Printer Friendly

Ozone hole over Antarctica weakens carbon sink in Southern Ocean.

Byline: ANI

London, Dec 10 (ANI): A new research has suggested that the hole in the ozone layer over Antarctica may be impairing the Southern Ocean's ability to mop up carbon dioxide (CO2) from Earth's atmosphere.

Earth's oceans are the largest sink of carbon dioxide, with the Southern Ocean accounting for more than 40 percent of the annual uptake of the greenhouse gas, Andrew Lenton, a marine biochemist at the Pierre and Marie Curie University in Paris, told Nature News.

In theory, seas should soak up more carbon dioxide as levels of the gas in the atmosphere rise.

But, recent measurements have showed that the Southern Ocean's surface waters have higher carbon levels than expected, which also makes them more acidic. As a result, the amount of CO2 that the ocean absorbs each year has also flattened out.

What was missing from the models, according to Lenton, was stratospheric ozone damage - which, along with the climatic effects of greenhouse-gas emissions, is thought to be behind the observed strengthening of southern winds.

According to Lenton, these winds may be causing ocean currents that stir up carbon stored in the deep ocean and bring it up to the surface.

Lenton and his colleagues built Southern Ocean simulations that coupled the ozone's effects on winds to ocean currents and marine carbon levels.

By running the models both with and without ozone depletion since 1975, the researchers "isolated the signal from ozone depletion", said Lenton's co-worker Francis Codron, an atmospheric scientist at the Dynamic Meteorology Laboratory in Paris.

Including the ozone hole reproduced the carbon sink that has observed by oceanographers.

"These sound like very different parts of the system, and yet one affects the other," said Codron.

The signal from ozone, the researchers found, drove a drop in Southern Ocean surface pH of 0.01 units from 1994 to 2004 - half the total pH decline in that period, and one-tenth of the change since the pre-industrial era.

Although the Antarctic ozone hole has stabilized in recent years and is expected to heal in the latter half of this century, climate models that don't include its effects may show an overly optimistic future, said Lenton.

According to Julie Arblaster of the Bureau of Meteorology Research Centre in Melbourne, Australia, "Understanding recent trends in the Southern Ocean carbon sink is key to understanding future projections of atmospheric CO2." (ANI)

Copyright 2008 Asian News International (ANI) - All Rights Reserved.

Provided by Syndigate.info an Albawaba.com company
COPYRIGHT 2008 Al Bawaba (Middle East) Ltd.
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2008 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Publication:Asian News International
Date:Dec 10, 2008
Words:411
Previous Article:Butch Cassidy had Brit ancestry!
Next Article:IPL bonanza ensures seven cricketers in list of top 50 Oz sport earners.
Topics:


Related Articles
Piecing together Australia's climate change picture.
Ozone hole caused increased growth in Antarctic sea ice.
Ozone hole responsible for saturation in Southern Ocean's CO2 absorption.
Ozone depletion reduces CO2 uptake of Southern Ocean.
Saving the ozone layer: thirty years ago, scientists fought to stop the destruction of Earth's protective ozone layer. Did their rescue effort work?

Terms of use | Privacy policy | Copyright © 2019 Farlex, Inc. | Feedback | For webmasters