BER launches Environmental System Science Program. Visit our new website under construction!

U.S. Department of Energy Office of Biological and Environmental Research

BER Research Highlights


First Evidence of Long-Term Human Influence in Pacific Decadal Oscillation
Published: November 01, 2010
Posted: November 05, 2010

Both natural systems, from salmon productivity to fires to river flow to the onset of spring, etc., and atmospheric variables are affected by decadal-scale natural fluctuations in northern Pacific Ocean sea surface temperatures, known as the Pacific Decadal Oscillation (PDO). However, it turns out that this natural climate variability may not be entirely “natural” after all. Two BER-funded scientists present the first evidence of a long-term human component in the PDO. They considered three definitions of a PDO index, two of which attempt to remove a global warming signal that could be present in the sea surface temperature data. These definitions were analyzed using sea surface temperature data from two observational datasets and from two coupled ocean-atmosphere model simulations of historical and future climate. In the 21st century scenarios, an anthropogenic component is systematically found in all three PDO indices. For the definition in which no attempt was made to remove a global warming signal, the human component is so large that it is already statistically detectable in the observed PDO index. This study illustrates the importance of separating internally-generated and externally-forced components of the PDO, suggests that caution should be exercised in using PDO indices for statistical removal of ‘‘natural variability’’ effects from observational datasets, and suggests that we should carefully examine other “natural” climate change fluctuations to understand the sources of the variations.

Reference: Bonfils, C. and B.D. Santer. 2010. "Investigating the Possibility of a Human Component in Various Pacific Decadal Oscillation Indices," Climate Dynamics. Online First.

Contact: Renu Joseph, SC-23.1, (301) 903-9237, Dorothy Koch, SC-23.1, (301) 903-0105
Topic Areas:

  • Research Area: Earth and Environmental Systems Modeling

Division: SC-33.1 Earth and Environmental Sciences Division, BER

 

BER supports basic research and scientific user facilities to advance DOE missions in energy and environment. More about BER

Recent Highlights

Mar 23, 2021
Molecular Connections from Plants to Fungi to Ants
Lipids transfer energy and serve as an inter-kingdom communication tool in leaf-cutter ants&rsqu [more...]

Mar 19, 2021
Microbes Use Ancient Metabolism to Cycle Phosphorus
Microbial cycling of phosphorus through reduction-oxidation reactions is older and more widespre [more...]

Feb 22, 2021
Warming Soil Means Stronger Microbe Networks
Soil warming leads to more complex, larger, and more connected networks of microbes in those soi [more...]

Jan 27, 2021
Labeling the Thale Cress Metabolites
New data pipeline identifies metabolites following heavy isotope labeling.

Analysis [more...]

Aug 31, 2020
Novel Bacterial Clade Reveals Origin of Form I Rubisco
Objectives

  • All plant biomass is sourced from the carbon-fixing enzyme Rub [more...]

List all highlights (possible long download time)