Biomass Burning and Black Carbon Aerosol from African Sources
Poster PDF
Authors
Allison C Aiken — Los Alamos National Laboratory
Arthur J Sedlacek — Brookhaven National Laboratory
Stephen R. Springston — Brookhaven National Laboratory
Thomas B. Watson — Brookhaven National Laboratory
Paquita Zuidema — University of Miami
Adeyemi A Adebiyi — University of Miami
Connor J. Flynn — University of Oklahoma School of Meteorology
Manvendra K. Dubey — Los Alamos National Laboratory
Kim L. Nitschke — Los Alamos National Laboratory
Maciej Ryczek — Los Alamos National Laboratory
Joshua Schwarz — NOAA - Earth System Research Laboratory/CIRES
Robert James Yokelson — University of Montana
Martin de Graaf — Royal Netherlands Meteorological institute
Sonia Kreidenweis — Colorado State University
Allen Robinson —
Category
Absorbing aerosol
Description
Biomass burning (BB) emissions are a large source of carbon to the atmosphere via particles and gas-phase species. Half or more Black Carbon (BC) aerosol in the atmosphere is from BB, estimated at 6-9 Tg/yr (IPCC, 5AR) and contributing up to ~0.6 W/m2 atmospheric warming (Bond et al., 2013). BC aerosols are also potentially underestimated in global models and are considered to be one of the most important global-warming factors behind CO2. With a potential rise in drought and extreme events in the future due to climate change, these numbers are expected to increase. For this reason, we focus on BC and organic carbon aerosol species that are emitted from forest fires and compare their physical and optical properties to those from controlled laboratory studies of single-source BB fuels to understand BB carbonaceous aerosols in the atmosphere. Specifically, we investigate BC in BB plumes sampled from the new U.S. DOE ARM Facility campaign, Layered Atlantic Smoke Interactions with Clouds (LASIC).
Early results from LASIC are put in context with other forest-fire emissions from the ground and aircraft in addition to laboratory BB studies that include African fuel types. The ARM Aerosol Mobile Facility 1 (AMF1) and Mobile Aerosol Observing System (MAOS) are currently located on Ascension Island in the South Atlantic Ocean, midway between Angola and Brazil, for LASIC. The far-field aged BC from LASIC is compared to BC from indoor generation from single-source fuels, e.g., African grass. BC is measured with a single-particle soot photometer (SP2) alongside numerous supporting instrumentation, e.g., particle counters, CO, and aerosol scattering and absorption measurements. Laboratory studies include both direct emissions and well-mixed aerosol samples that have undergone dilution, cooling, and condensation. Total aerosol optical properties, e.g., Absorption Angstrom Exponent (AAE), and Single-Scatter Albedo (SSA) will be compared from early LASIC results collected during the 2016 peak BB season in Africa with laboratory studies and other forest-fire data from the Southwest US. BC physical and optical properties change as particles are transported in the atmosphere due to oxidation, coagulation, and condensation, which is observed in the laboratory BC data. Laboratory BC is compared with observations from LASIC to improve model treatment of BB BC emissions and aging in global climate models.
