Report on the climate of Antarctica. Warmest month in Antarctica

Perhaps there is no place in the world more mysterious than Antarctica. The vast expanses of ice could tell a lot about what the Earth was like millions of years ago. But nature is in no hurry to reveal its secrets, and people return here again and again, fighting the cold and blizzard.

Antarctica is ice heart Antarctica: on an area of ​​13 million 661 thousand km 2 there are 30 million km 3 of ice! Geographical lines pass through the continent South Pole, pole of cold (-89.2 °C - the lowest temperature), pole of inaccessibility, conquered by a Soviet expedition in 1958, South geomagnetic pole.

The territory of the mainland does not belong to any country. In Antarctica, you cannot develop mineral resources or carry out production work - only scientific activity, therefore, in addition to seals and penguins, the mainland is inhabited by scientists from different countries. Only well-trained people, strong in spirit and body, live and work here. The reason for this is extreme conditions and harsh climate.

Features of the climate of Antarctica

The warmest time on the mainland occurs from November to February - this is spring and summer in the Southern Hemisphere. On the coast the air can warm up to 0°C, and near the cold pole the temperature rises to -30°C.

Summer in Antarctica is so sunny that you should never forget about sunglasses - you can seriously damage your eyesight. And you can’t do without lipstick either - without it, your lips instantly crack, and it’s impossible to eat or speak. Why then is it so cold, but the glaciers are not melting? Almost 90% of solar energy is reflected from ice and snow cover, and if we take into account that the continent receives solar heat mainly in the summer, it turns out that during the year Antarctica loses more heat than it gains.

The lowest temperature is from March to October, autumn and winter in Antarctica, when the thermometer drops to -75°C. This is a period of severe storms, planes do not fly to the mainland, and polar explorers find themselves cut off from the rest of the world for 8 long months.

Polar day and polar night in the Southern Hemisphere

Photo of the aurora near McMurdo Station, July 15, 2012

In Antarctica, as well as in the Northern Hemisphere, there is a polar night and a polar day, which last around the clock. If we rely only on astronomical calculations, then December 22, on the day summer solstice In the Southern Hemisphere, the sun should only be halfway below the horizon at midnight and then rise again. And June 22, on the day winter solstice- only half appear on the horizon at noon, and then disappear. But there is astronomical refraction - optical phenomenon associated with the refraction of light rays. Thanks to refraction, we see luminaries before they appear above the horizon, and for some time after they set. Therefore, the usual change of day and night occurs only in spring and autumn. In winter there is polar night, and in summer there is polar day.

Nature of Antarctica

Peculiar business card Antarctica - penguin. Several species of these funny birds live here: on the continental coast - emperor, king, gentoo, and Adelie penguins. And on the Antarctic and subantarctic islands live the crested, arctic, and golden-haired penguins.

There are other birds: petrels (Antarctic, snowy, silver-gray), skuas,

Antarctica is the habitat of several species of seals: Weddell seal, Ross seal, crabeater seal, southern elephant seal, leopard seal, Kerguelen fur seal.

Whales live here: blue whale, flat-faced bottlenose, sperm whale, killer whales, sei whale, southern minke whale.

It's hard to imagine, but even here, on icy continent, there is vegetation. Lichens, cereals and clove herbs, whose height does not exceed 1 cm, and some types of moss, hide in the crevices of rocks.

Polar stations of Antarctica

The photograph shows a view of the Antarctic McMurdo Station, November 2011

Most of the stations are located in the coastal zone of the continent, and only three of them are inland. These are the American Amundsen-Scott base, the French-Italian Concordia base and the Russian Vostok base.

