Feeds

Arctic freshening not due to ice melt after all, says NASA

Calm down, hippies

Providing a secure and efficient Helpdesk

Concern that the Arctic Ocean is becoming massively less salty due to its ice cap melting - which could have knock-on consequences for the planet's climate - is unfounded, NASA scientists have said.

For years, researchers have seen falling salinity readings in the Canadian half of the Arctic Ocean. This has led them to theorise that large amounts of fresh water were being added due to permanent disappearance of ice. In itself this might not mean a lot - sea levels would be unaffected, as the Arctic ice floats atop the sea - but it had been feared that addition of so much fresh water could impact the oceanic "conveyor belt" which moves heat around the planet, with major consequences for the climate.

As long ago as 1999, Greenpeace were saying things like this:

Calculations suggest that most, if not all, of the fresh water added to the Beaufort Sea came from melting Beaufort sea ice in the summer of 1997, and imply that much of the ice of the Beaufort Sea was much thinner (perhaps more than a meter thinner) at the end of the melt season in 1997 than it was during the end of the melt season in 1975.

But the hippies were wrong. Analysis of data from specialised NASA satellites monitoring the Arctic ice has disproven this.

"Changes in the volume and extent of Arctic sea ice in recent years have focused attention on melting ice," says Ron Kwok of NASA's Jet Propulsion Laboratory, which runs the Grace and ICESat spacecraft. "The Grace and ICESat data allow us to now examine the impacts of widespread changes in ocean circulation."

According to Kwok and his colleagues, analysing readings from the satellites overhead, new freshwater in the Beaufort Sea comes not from melted ice but from rivers in Russia. Formerly this freshwater would have stayed largely in the Russian side of the Arctic, but a shift in circulation has occurred.

According to a JPL statement:

The team attributes the redistribution to an eastward shift in the path of Russian runoff through the Arctic Ocean, which is tied to an increase in the strength of the Northern Hemisphere's west-to-east atmospheric circulation, known as the Arctic Oscillation. The resulting counterclockwise winds changed the direction of ocean circulation, diverting upper-ocean freshwater from Russian rivers away from the Arctic's Eurasian Basin, between Russia and Greenland, to the Beaufort Sea in the Canada Basin bordered by the United States and Canada. The stronger Arctic Oscillation is associated with two decades of reduced atmospheric pressure over the Russian side of the Arctic.

The shift has meant that the Beaufort Sea in particular is the freshest it has been in 50 years of recordkeeping - but only a "tiny fraction" of that results from melting ice, according to the NASA scientists. Taken as a whole the Arctic has got no fresher, it's merely that freshwater which was always present has shifted in the past two decades from the seldom visited Russian side to the Canadian, where many climate scientists are found.

"Climate models need to more accurately represent the Arctic Oscillation's low pressure and counterclockwise circulation on the Russian side of the Arctic Ocean," says oceanographer Jamie Morison, lead author of a paper on the new satellite research published yesterday by Nature. ®

Internet Security Threat Report 2014

More from The Register

next story
MARS NEEDS WOMEN, claims NASA pseudo 'naut: They eat less
'Some might find this idea offensive' boffin admits
SECRET U.S. 'SPACE WARPLANE' set to return from SPY MISSION
Robot minishuttle X-37B returns after almost 2 years in orbit
LOHAN crash lands on CNN
Overflies Die Welt en route to lively US news vid
Experts brand LOHAN's squeaky-clean box
Phytosanitary treatment renders Vulture 2 crate fit for export
You can crunch it all you like, but the answer is NOT always in the data
Hear that, 'data journalists'? Our analytics prof holds forth
No sail: NASA spikes Sunjammer
'Solar sail' demonstrator project binned
America's super-secret X-37B plane returns to Earth after nearly TWO YEARS aloft
674 days in space for US Air Force's mystery orbital vehicle
Carry On Cosmonaut: Willful Child is a poor taste Star Trek parody
Cringeworthy, crude and crass jokes abound in Steven Erikson’s sci-fi debut
Origins of SEXUAL INTERCOURSE fished out of SCOTTISH LAKE
Fossil find proves it first happened 385 million years ago
prev story

Whitepapers

Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
Why and how to choose the right cloud vendor
The benefits of cloud-based storage in your processes. Eliminate onsite, disk-based backup and archiving in favor of cloud-based data protection.
Three 1TB solid state scorchers up for grabs
Big SSDs can be expensive but think big and think free because you could be the lucky winner of one of three 1TB Samsung SSD 840 EVO drives that we’re giving away worth over £300 apiece.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
Security for virtualized datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.