TY - JOUR
T1 - Cloud processing and weeklong ageing affect biomass burning aerosol properties over the south-eastern Atlantic
AU - Che, Haochi
AU - Segal-Rozenhaimer, Michal
AU - Zhang, Lu
AU - Dang, Caroline
AU - Zuidema, Paquita
AU - Dobracki, Amie
AU - Arthur J. Sedlacek, III
AU - Coe, Hugh
AU - Wu, Huihui
AU - Taylor, Jonathan
AU - Zhang, Xiaoye
AU - Redemann, Jens
AU - Haywood, Jim
N1 - Funding Information:
The authors would like to thank the ORACLES team, CLARIFY team and the funding of the project by the DOE-ASR grant DE-SC0020084. This work benefitted from support from the CLARIFY NERC Large Grant NE/L013584/1, and support from ORACLES NASA through the Earth Venture Suborbital-2 (EVS-2) program Grant 13-EVS2-13-0028.
Publisher Copyright:
© 2022, The Author(s).
PY - 2022/12/1
Y1 - 2022/12/1
N2 - Southern Africa produces a third of global biomass burning emissions, which have a long atmospheric lifetime and influence regional radiation balance and climate. Here, we use airmass trajectories to link different aircraft observations to investigate the evolution of biomass-burning aerosols during their westward transport from Southern Africa over the south-eastern Atlantic, where a semi-permanent stratocumulus cloud deck is located. Our results show secondary organic aerosol formation during the initial 3 days of transport, followed by decreases in organic aerosol via photolysis before reaching equilibrium. Aerosol absorption wavelength dependency decreases with ageing, due to an increase in particle size and photochemical bleaching of brown carbon. Cloud processing, including aqueous-phase reaction and scavenging, contributes to the oxidation of organic aerosols, while it strongly reduces large diameter particles and single-scattering albedo of biomass burning aerosols. Together, these processes resulted in a marine boundary layer with fewer yet more oxidized and absorbing aerosols.
AB - Southern Africa produces a third of global biomass burning emissions, which have a long atmospheric lifetime and influence regional radiation balance and climate. Here, we use airmass trajectories to link different aircraft observations to investigate the evolution of biomass-burning aerosols during their westward transport from Southern Africa over the south-eastern Atlantic, where a semi-permanent stratocumulus cloud deck is located. Our results show secondary organic aerosol formation during the initial 3 days of transport, followed by decreases in organic aerosol via photolysis before reaching equilibrium. Aerosol absorption wavelength dependency decreases with ageing, due to an increase in particle size and photochemical bleaching of brown carbon. Cloud processing, including aqueous-phase reaction and scavenging, contributes to the oxidation of organic aerosols, while it strongly reduces large diameter particles and single-scattering albedo of biomass burning aerosols. Together, these processes resulted in a marine boundary layer with fewer yet more oxidized and absorbing aerosols.
UR - https://doi.org/10.1038/s43247-022-00517-3
U2 - 10.1038/s43247-022-00517-3
DO - 10.1038/s43247-022-00517-3
M3 - Article
SN - 2662-4435
VL - 3
JO - Communications Earth & Environment
JF - Communications Earth & Environment
IS - 1
M1 - 182
ER -
