Feeds

Svalbard overtakes medieval summers

Fat algae suggest record temperatures

Secure remote control for conventional and virtual desktops

The so-called “Medieval Warm Period” may not have been as warm – and certainly not as uniformly warm – as is commonly believed, according to research led by Columbia University’s Lamont-Doherty Earth Observatory.

While the research only covers a small area – Norway’s Svalbard archipelago in the north – but the researchers believe the area is now clearly warmer than it was in the period from 950 to 1250 AD, known as the “Medieval Warm Period”.

“Our record indicates that recent summer temperatures on Svalbard are greater than even the warmest periods at that time,” says Colombia researcher William D’Andrea, lead author of the study. Right now, he believes, the region is experiencing its highest temperatures in 1,800 years.

The temperature reconstruction is based on an analysis of algae deposited in sediments in the eastern Svalbard lake called Kongressvatnet. As D’Andrea explains, these provide a more continuous weather record than ice cores. The algae are deposited continuously, whereas ice cores only preserve cold-season snowfall (and thus are an indication to winter, rather than summer, temperatures).

The marker in the algae the researchers look for is in the balance of saturated and unsaturated fats they algae lay down. To cope with colder water, they produce more saturated fats; in warmer water, the balance swings to unsaturated fats.

Samples collected in the Kongressvatnet lake cores were dated against the glass sediments left behind by known volcanic eruptions in the years 170 (Snæfellsjökull), 1104 (Hekla) and 1362 (Öræfajökull).

While there’s no doubt that the combination of a solar maximum and volcanic activity drove the medieval climate, D’Andrea’s assertion is that it wasn’t as uniform a warming as is widely believed. While parts of the Northern Hemisphere were hotter than today, the Svalbard record indicates that the region is getting summers 2 to 2.5°C hotter than in the period 950-1250 AD.

Svalbard’s more recent warming seems to reflect a complex set of drivers, the researchers suggest. In the year 1600, the West Spitsbergen Current of the Gulf Stream seems to have brought more tropical water to the area; warming began to accelerate further since 1890, and scientists attribute most of the warming since 1960 to human activity.

The study is published on Geology (abstract). ®

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
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
Another step forward for diamond-based quantum computers
Square cut or pear-shaped, these qubits don't lose their shape
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.