Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists determine biological and ecosystem changes in polar regions linked to solar variability

29.09.2003


A Lawrence Livermore National Laboratory scientist, in collaboration with an international team of colleagues, has reported that noticeable changes in the sub-polar climate and ecosystems appear to be linked to variations in the sun’s intensity during the past 12,000 years.



The research, titled "Cyclic Variation and Solar Forcing of Holocene Climate in the Alaskan Subarctic," is reported in today’s (Sept. 26) issue of Science.

Using core sediment samples from Arolik Lake in the tundra region along the southwestern coast of Alaska, Thomas Brown of Livermore’s Center for Accelerator Mass Spectrometry measured the amount of carbon-14 in samples to provide a chronological framework for the biological and organic evidence of climate and ecosystem changes, which occurred during the Holocene Epoch (12,000 years ago to present).


By studying biological, geochemical and isotopic constituents of sediment samples (such as biogenic silica from single-celled algae, which reflects lake productivity), the researchers determined that variations of these components provided evidence of climate and ecosystem variations over the past 12,000 years.

The scientists identified significant cycles lasting 200, 435, 590 and 950 years in the 12,000-year record, which are consistent with previously recognized cycles of solar activity. By comparison of the Alaskan subarctic record to recent findings of North Atlantic ice cover variations and solar-activity-modulated production records of beryllium- 10 and carbon-14, the scientists showed that the changes in sub-polar climate and ecosystems are correlated with records related to slight variations in solar irradiance.

The data from biogenic silica, North Atlantic sea ice, and beryllium-10 and carbon-14 showed "remarkable correlation during the cycles", Brown said.

"We found natural cycles involving climate and ecosystems that seem to be related to weak solar cycles, which, if verified, could be an important factor to help us understand potential future changes of Earth’s climate," said principal investigator Feng Sheng Hu of the University of Illinois at Champaign- Urbana.

"Will changes in solar irradiation in the future mitigate or exacerbate global warming in the future? They may do both. A period of high solar irradiance on top of high levels of greenhouse gases could result in unprecedented warming."

Other contributors come from Northern Arizona University, the Weizmann Institute of Science in Israel, Brown University and Columbia University.


###
Founded in 1952, Lawrence Livermore National Laboratory is a national security laboratory, with a mission to ensure national security and apply science and technology to the important issues of our time. Lawrence Livermore National Laboratory is managed by the University of California for the U.S. Department of Energy’s National Nuclear Security Administration.

Anne Stark | EurekAlert!
Further information:
http://www.berkeley.edu/

More articles from Earth Sciences:

nachricht Global study of world's beaches shows threat to protected areas
19.07.2018 | NASA/Goddard Space Flight Center

nachricht NSF-supported researchers to present new results on hurricanes and other extreme events
19.07.2018 | National Science Foundation

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>