Study tracks impacts to southern hemisphere jet stream

Posted on February 2, 2013 by Bob Berwyn
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What’s driving changes in jet stream circulation?

Ozone depletion seen as bigger factor than greenhouse gas forcing

By Summit Voice

SUMMIT COUNTY — After running a complex set of climate models, Penn State researchers concluded that ozone depletion has been the biggest driver in shifting the southern hemisphere jet stream toward the South Pole.

By including short-term wind pattern changes in their calculations, and comparing changes in four different types of wind patterns, the scientist said they were able to determine that the buildup of greenhouse gases in the atmosphere plays a lesser role in the observed changes in the southern hemisphere.

“Previous research suggests that this southward shift in the jet stream has contributed to changes in ocean circulation patterns and precipitation patterns in the Southern Hemisphere, both of which can have important impacts on people’s livelihoods,” said Penn State meteorology professer Sukyoung Lee. (more…)

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Environment: Antarctic ozone hole closes early this year

Posted on December 22, 2012 by Bob Berwyn

Warmer stratosphere, active polar vortex help speed seasonal recovery

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A graphic from the WMO shows the progression of the Antarctic ozone hole.

By Summit Voice

FRISCO — Relatively warm stratospheric temperatures helped limit the size of this year’s Antarctic ozone hole, which disappeared completely by Nov. 10, earlier than in recent years.

Using data gathered from ground stations and weather balloons, the World Meteorological Organization said the warmer temps at an elevation of about 20 kilometers limited the formation of polar stratospheric clouds which, through a chemical chain reaction between water, nitric acid and halogenated reservoir gases cause ozone loss. In this respect, the 2012 ozone hole was similar to the one in 2010, when a sudden stratospheric warming in July and August gave rise to a smaller amount of polar stratospheric clouds than usual. (more…)

Filed under: air quality, Antarctica, climate and weather, Environment, seasons | Tagged: , , , , , | 3 Comments »

Environment: Antarctic ozone hole getting smaller

Posted on October 26, 2012 by Bob Berwyn

This year’s ozone hole over Antarctica was the second-smallest in 20 years, according to NASA.

Warmer temps in the lower stratosphere helped shrink the hole this year

By Summit Voice

FRISCO — The Antarctic ozone hole shrank to its second-smallest size in the past 20 years, down to “only” 8.2 million square miles, just barely big enough to cover all of North America.

NASA researchers said natural variations in weather patterns are the biggest factor in determining the size of the hole, which allows harmful ulraviolet radiation to reach the surface of the Earth. This year, those patterns generated warmer-than-average stratospheric temperatures in the region.

The ozone hole reached its maximum size Sept. 22. The average size of the 2012 ozone hole was 6.9 million square miles.  The largest ozone hole on record was in Sept. 6, 2000, when it reached 11.5 million square miles. (more…)

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Global warming linked with ozone depletion

Posted on July 27, 2012 by Bob Berwyn

New Harvard study shows links between warming, changes in atmospheric chemistry and skin cancer

A NASA photo from the International Space Station shows a large cumulonimbus cloud.

By Summit Voice

SUMMIT COUNTY — Along with serious global impacts like rising sea levels and increases in weather extremes, global warming may lead to a significantly higher risk for skin cancer, according to a new study published this week in the Journal Science.

Harvard researchers say they’ve discovered a connection between climate change and depletion of the ozone layer over the U.S. that could allow more damaging ultraviolet radiation to reach the Earth’s surface, leading to increased incidence of skin cancer.

The increase in UV radiation could also affect other species, including vitally important crops like wheat, that could also be susceptible to genetic damage. (more…)

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Global warming: Sea ice decline causing ozone depletion

Posted on April 18, 2012 by Bob Berwyn

Arctic ozone vanished at an unprecedented rate in the winter of 2010-2011.

New research suggests that sea ice loss may also be resulting in more mercury deposition in the Arctic

By Summit Voice

SUMMIT COUNTY — Loss of sea ice in polar regions isn’t just affecting the surface of the Earth, but is also having an impact on the atmosphere.

An international NASA-led team, coordinated by the National Ice Center,  is reporting that changes in sea ice are driving chemical reactions that result in ozone depletion and the toxic element mercury falling out of the Arctic atmosphere onto the ocean and icy surface. (more…)

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Canada slashes environmental programs

Posted on February 14, 2012 by Bob Berwyn

Cuts threaten trans-border researcher on climate, pollution

Research on climate change impacts to the tundra is suffering after Canadian budget cuts.

By Summit Voice

SUMMIT COUNTY —American scientists say they’re concerned that Canadian budget cuts will hamper important international research efforts on climate change, pollution and other regional issues that cut across political boundaries.

The cuts have affected the the scientific workforce of Environment Canada, the government agency responsible for meteorological services and environmental research.

Since the cuts were implemented last summer, ozone soundings have ceased at several Canadian stations. Lidar network measurements of particle pollution layers from five Canadian stations no longer occur, and the website that was distributing this data has disappeared, according to a report in the Feb. 14 issue of the American Geophysical Union’s Eos newspaper.

