Free Newsletters - Space News - Defense Alert - Environment Report - Energy Monitor
. Earth Science News .




CLIMATE SCIENCE
Past tropical climate change linked to ocean circulation
by Staff Writers
College Station TX (SPX) Aug 27, 2012


File image.

A new record of past temperature change in the tropical Atlantic Ocean's subsurface provides clues as to why the Earth's climate is so sensitive to ocean circulation patterns, according to climate scientists at Texas A and M University.

Geological oceanographer Matthew Schmidt and two of his graduate students teamed up with Ping Chang, a physical oceanographer and climate modeler, to help uncover an important climate connection between the tropics and the high latitude North Atlantic. Their new findings are in the current issue of PNAS (Proceedings of the National Academy of Sciences).

The researchers used geochemical clues in fossils called foraminifera, tiny sea creatures with a hard shell, collected from a sediment core located off the northern coast of Venezuela, to generate a 22,000-year record of past ocean temperature and salinity changes in the upper 1,500 feet of water in the western tropical Atlantic.

They also conducted global climate model simulations under the past climate condition to interpret this new observational record in the context of changes in the strength of the global ocean conveyor-belt circulation.

"What we found was that subsurface temperatures in the western tropical Atlantic rapidly warmed during cold periods in Earth's past," Schmidt explains.

"Together with our new modeling experiments, we think this is evidence that when the global conveyor slowed down during cold periods in the past, warm subsurface waters that are normally trapped in the subtropical North Atlantic flowed southward and rapidly warmed the deep tropics. When the tropics warmed, it altered climate patterns around the globe."

He notes that as an example, if ocean temperatures were to warm along the west coast of Africa, the monsoon rainfall in that region would be dramatically reduced, affecting millions of people living in sub-Saharan Africa.

The researchers also point out that the southward flow of ocean heat during cold periods in the North Atlantic also causes the band of rainfall in the tropics known as the Intertropical Convergence Zone to migrate southward, resulting in much drier conditions in northern South American countries and a wetter South Atlantic.

"Evidence is mounting that the Earth's climate system has sensitive triggers that can cause abrupt and dramatic shifts in global climate," Schmidt said.

"What we found in our subsurface reconstruction was that the onset of warmer temperatures, thought to reflect the opening of this 'gateway' mechanism, occurred in less than a few centuries.

"It also tells us that it might be a good idea to monitor subsurface temperatures in the western tropical Atlantic to assess how the strength of the ocean conveyor might be changing over the next few decades as Earth's climate continues to warm."

"One way to prepare for future climate change is to increase our understanding of how it has operated in the recent past."

.


Related Links
Texas A and M University
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
Nobel prize-winning scientist cites evidence of link between extreme weather, global warming
Philadelphia PA (SPX) Aug 22, 2012
New scientific analysis strengthens the view that record-breaking summer heat, crop-withering drought and other extreme weather events in recent years do, indeed, result from human activity and global warming, Nobel Laureate Mario J. Molina, Ph.D., said. Molina, who shared the 1995 Nobel Prize in Chemistry for helping save the world from the consequences of ozone depletion, presented the k ... read more


CLIMATE SCIENCE
Green Climate Fund to hold next meeting in South Korea

Tanker-bus crash inferno kills 36 in China

China bridge collapse kills three

Haiti demolishes quake-ruined presidential palace

CLIMATE SCIENCE
Is This Real or Just Fantasy? ONR Augmented-Reality Initiative Progresses

SciTechTalk: Tablets: Does size matter?

US braces for holiday clash of tech giants

Apple scores huge win over Samsung in patent case

CLIMATE SCIENCE
Isaac rains boost Cuba water reserves

Finland leads major counter-pollution drill in Baltic Sea

Sea life 'facing major shock'

U OF A expert pinpoints nutrient behind fresh water algae blooms

CLIMATE SCIENCE
Arctic ice melts to record low: US researchers

New climate history adds to understanding of recent Antarctic Peninsula warming

Greenpeace raids Russian Arctic oil platform

Google online maps embark on Arctic adventure

CLIMATE SCIENCE
Access to water key for food security: FAO chief

Underground solution to starving rice plants

Good news for banana lovers: Help may be on the way to slow that rapid over-ripening

Soybeans Susceptible to Man-Made Materials in Soil

CLIMATE SCIENCE
Floods kill 10, displace 20,000 in Nigeria after dam opened

7.3 quake off El Salvador, no injuries or damage

Flooding kills 11, displaces hundreds in northern Nigeria

Isaac hammers Haiti, delays US Republican convention

CLIMATE SCIENCE
U.S. AFRICOM wants more guard partnerships

South Sudan's military chief Paulino Matip dies

Kenyan, Ugandan troops battle al-Shabaab

S.Africa police say mine killings were self-defence; 34 dead

CLIMATE SCIENCE
Man mistakes son for monkey, shoots him dead

More Clues About Why Chimps and Humans Are Genetically Different

More sophisticated wiring, not just bigger brain, helped humans evolve beyond chimps

Once again with feeling: Australian science tugs heart-strings




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