Associated with the discovery of the “East” interesting story. When in the early 50s, at a meeting in Paris, questions about the development of Antarctica were decided, our delegation was given the task: to prove at all costs that Soviet Union there are enough resources to maintain the operation of the station at the southernmost geographic pole. But due to delays with passports and visas, our delegate was late for the start of the meeting, and this place had already been promised to the Americans. We got the South Geomagnetic Pole and the Pole of Inaccessibility. In 1957, the South Geomagnetic Pole was founded scientific station"East". And after 50 years, scientists managed to get a water sample underground lake, located, as it turned out, right under the station! Fifth in volume fresh water Hidden under ice at a depth of almost 4,000 m, Lake Vostok sheds light on the origins of the Earth and life on Earth. This is incredible luck!

The photo shows a spring sunset near the Palmer Arctic station, March 31, 2011

There are a total of 5 located in Antarctica Russian bases, working all year round: “Bellingshausen”, “Mirny”, “Vostok”, “Progress”, “Novolazarevskaya”. Scientists study the atmosphere, weather, ice, movement earth's crust. All bases have the most comfortable conditions: in addition to everything necessary for work, there are rest rooms, gym, billiards, library. IP-telephony and Internet access have been established, channel 1 is broadcast.

The closest neighbors of the scientists from the Novolazarevskaya base are specialists from India. The name of their base - "Maitri" - means "friendship" and best describes the relationship between the polar explorers. By the way, a warm, friendly atmosphere has always been here. Even during Cold War scientists conducted joint research and used each other’s work.

The photo shows a satellite communication dish on Antarctic station McMurdo

Except traditional holidays the bases mark the beginning and end of each expedition. At the gala dinner, a symbolic handover of the key to the station takes place. Despite see you soon with relatives, scientists leaving the station involuntarily envy those who remain for the winter - Antarctica does not let go. Cold, blizzardy, but so beautiful.

The material contains information about what climatic zones the mainland territory lies in. Tells about the history of the development of the continent. Explains the cause of climate change.

Antarctica is an extremely harsh continent by climatic standards globe. Almost the entire continental surface lies in the range where the air temperature does not rise above zero degrees. This is explained by the presence of the Antarctic Plate at the South Pole.

Antarctica wasn't always like this. During the Mesozoic period, when Pangea was still at the stage of splitting, the planet's climate was humid and warmer.

Rice. 1. Pangea.

After millions of years, continental lands fell into the polar region earth's surface. This caused the glaciation of Antarctica and marked the beginning of cooling throughout the planet. This is clearly expressed in the territories of the Southern Hemisphere.

Then other changes on a planetary scale occurred.

Cold currents began to form around Antarctica under the influence of the Western winds. These processes were expressed in a general cooling throughout the planet, glaciation of the polar regions, and the emergence of vast desert areas. The climate acquired more severe features, and at the same time became arid.

In what climatic zones is Antarctica located?

Two climate zones pass through Antarctica:

• Antarctic;
• subantactic.

At times, the region of the northern part of the Antarctic Peninsula is classified as a temperate zone.

Rice. 2. Climatic zones of Antarctica.

The Antarctic belt dominates almost all continental zones. The ice shell that covers this territory is up to 4,500 thousand meters thick. Thanks to this, Antarctica is the highest continent on the planet. Ice on the continental territory serves as a climate-forming component. Ice crust reflects up to 90% sun rays. This factor prevents the Sun from heating the surface of the continent. The climate is extremely harsh in the continental regions of Antarctica. There is almost never any precipitation there.

IN certain places total quantity precipitation is less than 50 mm. for calendar year. In the main zone of operation of the belt, this figure is less than 250-100 mm.

The temperature range in the interior of the continent during the polar night can drop to minus 64°C. IN summer period When the sun does not set, the temperature is close to minus 32°C. The planet's pole of inaccessibility passes here.

Rice. 3. Ice deserts.

An extremely low temperature of minus 89°C was recorded at the Vostok polar station.

The subantarctic belt runs along the northern part of the peninsula. Natural conditions in this area are somewhat milder. The amount of precipitation reaches levels above 500 mm. per year. In summer, temperatures rise above 0°C. The ice crust in these areas is much thinner and in some places turns into bare rocks, which are covered with mosses and lichens.

