Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Oceans’ acidity influences early carbon dioxide and temperature link estimates

17.03.2004


An international team of geoscientists believes that carbon dioxide, and not changes in cosmic ray intensity, was the factor controlling ancient global temperatures. The new findings resulted from the researchers inclusion of the ocean’s changing acidity in their calculations.



"Reviewing the geologic records of carbon dioxide and glaciations, we found that carbon dioxide was low during periods of long-lived and widespread continental glaciations and high during other, warmer periods," says Dr. Dana L. Royer, research associate in geosciences at Penn State. "Previous suggestions that cosmic ray flux correlated better with ancient temperatures than carbon dioxides do not appear true. While cosmic ray flux may be of some climatic significance, it is likely of second-order importance on a multimillion year timescale."

The researchers looked at climate changes that occurred over the past 570 million years. A direct record of global temperature and carbon dioxide exists for the past 100 years and ice cores provide carbon dioxide information for the past 400,000 years. However, for the remainder of the years, there are no direct measurements.


"A close correspondence between carbon dioxide and temperature has generally been found for the past 570 million years," says Royer. Scientists typically use proxies to determine carbon dioxide and temperatures in the distant past. Oxygen isotope ratios in shallow marine carbonate fossils were used by some researchers to determine surface water temperatures, and this indicated that carbon dioxide and temperature were not correlated, but that cosmic ray fluxes were correlated to temperature. Other proxies can determine carbon dioxide concentrations in both the atmosphere and the oceans.

Royer, working with Robert A. Berner, The Alan M. Bateman professor of geology and geophysics, Yale University; Isabel P. Montanez, professor of geology, University of California Davis; Neil J. Tabor, research associate, Southern Methodist University; and David J. Beerling, professor of animal and plant sciences, University of Sheffield, U.K., compared the results of a variety of carbon dioxide proxies to a model, GEOCARB III, that predicts carbon dioxide over time by tracking carbon entering and leaving the atmosphere. "Proxy estimates of paleo carbon dioxide agree, within modeling errors with GEOCARB model results," the researchers reported in the March issue of GSA Today.

The researchers also found good correlation between low levels of carbon dioxide in the atmosphere and the presence of extensive continental glaciations.

However, the proxy for temperature obtained from shallow oceanic carbonate deposits did not correlate well with the other temperature proxies or the carbon dioxide estimates.

"The acidity of the oceans changes depending on the amount of carbon dioxide in the atmosphere and the amounts of calcium and calcium carbonate in the water," says Royer. "When corrected for acidity, the temperature curve matches the glacial record much better."

The researchers applied correction factors for changes in acidity due to changes in carbon dioxide alone, changes in calcium ions in the water and carbon dioxide in the atmosphere and also for changes in calcium ions, carbon dioxide and calcium carbonate saturation of the water. The corrected temperature curves correctly predicted two major glaciations, one around 300 million years ago and one 30 million years ago. The cosmic ray flux does predict these glaciations, but also predicts cold temperatures when there is no evidence for ice.

"The global temperatures inferred from the cosmic ray flux model do not correlate with the temperature record determined from oxygen isotopes in shallow marine carbonate fossils, when these estimates were corrected for past changes in oceanic acidity," says the Penn State researcher.


The U.S. Department of Energy and the National Science Foundation supported this research.

A’ndrea Elyse Messer | EurekAlert!
Further information:
http://www.psu.edu/

More articles from Earth Sciences:

nachricht Research sheds new light on forces that threaten sensitive coastlines
24.04.2017 | Indiana University

nachricht NASA sees the end of ex-Tropical Cyclone 02W
21.04.2017 | NASA/Goddard Space Flight Center

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Molecular libraries for organic light-emitting diodes

24.04.2017 | Life Sciences

Research sheds new light on forces that threaten sensitive coastlines

24.04.2017 | Earth Sciences

Making lightweight construction suitable for series production

24.04.2017 | Machine Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>