -15° and the duration of the period with temperatures below this limit reached 57 days, which is observed very rarely. A steady cooling with the average temperature passing through -15° is observed on average only in 8% of winters. In the winter of 1965-66, anti-dyclonic weather prevailed not only in February, but throughout the entire season.

The predominance of cyclonic processes over the Norwegian and Barents seas and anticyclonic processes over the mainland in normal winters determines the predominance of wind (from the mainland) from the south-southeast and southwest directions. The total frequency of these wind directions reaches 74% in November, 84% in December, 83% in January, 80% in February and 68% in March. The frequency of occurrence of opposite directions of wind from the sea is much lower, and it is 16% in November, 11% in December and January, 14% in February and 21% in March. At south direction winds of the highest frequency are observed to have the lowest average temperatures, and in the case of northern winds, which are much less likely in winter, the highest temperatures are observed. Therefore, in winter, the south side of buildings loses more heat than the north. An increase in the frequency and intensity of cyclones causes an increase in both the average wind speed and the frequency of storms in winter. Average seasonal wind speed in winter by 1 m/sec. above the annual average, and the highest, about 7 m/sec., occurs in the middle of the season (January). Number of days with storm ≥ 15 m/sec. reaches 36 or 67% of their annual value in winter; In winter, the wind may increase to a hurricane ≥ 28 m/sec. However, hurricanes in Murmansk are unlikely even in winter, when they are observed once every 4 years. The most likely storms are from the south and southwest. Chance of light wind< 6 м/сек. колеблется от 44% в феврале до 49% в марте, а в среднем за сезон достигает 46%- Наибольшая облачность наблюдается в начале сезона, в ноябре. В течение сезона она постепенно уменьшается, достигая минимума в марте, который является наименее облачным. Наличие значительной облачности во время полярной ночи сокращает и без того короткий промежуток сумеречного времени и увеличивает неприятное ощущение, испытываемое во время полярной ночи.

The lowest temperatures in winter cause a decrease in both absolute moisture content and lack of saturation. The diurnal variation of these humidity characteristics in winter is practically absent, while the relative air humidity during the first three months of winter, from November to January, reaches an annual maximum of 85%, and from February it decreases to 79% in March. During most of the winter, until February inclusive, daily periodic fluctuations in relative humidity, confined to a certain time of day, are absent and become noticeable only in March, when their amplitude reaches 12%. Dry days from relative humidity≤30% for at least one of the observation periods in winter are completely absent, and humid days with a relative humidity of 13 hours ≥ 80% prevail and are observed on average in 75% of the total number of days in the season. A noticeable decrease in the number of humid days is observed at the end of the season, in March, when during the daytime the relative humidity decreases due to warming of the air.

Precipitation occurs more often in winter than in other seasons. On average, there are 129 days with precipitation per season, which is 86% of all days of the season. However, precipitation in winter is less intense than in other seasons. The average amount of precipitation per day with precipitation is only 0.2 mm in March and 0.3 mm for the remaining months from November to February inclusive, while the average duration per day with precipitation fluctuates around 10 hours in winter. On 52% of the total number of days with precipitation, the amount does not reach 0.1 mm. It is not uncommon for light snow to fall intermittently over a number of days without causing an increase in snow cover. Significant precipitation ≥ 5 mm per day is observed quite rarely in winter, only 4 days per season, and even more intense precipitation over 10 mm per day is very unlikely, only 3 days in 10 seasons. The highest daily amount of precipitation is observed in winter when precipitation falls in “charges”. During the entire winter season, an average of 144 mm of precipitation falls, which is 29% of the annual amount. The greatest amount of precipitation falls in November, 32 mm, and the least in March, 17 mm.

In winter, solid precipitation in the form of snow predominates. Their share of the total for the entire season is 88%. Mixed precipitation in the form of snow and rain or sleet falls much less frequently and accounts for only 10% of the total for the entire season. Liquid precipitation in the form of rain is even less likely. The share of liquid precipitation does not exceed 2% of its total seasonal amount. Liquid and mixed precipitation is most likely (32%) in November, when thaws are most frequent, and precipitation is least likely in January (2%).

In some months, depending on the frequency of cyclones and synoptic positions characteristic of precipitation with charges, their monthly amount can fluctuate widely. As an example of significant anomalies in monthly precipitation, we can cite December 1966 and January 1967. The circulation conditions of these months are described by the author in the work. In December 1966, Murmansk received only 3 mm of precipitation, 12% of the long-term average for that month. The depth of snow cover during December 1966 was less than 1 cm, and in the second half of the month there was virtually no snow cover. In January 1967, monthly precipitation reached 55 mm, or 250% of the long-term average, and the maximum daily amount reached 7 mm. In contrast to December 1966, January 1967 saw frequent bursts of precipitation, accompanied by strong winds and snowstorms. This caused frequent snow drifts, making transport difficult.

Anything is possible in winter atmospheric phenomena except for hail. The average number of days with various atmospheric phenomena is given in table. 38.

From the data in table. 38 it can be seen that evaporation fog, blizzard, fog, frost, ice and snow have the greatest frequency in the winter season, and therefore are characteristic of it. Most of these atmospheric phenomena characteristic of winter (evaporative fog, blizzard, fog and snowfall) impair visibility. These phenomena are associated with a deterioration in visibility in the winter season compared to other seasons. Almost all atmospheric phenomena characteristic of winter often cause serious difficulties in the work of various industries National economy. Therefore, the winter season is the most difficult for production activities all sectors of the national economy

Due to the short length of the day, the average number of hours of sunshine in winter during the first three months of winter, from November to January, does not exceed 6 hours, and in December, during the polar night, the sun is not visible for the entire month. At the end of winter, due to the rapid increase in day length and decrease in cloud cover, the average number of hours of sunshine increases to 32 in February and to 121 hours in March.

Spring

A characteristic sign of the beginning of spring in Murmansk is an increase in the frequency of daytime radiation thaws. The latter are observed already in March, but in March they are observed in the daytime only at relatively high average daily temperatures and with slight frosts at night and in the morning. In April, in clear or partly cloudy and calm weather, daytime thaws are possible with significant cooling at night, up to -10, -15°.

During spring there is a significant increase in temperature. So, on April 24, the average temperature, rising, passes through 0°, and on May 29, through 5°. In cold springs, these dates may be delayed, and in warm springs, they may be ahead of the average long-term dates.

In the spring, on cloudless nights, a significant drop in temperature in the cold Arctic air masses is still possible: to -26° in April and to -11° in May. When warm air is advected from the mainland or from the Atlantic, in April the temperature can reach 16°, and in May +27°. In April, there is an average of up to 19 days with a thaw, of which 6 with a thaw throughout the day. In April, with winds from the Barents Sea and significant cloudiness, an average of 11 days without a thaw is observed. In May, thaws are observed even more often for 30 days, of which 16 days there is no frost at all during the whole day.

24-hour frosty weather without a thaw is observed very rarely in May, on average one day per month.

In May there are already hot days with a maximum temperature of more than 20°. But hot weather in May is still a rare occurrence, possible in 23% of years: on average, this month has 4 hot days in 10 years, and then only with winds from the south and southwest.

The average monthly air temperature from March to April increases by 5.3° and reaches -1.7° in April, and from April to May by 4.8° and reaches 3.1° in May. In some years, the average monthly temperature in the spring months may differ significantly from the norm (long-term average). For example, the average long-term temperature in May is 3.1°. In 1963 it reached 9.4°, i.e. it exceeded the norm by 6.3°, and in 1969 it dropped to 0.6°, i.e. it was 2.5° below the norm. Similar anomalies in average monthly temperatures are possible in April.

The spring of 1958 was quite cold. The average temperature in April was 1.7° below normal, and in May - by 2.6°. The transition of the average daily temperature through -5° occurred on April 12 with a delay of 16 days, and through 0° only on May 24 with a delay of 28 days. May 1958 was the coldest for the entire observation period (52 years). The trajectories of cyclones, as can be seen from Fig. 21, passed south of the Kola Peninsula, and anticyclones prevailed over the Barents Sea. This direction in the development of atmospheric processes determined the predominance of advection of cold masses of Arctic air from the Barents, and at times from the Kara Sea.

