Ozone layer

Ozone layer

Оr ozonosphere, region of the stratosphere containing relatively high concentrations of ozone , located at altitudes of 19-48 km above the earth's surface. Ozone in the ozone layer is formed by the action of solar ultraviolet light on oxygen.

The ozone layer prevents most ultraviolet (UV) and other high energy radiation from penetrating to the earth's surface but does allow through sufficient ultraviolet rays to support the activation of vitamin D in humans. The full radiation, if unhindered by this filtering effect, would destroy animal tissue. Higher levels of radiation resulting from the depletion of the ozone layer have been linked with increases in skin cancers and cataracts and have been implicated in the decline of certain amphibian species.

In 1974 scientists warned that certain industrial chemicals, e.g., chlorofluorocarbons and to a lesser extent, halons and carbon tetrachloride, could migrate to the stratosphere. There, sunlight could free the chlorine or bromine atoms to form chlorine monoxide or other chemicals, which would deplete upper-atmospheric ozone. A seasonal decrease, or "hole," discovered in 1985 in the ozone layer above Antarctica was the first confirmation of a thinning of the layer. The hole occurs over Antarctica because the extreme cold helps the very high clouds characteristic of that area form tiny ice particles of water and nitric acid, which facilitate the chemical reactions involved. In addition, the polar winds, which follow a swirling pattern, create a confined vortex, trapping the chemicals. When the Antarctic sun rises in August or September and hits the trapped chemicals, a chain reaction begins in which chlorine, bromine , and ice crystals react with the ozone and destroy it very quickly. The effect usually lasts through November. There is a hole over the Arctic that similarly appears in the spring, although in some years warmer winters there do not result in a major depletion of the ozone layer. A global thinning of the ozone layer results as ozone-rich air from the remaining ozone layer flows into the ozone-poor areas.

Minimum ozone levels in the Antarctic decreased steadily throughout the 1990s, and less dramatic decreases have been found above other areas of the world. In 2000 (and again in 2003) the hole reached a record size, extending over 28 million sq km, an area greater than that of North America. In 1987 an international agreement, the Montreal Protocol , was reached on reducing the production of ozone-depleting compounds. Revisions in 1992 called for an end to the production of the worst of such compounds by 1996, and CFC emissions dropped dramatically by 1993. Recovery of the ozone layer, however, is expected to take 50 to 100 years. Damage to the ozone layer can also be caused by sulfuric acid droplets produced by volcanic eruptions.

Dictionary:

1. contain – содержать

2. altitude -высота

3. prevent – предотвращать

4. from penetrating – от проникновения

5. ozone layer – озоновый слой

6. sufficient – достаточное

7. unhindered – беспрепятственный

8. tissue – ткань

9. depletion – нарушение/опустошение

10. linked/ implicated – связанный с

11. decline – снижение/уменьшение

12. lesser extent – меньшая степень

13. deplete(-ion) -разрушать/истощать

14. hole – отверстие/дыра

15. confirmation – подтверждение

16. occur – возникать

17. facilitate – содействовать/способствовать

18. swirling pattern – завихрение

19. confined vortex - замкнутый вихрь

20. trap – задерживать

21. hit – попадать

22. remaining – оставшийся

23. flow – поступать

24. steadily – неуклонно

25. reach -достичь

26. extend over – простираться на

27. Revision – изменение

28. call for – призывать/ требовать

Aeroflot, Russian airline that was formerly the national airline of the Soviet Union.

The Soviet state airline was founded in 1928 under the name Dobroflot and was reorganized under the name Aeroflot in 1932. Dobroflot, or Dobrovolny Flot, grew out of two former airlines: Dobrolyot, founded in 1923, and Ukvozdukhput, or Ukrainian Airways, founded in 1925. These airlines together connected such cities as Moscow, Gorky (Nizhny Novgorod), Kiev, Kharkov and Odessa. After Dobroflot was reorganized as Aeroflot in 1932, progress was rapid; by 1935 its routes spanned the Soviet Union from Leningrad) to Vladivostok, with a network also extending southward to the Black Sea, the Caucasus, and Central Asia.

Aeroflot was responsible for all civil aviation in the Soviet Union. It flew all international and domestic routes in the country, and, in addition to transporting passengers and freight, it was responsible for such operations as crop spraying, aerial surveying, airborne rescue work, and flying ambulance services. Aeroflot used only aircraft made in the Soviet Union. It began the world’s first civilian jet air service in 1956 (using Soviet Tu-104 aircraft) and helped develop the world’s first supersonic airliner, the Soviet Tu-144, which first flew in 1968.

By the late 1980s Aeroflot’s fleet of 1,300 airliners and several thousand smaller planes, were serving 3,600 cities and towns in the Soviet Union and flying international routes to more than 100 countries. By 1990, when Aeroflot carried a total of 138 million passengers, it was the world’s largest airline, with about 15 percent of all civil air traffic. It flew to all continents, including, on occasion, Antarctica.

In the 1980s Aeroflot flew more routes than it does today and carried 120 million passengers per year. This Guiness record remains unmatched – it was the world’s biggest airline. Aeroflot once flew along the longest route in the world stretching 18,000 km via Moscow-Rabat-Havana-Lima-Santiago.

After the breakup of the Soviet Union in 1991, the renamed Aeroflot–Russian International Airlines in 1992 became the state-owned airline of the new Russian government, which remained a majority shareholder into the 21st century. Most domestic routes were assumed by regional airlines. In 1992 Aeroflot began flying aircraft made by foreign manufacturers such as Airbus and Boeing. Assuming the name Aeroflot–Russian Airlines in 2000, the airline remained a leader in the provision of international flights from Russia to more than 40 countries.

Dictionary:

1. formerly – прежде

2. grоw out – вырос из

3. span – охватить

4. southward – южное направление

5. freight – груз

6. crop spraying – опрыскивание с/х культур

7. aerial surveying -аэрофотосъемка

8. airborne rescue work - воздушно-спасательные работы

9. flying ambulance services- летающие скорая

10. air service – воздушные перевозки/сообщение

11. carried a total of – перевез в общей сложности

12. routes – пути сообщения

13. remains unmatched – остается непревзойденным

14. breakup – распад

15. shareholder – акционер

16. be assumed by – взяли на себя

⇐ Предыдущая 1 23