Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
..
. 24/7 Space News .




CLIMATE SCIENCE
New research shows complexity of global warming
by Staff Writers
Hilo HI (SPX) Feb 05, 2013


File image: Clouds over the Pacific ocean.

Global warming from greenhouse gases affects rainfall patterns in the world differently than that from solar heating, according to a study by an international team of scientists in the January 31 issue of Nature.

Using computer model simulations, the scientists, led by Jian Liu (Chinese Academy of Sciences) and Bin Wang (International Pacific Research Center, University of Hawaii at Manoa), showed that global rainfall has increased less over the present-day warming period than during the Medieval Warm Period, even though temperatures are higher today than they were then.

The team examined global precipitation changes over the last millennium and future projection to the end of 21st century, comparing natural changes from solar heating and volcanism with changes from man-made greenhouse gas emissions.

Using an atmosphere-ocean coupled climate model that simulates realistically both past and present-day climate conditions, the scientists found that for every degree rise in global temperature, the global rainfall rate since the Industrial Revolution has increased less by about 40% than during past warming phases of the earth.

Why does warming from solar heating and from greenhouse gases have such different effects on global precipitation?

"Our climate model simulations show that this difference results from different sea surface temperature patterns. When warming is due to increased greenhouse gases, the gradient of sea surface temperature (SST) across the tropical Pacific weakens, but when it is due to increased solar radiation, the gradient increases. For the same average global surface temperature increase, the weaker SST gradient produces less rainfall, especially over tropical land," says co-author Bin Wang, professor of meteorology.

But why does warming from greenhouse gases and from solar heating affect the tropical Pacific SST gradient differently?

"Adding long-wave absorbers, that is heat-trapping greenhouse gases, to the atmosphere decreases the usual temperature difference between the surface and the top of the atmosphere, making the atmosphere more stable," explains lead-author Jian Liu. "The increased atmospheric stability weakens the trade winds, resulting in stronger warming in the eastern than the western Pacific, thus reducing the usual SST gradient-a situation similar to El Nino."

Solar radiation, on the other hand, heats the earth's surface, increasing the usual temperature difference between the surface and the top of the atmosphere without weakening the trade winds. The result is that heating warms the western Pacific, while the eastern Pacific remains cool from the usual ocean upwelling.

"While during past global warming from solar heating the steeper tropical east-west SST pattern has won out, we suggest that with future warming from greenhouse gases, the weaker gradient and smaller increase in yearly rainfall rate will win out," concludes Wang.

Jian Liu, Bin Wang, Mark A. Cane, So-Young Yim, and June-Yi Lee: Divergent global precipitation changes induced by natural versus anthropogenic forcing. Nature, 493 (7434), 656-659; DOI: 10.1038/nature11784.

.


Related Links
University of Hawaii
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




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





CLIMATE SCIENCE
Study finds energy use in cities has global climate effects
Tallahassee FL (SPX) Feb 01, 2013
The heat generated by everyday energy consumption in metropolitan areas is significant enough to influence the character of major atmospheric circulation systems, including the jet stream during winter months, and cause continental-scale surface warming in high latitudes, according to a trio of climate researchers that includes Ming Cai, a professor in Florida State University's Department of Me ... read more


CLIMATE SCIENCE
Building a lunar base with 3D printing

US, Europe team up for moon fly-by

Russia to Launch Lunar Mission in 2015

US, Europe team up for moon fly-by

CLIMATE SCIENCE
AAS Division For Planetary Sciences Issues Statement On Mars 2020 Program

Curiosity Maneuver Prepares for Drilling

Ridges on Mars suggest ancient flowing water

Changes on Mars Caused by Seasonal Thawing of CO2

CLIMATE SCIENCE
Ahmadinejad says ready to be Iran's first spaceman

Iran's Bio-Capsule Comes Back from Space

A Hero For Humankind: Yuri Gagarin's Spaceflight

Internet wonders which monkey Iran sent into space

CLIMATE SCIENCE
Reshuffle for Tiangong

China to launch 20 spacecrafts in 2013

Mr Xi in Space

China plans manned space launch in 2013: state media

CLIMATE SCIENCE
NASA to Send Inflatable Pod to International Space Station

ISS to get inflatable module

ESA workhorse to power NASA's Orion spacecraft

Competition Hopes To Fine Tune ISS Solar Array Shadowing

CLIMATE SCIENCE
Zenit Engine Worked Normally

NASA Launches Rocket from Wallops Flight Facility in Virginia

Intelsat 27 Launch Unsuccessful

Floating platform unharmed after Zenit launch failure

CLIMATE SCIENCE
Herschel Finds Past-Prime Star May Be Making Planets

Stars can be late parents

Researchers develop model for identifying habitable zones around star

TW Hydrae: There's more to astronomers' favorite planetary nursery than previously thought

CLIMATE SCIENCE
South Korean Satellite Makes First Contact with Ground

Novel materials shake ship scum

Penn Research Shows Mechanism Behind Wear at the Atomic Scale

NTU research embraces laser and sparks cool affair




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