Climatic features. What climate is typical for Russia: arctic, subarctic, temperate and subtropical. Maritime climate of temperate latitudes

Climatic conditions may change and transform, but in general they remain the same, making some regions attractive for tourism and others difficult to survive. It is worth understanding the existing species for a better understanding of the geographical features of the planet and a responsible attitude to the environment - humanity may lose some belts during global warming and other catastrophic processes.

What is climate?

This definition is understood as the established weather regime that distinguishes a particular area. It is reflected in the complex of all changes observed in the territory. Climate types affect nature, determine the state of water bodies and soils, lead to the emergence of specific plants and animals, and affect the development of economic and agricultural sectors. Formation occurs as a result of exposure to solar radiation and winds in combination with the variety of the surface. All these factors directly depend on the geographic latitude, which determines the angle of incidence of the rays, and hence the volume of heat production.

What affects the climate?

Different 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 farther the territory is from large 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 contributes to the growth of forests there. At the same time, Greenland, which has a similar location, is covered with ice all year round. Strongly affects the formation of climate and relief. The higher the terrain, the lower the temperature, so it can be cold in the mountains even if they are in the tropics. In addition, the ridges can delay why there is a lot of precipitation on the windward slopes, and much less on the continent. Finally, it is worth noting the impact of winds, which can also seriously change the types of climate. Monsoons, hurricanes and typhoons carry moisture and noticeably affect 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 the example of a particular country. The Russian Federation occupies a large area, and the weather in the country is very different. The table will help to study everything. The types of climates and the places where they prevail are distributed in it according to each other.

continental climate

Such weather prevails in regions located further beyond the maritime climate zone. What are its features? The continental type of climate is distinguished by sunny weather with anticyclones and an impressive amplitude of both annual and daily temperatures. Here, summer quickly turns into winter. The continental type of climate can be further divided into temperate, harsh and normal. The best example is the central part of the territory of Russia.

Monsoon climate

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

) having an atmosphere.

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Subtitles

if you remove all the lies from the story, this does not mean that only the truth will remain as a result, nothing may remain at all 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, they have such an operation on written sources until the 18th century with great care, since there is nothing easier than forging paper, it is much more difficult to forge, for example, buildings here and we will not rely on those evidence of which it is almost impossible to fake, and these facts should not be considered separately, but in aggregate, a lot can be said about the climate of the 18th century and earlier on 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 centuries 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 very large area of ​​windows the wall between the windows is equal to or even less than the width of the windows themselves and the windows themselves are very high amazing huge building but as we are assured this is a summer palace it was allegedly built to come here exclusively in summer the version is funny considering that summer in st. petersburg is rather cool and short if you look at the facade of the palace you can clearly see a very large area of ​​windows which is typical for southern hot regions they are for northern territories if in doubt make such windows in your house and then look at the heating bills and questions will immediately disappear later already at the beginning of the 19th century an extension was made to the palace where the famous lyceum where Alexander Sergeyevich Pushkin studied was located. under but Because of the new climatic conditions, the window area is noticeably smaller in many buildings, a heating system was not originally intended, and later they built it into the finished building, there is a lot of evidence for this. they designed it all over the country almost according to a standard project, and they forgot to provide for the stoves; there is no doubt that they were here there is no doubt another example is how a ska cavalier and a silver dining stove look just put in a corner wall decoration ignores the presence of a stove in this corner, that is, it was done before it appeared there if you look at the top you can see that it is not tight close to the wall It’s only hindered by the curly gilded arille 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 the Catherine’s Palace, do you believe that such stoves could somehow heat such a room, we are so used to listening to the opinion of authorities that often seeing it obviously we don’t believe let's put our eyes on various experts who have called themselves such, and let's try to abstract ourselves from the explanations of various historians, guides, local historians, that is, everything that is extremely easy to fake and distort and just try to see someone's fantasies, and what is reality, carefully look at this photo, this is the building of the Kazan Kremlin the building is as usual filled up with windows on the horizon there are no trees but that’s not about it now pay attention to the building in the lower right corner apparently this building has not yet been reconstructed for new climatic conditions the building on the left as we can see already with chimneys and before this building on apparently just ru 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 that they were made of chimneys later than the buildings themselves, these frames clearly show that they do not fit into the architectural ensemble of buildings the vestibules are made of a different material, apparently then it froze a lot then there was no time for frills, somewhere the vestibules were made as elegantly as possible and adjusted to the style of the building, but somewhere they didn’t bother at all and made a blunder, here in these frames you can see that there is no vestibule in the old photos of the temple and now it exists and the layman will never understand that something was once rebuilt here, here is another similar example, there is no vestibule on the old photo, but now it is, why did these thermal vestibules suddenly need so much for beauty, or maybe such a fashion was then don’t rush to draw conclusions first look at other facts further

Study Methods

To draw conclusions about the features of the climate, long-term series of weather observations are needed. In temperate latitudes, 25-50-year trends are used; 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 atmospheric precipitation. In addition, they study the duration of solar radiation, the duration of the frost-free period, the visibility range, the temperature of the upper layers of soil and water in reservoirs, the evaporation of water from the earth's surface, the height and condition of the 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 the temperatures of 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.

To assess future climate changes, models of the general circulation of the atmosphere are used [ ] .

climate-forming factors

The climate of the planet depends on a whole complex of astronomical and geographical factors that affect the total amount of solar radiation received by the planet, as well as its distribution over seasons, hemispheres and continents. With the onset 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 the Earth's rotation, the density of matter in the surrounding space. The rotation of the globe around its axis causes daily weather changes, the movement of the Earth around the Sun and the inclination of the axis of rotation to the plane of the orbit cause seasonal and latitudinal differences in 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, it is a constantly acting factor. Due to the rotation of the Earth, there are trade winds and monsoons, and cyclones are also formed. [ ]

Geographic factors

Geographic factors include

Influence of solar radiation

The most important element of the climate, influencing its other characteristics, primarily temperature, is the radiant energy of the Sun. Enormous energy released in the process of nuclear fusion on the Sun is radiated into outer space. The power of solar radiation received by a 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 flow, at a distance of one astronomical unit from the Sun outside the earth's atmosphere, is called solar constant. In the upper part of the earth's atmosphere, each square meter perpendicular to the sun's rays receives 1,365 W ± 3.4% of solar energy. The energy varies throughout the year due to the ellipticity of the earth's orbit, the greatest power is absorbed by the Earth in January. Despite the fact that about 31% of the received radiation is reflected back into space, the remaining part is enough to support 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 slope 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  Cancer and on December 22 south of the tropic  Capricorn, in the tropics the maximum (90 °) is reached 2 times a year.