The highest frequency of wind in various directions in the spring of 1958, according to Fig. 22, was observed for winds of north-east, east and south-east directions, with which the coldest continental Arctic air usually comes to Murmansk from the Kara Sea. This causes significant cooling in winter and especially in spring. In May 1958, there were 6 days without a thaw, with the norm being one day, 14 days with an average daily temperature<0° при норме 6 дней, 13 дней со снегом и 6 дней с дождем. В то время как в обычные годы наблюдается одинаковое число дней с дождем и снегом. Снежный покров в 1958 г. окончательно сошел только 10 июня, т. е. с опозданием по отношению к средней дате на 25 дней.

The spring of 1963 can be considered warm, in which April and especially May were warm. The average air temperature in the spring of 1963 crossed 0° on April 17, 7 days earlier than usual, and after 5° on May 2, i.e. 27 days earlier than usual. May was especially warm in the spring of 1963. Its average temperature reached 9.4°, i.e. exceeded the norm by more than 6°. There has never been such a warm May as in 1963 during the entire observation period of the Murmansk station (52 years).

In Fig. Figure 23 shows the trajectories of cyclones and anticyclones in May 1963. As can be seen from Fig. 23, anticyclones prevailed over the European territory of the USSR throughout May. Throughout the month, Atlantic cyclones moved northeast through the Norwegian and Barents Seas, bringing very warm continental air from the south to the Kola Peninsula. This is clearly seen from the data in Fig. 24. The frequency of the warmest wind for spring in the southern and southwestern directions in May 1963 exceeded the norm. In May 1963 there were 4 hot days, which are observed on average 4 times in 10 years, 10 days with an average daily temperature of >10° with a norm of 1.6 days and 2 days with an average daily temperature of >15° with a norm of 2 days per 10 years. An anomaly in the development of atmospheric processes in May 1963 caused anomalies in a number of other climate characteristics. The average monthly relative air humidity was 4% below the norm, there were 3 days more clear days than the norm, and 2 days less cloudy days than the norm. Warm weather in May 1963 caused the snow cover to melt early, at the end of the first ten days of May, i.e. 11 days earlier than usual

During spring, there is a significant restructuring of the frequency of different wind directions.

In April, winds of the southern and southwestern directions still prevail, the frequency of which is 26% higher than the frequency of winds of the northern and northwestern directions. And in May, northern and northwestern winds are observed 7% more often than southern and southwestern ones. A sharp increase in the frequency of wind direction from the Barents Sea from April to May causes an increase in cloudiness in May, as well as the return of cold weather, often observed in early May. This is clearly visible from the average ten-day temperature data (Table 39).

From the first to the second and from the second to the third ten days of April, a more significant increase in temperature is observed than from the third ten days of April to the first ten days of May; The most likely temperature drop is from the third ten days of April to the first ten days of May. This change in successive ten-day temperatures in the spring indicates that spring returns of cold weather are most likely in early May and, to a lesser extent, in the middle of that month.

Average monthly wind speed and number of days with wind ≥ 15 m/sec. during the spring they decrease noticeably.

The most significant change in wind speed characteristics is observed in early spring (April). In the speed and direction of the wind in the spring, especially in May, daily periodicity begins to be traced. Thus, the daily amplitude of wind speed increases from 1.5 m/sec. in April up to 1.9 m/sec. in May, and the frequency amplitude of wind directions from the Barents Sea (northern, northwestern and northeastern) increases from 6% in April to 10% in May.

Due to rising temperatures, relative air humidity decreases in spring from 74% in April to 70% in May. An increase in the amplitude of daily air temperature fluctuations causes an increase in the same amplitude of relative humidity, from 15% in April to 19% in May. In spring, dry days are already possible with a decrease in relative humidity to 30% or lower, at least for one of the observation periods. Dry days in April are still very rare, one day every 10 years; in May they occur more often, 1.4 days annually. The average number of wet days with relative humidity ≥ 80% in 13 hours decreases from 7 in April to 6 in May.

An increase in the frequency of advection from the sea and the development of cumulus clouds during the daytime causes a noticeable increase in cloudiness in spring from April to May. Unlike April, in May, due to the development of cumulus clouds, the likelihood of clear weather in the morning and at night is greater than in the afternoon and evening.

In spring, the daily cycle of various cloud forms is clearly visible (Table 40).

Convective clouds (Cu and Cb) are most likely during the day at 12 and 15 hours and least likely at night. The probability of clouds Sc and St changes during the day in the opposite order.

In spring, an average of 48 mm of precipitation falls (according to the precipitation gauge), of which 20 mm in April and 28 mm in May. In some years, the amount of precipitation in both April and May may differ significantly from the long-term average. According to precipitation gauge observations, the amount of precipitation in April fluctuated in some years from 155% of the norm in 1957 to 25% of the norm in 1960, and in May from 164% of the norm in 1964 to 28% of the norm in 1959. Significant Deficiency of precipitation in spring is caused by the predominance of anticyclonic processes, and excess is caused by the increased frequency of southern cyclones passing through or near Murmansk.

In the spring, the intensity of precipitation also increases noticeably, hence the maximum amount falling per day. Thus, in April, daily precipitation ≥ 10 mm is observed once every 25 years, and in May the same amount of precipitation is much more frequent - 4 times in 10 years. The highest daily precipitation reached 12 mm in April and 22 mm in May. In April and May, significant daily precipitation occurs with continuous rain or snowfall. Rainfall in spring does not yet provide a large amount of moisture, since it is usually short-lived and not yet intense enough.

In spring, precipitation falls in the form of solid (snow), liquid (rain) and mixed (rain and snow and sleet). In April, solid precipitation still predominates, 61% of the total, 27% is mixed precipitation and only 12% is liquid. In May, liquid precipitation predominates, accounting for 43% of the total, mixed precipitation accounts for 35%, and solid precipitation accounts for the least, accounting for only 22% of the total. However, in both April and May, the largest number of days falls on solid precipitation, while the smallest number of days in April falls on liquid precipitation, and in May on mixed precipitation. This discrepancy between the largest number of days with solid precipitation and the smallest share of the total in May is explained by the greater intensity of rainfall compared to snowfall. The average date for the collapse of the snow cover is May 6, the earliest is April 8, and the average date for the melting of the snow cover is May 16, the earliest is April 17. In May, after heavy snowfall, snow cover may still form, but not for long, since the snow that falls melts during the day. In spring, all atmospheric phenomena possible in winter are still observed (Table 41).

All atmospheric phenomena except various types precipitation have a very low frequency in spring, the smallest in the year. The frequency of harmful phenomena (fog, snowstorm, evaporative fog, ice and frost) is significantly less than in winter. Atmospheric phenomena such as fog, frost, evaporation fog and ice in the spring usually break down during the daytime. Therefore, harmful atmospheric phenomena do not cause serious difficulties for the work of various sectors of the national economy. Due to the low frequency of fogs, heavy snowfalls and other phenomena that impair horizontal visibility, the latter improves noticeably in the spring. The probability of poor visibility <1 km decreases to 1% in April and to 0.4% of total observations in May, and the probability of good visibility >10 km increases to 86% in April and 93% in May.

Due to the rapid increase in day length in spring, the duration of sunshine also increases from 121 hours in March to 203 hours in April. However, in May, due to increasing cloudiness, despite the increase in day length, the number of hours of sunshine even decreases slightly to 197 hours. The number of days without sun also increases slightly in May compared to April, from three in April to four in May.

Summer

A characteristic feature of summer, as well as winter, is an increase in temperature differences between the Barents Sea and the mainland, causing an increase in day-to-day variability of air temperature, depending on the direction of the wind - from land or from sea.

The average maximum air temperature from June 2 until the end of the season and the average daily temperature from June 22 to August 24 are kept above 10°. The beginning of summer coincides with the beginning of the frost-free period, on average June 1, and the end of summer coincides with the earliest end of the frost-free period, September 1.

