Feeds

Clouds cloud climate modelling

Caltech scientists seek answers in moonshine

  • alert
  • submit to reddit

Security for virtualized datacentres

Caltech scientists looking to the moon for insights into the Earth's climate say they have observed unexpectedly large fluctuations in the planet's cloud cover over the last two decades.

Contrary to computer models of the climate system, the team found that Earth's average albedo (the amount of light reflected back into space, relative to the amount landing on it) is not constant from one year to the next, nor is it constant over decadal timescales.

The researchers combined eight years of 'earthshine' data - the amount of light Earth reflects on to the dark side of the moon, directly linked to how cloudy the planet is - with twenty years of satellite cloud data. The observation data were collected at the Big Bear Solar Observatory (BBSO) in California.

They found that the Earth's reflectiveness, or the amount of cloud cover, declined steadily from 1985 to 1995, and fell even more dramatically between 1996 and 1997. This low albedo remained roughly constant until 2001. This same period saw a massive increase in solar heating of the planet and as a consequence, an accelerated increase in mean global temperatures.

The last three years, however, have seen this decline largely reversed, and the Earth's albedo is now similar to pre 1995 levels, consistent with much cloudier skies.

Enric Palle, the lead scientist on the project acknowledged that climate is an extremely complex system. He explains that the Earth's surface temperature is determined by a balance between the warming effect of sunlight and the cooling effect of heat radiated back into space. This balance is determined by many factors in addition to albedo, such as the amount of greenhouse gases present in the atmosphere.

"Our results are only part of the story," he said. "But these new data emphasize that clouds must be properly accounted for and illustrate that we still lack the detailed understanding of our climate system necessary to model future changes with confidence."

The team has ambitious plans to continue its research, and is working to establish a global network of observing stations that would allow continuous monitoring of the albedo throughout the lunar month, regardless of local weather conditions. BBSO data are already supplemented by observations from Crimea in the Ukraine, and there will soon be observations from Yunnan in China, too.

The team is building a prototype robotic telescope to automate observations. Ultimately the researchers want to build and deploy eight of these fully automated observational posts around the globe. ®

Related stories

Red moonlight to bathe UK
Have sex, save the planet
Toxic PCs destroy life as we know it

Security for virtualized datacentres

More from The Register

next story
Boffins say they've got Lithium batteries the wrong way around
Surprises at the nano-scale mean our ideas about how they charge could be all wrong
Thought that last dinosaur was BIG? This one's bloody ENORMOUS
Weighed several adult elephants, contend boffins
Europe prepares to INVADE comet: Rosetta landing site chosen
No word yet on whether backup site is labelled 'K'
City hidden beneath England's Stonehenge had HUMAN ABATTOIR. And a pub
Boozed-up ancients drank beer before tearing corpses apart
'Duck face' selfie in SPAAAACE: Rosetta's snap with bird comet
Probe prepares to make first landing on fast-moving rock
Archaeologists and robots on hunt for more Antikythera pieces
How much of the world's oldest computer can they find?
prev story

Whitepapers

Secure remote control for conventional and virtual desktops
Balancing user privacy and privileged access, in accordance with compliance frameworks and legislation. Evaluating any potential remote control choice.
Saudi Petroleum chooses Tegile storage solution
A storage solution that addresses company growth and performance for business-critical applications of caseware archive and search along with other key operational systems.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?
Security for virtualized datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.
Providing a secure and efficient Helpdesk
A single remote control platform for user support is be key to providing an efficient helpdesk. Retain full control over the way in which screen and keystroke data is transmitted.