“Canada is a bellwether for environmental change, not only for Arctic ozone depletion but for pollutants that stream to North America from other continents, ” said Anne Thompson, professor of meteorology, Penn State. “It is unthinkable that data collection is beginning to shut down in this vast country, in some cases at stations that started decades ago.” (more…)

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Global warming: Arctic ozone on the edge?

Posted on January 22, 2012 by Bob Berwyn

Slight temperature shift in stratosphere could lead to massive Arctic ozone depletion

March 2011: Strongly reduced ozone values (left, dark blue) and significantly increased concentration of chlorine monoxide (right, red) that is directly involved in ozone degradation. GRAPHIC COURTESY KARLSRUHE INSTITUTE OF TECHNOLOGY.

By Summit Voice

SUMMIT COUNTY — In yet another climate change paradox, warmer temperatures in the lower layers of the atmosphere may be cooling the high-elevation stratosphere, where researchers last year documented for the first time ever a massive hole in the ozone layer above the Arctic.

Researchers from the Karlsruhe Institute of Technology, who first discovered the Arctic ozone hole now say that the ozone layer may be at a tipping point.

“We found that further decrease in temperature by just 1 degree (Celsius) would be sufficient to cause a nearly complete destruction of the Arctic ozone layer in certain areas,” says Dr. Björn-Martin Sinnhuber, main author of the study. (more…)

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Environment: Unprecendented ozone loss above Arctic

Posted on October 4, 2011 by Bob Berwyn

Arctic ozone vanished at an unprecedented rate in the winter of 2010-2011.

Stratospheric cold snap led to depletion of protective gas last winter

By Summit Voice

SUMMIT COUNTY — An unusually long-lasting cold snap in the stratosphere above the Arctic last winter caused an unprecedented depletion of the Earth’s protective ozone layer, according to the results of NASA-led study published Oct. 2 in Nature.

The researchers found the amount of ozone destroyed in the Arctic in 2011 was comparable to that seen in some years in the Antarctic, where an ozone “hole” has formed each spring since the mid 1980s. The stratospheric ozone layer, extending from about 15 to 35 kilometers above the surface, protects life on Earth from the sun’s harmful ultraviolet rays. (more…)

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CU team tracks Patagonian droughts and wildfires

Posted on August 24, 2011 by Bob Berwyn

Patagonian beech forests may become more fire-prone as ozone-depleting chemicals and greenhouse gases reinforce a cyclical climate pattern that leads to drought in the region.

Tree-ring study suggests the region could remain fire-prone for a century or more

By Summit Voice

SUMMIT COUNTY — A new study by CU Boulder researchers suggests that forests in Patagonia may become more fire-prone in the next 100 years, as a major climate oscillation in the southern hemisphere is reinforced and made more persistent by ozone-depleting chemicals and greenhouse gases.

The researchers used tree ring records dating back to 1506 to link past wildfire activity in the forests of Patagonia with the Southern Annular Mode, a climate cycle that creates low atmospheric pressure in the Antarctic that is tied to warmer and drier conditions in southern South America.

The tree rings showed that, when SAM was in its positive phase, there were widespread fires in both dry woodlands and rainforests in Patagonia, a region that straddles Argentina and Chile, said CU-Boulder Research Associate Andres Holz, lead study author. (more…)

Filed under: climate and weather, Environment, forest fires, Forest health, forests, global warming, Summit County news | Tagged: , , , , , , , , , , | 1 Comment »

Remember the ozone hole? It’s back, over the North Pole

Posted on March 19, 2011 by Bob Berwyn

Climate change linked to abnormally cold temperatures in the Arctic stratosphere; those conditions result in regional ozone loss

These clouds composed of frozen nitric acid and sulphuric acid form when temperatures in the stratosphere at an altitude of about 20 km fall below –78 degrees Celsius. This is currently the case in vast sections of the Arctic. Although these clouds are of natural origin – in isolated cases they have been substantiated by paintings from the 18th century – they have in the meantime become a portent of imminent ozone loss due to human activity. Chemical processes on the surface of the cloud particles transform the initially harmless degradation products of anthropogenically produced chlorofluorocarbons (CFCs) into aggressive ozone-depleting substances. Consequently the ozone-depleting impact of CFCs unfolds with full force whenever it is extremely cold in the stratosphere – like at the moment over the Arctic. Photo: Markus Rex, Alfred Wegener Institute.

By Summit Voice

SUMMIT COUNTY — While ozone hole over Antarctica has slowly started to heal — thanks to concerted global action to ban chlorofluorocarbons — unusually low temperatures in the Arctic ozone layer have recently initiated massive ozone depletion at the other end of the Earth.

The Arctic appears to be heading for a record loss of this trace gas that protects the Earth’s surface against ultraviolet radiation from the sun, according to measurements from an international network of more than 30 ozone sounding stations spread all over the Arctic and Subarctic and coordinated by the Potsdam Research Unit of the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association in Germany.

“Our measurements show that at the relevant altitudes about half of the ozone that was present above the Arctic has been destroyed over the past weeks,” AWI researcher Markus Rex said in a press release. “Since the conditions leading to this unusually rapid ozone depletion continue to prevail, we expect further depletion to occur.” (more…)

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