Frosts in summer are possible until June 12 and then cease until the end of the season. During the 24-hour day, advective frosts predominate, which are observed in cloudy weather, snowfall and strong winds; radiation frosts are observed less frequently on sunny nights.

During most of the summer, average daily air temperatures range from 5 to 15°. Hot days with maximum temperatures above 20° are not observed often, on average 23 days for the entire season. In July, the warmest summer month, hot days are observed in 98% of years, in June in 88%, in August in 90%. A hot year is mainly observed with winds from the mainland and is most severe with southern and southwestern winds. Highest temperature in hot weather summer days can reach 31° in June, 33° in July and 29° in August. In some years, depending on the prevailing direction of influx of air masses from the Barents Sea or the mainland, the average temperature in any of the summer months, especially in July, can fluctuate widely. Thus, with an average long-term July temperature of 12.4° in 1960, it reached 18.9°, i.e., exceeded the norm by 6.5°, and in 1968 it dropped to 7.9°, i.e. was below normal by 4.5°. Similarly, the dates of transition of the average air temperature through 10° may fluctuate in individual years. The dates of transition through 10°, possible once every 20 years (5 and 95% probability), may differ by 57 days in the beginning and 49 at the end of the season, and the duration of the period with a temperature >10° of the same probability - for 66 days. The imputations in individual years and the number of days with hot weather per month and season are significant.

The warmest summer for the entire observation period was in 1960. The average seasonal temperature for this summer reached 13.5°, i.e. it was 3° higher than the long-term average. The warmest month this summer was July. There was no such warm month during the entire 52-year observation period in Murmansk and the 92-year observation period at Sola station. In July 1960 there were 24 hot days with the norm being 2 days. Continuous hot weather persisted from June 30 to July 3. Then, after a short cooling, from July 5 to July 20, hot weather set in again. From July 21 to July 25 there was cool weather, which from July 27 to the end of the month again changed to very hot weather with maximum temperatures over 30°. The average daily temperature throughout the month remained above 15°, i.e., there was a steady transition of the average temperature through 15°.

In Fig. 27 shows the trajectories of cyclones and anticyclones, and in Fig. 26 frequency of wind directions in July 1960. As can be seen from Fig. 25, in July 1960, anticyclones prevailed over the European territory of the USSR; cyclones passed over the Norwegian Sea and Scandinavia in a northerly direction and carried very warm continental air to the Kola Peninsula. The predominance of very warm southern and southwestern winds in July 1960 is clearly visible from the data in Fig. 26. This month was not only very warm, but also partly cloudy and dry. The predominance of hot and dry weather caused persistent burning of forests and peat bogs and strong smoke in the air. Because of the smoke forest fires even on clear days the sun barely shone through, and in the morning, night and evening hours it was completely hidden behind a curtain of thick smoke. Due to the hot weather, fresh fish spoiled in the fishing port, which was not adapted to work in conditions of persistent hot weather.

The summer of 1968 was abnormally cold. The average seasonal temperature that summer was almost 2° below normal; only June was warm, the average temperature of which was only 0.6° higher than normal. July was especially cold, and August was also cold. Such a cold July has never been recorded for the entire observation period in Murmansk (52 years) and at Kola station (92 years). The average July temperature was 4.5° below normal; for the first time in the entire observation period in Murmansk there was not a single hot day with a maximum temperature of more than 20°. Due to the renovation of the heating plant, which coincides with the end of the heating season, it was very cold and damp in apartments with central heating.

The abnormally cold weather in July, and partly in August 1968, was due to the predominance of very stable advection of cold air from the Barents Sea. As can be seen from Fig. 27 in July 1968, two directions of cyclone movement prevailed: 1) from the north of the Norwegian Sea to the southeast, through Scandinavia, Karelia and further to the east and 2) from the British Isles, through Western Europe, the European territory of the USSR to the north of Western Siberia. Both main prevailing directions of cyclone movement passed south of the Kola Peninsula and, therefore, the advection of Atlantic, and even more so continental air on the Kola Peninsula, was absent and the advection of cold air from the Barents Sea prevailed (Fig. 28). Characteristics of anomalies of meteorological elements in July are given in table. 42.

July 1968 was not only cold, but wet and cloudy. From the analysis of two anomalous Julys, it is clear that the warm summer months are formed due to the high frequency of continental air masses, bringing partly cloudy and hot weather, and the cold ones - due to the predominance of wind from the Barents Sea, bringing cold and cloudy weather.

In summer, northern winds prevail in Murmansk. Their frequency for the entire season is 32%, southern - 23%. Just as rarely, as in other seasons, easterly and southeasterly and westerly winds are observed. The repeatability of any of these directions is no more than 4%. The most likely are northern winds, their frequency in July is 36%, in August it decreases to 20%, i.e. already 3% less than southern ones. During the day the wind direction changes. Breeze daily fluctuations in wind direction are especially noticeable in low-wind, clear and warm weather. However, breeze fluctuations are also clearly visible from the average long-term repeatability of wind direction at different hours of the day. Northern winds are most likely in the afternoon or evening; southern winds, on the contrary, are most likely in the morning and least likely in the evening.

In summer, Murmansk experiences the lowest wind speeds. The average speed for the season is only 4.4 m/sec, an increase of 1.3 m/sec. less than the annual average. The lowest wind speed is observed in August, only 4 m/sec. In summer, weak winds of up to 5 m/sec are most likely; the probability of such speeds ranges from 64% in July to 72% in August. Strong winds ≥ 15 m/sec are unlikely in summer. The number of days with strong wind for the entire season is 8 days or only about 15% of the annual number. During the day in summer there are noticeable periodic fluctuations in wind speed. The lowest wind speeds throughout the season are observed at night (1 hour), the highest - during the day (13 hours). The daily amplitude of wind speed fluctuates in summer about 2 m/sec, which is 44-46% of the average daily wind speed. Light winds, less than 6 m/sec, are most likely at night and least likely during the day. Wind speed ≥ 15 m/s, on the contrary, is least likely at night and most likely during the day. Most often in summer, strong winds are observed during thunderstorms or heavy rains and are short-lived.

Significant warming of air masses and their moistening due to evaporation from moist soil in summer compared to other seasons causes an increase in the absolute moisture content of the surface layer of air. The average seasonal water vapor pressure reaches 9.3 mb and increases from June to August from 8.0 to 10.6 mb. During the day, fluctuations in water vapor pressure are small, with an amplitude from 0.1 mb in June to 0.2 mb in July and up to 0.4 mb in August. The lack of saturation also increases in summer, since an increase in temperature causes a more rapid increase in the moisture capacity of the air compared to its absolute moisture content. The average seasonal lack of saturation reaches 4.1 MB in summer, increasing from 4.4 MB in June to 4.6 MB in July and sharply decreasing in August to 3.1 MB. Due to the increase in temperature during the day, there is a noticeable increase in the lack of saturation compared to the night.

Relative air humidity reaches an annual minimum of 69% in June, and then gradually increases to 73% in July and 78% in August.

During the day, fluctuations in relative air humidity are significant. The highest relative air humidity is observed on average after midnight and, therefore, its maximum value coincides with the daily minimum temperature. The lowest relative air humidity is observed on average in the afternoon, at 2 or 3 p.m., and coincides with the daily maximum temperature. The daily amplitude of relative air humidity according to hourly data reaches 20% in June, 23% in July and 22% in August.

Low relative humidity ≤ 30% is most likely in June and least likely in August. High relative humidity ≥ 80% and ≥ 90% are least likely in June and most likely in August. Dry days with relative humidity ≤30% for any of the observation periods are most likely to occur in summer. The average number of such days ranges from 2.4 in June to 1.5 in July and up to 0.2 in August. Humid days with a relative humidity of 13 hours ≥ 80% are observed more often than dry days even in summer. The average number of wet days ranges from 5.4 in June to 8.7 in July and 8.9 in August.

In the summer months, all characteristics of relative humidity depend on the air temperature, and therefore on the direction of the wind from the mainland or the Barents Sea.