Another important factor determining the latitudinal climatic regime is the length of daylight hours. Beyond the polar circles, that is, north of 66.5 ° N. sh. and south of 66.5 ° S. sh. the length of daylight varies from zero (in winter) to 24 hours in summer, at the equator a 12-hour day all year round. Since seasonal changes in the angle of inclination and length of the day are more noticeable at higher latitudes, the amplitude of temperature fluctuations during 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 the cloud cover, surface type, and terrain height, averaging 46% of that received into the upper atmosphere. Cloudiness that is always present, such as at the equator, contributes to the reflection of most of the incoming energy. The water surface absorbs the sun's 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 at high altitudes, due to the thinner atmosphere that scatters the sun's rays.

Atmospheric circulation

In the most heated 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. The movement of air occurs from a zone of high atmospheric pressure to a zone of low atmospheric pressure. Since the area is located closer to the equator and farther from the poles, 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 around its axis, so the Coriolis force acts on the moving air and deflects this movement to the west. In the upper layers of the troposphere, a reverse movement of air masses is formed: from the equator to the poles. Its Coriolis force constantly deflects to the east, and the farther, the more. And in areas around 30 degrees north and south latitude, movement becomes directed from west to east parallel to the equator. As a result, the air that has fallen into these latitudes has nowhere to go at such a height, and it sinks down to the ground. This is where the highest pressure area is formed. In this way, trade winds are formed - constant winds blowing towards the equator and to the west, and since the wrapping force acts constantly, when approaching the equator, the trade winds blow almost parallel to it. The air currents of the upper layers, directed from the equator to the tropics, are called antitrade winds. The trade winds and anti-trade winds, as it were, form an air wheel, along which a continuous circulation of air 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, in summer it is replaced by the opposite one. Such air transfers are called tropical monsoons. Cyclonic activity connects the tropical circulation zone with circulation in temperate latitudes, and between them there is an exchange of warm and cold air. As a result of interlatitudinal air exchange, heat is transferred from low to high latitudes and cold from high to low latitudes, which leads to the preservation of thermal equilibrium on Earth.

In fact, the circulation of the atmosphere 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, while cyclones deviate towards the poles, and anticyclones - away from the poles.

Climate types

The classification of the Earth's climates can be carried out both by direct climatic characteristics (W. Koeppen's classification), and based on the features of the general circulation of the atmosphere (B. P. Alisov's classification), or by the nature of geographical landscapes (L. S. Berg's classification). 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 differing at different moments and seasons. Nevertheless, the boundaries of climatic zones not only do not coincide with parallels, but do not even always go around 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 V. Köppen (1846-1940) is widespread in the world. It is based on the temperature regime and the degree of moisture. The classification has been repeatedly improved, and in the edition of 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 this type. Each type has exact parameters for temperature values, the amount of winter and summer precipitation, this makes it easier to assign a certain place to a certain type of climate, so the Köppen classification has become widespread.

On both sides of the low pressure band along the equator there are zones with high atmospheric pressure. Over the oceans here dominates 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 the mountainous islands. Tropical cyclones are relatively rare.

These oceanic regions 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 in the interior of 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, they 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 the trade winds is changing subequatorial, or tropical monsoon climate. Here, in summer, the intratropical 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 associated with the bulk of the precipitation falling here. The predominant types of vegetation are monsoon forests, forest avannas and tall grass savannas.

In the subtropics

In the zones of 25-40 ° north latitude and south latitude, subtropical climate types prevail, which are formed under the alternation of prevailing air masses - tropical in summer, moderate in winter. The average monthly air temperature in summer exceeds 20 °С, in winter - 4 °С. On land, the amount and regime of precipitation strongly depend on the distance from the oceans, as a result, landscapes and natural zones differ greatly. On each of the continents, three main climatic zones are clearly expressed.

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

In the east of the continents dominates monsoonal subtropical climate. The temperature conditions of the western and eastern margins of the continents differ little. Abundant precipitation brought by the oceanic monsoon falls here mainly in summer.

Temperate zone

In the zone of year-round dominance of moderate air masses, intense cyclonic activity causes frequent and significant changes in air pressure and temperature. The predominance of westerly winds is 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 ones - 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 distinguish it as an independent climatic 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, is characterized by dry (rainfall is not 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 the waterlogging of the area. Similar climate in the Southern Hemisphere - Subantarctic climate captures land only on the subantarctic islands and Graham's Land. In the Köppen classification, the subpolar or boreal climate is understood as the climate of the taiga growth zone.

Polar

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

climate and people

The climate has a decisive impact on the water regime, soil, flora and fauna, on the possibility of cultivating agricultural crops. Accordingly, the possibility of human settlement, the development of agriculture, industry, energy and transport, living conditions and the health of the population depend on the climate. Heat loss by the human body occurs by radiation, heat conduction, 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 wind increase the cooling effect. During weather changes, stress increases, appetite worsens, biorhythms are disturbed and resistance to diseases decreases. The climate determines the binding of diseases to certain seasons and regions, for example, pneumonia and influenza are mainly ill in winter in temperate latitudes, malaria is found in the humid tropics and subtropics, where climatic conditions favor the reproduction of malarial mosquitoes. The climate is also taken into account in health care (resorts, epidemic control, public hygiene), influences the development of tourism and sports. According to information from the history of mankind (famine, floods, abandoned settlements, migrations of peoples), it is possible to restore some of the climatic changes of the past.

Anthropogenic change in the environment for the functioning of climate-forming processes changes the nature of their course. Human activity has a marked effect on the local climate. Heat gain from fuel combustion, industrial pollution and carbon dioxide, which change the absorption of solar energy, cause an increase in air temperature, noticeable in large cities. Among the anthropogenic processes that have taken on a global character are

see also

Notes

1. (indefinite) . 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.

On Earth determines the nature of many features of nature. Climatic conditions also strongly influence the life, economic activity of people, their health and even biological characteristics. At the same time, the climates of individual territories do not exist in isolation. They are parts of a single atmospheric process for the entire planet.

Climate classification

The climates of the Earth, having similarities, are combined into certain types, which replace each other in the direction from the equator to the poles. In each hemisphere, 7 climatic zones are distinguished, of which 4 are main and 3 are transitional. Such a division is based on the distribution of air masses around the globe with different properties and features of air movement in them.

