Grantee Research Project Results

2018 Progress Report: Interplay Between Black and Brown Carbon from Biomass Burning and Climate

EPA Grant Number: R835883
Title: Interplay Between Black and Brown Carbon from Biomass Burning and Climate
Investigators: Murphy, Shane Michael
Institution: University of Wyoming
EPA Project Officer: Chung, Serena
Project Period: January 1, 2016 through December 31, 2018 (Extended to September 30, 2020)
Project Period Covered by this Report: January 1, 2018 through December 31,2018
Project Amount: $349,847
RFA: Particulate Matter and Related Pollutants in a Changing World (2014) RFA Text | Recipients Lists
Research Category: Air , Climate Change , Early Career Awards

Objective:

The objectives of this project are to determine the wavelength-resolved single scattering albedo (SSA), absorption, and extinction along with the chemical and physical properties of aerosol emissions from biomass burning (wildfires) in the Western United States. These data enable us to determine the contribution of black versus brown carbon to observed aerosol absorption and quantify the enhancement of black carbon absorption caused by organic coatings. We utilize these new in-situ observations to update the refractive indices of organic and black carbon aerosol from biomass burning in the NCAR Community Atmosphere Model (CAM5) and assess the regional and global climate impacts of improved optical properties under a range of future biomass burning scenarios. In particular, we investigate the current and future radiative forcing and climatic effect from brown carbon absorption utilizing CAM5.

Progress Summary:

The major accomplishments during this reporting period are:

1.) Deployment of mobile lab with full aerosol optical, chemical and physical instrumentation

suite to three different fires in Wyoming. Measurements were made over a wide range of

distances (5-100 miles) and dilution ratios.

2.) Publication (Brown et al, 2018) of inclusion of a brown carbon parameterization, which

including a bleaching parameter to remove absorbing brown carbon with time, into the

CAM/CESM global climate model

3.) Publication (Foster et al., 2019) of a new particle-based calibration technique for

photoacoustic absorption spectrometers.

4.) Drafting of a paper comparing laboratory to ambient observations of biomass burning optical

properties. This paper demonstrates that the optical properties observed in Western United

States wild fires are similar to those derived from laboratory experiments.

5.) Drafting of a paper comparing ambient observations to model derived optical properties for

biomass burning aerosol. This paper demonstrates that the radiative forcing of biomass

burning aerosol in several global climate models is inconsistent with optical properties

observed in field campaigns.

Future Activities:

Papers comparing ambient observations to laboratory studies and model results will be completed and published in the fall of 2019. The photoacoustic absorption spectrometer will be deployed to a suite of chamber experiments exploring the oxidation of volatile organic compounds observed to be emitted by biomass burning.

Journal Articles on this Report : 2 Displayed | Download in RIS Format

Publications Views
Other project views:	All 6 publications	2 publications in selected types	All 2 journal articles

Publications
Type	Citation	Project	Document Sources
Journal Article	Brown H, Liu X, Feng Y, Jiang Y, Wu M, Lu Z, Wu C, Murphy S, Pokhrel R. Radiative effect and climate impacts of brown carbon with the community atmosphere model (CAM5). Atmospheric Chemistry and Physics 2018;18:17745-17768.	R835883 (2018) R835883 (2019) R835883 (Final)	Full-text: ACP - Full Text HTML and PDF Exit
Journal Article	Foster K, Pokhrel RP, Burkhart MD, Murphy SM. A novel approach to calibrating a photo-acoustic absorption spectrometer using polydisperse absorbing aerosol. Atmospheric Measurement Techniques 2019;12(6): 3351-3363.	R835883 (2018) R835883 (2019) R835883 (Final)	Full-text: AMT - Full Text HTML and PDF Exit

Supplemental Keywords:

Air, Tropospheric, Atmosphere, Climate Models

Progress and Final Reports:

Original Abstract

The 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.