Feeds

Ozone layer hits new depletion record

Blame the weather

Secure remote control for conventional and virtual desktops

Despite optimism earlier this year that the ozone hole was stabilising and might even have begun to repair itself, scientists at the European Space Agency report that 2006 saw record losses of ozone over the south pole.

Data from ESA's Envisat satellite show that although the area of the ozone hole (this year, 28m square kilometres) is not quite as large as it was in 2000, some 40 million tonnes of ozone were lost during the southern hemisphere winter. This is one million tonnes greater than the previous record from 2000.

The loss is calculated by combining the area of the hole with the depth of the ozone layer. The depth is measured in Dobson units, which describes the thickness of the layer directly over the location being measured, ESA explains.

This year saw the ozone approach the thinnest it has ever been, around 100 dobson units, approaching the record of 1998.

So although it is not as large as the hole in 2000, nor quite as thin as the layer in 1998, the two combined mean the layer has been depleted this year more than ever before.

ESA's atmospheric engineer Claus Zehner explains that the conditions over the Southern pole this year were ideal for depleting the ozone layer:

"Such significant ozone loss requires very low temperatures in the stratosphere combined with sunlight. This year’s extreme loss of ozone can be explained by the temperatures above Antarctica reaching the lowest recorded in the area since 1979," he said.

The Ozone layer, to fill in an unlikely gap in your knowledge, is a protective layer of the atmosphere which absorbs much of the harmful UV from the sun's rays. Its composition naturally fluctuates during the year. It is typically thicker in summer, and thinner in the winter.

The conditions for the hole are set up during the Antarctic winter. In this cold season, a weather pattern known as the polar vortex keeps the atmospheric mass above the Antarctic continent isolated from exchanges with warmer mid-latitude air.

This keeps the air mass above the continent cold, and in the cold and dark, clouds that contain chlorine can form in the polar stratosphere.

Once the spring returns, this chlorine, much of it originating from man-made pollutants like chlorofluorocarbons, disrupts the ozone layer causing the hole with which we are all now so familiar.

Zehner says the current consensus is that the ozone layer will recover from its human induced damage by 2060. Long term measurements, he argues, are key to understanding this process. ®

Next gen security for virtualised datacentres

More from The Register

next story
Vulture 2 takes a battering in 100km/h test run
Still in one piece, but we're going to need MORE POWER
TRIANGULAR orbits will help Rosetta to get up close with Comet 67P
Probe will be just 10km from Space Duck in October
Boffins ID freakish spine-smothered prehistoric critter: The CLAW gave it away
Bizarre-looking creature actually related to velvet worms
CRR-CRRRK, beep, beep: Mars space truck backs out of slippery sand trap
Curiosity finds new drilling target after course correction
China to test recoverable moon orbiter
I'll have some rocks and a moon cheese pizza please, home delivery
What does a flashmob of 1,024 robots look like? Just like this
Sorry, Harvard, did you say kilobots or KILLER BOTS?
NASA's rock'n'roll shock: ROLLING STONE FOUND ON MARS
No sign of Ziggy Stardust and his band
Why your mum was WRONG about whiffy tattooed people
They're a future source of RENEWABLE ENERGY
Vulture 2 spaceplane autopilot brain surgery a total success
LOHAN slips into some sexy bespoke mission parameters
prev story

Whitepapers

5 things you didn’t know about cloud backup
IT departments are embracing cloud backup, but there’s a lot you need to know before choosing a service provider. Learn all the critical things you need to know.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Build a business case: developing custom apps
Learn how to maximize the value of custom applications by accelerating and simplifying their development.
Rethinking backup and recovery in the modern data center
Combining intelligence, operational analytics, and automation to enable efficient, data-driven IT organizations using the HP ABR approach.
Next gen security for virtualised datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.