In the main belts, one air mass is formed throughout the year. In the equatorial belt - equatorial, in the tropical - tropical, in the temperate - the air of temperate latitudes, in the arctic (antarctic) - arctic (antarctic). In the transitional belts located between the main ones, in different seasons of the year, they alternately enter from the adjacent main belts. Here the conditions change seasonally: in summer they are the same as in the neighboring warmer zone, in winter they are the same as in the neighboring colder one. Along with the change of air masses in transitional zones, the weather also changes. For example, in the subequatorial zone, hot and rainy weather prevails in summer, while cooler and drier weather prevails in winter.

The climate within the belts is heterogeneous. Therefore, the belts are divided into climatic regions. Above the oceans, where sea air masses are formed, there are areas of oceanic climates, and above the continents - continental. In many climatic zones on the western and eastern coasts of the continents, special types of climate are formed that differ from both continental and oceanic ones. The reason for this is the interaction of sea and continental air masses, as well as the presence of ocean currents.

Hot ones include and. These areas constantly receive a significant amount of heat due to the large angle of incidence of sunlight.

In the equatorial zone, the equatorial air mass dominates throughout the year. The heated air in the conditions constantly rises, which leads to the formation of rain clouds. Heavy rainfall falls here daily, often from. The amount of precipitation is 1000-3000 mm per year. This is more than moisture can evaporate. The equatorial zone has one season of the year: it is always hot and humid.

Tropical air masses dominate throughout the year. In it, air descends from the upper layers of the troposphere to the earth's surface. As it descends, it heats up, and even over the oceans no clouds form. Clear weather prevails, in which the sun's rays strongly heat the surface. Therefore, on land, the average summer is higher than in the equatorial zone (up to +35 ° FROM). Winter temperatures are lower than summer temperatures due to a decrease in the angle of incidence of sunlight. Due to the absence of clouds throughout the year, there is very little rainfall, so tropical deserts are common on land. These are the hottest areas of the Earth, where temperature records are noted. The exception is the eastern shores of the continents, which are washed by warm currents and are under the influence of the trade winds blowing from the oceans. Therefore, there is a lot of precipitation here.

The territory of the subequatorial (transitional) belts is occupied in summer by a humid equatorial air mass, and in winter - by a dry tropical air mass. Therefore, there are hot and rainy summers and dry and also hot - because of the high standing of the Sun - winter.

temperate climatic zones

They occupy about 1/4 of the Earth's surface. They have sharper seasonal differences in temperature and precipitation than hot zones. This is due to a significant decrease in the angle of incidence of the sun's rays and the complication of circulation. They contain air from temperate latitudes all year round, but there are frequent intrusions of arctic and tropical air.

The southern hemisphere is dominated by an oceanic temperate climate with cool summers (from +12 to +14 °С), mild winters (from +4 to +6 °С) and heavy rainfall (about 1000 mm per year). In the Northern Hemisphere, large areas are occupied by the continental temperate and. Its main feature is the sharply pronounced changes in temperature throughout the seasons.

The western shores of the continents receive moist air from the oceans all year round, brought by the western temperate latitudes; there is a lot of precipitation (1000 mm per year). Summers are cool (up to + 16 °С) and humid, and winters are humid and warm (from 0 to +5 °С). In the direction from west to east inland, the climate becomes more continental: the amount of precipitation decreases, summer temperatures increase, and winter temperatures decrease.

A monsoon climate is formed on the eastern shores of the continents: summer monsoons bring heavy rainfall from the oceans, and frosty and drier weather is associated with winter monsoons blowing from the continents to the oceans.

Air from temperate latitudes enters the subtropical transitional zones in winter, and tropical air in summer. The mainland subtropical climate is characterized by hot (up to +30 °С) dry summers and cool (from 0 to +5 °С) and somewhat wetter winters. There is less precipitation in a year than it can evaporate, therefore deserts and prevail. There is a lot of precipitation on the coasts of the continents, and on the western coasts it is rainy in winter due to the western winds from the oceans, and on the eastern coasts in the summer due to the monsoons.

Cold climate zones

During the polar day, the earth's surface receives little solar heat, and during the polar night it does not heat up at all. Therefore, the Arctic and Antarctic air masses are very cold and contain little. The Antarctic continental climate is the most severe: exceptionally frosty winters and cold summers with freezing temperatures. Therefore, it is covered with a powerful glacier. In the Northern Hemisphere, a similar climate is in, and over the sea - arctic. It is warmer than the Antarctic, since ocean waters, even covered with ice, provide additional heat.

In the subarctic and subantarctic belts, the arctic (antarctic) air mass dominates in winter, and the air of temperate latitudes dominates in summer. Summers are cool, short and wet, winters are long, harsh and with little snow.

The country is located in middle and high latitudes, which is why there is a clear division into seasons. Atlantic air influences the European part. The weather there is milder than in the east. The polar ones receive the least sun, the maximum value is reached in the Western Ciscaucasia.

The territory of the country lies at once in four main climatic zones. Each of them has its own temperature and precipitation rates. From east to west, there is a transition from the monsoon climate to the continental one. The central part is characterized by a distinct delimitation of the seasons. In the south, the temperature rarely drops below 0˚C in winter.

Climatic zones and regions of Russia

Map of climatic zones and regions of Russia / Source: smart-poliv.ru

Air masses play a decisive role in the division into belts. Within them are climatic regions. Between themselves, they differ in temperature, amount of heat and moisture. Below is a brief description of the climatic zones of Russia, as well as the areas that they include.

arctic belt

It includes the coast of the Arctic Ocean. In winter, severe frost prevails, the average January temperature exceeds -30˚C. The western part is slightly warmer due to the air from the Atlantic. In winter, the polar night sets in.

The sun shines in the summer, but due to the small angle of incidence of the sun's rays and the reflective properties of the snow, heat does not linger near the surface. A lot of solar energy is spent on melting snow and ice, so the temperature regime of the summer period approaches zero. The Arctic belt is characterized by a small amount of precipitation, most of which falls in the form of snow. The following climatic regions are distinguished:

• Intraarctic;
• Siberian;
• Pacific;
• Atlantic.

The most severe is the Siberian region, the Atlantic is mild, but windy.

subarctic belt

It includes the territories of the Russian and West Siberian Plains, located mainly and forest-tundra. Winter temperatures increase from west to east. Summer rates average +10˚C, and even higher near the southern borders. Even in the warm season, there is a threat of frost. There is little precipitation, the main share falls on rains and sleet. Due to this, waterlogging is observed in the soil. In this climatic zone, the following areas are distinguished:

• Siberian;
• Pacific;
• Atlantic.

The lowest temperatures in the country were recorded in the Siberian region. The climate of the other two is moderated by cyclones.

