Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ozone-hole recovery may spur Antarctic warming

25.04.2008
A full recovery of the stratospheric ozone hole could strongly
modify climate change in the Southern Hemisphere and possibly amplify warming of the Antarctic continent, a new study finds.
"If the successful control of ozone-depleting substances allows for a full recovery of the ozone hole over Antarctica, we may finally see the interior of Antarctica begin to warm with the rest of the world," says Judith Perlwitz of the University of Colorado at Boulder and the National Oceanic and Atmospheric

Administration (NOAA). Perlwitz is lead author of the study.

While average surface temperatures have been increasing globally, the interior of Antarctica has exhibited a unique cooling trend during the austral (Southern
Hemisphere) summer and fall, Perlwitz notes. The cooling is attributed to ozone
depletion. She and her colleagues conclude that, as stratospheric ozone levels
return to near pre-1969 levels by the end of the 21st century, large-scale
atmospheric circulation patterns currently shielding the Antarctic interior from
warmer air masses to the north will begin to break down during the austral summer.

These circulation patterns are collectively known as a positive phase of the Southern Annular Mode, or SAM.

The scientists find that, as ozone levels recover, the lower stratosphere over the polar region will absorb more ultraviolet radiation from the sun. This will cause air temperatures roughly 10-20 kilometers (6-12 miles) above Earth's surface to rise by as much as 9 degrees Celsius, reducing the strong north-south temperature gradient that currently favors the positive phase of SAM.

The new study also indicates that ozone-hole recovery would weaken the intense
westerly winds that currently whiz around Antarctica and block air masses from
crossing into the continent's interior. As a result, Antarctica would no longer be isolated from the warming patterns affecting the rest of the world.
Ozone recovery will essentially reverse summertime climate and atmospheric
circulation changes that have been caused by the presence of the ozone hole, says co-author Steven Pawson of NASA Goddard Space Flight Center in Greenbelt, Md.
To examine how changes in the ozone hole might influence climate and weather
near Earth's surface, the scientists used a NASA computer model that includes
interactions between the climate and stratospheric ozone chemistry. The team will publish its findings on 26 April 2008 in Geophysical Research Letters, a journal of the American Geophysical Union, or AGU.
Besides affecting Antarctica, the anticipated seasonal shift in large-scale
circulation patterns would also have repercussions for Australia and South
America. Studies show that the positive phase of SAM is associated with cooler
temperatures over much of Australia and increased rainfall over Australia's
southeast coastline. The positive phase of SAM is also associated, during late
spring and early summer, with drier conditions in South America's productive
agricultural areas: Argentina, Brazil, Uruguay and Paraguay. If ozone recovery
induces a shift away from a positive SAM, Australia could experience warmer and drier conditions while South America could get wetter, according to Perlwitz.
But just how influential a full stratospheric ozone recovery will be on Southern Hemisphere climate largely depends on the future rate of greenhouse gas emissions, according to the study. Projected increases in human-emitted

greenhouse gases such as carbon dioxide will be the main driver for strengthening the positive phase of SAM.

"In running our model simulations, we assumed that greenhouse gases like carbon dioxide would double over the next 40 years and then slowly taper off. If human activities cause more rapid increases in greenhouse gases, or if we continue to produce these gases for a longer period of time, then the positive SAM may dominate year-round and dwarf any climatic effects caused by ozone recovery," says Perlwitz.

Perlwitz of the NOAA Cooperative Institute for Research in Environmental
Studies, in Boulder, and Pawson also collaborated on the study with other
scientists at NASA Goddard and at NOAA's Earth System Research Laboratory,
also in Boulder.
NASA provided major funding for the study.

Peter Weiss | American Geophysical Union
Further information:
http://www.colorado.edu
http://www.agu.org
http://www.nasa.gov

More articles from Earth Sciences:

nachricht Live from the ocean research vessel Atlantis
13.12.2018 | National Science Foundation

nachricht NSF-supported scientists present new research results on Earth's critical zone
13.12.2018 | National Science Foundation

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Data use draining your battery? Tiny device to speed up memory while also saving power

The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.

Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...

Im Focus: An energy-efficient way to stay warm: Sew high-tech heating patches to your clothes

Personal patches could reduce energy waste in buildings, Rutgers-led study says

What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...

Im Focus: Lethal combination: Drug cocktail turns off the juice to cancer cells

A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.

The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...

Im Focus: New Foldable Drone Flies through Narrow Holes in Rescue Missions

A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.

Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...

Im Focus: Topological material switched off and on for the first time

Key advance for future topological transistors

Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

Data use draining your battery? Tiny device to speed up memory while also saving power

14.12.2018 | Power and Electrical Engineering

Tangled magnetic fields power cosmic particle accelerators

14.12.2018 | Physics and Astronomy

In search of missing worlds, Hubble finds a fast evaporating exoplanet

14.12.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>