Feeds

Clouds cloud climate modelling

Caltech scientists seek answers in moonshine

  • alert
  • submit to reddit

5 things you didn’t know about cloud backup

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

Boost IT visibility and business value

More from The Register

next story
Boffins attempt to prove the UNIVERSE IS JUST A HOLOGRAM
Is this the real life? Is this just fantasy?
China building SUPERSONIC SUBMARINE that travels in a BUBBLE
Shanghai to San Fran in two hours would be a trick, though
Our LOHAN spaceplane ballocket Kickstarter climbs through £8000
Through 25 per cent but more is needed: Get your UNIQUE rewards!
Cutting cancer rates: Data, models and a happy ending?
How surgery might be making cancer prognoses worse
CRR-CRRRK, beep, beep: Mars space truck backs out of slippery sand trap
Curiosity finds new drilling target after course correction
SpaceX prototype rocket EXPLODES over Texas. 'Tricky' biz, says Elon Musk
No injuries or near injuries. Flight stayed in designated area
Galileo, Galileo! Galileo, Galileo! Galileo fit to go. Magnifico
I'm just a poor boy, nobody loves me. But at least I can find my way with ESA GPS by 2017
prev story

Whitepapers

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.
Endpoint data privacy in the cloud is easier than you think
Innovations in encryption and storage resolve issues of data privacy and key requirements for companies to look for in a solution.
Scale data protection with your virtual environment
To scale at the rate of virtualization growth, data protection solutions need to adopt new capabilities and simplify current features.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.
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?