Temperate zone

It includes most of the territory of Russia. Winters are snowy, sunlight reflects off the surface, causing the air to become very cold. In the summer, the amount of light and heat increases. In the temperate zone, there is a significant contrast between cold winters and warm summers. There are four main types of climate:

1) Temperate continental is in the western part of the country. Winters are not particularly cold thanks to the Atlantic air, and thaws often occur. The average summer temperature is +24˚C. The influence of cyclones causes a significant amount of precipitation in the summer.

2) Continental climate affects the territory of Western Siberia. Throughout the year, both arctic and tropical air penetrates into this zone. Winters are cold and dry, summers are hot. The influence of cyclones is weakening, so there is little precipitation.

3) Sharply continental climate dominates in Central Siberia. Throughout the territory there are very cold winters with little snow. Winter temperatures can reach -40˚C. In summer, the air warms up to +25˚C. Precipitation is scarce and falls as rain.

4) Monsoon type of climate prevails in the eastern part of the belt. In winter, continental air dominates here, and in summer - sea. Winter is snowy and cold. January figures are -30˚C. Summers are warm but humid, with frequent showers. The average July temperature exceeds +20˚C.

The following climatic regions are located within the temperate zone:

• Atlantic-Arctic;
• Atlantic-continental European (forest);
• Continental West Siberian northern and central;
• Continental East Siberian;
• Monsoon Far East;
• Pacific;
• Atlantic-continental European (steppe);
• Continental West Siberian southern;
• Continental Eastern European;
• Mountainous region of the Greater Caucasus;
• Mountain region of Altai and Sayan.

subtropical climate

It includes a small area of ​​the Black Sea coast. The mountains of the Caucasus do not allow air flow from the east, so it is warm in the Russian subtropics in winter. Summer is hot and long. Snow and rain fall all year round, there are no dry periods. In the subtropics of the Russian Federation, only one region is distinguished - the Black Sea.

Climatic zones of Russia

Map of climatic zones of Russia / Source: meridian-workwear.com

A climate zone is a territory in which the same climatic conditions prevail. The division arose due to uneven heating of the Earth's surface by the sun. There are four climatic zones on the territory of Russia:

• the first includes the southern regions of the country;
• the second includes the regions of the west, north-west, as well as Primorsky Krai;
• the third includes Siberia and the Far East;
• the fourth includes the Far North and Yakutia.

Along with them, there is a special zone that includes Chukotka and territories beyond the Arctic Circle.

The climate of the regions of Russia

Krasnodar region

The minimum January temperature is 0˚C, the soil does not freeze through. The fallen snow quickly melts away. Most of the precipitation falls in the spring, causing numerous floods. Summer temperatures average 30˚C, drought begins in the second half. Autumn is warm and long.

central Russia

Winter starts from the end of November and lasts until mid-March. Depending on the region, January temperatures range from -12˚C to -25˚C. A lot of snow falls, which melts only with the onset of thaws. Extremely low temperatures occur in January. February is remembered by winds, often hurricanes. Heavy snowfalls in the last few years occur at the beginning of March.

Nature comes to life in April, but positive temperatures are set only next month. In some regions, the threat of frost occurs in early June. Summer is warm and lasts 3 months. Cyclones bring thunderstorms and showers. Night frosts occur as early as September. There is a lot of rainfall this month. In October, a sharp cold snap occurs, foliage flies off the trees, it rains, sleet can fall.

Karelia

The climate is influenced by 3 neighboring seas, the weather is very changeable throughout the year. The minimum January temperature is -8˚C. A lot of snow falls. February weather is changeable: cold snaps are followed by thaws. Spring comes in April, the air warms up to + 10˚С during the day. Summer is short, really warm days are only in June and July. September is dry and sunny, but frosts are already occurring in some areas. The final cold weather sets in October.

Siberia

One of the largest and coldest regions of Russia. Winter is not snowy, but very cold. In remote areas, the thermometer shows more than -40˚C. Snowfalls and winds are rare. The snow melts in April, and in the region with heat comes only in June. Summer marks are + 20˚С, there is little precipitation. In September, calendar autumn begins, the air cools quickly. By October, the rains are replaced by snow.

Yakutia

The average monthly temperature in January is -35˚C, in the Verkhoyansk region the air cools down to -60˚C. Cold time lasts at least seven months. There is little rainfall, daylight hours last 5 hours. Beyond the Arctic Circle, the polar night begins. Spring is short, comes in May, summer lasts 2 months. During the white nights, the sun does not set for 20 hours. Already in August, a rapid cooling begins. By October, the rivers are covered with ice, and the snow stops melting.

Far East

The climate is varied, ranging from continental to monsoonal. The approximate winter temperature is -24˚C, there is a lot of snow. There is little rainfall in spring. Summer is hot, with high humidity, August is considered a period of prolonged rains. Fog dominates the Kuriles, white nights begin in Magadan. The beginning of autumn is warm but rainy. The thermometer marks in mid-October show -14˚C. A month later, winter frosts set in.

Most of the country lies in the temperate zone, some territories have their own climatic features. The lack of heat is felt in almost all belts. The climate has a serious impact on human activities, and it must be taken into account in agriculture, construction, and transport.

Chapter III

Climatic characteristics of the seasons of the year

seasons of the year

Under the natural climatic season. should be understood as a period of time of the year, characterized by the same type of meteorological elements code 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 conditional. The end of this season and the beginning of the next one can hardly be fixed by a certain date. This is a certain period of time on the order of several days, during which there is a sharp change in atmospheric processes, the radiation regime, the physical properties of the underlying surface and weather conditions.

The average long-term boundaries of the seasons can hardly be tied to the average long-term dates of the transition of the average daily temperature through certain limits, for example, summer is considered from the day the average daily temperature rises above 10 ° during its increase, and the end of summer - from the date the average daily temperature falls below 10 ° during its decline, as suggested by A. N. Lebedev and G. P. Pisareva.

