Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cloudy with a chance of warming

10.12.2015

Clouds can increase warming in the changing Arctic region more than scientists expected, by delivering an unexpected double-whammy to the climate system, according to a new study by researchers at NOAA, the University of Colorado Boulder and colleagues.

"As the Arctic atmosphere warms and moistens, it becomes a better insulator. While we expected this to reduce the influence from clouds, which provide additional insulation, we find that clouds forming in the Arctic in these conditions appear to further warm the surface, especially in the fall and winter," said Christopher Cox, lead author of the new paper published today in Nature Communications.


Clouds are shown over the western edge of the Greenland Ice Sheet.

Photo by Matt Shupe/CIRES

Cox is a research scientist with the Cooperative Institute for Research in Environmental Sciences (CIRES), who works at NOAA's Earth System Research Laboratory in Boulder, Colorado.

Clouds are a complicated character in the climate change story: They can cool the planet's surface by reflecting sunlight, and they can insulate it and keep it warm.

"To understand why and where Earth is warming, you have to understand the overall effect of clouds," Cox said.

Head north to the Arctic, and clouds' impact on climate is particularly difficult to understand, he said. The amount and manner in which clouds warm the surface is determined by an intricate dance between moisture (relative humidity), temperatures and the properties of the clouds--and that dance "is different in the Arctic, where the air is colder and drier than at lower latitudes," Cox said.

To nail down the overarching influence of Arctic clouds on temperatures, he and colleagues from CIRES, NOAA, Washington State University, Idaho and Chile analyzed measurements from three science research stations in the far north: Barrow, Alaska; Eureka, Canada; and Summit, Greenland.

They assessed things like temperature, relative humidity, and a measure of the cloud insulating properties ("the downwelling infrared cloud radiative effect"), and they looked at how those factors interacted with one another (in different parts of the infrared spectrum).

Previous work suggested that as the atmosphere itself warms and becomes more moist it becomes a better insulator, so the clouds themselves have a diminishing contribution to warming. This is likely true on a global scale: It's as if a person is already warm under a blanket and adding another blanket has little additional effect.

However, this team found a different behavior when temperature and humidity increase in the cold Arctic. There, clouds can retain their ability to warm the surface, and actually appear to be amplifying regional warming. In this cold, dry region, adding a second "blanket" can, in fact, make it even warmer.

The effect--strongest in autumn and winter--is related to the way that temperature and moisture are changing relative to each other in the region, according to the new analysis, which relied on climate modeling as well as observations. Because there is little sunlight in the Arctic in autumn and winter, the insulating properties of clouds far outweigh their shading properties, making this result all the more important, said co-author Matthew Shupe, also a CIRES researcher who works at NOAA.

He and his colleagues said their findings call for better monitoring of changes in the Arctic atmosphere, including temperature and moisture levels as well as cloud properties, and continued work to improve the representation of clouds in computer models designed to understand the rapidly evolving Arctic region.

###

Authors of "Humidity trends imply increased sensitivity to clouds in a warming Arctic" in Nature Communications are Christopher J. Cox (CIRES and NOAA), Von P. Walden (Washington State University), Penny M. Rowe (University of Idaho and Universidad de Santiago de Chile), and Matthew D. Shupe (CIRES and NOAA). This work was supported by the NOAA Climate Program Office (CPO) Arctic Research Program, the CIRES Visiting Fellows Program, the National Science Foundation (NSF), the Universidad de Santiago de Chile/FONDECYT/DICYT, and the US DOE Atmospheric Radiation Measurement (ARM) Program.

CIRES is a partnership of NOAA and CU-Boulder.

Media Contact

Christopher Cox
303-497-4518

 @cubouldernews

http://www.colorado.edu/news 

Christopher Cox | EurekAlert!

More articles from Earth Sciences:

nachricht Lightning, with a chance of antimatter
24.11.2017 | Kyoto University

nachricht A huge hydrogen generator at the Earth's core-mantle boundary
24.11.2017 | Science China Press

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New proton record: Researchers measure magnetic moment with greatest possible precision

High-precision measurement of the g-factor eleven times more precise than before / Results indicate a strong similarity between protons and antiprotons

The magnetic moment of an individual proton is inconceivably small, but can still be quantified. The basis for undertaking this measurement was laid over ten...

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Lightning, with a chance of antimatter

24.11.2017 | Earth Sciences

A huge hydrogen generator at the Earth's core-mantle boundary

24.11.2017 | Earth Sciences

Scientists find why CP El Niño is harder to predict than EP El Niño

24.11.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>