Cloudiness does not change significantly from June to July, but increases noticeably in August. Due to the development of cumulus and cumulonimbus cloudiness, an increase in it is observed in the daytime.

The daily cycle of various forms of clouds in summer can be traced just as well as in spring (Table 43).

Cumulus clouds are possible between 9 a.m. and 6 p.m. and have a return maximum around 3 p.m. Cumulonimbus clouds are least likely in the summer at 3 o'clock, most likely as cumulus clouds at about 15 o'clock. Stratocumulus clouds, which form during the summer when thick cumulus clouds break up, are most likely around midday and least likely at night. Stratus clouds, carried out from the Barents Sea in summer as a rising fog, are most likely at 6 a.m. and least likely at 3 p.m.

Precipitation during the summer months falls mainly in the form of rain. Wet snow does not fall every year, only in June. In July and August, wet snow is observed very rarely, once every 25-30 years. The least amount of precipitation (39 mm) falls in June. Subsequently, monthly precipitation increases to 52 in July and 55 in August. Thus, about 37% of the annual precipitation falls during the summer season.

In some years, depending on the frequency of cyclones and anticyclones, monthly precipitation can vary significantly: in June from 277 to 38% of the norm, in July from 213 to 35%, and in August from 253 to 29%

Excess precipitation in the summer months is caused by the increased frequency of southern cyclones, and deficiency is caused by persistent anticyclones.

Over the entire summer season, there is an average of 46 days with precipitation up to 0.1 mm, of which 15 days occur in June, 14 in July and 17 in August. Significant precipitation with an amount of ^10 mm per day occurs rarely, but more often than in other seasons. In total, during the summer season there is an average of about 4 days with daily precipitation of ^10 mm and one day with precipitation of ^20 mm. Daily precipitation amounts of ^30 mm are possible only in summer. But such days are very unlikely, only 2 days in 10 summer seasons. The highest daily precipitation for the entire observation period in Murmansk (1918-1968) reached 28 mm in June 1954, 39 mm in July 1958 and 39 mm in August 1949 and 1952. Extreme daily rainfall amounts during the summer months occur during prolonged continuous rainfall. Thunderstorm rainfall very rarely produces significant daily amounts.

Snow cover can form during snowfall only at the beginning of summer, in June. During the rest of the summer, although wet snow is possible, the latter does not form a snow cover.

The only atmospheric phenomena possible in summer are thunderstorms, hail and fog. In early July, a snowstorm is still possible, no more than once in 25 years. Thunderstorms occur annually in summer, on average about 5 days per season: 2 days in June-July and one day in August. The number of days with thunderstorms varies significantly from year to year. In some years, there may be no thunderstorm in any month of summer. Largest number days with thunderstorms range from 6 in June and August to 9 in July. Thunderstorms are most likely during the day, from 12 to 18 hours, and least likely at night, from 0 to 6 hours. Thunderstorms are often accompanied by squalls up to 15 m/sec. and more.

In summer, advective and radiation fogs are observed in Murmansk. They are observed at night and in the morning, mainly during northern winds. The fewest days with fog, only 4 days in 10 months, are observed in June. In July and August, as the night length increases, the number of days with fog increases: up to two in July and three in August

Due to the low frequency of snowfall and fog, as well as haze or haze, the best horizontal visibility is observed in summer in Murmansk. Good visibility ^10 km has a repeatability of 97% in June to 96% in July and August. Good visibility is most likely in any of the summer months at 13:00, least likely at night and in the morning. The probability of poor visibility in any month of summer is less than 1%; visibility in any month of summer is less than 1%. The largest number of hours of sunshine occur in June (246) and July (236). In August, due to a decrease in day length and an increase in cloudiness, the average number of hours of sunshine decreases to 146. However, due to cloudiness, the actually observed number of hours of sunshine does not exceed 34% of the possible

Autumn

The beginning of autumn in Murmansk closely coincides with the beginning of a stable period with an average daily temperature< 10°, который Начинается еще в конце лета, 24 августа. В дальнейшем она быстро понижается и 23 сентября переходит через 5°, а 16 октября через 0°. В сентябре еще возможны жаркие дни с максимальной температурой ^20°. Однако жаркие дни в сентябре ежегодно не наблюдаются, они возможны в этом месяце только в 7% лет - всего два дня за 10 лет. Заморозки начинаются в среднем 19 сентября. Самый ранний заморозок 1 сентября наблюдался в 1956 г. Заморозки и в сентябре ежегодно не наблюдаются. Они возможны в этом месяце в 79% лет; в среднем за месяц приходится два дня с заморозками. Заморозки в сентябре возможны только в ночные и утренние часы. В октябре заморозки наблюдаются практически ежегодно в 98% лет. Самая высокая температура достигает 24° в сентябре и 14° в октябре, а самая низкая -10° в сентябре и -21° в октябре.

In some years, the average monthly temperature, even in autumn, can fluctuate significantly. Thus, in September, the average long-term air temperature at a norm of 6.3° in 1938 reached 9.9°, and in 1939 dropped to 4.0°. The average long-term temperature in October is 0.2°. In 1960 it dropped to -3.6°, and in 1961 it reached 6.2°.

The largest absolute value temperature anomalies of different signs were observed in September and October in adjacent years. The most Warm autumn for the entire observation period in Murmansk was in 1961. Its average temperature exceeded the norm by 3.7°. October was especially warm this fall. Its average temperature exceeded the norm by 6°. Such a warm October for the entire observation period in Murmansk (52 years) and at station. Cola (92 years old) was not there yet. In October 1961 there was not a single day with frost. The absence of frosts in October for the entire observation period in Murmansk since 1919 was noted only in 1961. As can be seen from Fig. 29, in an abnormally warm October 1961, anticyclones prevailed over the European territory of the USSR, and active cyclonic activity over the Norwegian and Barents seas

Cyclones from Iceland moved mainly to the northeast through the Norwegian to the Barents Sea, bringing masses of very warm Atlantic air to the northwestern regions of the European territory of the USSR, including the Kola Peninsula. In October 1961, other meteorological elements were anomalous. So, for example, in October 1961, the frequency of occurrence of the south and southwest wind was 79% with a norm of 63%, and the frequency of the north, northwest and northeast was only 12% with a norm of 24%. The average wind speed in October 1961 exceeded the norm by 1 m/sec. In October 1961 there was not a single clear day, with the norm being three such days, and the average level of low cloudiness reached 7.3 points, with the norm being 6.4 points.

In the fall of 1961, the autumn dates for the transition of the average air temperature through 5 and 0° were delayed. The first was celebrated on October 19 with a delay of 26 days, and the second on November 6 with a delay of 20 days.

The autumn of 1960 can be considered cold. Its average temperature was 1.4° below normal. October was especially cold this fall. Its average temperature was 3.8° below normal. During the entire observation period in Murmansk (52 years) there was no such cold October as in 1960. As can be seen from Fig. 30, in cold October 1960, active cyclonic activity prevailed over the Barents Sea, just like in October 1961. But unlike October 1961, the cyclones moved from Greenland to the southeast to the Upper Ob and Yenisei, and in their rear, very cold Arctic air occasionally penetrated the Kola Peninsula, causing brief, significant cold snaps during clearings. In the warm sectors of the cyclones, the Kola Peninsula did not receive warm air from the low latitudes of the North Atlantic with abnormally high temperatures, as in 1961, and therefore did not cause significant warming.

The average daily temperature in the fall of 1960 crossed 5° on September 21, one day earlier than usual, and after 0° on October 5, 12 days earlier than usual. In the fall of 1961, stable snow cover formed 13 days earlier than usual. In October 1960, the wind speed (below the norm by 1.5 m/sec.) and cloudiness were anomalous (7 clear days with a norm of 3 days and only 6 cloudy days with a norm of 12 days).

In autumn, the winter regime of the prevailing wind direction gradually sets in. The frequency of occurrence of northern wind directions (north, northwest and northeast) decreases from 49% in August to 36% in September and 19% in November, and the frequency of southern and southwestern directions increases from 34% in August to 49%) in September and 63% in October.