In the conditions of Murmansk, located between the vast mainland and the water area of ​​the Barents Sea, when dividing the year into seasons, it is advisable to be guided by differences in the temperature regime over land and sea, which depends on the conditions for the transformation of air masses over the underlying surface. These differences are most significant in the period from November to March, when the air masses warm up over the Barents Sea and cool down over the mainland, and from June to August, when the air mass transformations over the mainland and the sea area are opposite to those in winter. In April and May, as well as in September and October, the temperature differences between sea and continental air masses smooth out to a certain extent. Differences in the temperature regime of the lower layer of air over land and sea form meridional temperature gradients that are significant in absolute value in the coldest and warmest periods of the year in the Murmansk region. In the period from November to March, the average value of the meridional component of the horizontal temperature gradient reaches 5.7°/100 km with the direction of the gradient to the south, towards the mainland, from June to August - 4.2°/100 km with the direction to the 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. These characteristics include the average monthly variability of the average daily air temperature, which depends on the direction of advection of air masses and partly on changes in the conditions of transformation from one day to another of the surface air layer with clearing or increasing cloudiness, increased wind, etc. We present the annual variation of the average inter - daily variability of air temperature in Murmansk conditions:

From November to March, in any of the months, the average monthly value of the daily temperature variability is greater than the average annual, from June to August it is approximately equal to 2.3 °, i.e. close to the average annual, and in other months - below the average annual. 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 from these days to the next (> 10 °) are most likely in winter (November-March) - 74 cases, somewhat less likely in summer (June-August) - 43 cases and the least probable in transitional seasons: in spring (April-May) -9 and in autumn (September-October) - only 2 cases in 10 years. This division is also confirmed by the fact that sharp fluctuations in temperature are largely associated with a change in the direction of advection, and, consequently, with temperature differences between land and sea. No less indicative for the division of 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 can be neglected in this case, 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, directly or indirectly related to temperature differences over the mainland and the sea, but it can already be considered obvious that the period from November to March should be attributed to 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 closely coincides 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 beginning of frosts, the end - with the onset of a steady frost. During spring, the average daily temperature rises by 11°, and during autumn it decreases by 9°, i.e., the temperature increase in spring and its decrease in autumn reaches 93% of the annual amplitude.

Winter

The beginning of the winter season coincides with the average date of the formation of stable snow cover (10 November) and the beginning of the period with stable frost (12 November). 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° a little earlier, even in autumn (October 17), and in the first half of the season it continues to decrease further: passing through -5° on November 22 and through -10° on January 22. January and February are the coldest months of winter. From the second half of February, the average temperature begins to rise and on February 23 passes through -10 °, and at the end of the season, on March 27 - through -5 °. In winter, on clear nights, severe frosts are possible. Absolute lows 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°C 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 западных направлениях ветра. При уменьшении облачности и ослаблении ветра оттепель обычно прекращается.

Round-the-clock 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 of the months, significant anomalies in the average monthly air temperature are possible. So, for example, with an average long-term air temperature in February equal to -10.1 °, the average temperature in February in 1959 reached -3.6 °, that is, it was 6.5 ° above the norm, and in 1966 decreased to -20.6°, i.e., was below the norm by 10.5°. Similar significant air temperature anomalies are also 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 to the southeast to the Kara Sea. In the warm sectors of these cyclones, very warm masses of Atlantic air are brought 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, which was warmer than the norm by almost 3°, can be attributed to the number of abnormally warm ones. 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. There was no such warm February during the years of observations not only in Murmansk since 1918, but also at st. Cola since 1878, that is, 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 the average long-term values. The trajectories of cyclones and anticyclones are shown in Figs. 19, which shows that during the whole month cyclones moved from Iceland through the Norwegian and Barents Seas, carrying warm Atlantic air to the north of the European territory of the USSR, anticyclones - from west to east along more southern trajectories than in ordinary 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/s. 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 the norm. For the whole month there was only one clear day with lower cloudiness at a norm of 5 days and 8 overcast days at a norm of 6 days. Similar anomalies of other meteorological elements were observed in the anomalously warm March of 1969, the average temperature of which exceeded the norm by more than 5°. In December 1958 and January 1959 a lot of snow fell. However, by the end of winter, it almost completely melted. In table. Figure 37 shows observational data for the second half of the winter of 1958-59, from which it can be seen that the transition of the average temperature through -10° during the period of its increase took place 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, one can indicate the winter of 1965-66. In that winter, the average seasonal temperature was almost 6 ° lower than the long-term average for this season. The coldest months were February and March. Such cold months 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 cyclones were located south of the Kola Peninsula, and those of anticyclones were located above the extreme northwest of the European territory of the USSR. There were episodic inflows of continental Arctic air from the Kara Sea, which also caused significant and persistent cooling.

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 cloudiness and wind speed. Thus, the average wind speed reached 4.2 m/s, or was below the norm by 2.5 m/s. There were 8 clear days in terms of lower cloudiness this month at a norm of 6 and only one cloudy day at the same norm. During December, January, 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 from December to March. The Kola Bay is covered with ice very rarely and only in exceptionally cold winters. In the winter of 1965-66, a long continuous ice cover was established in the Kola Bay in the region of Murmansk: once in February and once in March * and loose, sparse ice with streaks was observed in most of February and March and sometimes 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 steady transition of the average temperature through -15° and the duration of the period with temperatures below this limit reached 57 days, which is very rare. A stable cooling with the transition of the average temperature through -15 ° is observed on average only for 8% of winters. In the winter of 1965-66, anti-Dyclonic weather prevailed not only in February, but throughout the season.

The predominance of cyclonic processes over the Norwegian and Barents Seas and anticyclonic processes over the mainland in ordinary winters determines the predominance of the wind (from the mainland) of the southern 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 opposite wind directions from the sea is much less, and it is 16% in November, 11% in December and January, 14% in February and 21% in March. With the southerly wind direction of the highest frequency, the lowest average temperatures are observed, and with the northerly direction, which is much less likely in winter, the highest. 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 average annual, and the largest, about 7 m/sec., occurs in the middle of the season (January). Number of days with storm ≥ 15 m/s. reaches 36 or 67% of their annual value in winter; in winter, wind intensification up to a hurricane ≥ 28 m/s is possible. However, hurricanes in Murmansk are also unlikely in winter, when they are observed once every 4 years. The most likely storms are from the south and southwest. Probability 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 the absolute moisture content and the lack of saturation. The diurnal variation of these humidity characteristics is practically absent in winter, 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. In most of the winter, up to February inclusive, diurnal periodic fluctuations in relative humidity associated with a certain time of the day are absent and become noticeable only in March, when their amplitude reaches 12%. Dry days with relative humidity ≤30% are completely absent for at least one of the observation periods in winter, and wet days with relative humidity ≥ 80% at 1 pm prevail and are observed on average on 75% of the total number of days in the season. A noticeable decrease in the number of wet days is observed at the end of the season, in March, when the relative humidity decreases during the daytime due to the warming of the air.

Precipitation occurs more frequently 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 their average duration per day with precipitation fluctuates around 10 hours in winter. In 52% of the total number of days with precipitation, their amount does not even reach 0.1 mm. Often, light snow falls intermittently over a number of days without causing an increase in snow cover. Significant precipitation ≥ 5 mm per day is quite rare in winter, only 4 days per season, and even more intense precipitation over 10 mm per day is very unlikely, only 3 days per 10 seasons. The greatest 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 their 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 prevails. Their share of the total for the entire season is 88%. Mixed precipitation in the form of snow with 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 their total seasonal amount. Liquid and mixed precipitations are most probable (32%) in November, in which thaws are most frequent, these precipitations are least probable in January (2%).

