Taylor & Francis Group
Browse
uast_a_1769837_sm3565.docx (3.35 MB)

Emissions and radiative impacts of sub-10 nm particles from biofuel and fossil fuel cookstoves

Download (3.35 MB)
Version 2 2020-06-12, 11:42
Version 1 2020-05-15, 16:24
journal contribution
posted on 2020-06-12, 11:42 authored by Shantanu H. Jathar, Naman Sharma, Kelsey R. Bilsback, Jeffrey R. Pierce, Joonas Vanhanen, Timothy D. Gordon, John Volckens

Combustion sources have been shown to directly emit particles smaller than 10 nm. The emission of 1-3 nm particles from biofuel or fossil fuel cookstoves has not been studied previously, nor have the radiative impacts of these emissions been investigated. In this work, emissions (number of particles) were measured during a water boiling test performed on five different cookstoves (three-stone fire, rocket elbow, gasifier, charcoal, and liquified petroleum gas [LPG]) for particle diameters between ∼1 and ∼1000 nm. We found significant emissions of particles smaller than 10 nm for all cookstoves (>5 × 1015 # kg-fuel−1). Furthermore, cleaner (e.g., LPG) cookstoves emitted a larger fraction of sub-10 nm particles (relative to the total particle counts) than traditional cookstoves (e.g., three-stone fire). Simulations performed with the global chemical transport model GEOS-Chem-TOMAS that were informed by emissions data from this work suggested that sub-10 nm particles were unlikely to significantly influence number concentrations of particles with diameters larger than 80 nm that can serve as cloud condensation nuclei (CCN) (<0.3%, globally averaged) or alter the cloud-albedo indirect effect (absolute value <0.005 W m−2, globally averaged). The largest, but still relatively minor, localized changes in CCN-relevant concentrations (<10%) and the cloud-albedo indirect effect (absolute value <0.5 W m−2) were found in large biofuel combustion source regions (e.g., Brazil, Tanzania, Southeast Asia) and in the Southern Ocean. Enhanced coagulation-related losses of these sub-10 nm particles at sub-grid scales will tend to further reduce their impact on particle number concentrations and the aerosol indirect effect, although they might still be of relevance for human health.

Copyright © 2020 American Association for Aerosol Research

Funding

This work was partly supported by the National Oceanic and Atmospheric Administration (NA17OAR4310003 and NA17OAR4310001) and the National Science Foundation (HCBU AGS-1831013). We thank Airmodus Inc. (Finland) for providing access and technical support for the A11 nCNC system. We also thank Kirk Evans and John Mizia from the Energy Institute for support with the cookstove experiments.

History