In autumn, the daily periodicity of wind direction still remains. For example, a north wind is most likely in the afternoon (13%) and least likely in the morning (11%), while a south wind is most likely in the morning (42%) and least likely in the afternoon and evening (34%).

An increase in the frequency and intensity of cyclones over the Barents Sea causes a gradual increase in wind speed and the number of days with strong winds of ^15 m/sec in autumn. Thus, the average wind speed increases from August to October by 1.8 m/sec., and the number of days with wind speed ^15 m/sec. from 1.3 in August to 4.9 in October, i.e. almost four times. Daily periodic fluctuations in wind speed gradually die out in autumn. The likelihood of weak winds decreases in autumn.

Due to the decrease in temperature in autumn, the absolute moisture content of the ground layer of air gradually decreases. Water vapor pressure decreases from 10.6 mb in August to 5.5 mb in October. The daily periodicity of water vapor pressure in autumn is as insignificant as in summer, reaching only 0.2 mb in September and October. The lack of saturation also decreases in the fall from 4.0 mb in August to 1.0 mb in October, and the daily periodic fluctuations of this value gradually die out. For example, the daily amplitude of saturation deficiency decreases from 4.1 mb in August to 1.8 mb in September and to 0.5 mb in October.

Relative humidity in autumn increases from 81% in September to 84% in October, and its daily periodic amplitude decreases from 20% in September to 9% in October.

Daily fluctuations in relative humidity and its average daily value in September also depend on the direction of the wind. In October, its amplitude is so small that it is no longer possible to trace its change depending on the wind direction. There are no dry days with a relative humidity of ^30% for any of the observation periods in autumn, and the number of wet days with a relative humidity of ^80% at 13 hours increases from 11.7 in September to 19.3 in October

An increase in the frequency of cyclones causes an increase in the frequency of frontal clouds in autumn (high-stratus As and nimbostratus Ns clouds). At the same time, the cooling of surface air layers causes an increase in the frequency of temperature inversions and associated sub-inversion clouds (stratocumulus St and stratus Sc clouds). Therefore, the average lower cloudiness during autumn gradually increases from 6.1 points in August to 6.4 in September and October, and the number of cloudy days based on lower cloudiness from 9.6 in August to 11.5 in September.

In October, the average number of clear days reaches the annual minimum, and the average number of cloudy days reaches the annual maximum.

Due to the predominance of stratocumulus clouds associated with inversions, the greatest cloudiness in the autumn months is observed in the morning, 7 hours, and coincides with the lowest surface temperature, and therefore with the highest probability and intensity of inversion. In September, the daily frequency of occurrence of cumulus Cu and stratocumulus Sc clouds is still visible (Table 44).

In autumn, an average of 90 mm of precipitation falls, of which 50 mm in September and 40 mm in October. Precipitation in autumn occurs in the form of rain, snow and sleet. The share of liquid precipitation in the form of rain in the fall reaches 66% of their seasonal amount, and solid (snow) and mixed (wet snow with rain) only 16 and 18% of the same amount. Depending on the prevalence of cyclones or anticyclones, the amount of precipitation in the autumn months may differ significantly from the long-term average. Thus, in September, monthly precipitation can vary from 160 to 36%, and in October from 198 to 14% of the monthly norm.

Precipitation occurs more often in autumn than in summer. The total number of days with precipitation, including days when it was observed, but the amount was less than 1 mm, reaches 54, i.e., rain or snow is observed on 88% of the days of the season. However, light precipitation prevails in autumn. Precipitation ^=5 mm per day is much less common, only 4.6 days per season. Heavy precipitation of ^10 mm per day occurs even less frequently, 1.4 days per season. Rainfall of ^20mm in autumn is very unlikely, only one day in 25 years. The highest daily rainfall of 27 mm fell in September 1946 and 23 mm in October 1963

Snow cover first forms on October 14, and in cold and early autumn on September 21, but in September the snow that falls does not cover the soil for long and always disappears. A stable snow cover will form in the next season. In an abnormally cold autumn, it may form no earlier than October 5th. In autumn, all atmospheric phenomena observed in Murmansk throughout the year are possible (Table 45)

From the data in table. 45 it can be seen that fog and rain, snow and sleet are most often observed in autumn. Other phenomena characteristic of summer, thunderstorms and hail, cease in October. Atmospheric phenomena characteristic of winter - blizzards, evaporative fog, ice and frost - which cause the greatest difficulties to various sectors of the national economy, are still unlikely in the fall.

An increase in cloudiness and a decrease in day length causes in autumn a rapid decrease in the duration of sunshine, both actual and possible, and an increase in the number of days without sun

Due to the increasing frequency of snowfalls and fogs, as well as haze and air pollution from industrial facilities, a gradual deterioration in horizontal visibility is observed in the fall. The frequency of good visibility ^10 km decreases from 90% in September to 85% in October. The best visibility in autumn is observed in the daytime, and the worst - at night and in the morning.

in winter highest values total solar radiation reaches in the south of the Far East, in southern Transbaikalia and Ciscaucasia. In January, the extreme south of Primorye receives over 200 MJ/m2, the rest of the listed areas receive over 150 MJ/km2. To the north, the total radiation decreases rapidly due to the lower position of the Sun and the shortening of the day. To 60° N it is already decreasing by 3-4 times. North of the Arctic Circle is established polar night, the duration of which is at 70° N. is 53 days. The radiation balance in winter throughout the country is negative.

Under these conditions, a strong cooling of the surface and the formation of the Asian maximum occurs with its center over Northern Mongolia, southeastern Altai, Tuva and the south of the Baikal region. The pressure at the center of the anticyclone exceeds 1040 hPa (mbar). Two spurs extend from the Asian High: to the northeast, where the secondary Oymyakon center with pressure above 1030 hPa is formed, and to the west, to connect with the Azores High, the Voeikov axis. It stretches through the Kazakh small hills to Uralsk - Saratov - Kharkov - Chisinau and further up to south coast France. IN western regions In Russia, within the Voeikov axis, the pressure drops to 1021 hPa, but remains higher than in the territories located north and south of the axis.

The Voeikov axis plays an important role as a climate divide. To the south of it (in Russia this is the south of the East European Plain and Ciscaucasia) easterly and northeasterly winds, carrying dry and cold continental air of temperate latitudes from the Asian High. Southwestern and western winds blow north of the Voeikov axis. The role of western transport in the northern part of the East European Plain and in the north-west of Western Siberia is enhanced by the Icelandic minimum, the trough of which reaches the Kara Sea (in the Varangerfjord area the pressure is 1007.5 hPa). Westerly transport often brings relatively warm and humid Atlantic air into these areas.

In the rest of Siberia, winds with a southern component predominate, carrying continental air from the Asian High.

Over the territory of the North-East, under the conditions of a basin topography and minimal solar radiation in winter, continental Arctic air is formed, very cold and dry. From the northeastern spur of high pressure it rushes towards the Arctic and Pacific oceans.

The Aleutian Low forms off the eastern coast of Kamchatka in winter. On the Commander Islands, in the southeastern part of Kamchatka, in the northern part of the Kuril island arc, the pressure is below 1003 hPa, and on a significant part of the Kamchatka coast the pressure is below 1006 hPa. Here, on the eastern outskirts of Russia, the region low pressure is located in close proximity to the northeastern spur, therefore a high pressure gradient is formed (especially near the northern coast of the Sea of ​​Okhotsk); cold continental air of temperate latitudes (in the south) and arctic air (in the north) is carried to the seas. The prevailing winds are from the north and north-west directions.

The Arctic front in winter is established over the Barents and Kara seas, and in the Far East - over Sea of ​​Okhotsk. The polar front at this time passes south of Russia. Only on the Black Sea coast of the Caucasus is the influence of cyclones of the Mediterranean branch of the polar front affected, the paths of movement of which shift from Western Asia to the Black Sea due to lower pressure over its expanses. The distribution of precipitation is associated with frontal zones.