In some months, depending on the frequency of cyclones and synoptic positions characteristic of precipitation with charges, their monthly number can vary widely. December 1966 and January 1967 can be cited as an example of significant anomalies in monthly precipitation. The circulation conditions of these months are described by the author in his work. In December 1966, only 3 mm of precipitation fell in Murmansk, which is 12% of the long-term average for that month. The height of the 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, the 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, in January 1967, frequent precipitation was observed in charges, accompanied by strong winds and snowstorms. This caused frequent snow drifts, which hampered the work of transport.

In winter, all atmospheric phenomena are possible, except for hail. The average number of days with various atmospheric phenomena is given in Table. 38.

From the data in Table. 38 shows that evaporation fog, blizzard, fog, hoarfrost, ice and snow have the highest frequency in the winter season, and therefore are characteristic of it. Most of these winter atmospheric phenomena (evaporative fog, blizzard, fog and snowfall) reduce 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 branches of the national economy. Therefore, the winter season is the most difficult for the production activities of all sectors of the national economy.

Due to the short duration 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 observed for the entire month. At the end of winter, due to the rapid increase in the length of the day and the decrease in cloudiness, the average number of hours of sunshine increases to 32 hours 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 daily 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, with clear or slightly cloudy and calm weather, daytime thaws are possible with significant cooling at night, up to -10, -15 °.

During the 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 late, and in warm springs, they may be ahead of the average multi-year dates.

In the spring, on cloudless nights, in the masses of cold Arctic air, a significant drop in temperature is still possible: down to -26 ° in April and down to -11 ° in May. With advection of warm air from the mainland or from the Atlantic, in April the temperature can reach 16°, and in May +27°. In April, on average, up to 19 days with a thaw are observed, of which 6 are with a thaw during the whole day. In April, with winds from the Barents Sea and significant cloudiness, an average of 11 days are observed without a thaw. In May, thaws are observed even more often for 30 days, of which, on 16 days, frost is completely absent throughout the day.

Round-the-clock frosty weather without a thaw in May is very rare, on average one day a 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 there are 4 hot days in 10 years, and then only with southerly and southwesterly winds.

The average monthly air temperature from March to April rises 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 of the spring months can differ significantly from the norm (long-term average). For example, the average long-term temperature in May is 3.1°C. In 1963, it reached 9.4°, i.e., exceeded the norm by 6.3°, and in 1969 it dropped to 0.6°, i.e., was below the norm by 2.5°. Similar anomalies of the mean monthly temperature are possible in April as well.

The spring of 1958 was rather cold. The average temperature in April was below the norm by 1.7°, and in May - by 2.6°. The average daily temperature passed through -5° 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). Trajectories of cyclones, as can be seen from Fig. 21, passed south of the Kola Peninsula, and anticyclones prevailed over the Barents Sea. Such a direction in the development of atmospheric processes determined the predominance of advection of cold Arctic air masses from the Barents Sea, and sometimes from the Kara Sea.

The highest frequency of wind of various directions in the spring of 1958, according to Fig. 22 was observed for northeast, east, and southeast winds, which usually bring the coldest continental arctic air to Murmansk from the Kara Sea. This causes a significant cooling in winter and especially in spring. In May 1958, there were 6 days without a thaw at a norm of 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 indicated as warm, in which April and especially May were warm. The average air temperature in the spring of 1963 passed through 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., it exceeded the norm by more than 6°. There has never been such a warm May as in 1963 for the entire observation period of Murmansk station (52 years).

On fig. 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. During the whole month, Atlantic cyclones moved to the 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 for spring winds of the southern and south-western 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° at a norm of 1.6 days and 2 days with an average daily temperature of >15° at a norm of 2 days per day. 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 humidity was below the norm by 4%, on clear days it was 3 days more than the norm, and on cloudy days it was 2 days less than the norm. Warm weather in May 1963 caused an early melting of the snow cover, at the end of the first decade of May, that is, 11 days earlier than usual

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

In April, the winds of the southern and southwestern directions still prevail, the frequency of which is 26% higher than the frequency of the wind 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 a return of cold weather, often observed in early May. This is clearly seen from the average ten-day temperature data (Table 39).

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

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

The most significant change in wind speed characteristics is observed in early spring (in April). In the speed and direction of the wind in spring, especially in May, a 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 amplitude of frequency of wind directions from the Barents Sea (northern, northwestern and northeastern) increases from 6% in April to 10% in May.

In connection with the increase in temperature, the relative humidity of the air decreases in spring from 74% in April to 70% in May. An increase in the amplitude of daily fluctuations in air temperature 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 in 10 years, in May they occur more often, 1.4 days annually. The average number of wet days with relative humidity ≥ 80% for 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 in 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 probability of clear weather in the morning and at night is greater than in the afternoon and evening.

In spring, the diurnal variation of various cloud forms can be clearly seen (Table 40).

Convective clouds (Cu and Cb) are most likely during the day at 12:00 and 15:00 and least likely at night. The probability of Sc and St clouds changes during the day in reverse order.

In spring, an average of 48 mm of precipitation falls (according to precipitation gauge data), of which 20 mm in April and 28 mm in May. In some years, the amount of precipitation both in April and May can differ significantly from the long-term average. According to precipitation measurements, the amount of precipitation in April varied 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 the deficit of precipitation in spring is caused by the predominance of anticyclonic processes, and the excess is caused by the increased frequency of southern cyclones passing through Murmansk or near it.

The intensity of precipitation also increases markedly in spring, hence the maximum amount of precipitation per day. So, in April, the daily amount of 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, a significant daily amount of precipitation falls during heavy rain or snowfall. Heavy rainfall in spring does not yet provide a large amount of moisture, since they are usually short-lived and not yet intense enough.

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

All atmospheric phenomena, except for various types of precipitation, have a very low frequency in spring, the smallest in the year. The recurrence of harmful phenomena (fog, blizzard, evaporative fog, ice and frost) is much less than in winter. Atmospheric phenomena such as fog, hoarfrost, evaporative fog and ice in the spring usually break up during the daytime hours. 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 worsen horizontal visibility, the latter improves markedly in spring. The probability of poor visibility below 1 km decreases to 1% in April and to 0.4% of the total number of observations in May, while the probability of good visibility over >10 km increases to 86% in April and 93% in May.

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

Summer

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

The average maximum air temperature from June 2 to 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 quarter of the end of the frost-free period, September 1.