What have we learned?

We found out what factors influenced sudden changes climate over millions of years. We learned about critical temperature values. Studied climatic zones Antarctica and remembered that there are only two of them - Arctic and Subarctic.

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One of the reasons for the severity of Antarctica's climate is its altitude (the highest continent on the planet). As is known, with altitude, the air temperature at the Earth's surface drops by an average of 0.6°C for every 100 m of rise. In this regard, Antarctica should be 6-7 °C colder than any continent. However, the root cause of glaciation is not altitude, but geographical location circumpolar sixth continent: the further from the equator to the pole, the less solar heat a unit of the Earth's surface receives due to the greater inclination of the sun's rays. An additional reason for the cooling is that there is land around the pole, not ocean. Soil absorbs 70% solar radiation, and the ocean is more than 90%. The snow-ice surface of Antarctica absorbs only 10 - 20% of solar radiation; Like a giant mirror, it reflects 90% of the sun's rays into outer space.

A very cold layer of air forms over the glacial surface of Antarctica, in which the temperature does not fall with height, but increases, i.e., there is a temperature inversion (unlike all other continents of the Earth). Heavy cold air from central regions the continent spreads in all directions along the slopes of the ice sheet, forming a katabatic wind. The loss of air over the center of the continent is replenished by the arrival of new air masses from higher layers of the atmosphere. Air masses from adjacent latitudes enter the high layers. A downward circulation is created, a typical anticyclonic process, which is accompanied by drying of the air. The lack of cloudiness contributes to further cooling of the continent. The 10% of solar energy that is absorbed by the surface of Antarctica also mostly goes into space. Like any body heated above absolute zero, snow emits heat in the form of infrared waves. Since there are no clouds over the central regions of Antarctica, this long-wave radiation freely escapes into space.

According to the nature of the climate in Antarctica, there are: inland high mountain region, glacial slope and coastal zone. The glacial plateau is characterized by extreme frosts, a polar anticyclone, the predominance of clear weather, and a small amount of precipitation that falls all year round in the form of snow (30-50 mm/year). Here is the center of the continent - the Pole of relative inaccessibility. The circumpolar zone of glacial slopes, along which glacial runoff paths fan out from the high mountain massifs, has a width of 700-800 km. Average monthly temperatures in the zone range from 50°C in winter to 30°C in summer months. Low temperatures combined with constant winds blowing from the highlands, and snowstorms. Precipitation in the form of snow falls 100-250 mm/year. The narrow coastal zone receives up to 700 mm of precipitation, mainly in the form of snow. In winter, average monthly temperatures range from 8 to -35 °C, in summer - from O to + 2 °C. The usual wind speed is 50-60 m/s.

Antarctica is the coldest continent on Earth. Excluding the coast of the northern part of the Antarctic Peninsula, the entire continent lies in. Despite the fact that the polar night continues for several months in Central winter, the annual total radiation approaches the annual total radiation equatorial zone(Vostok station - 5 GJ / (m2-year) or 120 kcal / (cm2-year)), and in summer it reaches very large values- up to 1.25 GJ / (m 2 -month) or 30 kcal / (cm 2 -month). However, up to 90% of the incoming heat is reflected by the snow surface back into outer space and only 10% goes to heating it. Therefore, Antarctica is negative, but very low. Our planet's pole of cold is located in Central Antarctica. At Vostok station on August 24, 1960, a temperature of -88.3°C was recorded. Average temperature winter months from -60 to -70°С, in summer from -30 to -50°С. Even in summer, the temperature never rises above -20°C. On the coast, especially in the area of ​​the Antarctic Peninsula, it reaches 10-12°C in summer, and on average in the warmest month (January) it is 1°C, 2°C. In winter (July) on the coast, the average monthly temperature ranges from -8 on the Antarctic Peninsula to -35°C at the edge of the Ross Shelf. Cold air rolls down from the central regions of Antarctica, forming katabatic winds that reach high speeds near the coast (the annual average is up to 12 m/sec), and when merging with cyclonic air flows, they turn into (up to 50-60, and sometimes 90 m/sec) . Due to the predominance of downdrafts relative air small (60-80%), near the coast and especially in the Antarctic oases it decreases to 20 and even 5%. Relatively small and. fall almost exclusively in the form of snow: in the center of the continent their amount reaches 30-50 mm per year, in the lower part of the continental slope it increases to 600-700 mm, decreases somewhat at its foot (up to 400-500 mm) and increases again in some ice shelves and on the northwestern coast of the Antarctic Peninsula (up to 700-800 and even 1000 mm). Due to heavy and heavy snowfalls, they are very frequent.

