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

BER Research Highlights


Why Climate Models Underestimate Organic Aerosols
Published: January 30, 2012
Posted: May 24, 2012

Airborne particles impact human health, cause haze, and influence climate. New findings from researchers at the University of California, Irvine; Pacific Northwest National Laboratory (PNNL); Imre Consulting; and Portland State University may explain why the abundance of secondary organic aerosols (SOA), which make up more than half of airborne particle mass, has been significantly underestimated by currently accepted air quality and climate models. SOAs are derived from the oxidation of volatile organics, such as pinene, a substance excreted from pine trees. Using the SPLAT II mass spectrometer at PNNL's Environmental Molecular Sciences Laboratory (EMSL), a unique instrument that allows users to study fundamental processes governing the chemistry and physics of particles at the nano- and microscale, the team showed that a-pinene reacts with ozone and nitrate to form organic nitrates and ozonolysis products, and that the latter nucleates and forms seed particles on which other products condense to form SOAs. The findings are contrary to expectations, including the view that SOAs evolve in the atmosphere as equilibrated liquid droplets and evaporate with time. Instead, the data show that SOA particles are quasi-solids that stick around for a long time. If found to be a general phenomena in the atmosphere, aerosol models may need to be reformulated to better predict SOA evolution in both indoor and outdoor environments, including climate prediction models.

Reference: Perraud, V., E. A. Bruns, M. J. Ezell, S. N. Johnson, Y. Yu, M. L. Alexander, A. Zelenyuk, D. Imre, W. L. Chang, D. Dabdub, J. F. Pankow, and B. J. Finlayson-Pitts. 2012. "Non-Equilibrium Atmospheric Secondary Organic Aerosol Formation and Growth," Proceedings of the National Academy of Sciences 109(8), 2836-41. DOI: 10.1073/pnas.1119909109. (Reference link)

For more information, see the recent UC Irvine press release, Gases Drawn into Smog Particles Stay There, UCI-Led Study Reveals. (link expired)

Contact: Paul E. Bayer, SC-23.1, (301) 903-5324, Ashley Williamson, SC-23.1, (301) 903-3120
Topic Areas:

  • Research Area: Earth and Environmental Systems Modeling
  • Research Area: Atmospheric System Research
  • Research Area: DOE Environmental Molecular Sciences Laboratory (EMSL)

Division: SC-23.1 Climate 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

May 10, 2019
Quantifying Decision Uncertainty in Water Management via a Coupled Agent-Based Model
Considering risk perception can improve the representation of human decision-making processes in age [more...]

May 09, 2019
Projecting Global Urban Area Growth Through 2100 Based on Historical Time Series Data and Future Scenarios
Study provides country-specific urban area growth models and the first dataset on country-level urba [more...]

May 05, 2019
Calibrating Building Energy Demand Models to Refine Long-Term Energy Planning
A new, flexible calibration approach improved model accuracy in capturing year-to-year changes in bu [more...]

May 03, 2019
Calibration and Uncertainty Analysis of Demeter for Better Downscaling of Global Land Use and Land Cover Projections
Researchers improved the Demeter model’s performance by calibrating key parameters and establi [more...]

Apr 22, 2019
Representation of U.S. Warm Temperature Extremes in Global Climate Model Ensembles
Representation of warm temperature events varies considerably among global climate models, which has [more...]

List all highlights (possible long download time)