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

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Smallest transistor worldwide switches current with a single atom in solid electrolyte

17.08.2018 | Physics and Astronomy

Robots as Tools and Partners in Rehabilitation

17.08.2018 | Information Technology

Climate Impact Research in Hannover: Small Plants against Large Waves

17.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>