NOAA-ISET Center, North Carolina A&T State University, Greensboro, North Carolina, USA
Department of Physics, North Carolina A&T State University, Greensboro, North Carolina, USA
Abstract. We describe here the construction and characterization of a new smog chamber facility (NCAT chamber) for studying the chemical and optical properties of biomass burning (BB) aerosols from biomass fuels native to sub-Saharan Africa. This facility is comprised of a ~9 m3 fluorinated ethylene propylene film (FEP) reactor placed in a temperature-controlled room and coupled with a cavity ring-down spectrometer, nephelometer, condensation particle counter, differential mobility analyzer and other analytical instruments, such as NOX and O3 analyzers, a GC, a filter sampler, and an impinger for collecting particles in water. Construction details and characterization experiments are described, including measurements of BB particulate size distribution and deposition rate, gas wall loss rates, dilution rate, light intensity, mixing speed, temperature and humidity variations, and air purification method. The wall loss rates for NO, NO2, and O3 were found to be (7.40 ± 0.01) × 10−4, (3.47 ± 0.01) × 10−4, and (5.90 ± 0.08) × 10−4 min−1 respectively. The NO2 photolysis rate constant was 0.165 ±0.005 min−4, which corresponds to a flux of (7.72 ± 0.25) × 1017 photons•nm•cm−2•s−1 from 296.0−516.8 nm. Particle deposition rate was found to be (2.46 ± 0.11) × 10−3 min−1 for pine at Dp = 100 nm. After initial mixing in the chamber, with the ultraviolet (UV) light off, the particle size distribution for BB samples used for the initial work did not stabilize until ~7.5 hours after injection peaking near a mobility diameter of ~340 nm. The chamber demonstrated gas and particle loss rates, and other properties comparable to other similar indoor smog chambers.
How to cite. Smith, D. M., Fiddler, M. N., Sexton, K. G., and Bililign, S.: Construction and Characterization of an Indoor Smog Chamber
for the Measurement of the Optical and Physicochemical
Properties of Aging Biomass Burning Aerosols Native to sub-Saharan Africa, Atmos. Meas. Tech. Discuss. [preprint], https://doi.org/10.5194/amt-2018-43, 2018.
Received: 07 Feb 2018 – Discussion started: 19 Mar 2018
Biomass burning (BB) aerosols can substantially degrade air quality and climate. Smog chambers provide a controlled environment to study the formation and the evolution of these smoke particles produced from specific fuel sources of interest by isolating the influence of emissions, meteorology, and mixing effects. The NCAT Chamber is built to conduct a study of optical properties of African fuels. The paper describes the chamber construction and properties.
Biomass burning (BB) aerosols can substantially degrade air quality and climate. Smog chambers...