The distribution of not only moisture, but also heat on the territory of Russia during the cold period is largely associated with circulation processes, as is clearly evidenced by the course of January isotherms.

The -4°С isotherm passes meridionally through the Kaliningrad region. Near the western borders of the compact territory of Russia there is an isotherm of -8°C. In the south it deviates to the Tsimlyansk Reservoir and further to Astrakhan. The further you go to the east, the lower the January temperatures. Isotherms -32...-36°С form closed contours over Central Siberia and the North-East. In the basins of the Northeast and eastern part of Central Siberia, average January temperatures drop to -40..-48°C. The cold pole of the northern hemisphere is Oymyakon, where the absolute minimum temperature in Russia is recorded at -71°C.

The increasing severity of winter to the east is associated with a decrease in the frequency of Atlantic air masses and an increase in their transformation as they move over cooled land. Where warmer air from the Atlantic penetrates more often (western regions of the country), winter is less severe.

In the south of the East European Plain and in the Ciscaucasia, isotherms are located sublatitudinally, increasing from -10°C to -2...-3°C. This is where the radiation factor comes into play. Winter is milder than in the rest of the territory on the northwestern coast of the Kola Peninsula, where the average January temperature is -8°C and slightly higher. This is due to the influx of air heated over the warm North Cape Current.

In the Far East, the course of isotherms follows the contours coastline, forming a clearly defined concentration of isotherms along the coastline. The warming effect here affects the narrow coastal strip due to the predominant removal of air from the mainland. An isotherm of -4°C stretches along the Kuril ridge. Slightly higher than the temperature on the Commander Islands. An isotherm of -8°C stretches along the eastern coast of Kamchatka. And even in the coastal strip of Primorye, January temperatures are -10...-12°C. As you can see, in Vladivostok the average January temperature is lower than in Murmansk, which lies beyond the Arctic Circle, 25° to the north.

The greatest amount of precipitation falls in the southeastern part of Kamchatka and the Kuril Islands. They are brought by cyclones not only of the Okhotsk, but also mainly of the Mongolian and Pacific branches of the polar front, rushing into the Aleutian low. Pacific sea air, drawn into the front of these cyclones, carries the bulk of precipitation. But Atlantic air masses bring precipitation to most of Russia in winter, so the bulk of precipitation falls in the western regions of the country. To the east and northeast the amount of precipitation decreases. A lot of precipitation falls on the southwestern slopes of the Greater Caucasus. They are brought by Mediterranean cyclones.

Winter precipitation falls in Russia mainly in solid form and snow cover is established almost everywhere, the height of which and the duration of its occurrence vary within very wide limits.

The shortest duration of snow cover is typical for the coastal regions of Western and Eastern Ciscaucasia (less than 40 days). In the south of the European part (up to the latitude of Volgograd) snow lies less than 80 days a year, and in the extreme south of Primorye - less than 100 days. To the north and northeast, the duration of snow cover increases to 240-260 days, reaching a maximum in Taimyr (over 260 days a year). Only on the Black Sea coast of the Caucasus does a stable snow cover form, but during the winter there may be 10-20 days with snow.

Less than 10 cm of snow depth in the deserts of the Caspian region, in the coastal regions of Eastern and Western Ciscaucasia. In the rest of the Ciscaucasia, on the East European Plain south of Volgograd, in Transbaikalia and Kaliningrad region the snow cover height is only 20 cm. In most of the territory it ranges from 40-50 to 70 cm. In the north-eastern (Ural) part of the East European Plain and in the Yenisei part of Western and Central Siberia, the snow cover height increases to 80-90 cm , and in the snowiest areas of the southeast of Kamchatka and the Kuril Islands - up to 2-3 m.

Thus, the presence of a fairly thick snow cover and its long-term occurrence is characteristic of most of the country’s territory, which is due to its position in temperate and high latitudes. Given the northern location of Russia, the severity of the winter period and the depth of snow cover are of great importance for agriculture.

Climate- This is a long-term weather regime characteristic of a particular area. It manifests itself in the regular change of all types of weather observed in this area.

Climate influences living and inanimate nature. IN close dependence from the climate are water bodies, soil, vegetation, animals. Certain sectors of the economy, primarily Agriculture, are also very dependent on climate.

The climate is formed as a result of the interaction of many factors: the amount of solar radiation reaching the earth's surface; atmospheric circulation; the nature of the underlying surface. At the same time, climate-forming factors themselves depend on the geographical conditions of a given area, primarily on geographical latitude.

The geographic latitude of the area determines the angle of incidence of the sun's rays, obtaining a certain amount of heat. However, receiving heat from the Sun also depends on proximity to the ocean. In places far from the oceans, there is little precipitation, and the precipitation regime is uneven (more in the warm period than in the cold), cloudiness is low, winters are cold, summers are warm, and the annual temperature range is large. This climate is called continental, as it is typical for places located in the interior of continents. A maritime climate is formed over the water surface, which is characterized by: a smooth variation in air temperature, with small daily and annual temperature amplitudes, large clouds, and a uniform and fairly large amount of precipitation.

The climate is also greatly influenced by sea ​​currents. Warm currents warm the atmosphere in the areas where they flow. For example, the warm North Atlantic Current creates favorable conditions for the growth of forests in the southern part of the Scandinavian Peninsula, while most of the island of Greenland, which lies at approximately the same latitudes as Scandinavian Peninsula, but located outside the zone of influence of the warm current, is covered with a thick layer of ice all year round.

A major role in climate formation belongs to relief. You already know that with every kilometer the terrain rises, the air temperature drops by 5-6 °C. Therefore, on the high mountain slopes of the Pamirs the average annual temperature is 1 ° C, although it is located just north of the tropics.

The location of mountain ranges greatly influences the climate. For example, Caucasus Mountains retain wet sea ​​winds, and on their windward slopes facing the Black Sea, significantly more precipitation falls than on the leeward ones. At the same time, the mountains serve as an obstacle to cold northern winds.

There is a dependence of climate on prevailing winds. On the territory of the East European Plain, westerly winds coming from the Atlantic Ocean prevail throughout almost the entire year, so winters in this territory are relatively mild.

Regions of the Far East are under the influence of monsoons. In winter, winds from the interior of the mainland constantly blow here. They are cold and very dry, so there is little precipitation. In summer, on the contrary, winds bring a lot of moisture from the Pacific Ocean. In autumn, when the wind from the ocean subsides, the weather is usually sunny and calm. This is the best time of year in the area.

Climatic characteristics are statistical inferences from long-term weather observation series (25-50 year series are used in temperate latitudes; in the tropics their duration may be shorter), primarily on the following basic meteorological elements: atmospheric pressure, wind speed and direction, temperature and air humidity, cloudiness and precipitation. They also take into account the duration of solar radiation, visibility range, temperature of the upper layers of soil and reservoirs, evaporation of water from the earth's surface into the atmosphere, height and condition of snow cover, various atmospheric phenomena and ground hydrometeors (dew, ice, fog, thunderstorms, blizzards, etc.) . In the 20th century The climatic indicators included the characteristics of the elements of the heat balance of the earth's surface, such as total solar radiation, radiation balance, the amount of heat exchange between the earth's surface and the atmosphere, and heat consumption for evaporation. Complex indicators are also used, i.e. functions of several elements: various coefficients, factors, indices (for example, continentality, aridity, moisture), etc.

Climate zones

Long-term average values ​​of meteorological elements (annual, seasonal, monthly, daily, etc.), their sums, frequency, etc. are called climate standards: corresponding values ​​for individual days, months, years, etc. are considered as a deviation from these norms.

Maps with climate indicators are called climatic(temperature distribution map, pressure distribution map, etc.).

Depending on temperature conditions, prevailing air masses and winds, climatic zones.

The main climatic zones are:

• equatorial;
• two tropical;
• two moderate;
• Arctic and Antarctic.