Frosts in summer are possible until June 12 and then stop until the end of the season. During the round-the-clock day, advective frosts predominate, which are observed during cloudy weather, snowfall and strong winds, radiation frosts are less common on sunny nights.

During most of the summer, average daily air temperatures from 5 to 15°C prevail. Hot days with a maximum temperature above 20° are not frequent, with an average of 23 days over 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%. The hot weather is mainly observed during winds from the mainland and is most pronounced during the south and southwest winds. The highest temperature on hot summer days can reach 31° in June, 33° in July and 29° in August. In some years, depending on the prevailing direction of air mass inflow from the Barents Sea or the mainland, the average temperature in any of the summer months, especially in July, can vary widely. Thus, at an average long-term July temperature of 12.4° in 1960, it reached 18.9°, i.e., it exceeded the norm by 6.5°, and in 1968 it dropped to 7.9°, i.e. .was below the norm by 4.5°. Similarly, the dates of the transition of the average air temperature through 10° may fluctuate in individual years. The dates of the transition through 10°, which are possible once every 20 years (5 and 95% probability), may differ by 57 days in Nala 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. There are significant imputations in individual years and the number of days with hot weather per month and season.

The warmest summer for the entire period of observations was in 1960. The mean seasonal temperature during this summer reached 13.5°C, i.e., it was 3°C higher than the long-term average. The warmest this summer is 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 a norm of 2 days. Continuous hot weather persisted from 30 June to 3 July. Then, after a short cold snap, from 5 to 20 July, hot weather set in again. From July 21 to July 25, the weather was cool, which from July 27 until the end of the month again changed to very hot with maximum temperatures over 30 °. The average daily temperature during the whole month was kept above 15°, i.e., a steady transition of the average temperature through 15° was observed.

On 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, the cyclones passed over the Norwegian Sea and Scandinavia in a northerly direction and brought very warm continental air to the Kola Peninsula. The predominance of a very warm southern and southwestern wind in July 1960 is clearly seen from the data in Figs. 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. Due to the smoke of 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 in the fishing port, which was not adapted to work in conditions of stable hot weather, fresh fish spoiled.

The summer of 1968 was anomalously cold. The average seasonal temperature in that summer was almost 2° below the norm; only June was warm, the average temperature of which exceeded the norm by only 0.6°. July was especially cold, and August was also cold. Such a cold July for the entire period of observations in Murmansk (52 years) and at Kola station (92 years) has not yet been observed. The average temperature in July was below the norm by 4.5°; for the first time in the entire period of observations in Murmansk, there was not a single hot day with a maximum temperature of more than 20 °. Due to the repair of the heating plant, which is timed to coincide with the end of the heating season, it was very cold and damp in apartments with central heating.

The anomalously cold weather in July, and partly in August 1968, was due to the predominance of a very stable advection of cold air from the Barents Sea. As can be seen from fig. On July 27, 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, consequently, the advection of the Atlantic, and even more so of the continental air to the Kola Peninsula, was absent and the advection of cold air from the Barents Sea prevailed (Fig. 28). The characteristics of the anomalies of meteorological elements in July are given in Table. 42.

July 1968 was not only cold, but wet and cloudy. It can be seen from the analysis of two anomalous Julys that the warm summer months are formed due to the high frequency of continental air masses, bringing cloudy and hot weather, and the cold ones, due to the predominance of the wind from the Barents Sea, which brings cold and cloudy weather.

Northern winds prevail in Murmansk in summer. Their recurrence for the whole season is 32%, southern - 23%. Just as rarely as in other seasons, east and southeast and west winds are observed. The repeatability of any of these directions is not more than 4%. The northern winds are most probable, their frequency in July is 36%, in August it decreases to 20%, i.e., already 3% less than the southern ones. During the day, the direction of the wind changes. The breeze daily fluctuations in wind direction are especially clearly visible in low-wind, clear and warm weather. However, breeze fluctuations are also clearly visible in the average long-term frequency of wind direction at different hours of the day. Northerly winds are most likely in the afternoon or evening, southerly winds, on the contrary, are most likely in the morning and least likely in the evening.

The lowest wind speeds are observed in Murmansk in summer. The average speed for the season is only 4.4 m/s, at 1.3 m/s. less than the annual average. The lowest wind speed is observed in August, only 4 m/s. In summer, weak winds up to 5 m/s are most likely, the probability of such speeds varies from 64% in July to 72% in August. Strong winds ≥ 15 m/s are unlikely in summer. The number of days with strong winds for the entire season is 8 days, or only about 15% of the annual amount. 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 wind speed amplitude fluctuates around 2 m/sec in summer, which is 44-46% of the average daily wind speed. Light winds, less than 6 m/s, 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 of a short duration.

Significant heating of air masses and their moistening due to evaporation from moist soil in summer, compared with other seasons, causes an increase in the absolute moisture content of the surface air layer. The average seasonal pressure of water vapor reaches 9.3 mb and increases from June to August from 8.0 to 10.6 mb. During the day, fluctuations in water vapor elasticity are small, with an amplitude of 0.1 mb in June to 0.2 mb in July and up to 0.4 mb in August. In summer, the lack of saturation also increases, since an increase in temperature causes a faster increase in the moisture content of 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 humidity are significant. The highest relative air humidity is observed on average after midnight and, therefore, its maximum value coincides with the daily temperature minimum. The lowest relative air humidity is observed on average in the afternoon, at 2 or 3 pm, and coincides with the daily temperature maximum. According to hourly data, the daily amplitude of relative air humidity 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% is least likely in June and most likely in August. Most probable in summer and dry days with relative humidity ≤30% for any of the observation periods. The average number of such days varies from 2.4 in June to 1.5 in July and up to 0.2 in August. Humid days with relative humidity at 13:00 ≥ 80%, even in summer, are more common than dry days. The average number of wet days ranges from 5.4 in June to 8.7 in July and 8.9 in August.

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

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

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

Cumulus clouds are possible between 09:00 and 18:00 and have a maximum frequency around 15:00. Cumulonimbus clouds are least likely in the summer at 3 o'clock, most likely as well as cumulus, around 15 o'clock. Stratocumulus Clouds, Formed during the summer by the breakup of powerful cumulus clouds, are most likely around noon and least likely at night. The stratus clouds, carried from the Barents Sea in summer as a raised fog, are most likely at 6 o'clock, and least likely at 15 o'clock.

Precipitation during the summer months falls mainly as rain. Wet snow falls, and even then not annually, 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, the monthly amount of 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%

The excess of precipitation in the summer months is due to the increased frequency of southern cyclones, and the deficit is due to stable anticyclones.

