http___metro-portal.hr_ozonska-rupa-iznad-antarktike-najmanja-od-1988_109583_1.xml
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Observing the Ozone Hole from Space: A Science Success Story Using our unique ability to view Earth from space, we are working together with NOAA to monitor an emerging success story – the shrinking ozone hole over Antarctica. Thirty years ago, the nations of the world agreed to the landmark ‘Montreal Protocol on Substances that Deplete the Ozone Layer.’ The Protocol limited the release of ozone-depleting chlorofluorocarbons (CFCs) into the atmosphere. Since the 1960s our scientists have worked with NOAA researchers to study the ozone layer. We use a combination of satellite, aircraft and balloon measurements of the atmosphere. The ozone layer acts like a sunscreen for Earth, blocking harmful ultraviolet, or UV, rays emitted by the Sun. In 1985, scientists first reported a hole forming in the ozone layer over Antarctica. It formed over Antarctica because the Earth’s atmospheric circulation traps air over Antarctica. This air contains chlorine released from the CFCs and thus it rapidly depletes the ozone. Because colder temperatures speed up the process of CFCs breaking up and releasing chlorine more quickly, the ozone hole fluctuates with temperature. The hole shrinks during the warmer summer months and grows larger during the southern winter. In September 2006, the ozone hole reached a record large extent. But things have been improving in the 30 years since the Montreal Protocol. Thanks to the agreement, the concentration of CFCs in the atmosphere has been decreasing, and the ozone hole maximum has been smaller since 2006’s record. That being said, the ozone hole still exists and fluctuates depending on temperature because CFCs have very long lifetimes. So, they still exist in our atmosphere and continue to deplete the ozone layer. To get a view of what the ozone hole would have looked like if the world had not come to the agreement to limit CFCs, our scientists developed computer models. These show that by 2065, much of Earth would have had almost no ozone layer at all. Luckily, the Montreal Protocol exists, and we’ve managed to save our protective ozone layer. Looking into the future, our scientists project that by 2065, the ozone hole will have returned to the same size it was thirty years ago. Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
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Ozonska rupa iznad Antarktike najmanja od 1988. Znanstvenici tvrde kako njihove satelitske snimke prvi put dokazuju da se smanjuje koncentracija klora koji razara ozonski omotač Ozonske rupe malo su se povukle s naslovnica, ustupivši mjesto ostalih katastrofalnim posljedicama ljudskog nemara, no ovu vijest vrijedi objaviti kako bi se pokazalo da se zajedničkim snagama ipak nešto može. Naime, najnovije istraživanje koje je provela NASA jasno je potvrdilo da se svijet može ujediniti u sprječavanju ekoloških katastrofa i ispraviti pogreške. Ozonska rupa iznad Antarktike pokazuje znakove oporavka. Znanstvenici tvrde kako njihove satelitske snimke prvi put dokazuju da se smanjuje koncentracija klora koji razara ozonski omotač, a tu pozitivnu promjenu izravno povezuju s preventivnim djelovanjem čovječanstva, započetim još 80-ih godina prošlog stoljeća. Ozonski omotač iznad Antarktike otvori se svakog rujna, a rupa je 2017. bila veličine 20 milijuna m2, što je ispod prosjeka od 26 milijuna m2. Također, to je najmanja površina ozonske rupe od 1988. godine. Znači, možda ipak ima vremena za nas...