Grantee Research Project Results
Final Report: Black Carbon, Air Quality and Climate: From the Local to the Global Scale
EPA Grant Number: R835035Title: Black Carbon, Air Quality and Climate: From the Local to the Global Scale
Investigators: Pandis, Spyros N. , Robinson, Allen , Donahue, Neil , Adams, Peter
Institution: Carnegie Mellon University
EPA Project Officer: Chung, Serena
Project Period: September 1, 2011 through August 31, 2014
Project Amount: $900,000
RFA: Black Carbon's Role In Global To Local Scale Climate And Air Quality (2010) RFA Text | Recipients Lists
Research Category: Air Quality and Air Toxics , Air , Climate Change
Objective:
Reduction of black carbon (BC) emissions represents a potential win-win strategy in our effort to improve air quality while limiting climate change. However, the magnitude of the benefits remains quite uncertain because of our limited understanding of the contributions of the various source sectors to the BC mass and number concentrations, the atmospheric processing of black carbon particles including their physical and chemical changes, the role of other absorbing organics (brown carbon), the contributions of the various source sectors (and long range transport) to the direct and indirect effects of BC on climate, and the effect of BC on local and regional meteorology. Control strategies resulting in changes to BC emissions will often result in changes to emissions of various co-pollutants (primary and secondary organic aerosol, sulfur, particle number concentration) and may have significant effects on the aerosol and cloud droplet number concentrations. Reduction of the above uncertainties and quantification of the effects of the various BC control strategies on both air quality and climate change in the United States are the main objectives of the proposed study. More specifically focusing on the United States, we will:
- Develop size- and composition-resolved number emission inventories for BC-containing sources for the Unites States and also improve the existing mass inventories using a consistent definition of BC.
- Improve our understanding of the atmospheric processing of BC particles.
- Improve the ability of the existing regional and global chemical transport and climate models to simulate the BC mass and number concentrations and their effects on climate.
- Quantify the contributions of the different BC source sectors (including long-range transport) to BC mass and number concentrations.
- Quantify the contributions of the same source sectors to the direct, indirect and semi-direct effects of BC on climate.
- Elucidate the role of BC in local and regional meteorology, including temperature and the hydrological cycle.
- Quantify the effectiveness of various U.S. and global strategies of reducing BC on BC mass and particle number concentrations, direct, indirect and semi-direct radiative forcing and climate change.
- Identify and quantify major uncertainties in emissions, atmospheric processing, and climate impacts of BC mitigation.
Summary/Accomplishments (Outputs/Outcomes):
1.1 Laboratory Studies of Aging of Primary Emissions
Atmospheric particulate matter plays an important role in the Earth’s radiative balance. Over the past two decades, it has been established that a portion of particulate matter, black carbon, absorbs significant amounts of light and exerts a warming effect rivaling that of anthropogenic carbon dioxide. Most climate models treat black carbon as the sole light-absorbing carbonaceous particulate. However, some organic aerosols, dubbed brown carbon and mainly associated with biomass burning emissions, also absorbs light. Unlike black carbon, whose light absorption properties are well understood, brown carbon comprises a wide range of poorly characterized compounds that exhibit highly variable absorptivities, with reported values spanning two orders of magnitude. We performed smog chamber experiments to characterize the effective absorptivity of organic aerosol from biomass burning under a range of conditions (Saleh et al., 2014). We showed that brown carbon in emissions from biomass burning is associated mostly with organic compounds of extremely low volatility. In addition, we found that the effective absorptivity of organic aerosol in biomass burning emissions can be parameterized as a function of the ratio of black carbon to organic aerosol (Fig. 1) indicating that aerosol absorptivity depends largely on burn conditions, not fuel type. Brown carbon from biomass burning can be an important factor in aerosol radiative forcing.
Fig. 1. Dependence of the imaginary component (absorption) of the refractive index of OA at 550 nm on BC-to-OA ratio. Filled diamonds and open squares correspond to fresh and chemically aged emissions, respectively. Colours correspond to different fuels: black, black spruce; magenta, ponderosa pine; cyan, rice straw; forest green, organic hay; light green, saw grass; and blue, wire grass.
The photochemical aging of smoke emitted from the burning of biofuels commonly used for residential heating (oak) or consumed in wild-land and prescribed fires in the United States (pocosin pine and gallberry) was investigated in a smog chamber (Saleh et al., 2013). These experiments focused among others on the light absorption of organic aerosol (OA) in photochemically aged biomass-burning emissions. We constrained the effective light-absorption properties of the OA using conservative limiting assumptions, and found that both primary organic aerosol (POA) in the fresh emissions and secondary organic aerosol (SOA) produced by photo-chemical aging contain brown carbon, and absorb light to a significant extent. This work presents the first direct evidence that SOA produced in aged biomass-burning emissions is absorptive (Fig. 2). For the investigated fuels, SOA is less absorptive than POA in the long visible, but exhibits stronger wavelength-dependence and is more absorptive in the short visible and near-UV.