Between the main zones there are transitional climatic zones: subequatorial, subtropical, subarctic, subantarctic. IN transitional belts air masses change with the seasons. They come here from neighboring zones, so the climate is sub equatorial belt in summer it is similar to the climate of the equatorial zone, and in winter - to the tropical climate; The climate of the subtropical zones in summer is similar to the climate of the tropical zones, and in winter - to the climate of the temperate zones. This is due to the seasonal movement of atmospheric pressure belts over the globe following the Sun: in summer - to the north, in winter - to the south.

Climatic zones are divided into climatic regions . For example, in the tropical zone of Africa, areas of tropical dry and tropical humid climate, and in Eurasia the subtropical zone is divided into areas of Mediterranean, continental and monsoon climate. IN mountainous areas is being formed altitudinal zone due to the fact that the air temperature decreases with altitude.

Diversity of Earth's climates

The climate classification provides an orderly system for characterizing climate types, their zoning and mapping. Let us give examples of climate types that prevail over vast territories (Table 1).

Arctic and Antarctic climate zones

Antarctic and Arctic climate dominates in Greenland and Antarctica, where average monthly temperatures are below 0 °C. During the dark winter season, these regions receive absolutely no solar radiation, although there are twilights and auroras. Even in summer, the sun's rays hit the earth's surface at a slight angle, which reduces the efficiency of heating. Most of the incoming solar radiation is reflected by the ice. In both summer and winter, the higher elevations of the Antarctic Ice Sheet experience low temperatures. The climate of the interior of Antarctica is much colder than the climate of the Arctic, because southern mainland It is distinguished by its large size and altitude, and the Arctic Ocean moderates the climate, despite the widespread distribution of pack ice. During short periods of warming in summer, drifting ice sometimes melts. Precipitation on ice sheets falls in the form of snow or small particles of freezing fog. Inland areas receive only 50-125 mm of precipitation annually, but the coast can receive more than 500 mm. Sometimes cyclones bring clouds and snow to these areas. Snowfalls are often accompanied by strong winds that carry significant masses of snow, blowing it off the slope. Strong katabatic winds with snowstorms blow from the cold glacial sheet, carrying snow to the coast.

Subarctic continental climate is formed in the north of the continents (see climate map of the atlas). In winter, arctic air predominates here, which forms in areas of high pressure. Arctic air spreads to the eastern regions of Canada from the Arctic.

Continental subarctic climate in Asia is characterized by the largest annual amplitude of air temperature on the globe (60-65 °C). The continental climate here reaches its maximum value.

The average temperature in January varies across the territory from -28 to -50 °C, and in the lowlands and basins due to stagnation of air, its temperature is even lower. In Oymyakon (Yakutia), a record negative air temperature for the Northern Hemisphere was recorded (-71 °C). The air is very dry.

Summer in subarctic zone although short, it is quite warm. The average monthly temperature in July ranges from 12 to 18 °C (daytime maximum is 20-25 °C). During the summer, more than half of the annual precipitation falls, amounting to 200-300 mm on the flat territory, and up to 500 mm per year on the windward slopes of the hills.

The climate of the subarctic zone of North America is less continental compared to the corresponding climate of Asia. There are less cold winters and colder summers.

Temperate climate zone

Temperate climate of the western coasts of the continents has bright pronounced features marine climate and is characterized by the predominance of marine air masses throughout the year. It is observed on the Atlantic coast of Europe and the Pacific coast of North America. The Cordillera is a natural boundary separating the coast with a maritime climate from inland areas. The European coast, except Scandinavia, is open to free access of temperate sea air.

The constant transport of sea air is accompanied by large clouds and causes long springs, in contrast to the interior of the continental regions of Eurasia.

Winter in temperate zone It's warm on the western coasts. The warming influence of the oceans is enhanced by warm sea currents washing the western shores of the continents. The average temperature in January is positive and varies across the territory from north to south from 0 to 6 °C. When arctic air invades, it can drop (on the Scandinavian coast to -25 °C, and on the French coast - to -17 °C). As tropical air spreads northward, the temperature rises sharply (for example, it often reaches 10 °C). In winter, on the western coast of Scandinavia, large positive temperature deviations from the average latitude (by 20 °C) are observed. The temperature anomaly on the Pacific coast of North America is smaller and amounts to no more than 12 °C.

Summer is rarely hot. The average temperature in July is 15-16 °C.

Even during the day, the air temperature rarely exceeds 30 °C. Due to frequent cyclones, all seasons are characterized by cloudy and rainy weather. There are especially many cloudy days on the west coast of North America, where mountain systems Cordillera cyclones are forced to slow down. In connection with this, great uniformity characterizes the weather regime in southern Alaska, where there are no seasons in our understanding. Eternal autumn reigns there, and only plants remind of the onset of winter or summer. Annual precipitation ranges from 600 to 1000 mm, and on the slopes of mountain ranges - from 2000 to 6000 mm.

In conditions of sufficient moisture on the coasts, developed broadleaf forests, and in conditions of excess - conifers. The lack of summer heat reduces the upper limit of the forest in the mountains to 500-700 m above sea level.

Temperate climate of the eastern coasts of the continents has monsoon features and is accompanied by a seasonal change in winds: in winter, northwestern currents predominate, in summer - southeastern ones. It is well expressed on the eastern coast of Eurasia.

In winter, with the north-west wind, cold continental temperate air spreads to the coast of the mainland, which is the reason for the low average temperature of the winter months (from -20 to -25 ° C). Clear, dry, windy weather prevails. There is little precipitation in the southern coastal areas. The north of the Amur region, Sakhalin and Kamchatka often fall under the influence of cyclones moving over the Pacific Ocean. Therefore, in winter there is a heavy snow cover, especially in Kamchatka, where it maximum height reaches 2 m.

In summer, temperate sea air spreads along the Eurasian coast with a southeast wind. Summers are warm, with an average July temperature of 14 to 18 °C. Frequent precipitation is caused by cyclonic activity. Their annual quantity is 600-1000 mm, with most of them falling in summer. Fogs are common at this time of year.

Unlike Eurasia, the east coast of North America is characterized by monkfish climate, which are expressed in the predominance of winter precipitation and marine type annual progress air temperatures: the minimum occurs in February, and the maximum in August, when the ocean is warmest.

The Canadian anticyclone, unlike the Asian one, is unstable. It forms far from the coast and is often interrupted by cyclones. Winter here is mild, snowy, wet and windy. In snowy winters, the height of the snowdrifts reaches 2.5 m. With a southerly wind, there is often black ice. Therefore, some streets in some cities in eastern Canada have iron railings for pedestrians. Summer is cool and rainy. Annual precipitation is 1000 mm.

Temperate continental climate most clearly expressed on the Eurasian continent, especially in the regions of Siberia, Transbaikalia, northern Mongolia, as well as in the Great Plains in North America.

A feature of the temperate continental climate is the large annual amplitude of air temperature, which can reach 50-60 °C. During the winter months, with a negative radiation balance, the earth's surface cools. The cooling effect of the land surface on the surface layers of air is especially great in Asia, where in winter a powerful Asian anticyclone forms and partly cloudy, windless weather prevails. The temperate continental air formed in the area of ​​the anticyclone has a low temperature (-0°...-40 °C). In valleys and basins, due to radiation cooling, the air temperature can drop to -60 °C.

In midwinter, the continental air in the lower layers becomes even colder than the Arctic air. This very cold air of the Asian anticyclone extends to Western Siberia, Kazakhstan, and the southeastern regions of Europe.

The winter Canadian anticyclone is less stable than the Asian anticyclone due to the smaller size of the North American continent. Winters here are less severe, and their severity does not increase towards the center of the continent, as in Asia, but, on the contrary, decreases somewhat due to the frequent passage of cyclones. Continental temperate air in North America has a higher temperature than continental temperate air in Asia.

The formation of a continental temperate climate is significantly influenced by the geographical features of the continents. In North America, the Cordillera mountain ranges are a natural boundary separating the maritime coastline from the continental inland areas. In Eurasia, a temperate continental climate is formed over a vast expanse of land, from approximately 20 to 120° E. d. Unlike North America, Europe is open to the free penetration of sea air from the Atlantic deep into its interior. This is facilitated not only by the westerly transport of air masses, which dominates in temperate latitudes, but also by the flat nature of the relief, highly rugged coastlines and deep penetration into the land of the Baltic and North Seas. Therefore, a temperate climate of a lesser degree of continentality is formed over Europe compared to Asia.

