Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ocean Salinity Trends Show Human Fingerprint

02.11.2012
Changes in ocean salinity over the second half of the 20th Century are consistent with the influence of human activities and inconsistent with natural climate variations, according to a new study.

Observed changes agree with computer modeling of salinity trends in a steadily warming world, said Scripps Institution of Oceanography, UC San Diego, climate researcher David Pierce, the study's lead author.

Ocean salinity changes are driven by the world's patterns of evaporation and rainfall, which themselves are changing. Observations over recent decades have found a general intensification of salinity differences in which salty ocean regions experience even more evaporation of surface waters and relatively fresh regions are becoming even more diluted with precipitation. These patterns are part of global changes in precipitation and evaporation.

Pierce said the significance of the study is that it provides an independent check of the effects of climate change on the water cycle using different instruments and techniques than weather station rainfall measurements. Studies of rainfall over land are harder to measure and place in context because of changes to weather stations over the years and the episodic nature of storms.

"The salinity in the ocean averages out all that variability," said Pierce. The paper will be published 2 November in the American Geophysical Union journal Geophysical Research Letters. Co-authors include Peter J. Gleckler, Benjamin Santer and Paul Durack of the Lawrence Livermore National Laboratory in Livermore, Calif. and Tim Barnett of Scripps Oceanography.

The study builds on previous analyses conducted in the last decade by Barnett, Pierce and others. They demonstrated that rising temperatures in the upper 700 meters (2,000 feet) of the ocean also can only be explained by anthropogenic climate change, which is caused mostly by an accumulation of carbon dioxide created by fossil fuel use.

This research complements the temperature analysis by considering salinity, the other main factor that determines the density of ocean water. Ocean water density is a key factor determining how water moves in the oceans.

"By combining the analysis of salinity and temperature, this study brings our level of understanding global scale oceanic changes to a new level," said Gleckler.

The previous temperature studies and this analysis of ocean salinity use a technique known as detection and attribution. In this method, observed trends in ocean salinity are compared to the effects of various historical phenomena such as volcanic eruptions or solar fluctuations and to climate cycles such as El Niño. When the computer climate models were run, the influence of those phenomena does not replicate the salinity or temperature patterns that researchers have observed since 1955. Only when the warming trends associated with human activity were added could the observed salinity trends and temperature changes be explained.

The research performed in this study will likely contribute to the next report of the Intergovernmental Panel on Climate Change, scheduled to be released in phases beginning in 2013.

The U.S. Department of Energy and NOAA funded the research.

Notes for Journalists

Journalists and public information officers (PIOs) of educational and scientific institutions who have registered with AGU can download a PDF copy of this paper in press by clicking on this link: http://dx.doi.org/10.1029/2012GL053389

Or, you may order a copy of the paper by emailing your request to Kate Ramsayer at kramsayer@agu.org. Please provide your name, the name of your publication, and your phone number.


Title:
"The fingerprint of human-induced changes in the ocean's salinity and temperature fields"
Authors:
David W. Pierce: Division of Climate, Atmospheric Sciences, and Physical Oceanography,

Scripps Institution of Oceanography, La Jolla, California, USA;

Peter J. Gleckler: Program for Climate Model Diagnosis and Intercomparison, Lawrence Livermore National Laboratory, Livermore, California, USA;

Tim P Barnett: Division of Climate, Atmospheric Sciences, and Physical Oceanography, Scripps Institution of Oceanography, La Jolla, California, USA;

Benjamin D. Santer and Paul James Durack: Program for Climate Model Diagnosis and Intercomparison, Lawrence Livermore National Laboratory, Livermore, California, USA;

Contact information for the authors:
Dave Pierce, Telephone: (858) 534-8276, email: dpierce@ucsd.edu.

Kate Ramsayer | American Geophysical Union
Further information:
http://www.agu.org

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Gold shines through properties of nano biosensors

17.08.2017 | Physics and Astronomy

Greenland ice flow likely to speed up: New data assert glaciers move over sediment, which gets more slippery as it gets wetter

17.08.2017 | Earth Sciences

Mars 2020 mission to use smart methods to seek signs of past life

17.08.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>