Development of a Quantitative Accounting Framework for Black Carbon and Brown Carbon from Emissions Inventory to ImpactsEPA Grant Number: R835039
Title: Development of a Quantitative Accounting Framework for Black Carbon and Brown Carbon from Emissions Inventory to Impacts
Investigators: Schauer, James J. , Bergin, Michael
Institution: University of Wisconsin - Madison , Georgia Institute of Technology
EPA Project Officer: Chung, Serena
Project Period: October 1, 2011 through September 30, 2014 (Extended to September 30, 2016)
Project Amount: $899,600
RFA: Black Carbon's Role In Global To Local Scale Climate And Air Quality (2010) RFA Text | Recipients Lists
Research Category: Global Climate Change , Climate Change , Air
The overall goal of this project is to develop a framework, and the necessary supporting data, to quantitatively account for the contributions of source emissions and atmospheric processing to the radiative absorption by carbonaceous aerosols in the atmosphere. This goal will be achieved through two integrated approaches: 1) quantification of the relationships of the optical and chemical properties of the major components of light absorbing carbon in the emissions from key air pollution sources, and 2) elucidating how these relationships evolve during atmospheric processing and transport. The project team will integrate expertise in molecular marker source apportionment tools as well as in the measurement of aerosol optical properties that will provide a mechanism to quantitatively determine the source contributions to light absorbing carbon. The work will combine direct measurements of the emissions of dominant light absorbing carbon sources with field measurements in both urban, and background locations to understand the influence of sources and atmospheric aging on aerosol light absorption.
Using a dilution source sampler and associated aerosol measurement techniques, the optical and chemical properties of isolated components of aerosol emissions will be measured using a combination of real time and off-line methods. This will include the isolation of the organic compound fraction using solvent extraction and atomization methods, the isolation of non-volatile refractory carbon using thermal denuder methods, and size classification using differential electrical mobility. These approaches will be used to more completely map the association of chemical components of primary emissions with optical properties (i.e. wavelength dependant absorption coefficients, and mass absorption efficiencies) of carbonaceous aerosols. Such efforts will be directed at key sources of light absorbing carbon including diesel engines, biomass burning, fuel oil combustion, smoking gasoline engines, and incomplete combustion of coal.
Parallel measurements, along with molecular markers for source apportionment, will be conducted at well targeted urban and remote sampling sites to use source receptor relationships for the key components of PM2.5 to quantify how atmospheric processing and aging of aerosols impacts the relationships of key chemical components and aerosol radiative properties. Ultimately, these results will be integrated to develop a comprehensive framework to relate primary emissions of light absorbing compounds to both the optical properties of the fresh emissions and of aged aerosols.
The project will greatly advance the understanding of the relationship of optical and chemical measurements of black and brown carbon from fresh emissions to aged emissions at remote locations. This understanding will ultimately provide the basis for developing robust emissions inventory data for black and brown carbon, and will supply important information on the impact of aging on climate relevant aerosol properties.