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

BER Research Highlights


Possible Overestimation of Black Carbon Effects in Climate Models
Published: August 31, 2012
Posted: October 18, 2012

Black carbon (BC) in the atmosphere has a strong effect on global and regional climate. Some estimates suggest that the positive (warming) radiative forcing by BC is second only to CO2, making it an important near-term climate mitigation target. In a recent study, direct measurements of BC absorption enhancements and average mixing state for BC in the atmosphere around California are reported from two field campaigns: the 2010 CalNex study and the U.S. Department of Energy's Carbonaceous Aerosols and Radiative Effects Study (CARES). The CalNex measurements were made onboard the R/V Atlantis, whereas the CARES measurements were made at a ground site in the Sacramento urban area. Observations indicate that the BC absorption enhancements for ambient particles around large urban centers do not vary much with photochemical aging, are significantly less than predicted from traditional theory, and are in contrast to laboratory experiments. These findings suggest that the warming by BC may be overestimated in climate models. Further, they indicate a role for absorption at short visible wavelengths by non-BC aerosol components [brown carbon (BrC) in urban environments], which are not well quantified in current measurements or models.

Reference: Cappa, C. D., T. B. Onasch, P. Massoli, D. R. Worsnop, T. S. Bates, E. S. Cross, P. Davidovits, J. Hakala, K. L. Hayden, B. T. Jobson, K. R. Kolesar, D.A. Lack, B. M. Lerner, S.-M. Li, D. Mellon, I. Nuaaman, J. S. Olfert, T. Petäjä, P. K. Quinn, C. Song, R. Subramanian, E. J. Williams, and R. A. Zaveri. 2012. "Radiative Absorption Enhancements Due to the Mixing State of Atmospheric Black Carbon," Science 337, 1078-81. DOI: 10.1126/science.1223447. (Reference link)

Contact: Wanda Ferrell, SC-23.1, (301) 903-0043, Rickey Petty, SC-23.1, (301) 903-5548, Ashley Williamson, SC-23.1, (301) 903-3120
Topic Areas:

  • Research Area: Atmospheric System Research
  • Facility: DOE ARM User Facility

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)