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

More articles from Earth Sciences:

nachricht Novel method for investigating pore geometry in rocks
17.06.2018 | Kyushu University, I2CNER

nachricht Decades of satellite monitoring reveal Antarctic ice loss
14.06.2018 | University of Maryland

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

Im Focus: Photoexcited graphene puzzle solved

A boost for graphene-based light detectors

Light detection and control lies at the heart of many modern device applications, such as smartphone cameras. Using graphene as a light-sensitive material for...

Im Focus: Water is not the same as water

Water molecules exist in two different forms with almost identical physical properties. For the first time, researchers have succeeded in separating the two forms to show that they can exhibit different chemical reactivities. These results were reported by researchers from the University of Basel and their colleagues in Hamburg in the scientific journal Nature Communications.

From a chemical perspective, water is a molecule in which a single oxygen atom is linked to two hydrogen atoms. It is less well known that water exists in two...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

A sprinkle of platinum nanoparticles onto graphene makes brain probes more sensitive

15.06.2018 | Materials Sciences

100 % Organic Farming in Bhutan – a Realistic Target?

15.06.2018 | Ecology, The Environment and Conservation

Perovskite-silicon solar cell research collaboration hits 25.2% efficiency

15.06.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>