Ozone hole over Antarctica expands to 28.2 million squire kilometer this year, which is larger than the continent of North America
The ozone hole has expanded to nearly record-breaking levels this year.
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According to NASA and National Oceanic and Atmospheric Administration (NOAA), on October 2, ozone hole has touched its peak expansion of 28.2 million square kilometer (10.9 million square miles), larger than the whole continent of North America, making it the third largest observed after the ozone holes of 2000 and 2006. The hole maintained its size throughout the month of October.
The temperature conditions of high altitude (stratospheric) Antarctic region continue to vary from one year to another and determine the size of ozone hole each year. The conditions were colder than usual this year.
“While the current ozone hole is larger than in recent years, the area occupied by this year’s hole is consistent with our understanding of ozone depletion chemistry and consistent with colder than average weather conditions in Earth’s stratosphere, which help drive ozone depletion." Paul A. Newman, chief scientists for Earth Sciences at NASA’s Goddard Space Flight Center in Greenbelt, Maryland said in a statement.
Ozone is a thin layer of atmosphere made up of oxygen which protects us from harmful ultraviolent radiations of the sun. The depletion of ozone layer was first detected in 1980s which was directly caused by man-made chemicals that release chlorine and bromine gases. The levels of these gases steadily increases in the stratosphere and damages ozone layer. The readings in ozone hole are typically observed in late September or early October each year.
“This year, our balloon borne instruments measured nearly 100 percent ozone depletion in the layer above South Pole Station, Antarctica, that was 14 to 19 kilometers (9 to 12 miles) above Earth’s surface,” said Bryan Johnson, a researcher at NOAA’s laboratory in Boulder, Colorado.
“During September, we typically see a rapid ozone decline, ending with about 95 percent depletion in that layer by October 1. This year depletion held on an extra two weeks, resulting in nearly 100 percent depletion by October 15.”
Ozone layer works as a shield against harmful rays of the Sun which may contribute in skin cancer, sunburn and weakening immune system. One may feel that large size of ozone layer may pose threat for Earth surface, particularly in Southern Hemisphere but World Meteorological Organization (WMO) suggests that there is no need to panic.
"This shows us that the ozone hole problem is still with us and we need to remain vigilant. But there is no reason for undue alarm." Geir Braathen, a senior scientist in WMO’s Atmospheric and Environment Research Division said.
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Thanks to 1987 ban on harmful gases, ozone depletion is continued to decrease. But ‘substantial recovery of the ozone layer is expected by the middle of 21st century, although over the Antarctic it will be later – probably around 2070.