Subscribe free to our newsletters via your
. 24/7 Space News .




CLIMATE SCIENCE
Climate Likely to Be on Hotter Side of Projections
by Staff Writers
Pasadena CA (JPL) Nov 14, 2012


Scientists used observations from two NASA satellite instruments, including relative humidity data similar to these, from the Atmospheric Infrared Sounder (AIRS) instrument on NASA's Aqua spacecraft, to analyze how well leading global climate models reproduce observed relative humidity in Earth's tropics and subtropics. The study found climate models that most accurately captured these complex moisture processes and associated clouds were also the ones that showed the greatest amounts of warming as atmospheric greenhouse gases increase. The AIRS surface relative humidity data shown here are representative only and are not from the study. Areas shown in reds and yellows are the driest; blue areas the moistest. Image credit: NASA/JPL-Caltech

A new NASA-funded study by the National Center for Atmospheric Research, Boulder, Colo., finds climate model projections that show a greater rise in global temperature are likely to prove more accurate than those showing a lesser rise. The findings, published in the journal Science, could provide a breakthrough in the longstanding quest to narrow the range of global warming expected in coming decades and beyond.

National Center for Atmospheric Research scientists John Fasullo and Kevin Trenberth analyzed how well 16 leading sophisticated climate models reproduce observed relative humidity in Earth's tropics and subtropics.

They used observations from two NASA satellite instruments - the Atmospheric Infrared Sounder (AIRS) instrument on NASA's Aqua spacecraft and the Clouds and Earth's Radiant Energy System (CERES) instruments that fly on several NASA Earth satellites - along with a NASA data analysis called the Modern-Era Retrospective Analysis for Research and Applications (MERRA).

AIRS was built by and is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif. NASA's Langley Research Center, Hampton, Va., manages the CERES mission.

The researchers found the climate models that most accurately captured these complex moisture processes and associated clouds, which have a major influence on global climate, were also the ones that showed the greatest amounts of warming as society emits more greenhouse gases into the atmosphere.

"There is a striking relationship between how well climate models simulate relative humidity in key areas and how much warming they show in response to increasing carbon dioxide," said Fasullo.

"Given how fundamental these processes are to clouds and the overall global climate, our findings indicate that warming is likely to be on the high side of current projections."

The world's major global climate models are all based on long-established physical laws known to guide the atmosphere. However, because these relationships are challenging to translate into software, each model differs slightly in its portrayal of global climate.

In particular, some processes, such as those associated with clouds, are too small to be represented properly. Although satellites observe many types of clouds, satellite failure, observing errors and other inconsistencies make it challenging to build a comprehensive global cloud census that is consistent over many years.

However, satellites perform better in measuring water vapor, and estimates of the global distribution of relative humidity, such as provided by AIRS, have become more reliable. Relative humidity also is incorporated in climate models to generate and dissipate clouds.

The authors focused on the dry subtropics because seasonal drying and associated decrease in clouds there, especially during May through August, serve as a good analog for patterns projected by climate models.

"If we can better represent these regions in models, we can improve our predictions and provide society with a better sense of the impacts to expect in a warming world," said Fasullo.

AIRS project scientist Eric Fetzer of JPL, who was not involved with the study, called the work both encouraging and sobering.

"These results were hiding in plain sight," he said.

"We have known for 30 years that clouds complicate climate forecasts, but instead of looking directly at clouds, this study examines clear regions. Their conclusions indicate that better model physics for clear areas will lead to improved climate forecasts, but warming is likely to be at the high end of current forecasts."

Launched in 2002, AIRS, along with its partner microwave instrument, the Advanced Microwave Sounding Unit (AMSU-A), measures Earth's atmospheric temperature, water vapor, clouds and greenhouse gases with unprecedented accuracy and stability.

Over the past decade, AIRS and AMSU-A have improved our understanding of Earth's global water and energy cycles, climate change and trends and how Earth's climate system is responding to increased greenhouse gases.

.


Related Links
Advanced Microwave Sounding Unit
Climate Science News - Modeling, Mitigation Adaptation






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle








CLIMATE SCIENCE
Australia to sign up for Kyoto 2
Sydney (AFP) Nov 9, 2012
Key greenhouse gas emitter Australia on Friday said it will sign up for a second round of the Kyoto Protocol environmental protection treaty, but New Zealand opted out. Climate Minister Greg Combet made the announcement in a speech to a carbon expo, saying: "Australia is ready to join a second commitment period of the Kyoto Protocol." So far, only the European Union and several smaller e ... read more


CLIMATE SCIENCE
China's Chang'e-3 to land on moon next year

Moon crater yields impact clues

Study: Moon basin formed by giant impact

NASA's LADEE Spacecraft Gets Final Science Instrument Installed

CLIMATE SCIENCE
Mars orbiter back online after system swap

What Arctic Rocks Say About Mars: An Interview with Hans Amundsen

More Driving And Imaging At 'Matijevic Hill'

Curiosity Team Switches Back to Earth Time

CLIMATE SCIENCE
Get some bed rest - all 21 days of it

Latest China military hardware displayed at airshow

Obama Win Keeps NASA's Space Plans on Course

Next steps into the final frontier

CLIMATE SCIENCE
Mr Xi in Space

China plans manned space launch in 2013: state media

China to launch manned spacecraft

Tiangong 1 Parked And Waiting As Shenzhou 10 Mission Prep Continues

CLIMATE SCIENCE
Crew Prepares for Spacewalk After Progress Docks

Crew Preparing for Cargo Ship, Spacewalk

Russian cargo ship docks with ISS: official

Packed Week Ahead for Six-Member Crew

CLIMATE SCIENCE
Arianespace's fourth Spaceport mission with Soyuz ready for fueling

Ariane 5's sixth launch of 2012

Ariane 5 is poised for Arianespace's launch with the EUTELSAT 21B and Star One C3 satellites

Ariane 5 orbits EUTELSAT 21B and Star One C3 satellites

CLIMATE SCIENCE
Discovery of a Giant Gap in the Disk of a Sun-like Star May Indicate Multiple Planets

New habitable zone super-Earth found in exosolar system

Cosmic sprinklers explained in active planetary nebula

Nearby six-planet system could be life friendly

CLIMATE SCIENCE
Microsoft holds Windows Phone 8 hopes

Making a better invisibility cloak

Head of Windows unit leaves Microsoft

Online TEDTalks hit billion-view milestone




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement