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Low temperatures enhance ozone degradation above the Arctic
March 2011: This shows strongly reduced ozone values (left, dark blue) and significantly increased concentration of chlorine monoxide (right, red) that is directly involved in ozone degradation. Credit: Figure: IMK-ASF, KIT
About a year ago, IMK scientists, together with colleagues from Oxford, detected that ozone degradation above the Arctic for the first time reached an extent comparable to that of the ozone hole above the South Pole. Then, the KIT researchers studied the mechanisms behind. Their results have now been published in the journal Geophysical Research Letters.
According to IMK studies, occurrence of the Arctic ozone hole was mainly due to the extraordinarily cold temperatures in the ozone layer that is located at about 18 km height in the stratosphere, i.e. the second layer of the earth’s atmosphere. There, chlorine compounds originating from chlorofluorocarbons (CFC, e.g. greenhouse gases and refrigerants) and other pollutants are converted chemically at temperatures below -78°C. These chemical conversion products attack the ozone layer and destroy it partly. One of the main statements in the study: If the trend to colder temperatures in the stratosphere observed in the past decades will continue, repeated occurrence of an Arctic ozone hole has to be expected.
The team of IMK researchers analyzed measurements of the chemical composition of the atmosphere by the MIPAS satellite instrument developed by KIT. In addition, model calculations were made to Read more…
‘Unprecedented’ ozone hole opens over Canadian Arctic
Euan Rocha / Reuters
A view of the tundra landscape in Nunavut, at the rim of the Arctic Circle.
A massive Arctic ozone hole opened up over the Northern Hemisphere for the first time this year, an international research team reported Sunday.
The hole covered two million square kilometres — about twice the size of Ontario — and allowed high levels of harmful ultraviolet radiation to hit large swaths of northern Canada, Europe and Russia this spring, the 29 scientists say.
The discovery of the “unprecedented” hole comes as the Canadian government is moving to cut its ozone monitoring network.
Environment Canada scientist David Tarasick, whose team played a key role in the Read more…
Ozone hole linked to southern rain increases
WASHINGTON — The hole in the ozone layer over Antarctica is a significant driver of climate change and rain increases in the southern hemisphere over the past 50 years, US scientists said Thursday.
The findings by a team at Columbia University’s School of Engineering and Applied Science are the first to link ozone depletion in the polar region to climate change all the way to the equator.
Researchers said the analysis should lead policy-makers to consider the ozone layer along with other environmental factors such as Arctic ice melt and greenhouse gas emissions when considering how to tackle climate change.
“It’s really amazing that the ozone hole, located so high up in the atmosphere over Antarctica, can have an impact all the way to the tropics and affect rainfall there,” said Sarah Kang, lead author of the study in the journal Science. Read more…
First North Pole Ozone Hole Forming?
Spawned by strangely cold temperatures, “beautiful” clouds helped strip the Arctic atmosphere of most of its protective ozone this winter, new research shows.
The resulting zone of low-ozone air could drift as far south as New York, according to experts who warn of increased skin-cancer risk.
The stratosphere’s global blanket of ozone—about 12 miles (20 kilometers) above Earth—blocks most of the sun‘s high-frequency ultraviolet (UV) rays from hitting Earth’s surface, largely preventing sunburn and skin cancer.
But a continuing high-altitude freeze over the Arctic may have already reduced ozone to half its normal concentrations—and “an end is not in sight,” said research leader Markus Rex, a physicist for the Alfred Wegener Institute for Polar and Marine Research in Bremerhaven, Germany.
Preliminary data from 30 ozone-monitoring stations throughout the Arctic show the Read more…
Limited Nuclear War Could Deplete Ozone Layer, Increasing Radiation
By Chris Schneidmiller
WASHINGTON — A nuclear conflict involving as few as 100 weapons could produce long-term damage to the ozone layer, enabling higher than “extreme” levels of ultraviolet radiation to reach the Earth’s surface, new research indicates (see GSN, March 16, 2010).
(Feb. 24) – A 1971 French nuclear test at Mururoa Atoll. The ozone layer could sustain lasting harm from a nuclear exchange involving as few as 100 weapons, allowing increased levels of ultraviolet radiation to reach the Earth’s surface, according to new research (Getty Images).
Increased levels of UV radiation from the sun could persist for years, possibly with a drastic impact on humans and the environment, even thousands of miles from the area of the nuclear conflict.
“A regional nuclear exchange of 100 15-kiloton weapons … would produce unprecedented low-ozone columns over populated areas in conjunction with the coldest surface temperatures experienced in the last 1,000 years, and would likely result in a global nuclear famine,” according to a presentation delivered on Friday at a major science conference in Washington.
Today, there are five recognized nuclear powers — China, France, Russia, the United Kingdom and the United States. India, Israel and Pakistan are all known or widely assumed to hold nuclear weapons, while North Korea has a Read more…
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