For the entire summer season, there are an average of 46 days with precipitation up to 0.1 mm, of which 15 days fall in June, 14 in July and 17 in August. Significant precipitation with an amount of ^ 10 mm per day is rare, but more frequent than in other seasons. In total, during the summer season, on average, about 4 days are observed with daily precipitation of ^10 mm and one day with precipitation of ^20 mm. Daily precipitation of ^30 mm is 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 in the summer months occurs during long continuous rains. Showers of thunderstorm character very seldom give significant daily amounts.

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

Of the atmospheric phenomena in summer, only thunderstorms, hail and fog are possible. In early July, a snowstorm is still possible, no more than one day in 25 years. A thunderstorm in summer is observed annually, on average, about 5 days per season: 2 of them in June-July and one day in August. The number of thunderstorm days varies greatly from year to year. In some years, in any of the summer months, a thunderstorm may be absent. The greatest number of thunderstorm days ranges from 6 in June and August to 9 in July. Thunderstorms are most likely during the day, 12:00 to 18:00 and least likely at night, from 00:00 to 06:00. 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 hours mainly at northern winds. The smallest number of days with fog, only 4 days in 10 months, is 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 snowfalls and fogs, as well as haze or haze, the best horizontal visibility is observed in Murmansk in summer. Good visibility ^10 km has a frequency of 97% in June to 96% in July and August. Good visibility is most likely in any of the summer months at 1 pm, least likely at night and in the morning. The probability of poor visibility in any of the summer months is less than 1%; visibility in any of the summer months is less than 1%. The largest number of hours of sunshine falls on June (246) and July (236). In August, due to a decrease in day length and an increase in cloudiness, the average number of sunshine hours decreases to 146. However, due to cloudiness, the actually observed number of sunshine hours 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 it 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 temperature anomalies of different signs were observed in September and October in adjacent years. The warmest autumn for the entire period of observations in Murmansk was in 1961. Its average temperature exceeded the norm by 3.7°. October was especially warm this autumn. Its average temperature exceeded the norm by 6°. Such a warm October for the entire observation period in Murmansk (52 years) and at st. Cola (92 years old) was not there yet. In October 1961 there was not a single day with frosts. 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 anomalously warm October 1961, anticyclones prevail 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 Sea 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 the south and southwest wind was 79% at a norm of 63%, and the north, northwest and northeast winds were only 12% at 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 of three such days, and the average value of the lower cloudiness reached 7.3 points against the norm of 6.4 points.

In the autumn of 1961, the autumn dates for the transition of the average air temperature through 5 and 0° were late. 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 attributed to the number of cold ones. Its average temperature was below the norm by 1.4°. October was especially cold this autumn. His average temperature was below the norm by 3.8°. There was no such cold October as in 1960 for the entire observation period in Murmansk (52 years). As can be seen from fig. 30, in cold October 1960, active cyclonic activity prevailed over the Barents Sea, just as in October 1961. But in contrast to October 1961, the cyclones moved from Greenland to the southeast to the upper reaches of the Ob and Yenisei, and in their rear, very cold Arctic air occasionally penetrated into the Kola Peninsula, causing short, significant cooling 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 anomalously high temperatures, as in 1961, and therefore did not cause significant warming.

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

In autumn, the winter mode of the prevailing wind direction gradually sets in. The frequency 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 south and southwest directions increases from 34% in August to 49%) in September and 63% in October.

In autumn, the daily frequency of the wind direction is still preserved. So, for example, the north wind is most likely in the afternoon (13%), and the least likely in the morning (11%), and the south wind is most likely in the morning (42%) and the least likely in the afternoon and evening (34%).

An increase in the frequency and intensity of cyclones over the Barents Sea in autumn causes a gradual increase in wind speed and the number of days with a strong wind of ^15 m/sec. 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, that is, almost four times. Daily periodic fluctuations in wind speed gradually fade in autumn. The probability of weak wind decreases in autumn.

In connection with the decrease in temperature in autumn, the absolute moisture content of the surface air layer gradually decreases. The 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, and in September and October it reaches only 0.2 mb. The lack of saturation also decreases in autumn from 4.0 mb in August to 1.0 mb in October, and the daily periodic fluctuations of this value gradually fade. So, for example, the daily amplitude of the lack of saturation decreases from 4.1 mb in August to 1.8 mb in September and to 0.5 mb in October.

Relative humidity increases in autumn 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 from the direction of the wind. There are no dry days with relative humidity ^30% for any of the periods of observations in autumn, and the number of wet days with relative humidity at 13 hours ^80% 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 (highly stratified 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 subinversion 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 for lower cloudiness from 9.6 in August to 11.5 in September.

In October, the average number of clear days reaches an annual minimum, and cloudy days reach an 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, consequently, with the highest probability and intensity of inversion. In September, the daily frequency of recurrence of cumulus Cu and stratocumulus Sc clouds is still traced (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 falls in the form of rain, snow and sleet with rain. The share of liquid precipitation in the form of rain reaches 66% of their seasonal amount in autumn, while 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. So, in September, the monthly amount of precipitation can vary from 160 to 36%, and in October from 198 to 14% of the monthly norm.

Precipitation falls more frequently in autumn than in summer. The total number of days with precipitation, including the days when they were observed, but their 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 rarer, only 4.6 days per season. Abundant precipitation of ^10 mm per day falls even less frequently, 1.4 days per season. Precipitation ^20 mm in autumn is very unlikely, only one day in 25 years. The largest daily precipitation of 27 mm fell in September 1946 and 23 mm in October 1963

For the first time, the snow cover is formed on October 14, and in the cold and early autumn on September 21, but in September the fallen snow does not cover the soil for long and always disappears. A stable snow cover is formed already in the next season. In an abnormally cold autumn, it can form no earlier than October 5th. In autumn, all atmospheric phenomena observed in Murmansk during the year are possible (Table 45)

From the data in Table. 45 shows that fog and rain, snow and sleet are most often observed in autumn. Other phenomena characteristic of summer, thunder and hail, cease in October. Atmospheric phenomena characteristic of winter - a blizzard, fog of evaporation, ice and frost - causing the greatest difficulties to various sectors of the national economy, are still unlikely in autumn.

An increase in cloudiness and a decrease in the length of the day 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 increase in the frequency of snowfalls and fogs, as well as haze and air pollution by industrial facilities, a gradual deterioration in horizontal visibility is observed in autumn. The frequency of good visibility over 10 km decreases from 90% in September to 85% in October. The best visibility in autumn is observed during the daytime, and the worst - at night and in the morning.