Why is the ozone hole over the Arctic appears?

28.03.2013


Recently, every spring Petersburg atmospheric scientists, met with alarm. In late March of 2011 — after a particularly snowy and cold winter — for the first time over the Arctic ozone hole was discovered. Until then, the phenomenon of a sharp decrease in the heavy layer of oxygen (also known as ozone) appeared only over the South Pole. Monitoring the state of the ozone layer over the Arctic are being held this spring.
 

© Flickr.com / Wen Nag (aliasgrace) / cc-by-nc-sa 3.0

Screen from solar radiation


— The ozone hole as a phenomenon is quite well understood, although there were only discovered in the mid-1980s in Antarctica. Since then, the lack of ozone in September — November, when the southern hemisphere spring is fixed every year, which is already beginning to affect the climate and nature of the continent, — the head of the laboratory of the Main Geophysical Observatory. Voeikov Igor Karol. — In March-April 2011, the ozone hole first appeared over the Arctic. And in the southern hemisphere hole located above the pole, and we have captured almost all the northern parts of Russia.

Ozone — a gas with three oxygen atoms — protects the biosphere from the hard sunlight. If it is in the atmosphere is small, the power of UV rays will increase many times, which is detrimental effect on a person. Now, while the ozone holes over the poles appear only and only for a few weeks, for us it is very dangerous. First, in the high latitudes of the sun is low on the horizon and its rays are not as intense. And the people in those areas, except for polar scientists, no.

The danger arises if the hole will expand. Their appearance is explained by global warming. Because of the growth of industrial production emissions of so-called greenhouse gases in recent decades has increased dramatically. They trap heat in the lower atmosphere, not passing it to the upper layers — in the stratosphere (at a height of 20 — 35 km from the Earth), which is cooled from this. And ozone molecules react with chloride and bromine compounds — harmful substances that enter the stratosphere, too, as a result of human activity, and are destroyed. This forms the ozone hole. It appears over the poles immediately after the winter, especially when the stratosphere vystuzhena.

Unpleasant surprise


— However, as long as nothing catastrophic happens — soothes a specialist in atmospheric physics professor Sergei Smyshlyaev Hydrometeorological University. — Moreover, after the signing at the end of the 1980s, the Montreal Protocol, which limits emissions, in particular, Freon, the concentration in the atmosphere of substances that deplete the ozone layer, according to some, is reduced. We expect that in the next decade, emissions of harmful compounds are so reduced that the ozone hole will no longer occur at all. Some of our colleagues were hoping that the size of the holes in the Southern Hemisphere had been reduced over the years.

…While these expectations are not met. And the appearance of the hole above the Arctic has become an unpleasant surprise for the scientists, so monitor the atmosphere of the Northern Hemisphere, they are now paying attention. In a research plan last polar expedition "North Pole" who work near the "top of the world", at the 84th parallel, be sure to include the monitoring of ozone in the atmosphere.

The probe is not worse than the satellite


— Expedition "North Pole-40" planted in the Arctic in September of 2012, will stay on the ice until the end of the summer of 2013 — said Sergey Smyshlyaev. — The concentration of ozone in the atmosphere and stratosphere scientists measured by probes, they typically run twice a day. This "old-world" research method is good because it is very accurate and gives results at any time. The concentration of ozone is measured and from satellites such program is the Americans at NASA. But satellite measurements are possible only when the sun shines. However, ozone holes are formed in the spring when the polar night ends. Graduate students of the University this spring will track the information on ozone, obtained from NASA, it is open and it can be found in the Internet.

Pessimistic views on the phenomenon of ozone in the majority of scientists do not: most importantly, in their opinion — to continue to study this natural phenomenon and to monitor trends. There is also a philosophical point of view on the issue.

— Mammoths on Earth died out in due time, but life goes on. Do not overestimate the value of any one species of the planet, even if it is a man — once said the vice-president of the Russian Geographical Society Kirill Chistyakov. — In the history of the Earth had periods when 90 percent of the biological species inhabiting it died out due to natural changes … However, nothing like this in the near future on this planet is not expected.
Oleg Rogozin

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