 Investigation of the chemical aging and absorption of carbonaceous aerosol from wood burning, in preparation.</p>
<p>
Fountoukis C. and S. N. Pandis (2015) A computationally efficient module for the explicit simulation of the black carbon mixing state in atmospheric particles, in preparation. </p>
<p></p>
<br>
<strong>Journal Articles
on this Report
:</strong> <font size=)
11 Displayed | Download in RIS Format
| Other project views: | All 25 publications | 11 publications in selected types | All 11 journal articles |
|---|
| Type | Citation | ||
|---|---|---|---|
|
|
Day MC, Zhang M, Pandis SN. Evaluation of the ability of the EC tracer method to estimate secondary organic aerosol carbon. Atmospheric Environment 2015;112:317-325. |
R835035 (Final) R835405 (2014) R835405 (Final) |
Exit Exit Exit |
|
|
Day MC, Pandis SN. Effects of a changing climate on summertime fine particulate matter levels in the eastern U.S. Journal of Geophysical Research: Atmospheres 2015;120(11):5706-5720. |
R835035 (2013) R835035 (Final) R833374 (Final) |
Exit Exit Exit |
|
|
Gkatzelis GI, Papanastasiou DK, Florou K, Kaltsonoudis C, Louvaris E, Pandis SN. Measurement of nonvolatile particle number size distribution. Atmospheric Measurement Techniques 2016;9(1):103-114. |
R835035 (Final) R835405 (Final) |
Exit Exit |
|
|
Posner LN, Pandis SN. Sources of ultrafine particles in the Eastern United States. Atmospheric Environment 2015;111:103-112. |
R835035 (2013) R835035 (Final) R833374 (Final) R835405 (2014) R835405 (Final) |
Exit Exit Exit |
|
|
Saleh R, Hennigan CJ, McMeeking GR, Chuang WK, Robinson ES, Coe H, Donahue NM, Robinson AL. Absorptivity of brown carbon in fresh and photo-chemically aged biomass-burning emissions. Atmospheric Chemistry and Physics 2013;13(15):7683-7693. |
R835035 (2013) R835035 (Final) R833747 (Final) |
Exit Exit Exit |
|
|
Saleh R, Robinson ES, Tkacik DS, Ahern AT, Liu S, Aiken AC, Sullivan RC, Presto AA, Dubey MK, Yokelson RJ, Donahue NM, Robinson AL. Brownness of organics in aerosols from biomass burning linked to their black carbon content. Nature Geoscience 2014;7(9):647-650. |
R835035 (Final) |
Exit Exit Exit |
|
|
Saleh R, Marks M, Heo J, Adams PJ, Donahue NM, Robinson AL. Contribution of brown carbon and lensing to the direct radiative effect of carbonaceous aerosols from biomass and biofuel burning emissions. Journal of Geophysical Research-Atmospheres 2015;120(19):10285-10296. |
R835035 (Final) |
Exit Exit |
|
|
Shamjad PM, Tripathi SN, Pathak R, Hallquist M, Arola A, Bergin MH. Contribution of brown carbon to direct radiative forcing over the Indo-Gangetic Plain. Environmental Science & Technology 2015;49(17):10474-10481. |
R835035 (Final) R835039 (2015) R835039 (Final) |
Exit Exit Exit |
|
|
Westervelt DM, Pierce JR, Riipinen I, Trivitayanurak W, Hamed A, Kulmala M, Laaksonen A, Decesari S, Adams PJ. Formation and growth of nucleated particles into cloud condensation nuclei: model-measurement comparison. Atmospheric Chemistry and Physics 2013;13(15):7645-7663. |
R835035 (2013) R835035 (Final) R833374 (Final) |
Exit Exit Exit |
|
|
Westervelt DM, Pierce JR, Adams PJ. Analysis of feedbacks between nucleation rate, survival probability and cloud condensation nuclei formation. Atmospheric Chemistry and Physics 2014;14(11):5577-5597. |
R835035 (Final) R833374 (Final) |
Exit Exit |
|
|
Tasoglou A, Saliba G, Subramanian R, Pandis SN. Absorption of chemically aged biomass burning carbonaceous aerosol. Journal of Aerosol Science 2017;113:141-152. |
R835035 (Final) R835438 (Final) |
Exit Exit Exit |
Supplemental Keywords:
Air quality modeling, smog, PM, general circulation modelProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.