In winter, sea Atlantic air moving over the cold land surface of temperate latitudes of Europe retains its properties for a long time. physical properties, and its influence extends throughout Europe. In winter, as the Atlantic influence weakens, the air temperature decreases from west to east. In Berlin it is 0 °C in January, in Warsaw -3 °C, in Moscow -11 °C. In this case, the isotherms over Europe have a meridional orientation.

The fact that Eurasia and North America face the Arctic basin as a broad front contributes to the deep penetration of cold air masses onto the continents throughout the year. Intense meridional transport of air masses is especially characteristic of North America, where arctic and tropical air often replace each other.

Tropical air entering the plains of North America with southern cyclones is also slowly transformed due to the high speed of its movement, high moisture content and continuous low clouds.

In winter, the consequence of intense meridional circulation of air masses is the so-called “jumps” of temperatures, their large inter-day amplitude, especially in areas where cyclones are frequent: in northern Europe and Western Siberia, the Great Plains of North America.

During the cold period, they fall in the form of snow, a snow cover is formed, which protects the soil from deep freezing and creates a supply of moisture in the spring. The depth of the snow cover depends on the duration of its occurrence and the amount of precipitation. In Europe, stable snow cover on flat areas forms east of Warsaw, its maximum height reaches 90 cm in the northeastern regions of Europe and Western Siberia. In the center of the Russian Plain, the height of snow cover is 30-35 cm, and in Transbaikalia - less than 20 cm. On the plains of Mongolia, in the center of the anticyclonic region, snow cover forms only in some years. The lack of snow, along with low winter air temperatures, causes the presence of permafrost, which is not observed anywhere else on the globe at these latitudes.

In North America, snow cover is negligible on the Great Plains. To the east of the plains, tropical air increasingly begins to take part in frontal processes; it aggravates frontal processes, which causes heavy snowfalls. In the Montreal area, snow cover lasts up to four months, and its height reaches 90 cm.

Summer in the continental regions of Eurasia is warm. The average July temperature is 18-22 °C. In the arid regions of south-eastern Europe and Central Asia The average air temperature in July reaches 24-28 °C.

In North America, continental air in summer is somewhat colder than in Asia and Europe. This is due to the smaller latitudinal extent of the continent, the large ruggedness of its northern part with bays and fjords, the abundance of large lakes, and the more intense development of cyclonic activity compared to the interior regions of Eurasia.

In the temperate zone, the annual precipitation on the flat continental areas varies from 300 to 800 mm; on the windward slopes of the Alps more than 2000 mm falls. Most of the precipitation falls in summer, which is primarily due to an increase in the moisture content of the air. In Eurasia, there is a decrease in precipitation across the territory from west to east. In addition, the amount of precipitation decreases from north to south due to a decrease in the frequency of cyclones and an increase in dry air in this direction. In North America, a decrease in precipitation across the territory is observed, on the contrary, towards the west. Why do you think?

Most of the land in the continental temperate climate zone is occupied by mountain systems. These are the Alps, Carpathians, Altai, Sayans, Cordillera, Rocky Mountains, etc. In mountainous areas, climatic conditions differ significantly from the climate of the plains. In summer, the air temperature in the mountains drops quickly with altitude. In winter, when cold air masses invade, the air temperature on the plains is often lower than in the mountains.

The influence of mountains on precipitation is great. Precipitation increases on windward slopes and at some distance in front of them, and decreases on leeward slopes. For example, differences in annual precipitation between the western and eastern slopes of the Ural Mountains in some places reach 300 mm. In mountains, precipitation increases with altitude to a certain critical level. In the Alps, the highest precipitation occurs at altitudes of about 2000 m, in the Caucasus - 2500 m.

Subtropical climate zone

Continental subtropical climate determined by the seasonal change of temperate and tropical air. The average temperature of the coldest month in Central Asia is below zero in some places, in the northeast of China -5...-10°C. The average temperature of the warmest month ranges from 25-30 °C, with daily maximums exceeding 40-45 °C.

The most strongly continental climate in the air temperature regime is manifested in the southern regions of Mongolia and northern China, where the center of the Asian anticyclone is located in the winter season. Here the annual air temperature range is 35-40 °C.

Sharply continental climate in the subtropical zone for the high mountain regions of the Pamirs and Tibet, the altitude of which is 3.5-4 km. The climate of the Pamirs and Tibet is characterized by cold winter, cool summers and little rainfall.

In North America, the continental arid subtropical climate is formed in closed plateaus and in intermountain basins located between the Coast and Rocky Ranges. Summers are hot and dry, especially in the south, where the average July temperature is above 30 °C. The absolute maximum temperature can reach 50 °C and above. A temperature of +56.7 °C was recorded in Death Valley!

Humid subtropical climate characteristic of the eastern coasts of continents north and south of the tropics. The main areas of distribution are the southeastern United States, some southeastern parts of Europe, northern India and Myanmar, eastern China and southern Japan, northeastern Argentina, Uruguay and southern Brazil, the coast of Natal in South Africa and the eastern coast of Australia. Summer in the humid subtropics is long and hot, with temperatures similar to those in the tropics. The average temperature of the warmest month exceeds +27 °C, and the maximum is +38 °C. Winters are mild, with average monthly temperatures above 0 °C, but occasional frosts have a detrimental effect on vegetable and citrus plantations. In the humid subtropics, average annual precipitation amounts range from 750 to 2000 mm, and the distribution of precipitation across seasons is quite uniform. In winter, rain and rare snowfalls are brought mainly by cyclones. In summer, precipitation falls mainly in the form of thunderstorms associated with powerful inflows of warm and humid oceanic air, characteristic of the monsoon circulation of East Asia. Hurricanes (or typhoons) occur in late summer and fall, especially in the Northern Hemisphere.

Subtropical climate with dry summers, typical for the western coasts of continents north and south of the tropics. IN Southern Europe And North Africa Such climatic conditions are typical for the coasts of the Mediterranean Sea, which is the reason for calling this climate also Mediterranean. Similar climate in southern California, the central regions of Chile, in the extreme south of Africa and in several areas in southern Australia. All these areas have hot summers and mild winters. As in the humid subtropics, there are occasional frosts in winter. In inland areas, summer temperatures are significantly higher than on the coasts, and are often the same as in tropical deserts. In general, clear weather prevails. In summer, there are often fogs on the coasts near which ocean currents pass. For example, in San Francisco, summers are cool, foggy, and the most warm month- September. The maximum precipitation is associated with the passage of cyclones in winter, when the prevailing air currents mix towards the equator. The influence of anticyclones and downdrafts of air over the oceans cause dryness summer season. The average annual precipitation in a subtropical climate ranges from 380 to 900 mm and reaches maximum values ​​on the coasts and mountain slopes. In summer there is usually not enough rainfall for normal tree growth, and therefore a specific type of evergreen shrubby vegetation develops there, known as maquis, chaparral, mali, macchia and fynbos.

Equatorial climate zone

Equatorial climate type distributed in equatorial latitudes in the Amazon basin in South America and the Congo in Africa, on the Malacca Peninsula and on the islands of Southeast Asia. Usually the average annual temperature is about +26 °C. Due to the high midday position of the Sun above the horizon and the same length of day throughout the year, seasonal temperature fluctuations are small. Moist air, cloud cover and dense vegetation prevent night cooling and keep maximum daytime temperatures below 37°C, lower than at higher latitudes. The average annual precipitation in the humid tropics ranges from 1500 to 3000 mm and is usually evenly distributed over the seasons. Precipitation is mainly associated with the Intertropical Convergence Zone, which is located slightly north of the equator. Seasonal shifts of this zone to the north and south in some areas lead to the formation of two maximum precipitation during the year, separated by drier periods. Every day, thousands of thunderstorms roll over the humid tropics. In between, the sun shines in full force.