Large areas of exposed areas near the coast, with specific natural conditions, are called Antarctic oases; summer temperatures here are 3-4 higher than above the surrounding glaciers. Antarctic lakes are unique, located mainly in coastal oases. Many of them are drainless, with high salinity waters, even bitterly salty. Some lakes are not free of ice cover even in summer. Lagoon lakes are very characteristic, located between the coastal cliffs of the oasis and the surrounding ice shelf, under which they are connected to the sea.

The climate zone is called certain part the earth's surface with a certain climate, atmospheric circulation and intensity of heating by the Sun.

There are 7 main types of climate zones on Earth. Broadly speaking, they are divided into permanent and transitional. Constant climate zones are those in which one air mass. And in transitional ones there are different and changing masses. The permanent ones include: equatorial, tropical, temperate and arctic, and the transitional ones include subequatorial, subtropical and subarctic.

Natural zones of the Arctic and Antarctic belts

Arctic climate zone

The Siberian coast of Russia, located on the coast of the Northern Arctic Ocean, and the adjacent islands belong to Arctic belt. The exception is the territory of the island New Earth, Vaigach Island, Kolguev Island and other islands located in the Barents Sea.

The Siberian coast is exposed to an arctic climate all year round, solar radiation comes to Siberian lands only in summer and in small quantities. And in winter, when Siberia falls into the power of the polar night, solar radiation does not reach the earth at all. Only water heats some air layers. That's why average temperature January on the mainland is higher than on the coast.

Atlantic influences western territories Siberia, bringing warm air there.

During the polar day, solar insolation increases. In summer, most of the sun's energy is spent melting snow and ice. And yet the temperature rises - in July it is about 0 degrees, and on the coast it is +5 degrees. Southern part Siberian territories warm up to +10 degrees.

About 200-300 mm of snow falls here annually.

Antarctic climate zone

On southern hemisphere The earth is located Antarctic natural belt. It covers the territory of Antarctica, nearby islands and parts of the Pacific, Indian, and Atlantic oceans.

A cold, harsh climate prevails here. Winter temperature air temperature ranges from -60 to -70 degrees, and in summer - from -30 to -50. The maximum mark on the thermometer is -20 degrees.

The radiation level is quite high, about 30 kcal/cm² per month, but only a small part goes to warming the Earth's surface - 10%. Everything else is reflected into space. That is why these areas have a reduced radiation balance.

The amount of precipitation in the form of snow varies depending on the area. The closer to the center of the continent, the less precipitation. Strong winds blow on the coast, reaching up to 12 m/s. Constant phenomena near the oceans are storms and fogs, when at the same time in the center of the continent it is sunny and clear.

Part of the ocean surface is covered with ice. The scale of these covers depends on the time of year, and at its peak reaches 500-2000 km. in width. Icebergs are quite common here.

On land they dominate arctic deserts, covered with ice sheets. Antarctic oases are found only in coastal areas. Some mountain ranges are also free of ice crust, they are called nunataks.

Greenland and Antarctica are subordinate to the Antarctic and Arctic belts.