Details:

Journal Title:
Atmospheric Chemistry and Physics
Personal Author:
May, Nathaniel W. ; Bernays, Noah ; Farley, Ryan ; Zhang, Qi ; Jaffe, Daniel A.
May, Nathaniel W. ; Bernays, Noah ; Farley, Ryan ; Zhang, Qi ; Jaffe, Daniel A. Less -
NOAA Program & Office:
NOAA General Documents
Description:
We characterize the aerosol physical and optical properties of 13 transported biomass burning (BB) events. BB events included long-range influence from fires in Alaskan and Siberian boreal forests transported to Mt. Bachelor Observatory (MBO) in the free troposphere (FT) over 8–14+ d and regional wildfires in northern California and southwestern Oregon transported to MBO in the boundary layer (BL) over 10 h to 3 d. Intensive aerosol optical properties and normalized enhancement ratios for BB events were derived from measured aerosol light scattering coefficients (σscat), aerosol light-absorbing coefficients (σabs), fine particulate matter (PM1), and carbon monoxide (CO) measurements made from July to September 2019, with particle size distribution collected from August to September. The observations showed that the Siberian BB events had a lower scattering Ångström exponent (SAE), a higher mass scattering efficiency (MSE; Δσscat/ΔPM1), and a bimodal aerosol size distribution with a higher geometric mean diameter (Dg). We hypothesize that the larger particles and associated scattering properties were due to the transport of fine dust alongside smoke in addition to contributions from condensation of secondary aerosol, coagulation of smaller particles, and aqueous-phase processing during transport. Alaskan and Siberian boreal forest BB plumes were transported long distances in the FT and characterized by lower absorption Ångström exponent (AAE) values indicative of black carbon (BC) dominance in the radiative budget. Significantly elevated AAE values were only observed for BB events with <1 d transport, which suggests strong production of brown carbon (BrC) in these plumes but limited radiative forcing impacts outside of the immediate region.
Keywords:
[+]
Atmospheric Science
Source:
Atmospheric Chemistry and Physics, 23(4), 2747-2764
DOI:
https://doi.org/10.5194/acp-23-2747-2023
ISSN:
1680-7324
Format:
PDF
Publisher:
Copernicus GmbH
Document Type:
Journal Article
License:
https://creativecommons.org/licenses/by/4.0/
Rights Information:
CC BY
Compliance:
Library
Main Document Checksum:
[+]
urn:sha256:c714c8e8a22be2eae74f22f75849438b14a9e388d5d8b5ca34da568f7a75ecd3
Download URL:
https://repository.library.noaa.gov/view/noaa/58251/noaa_58251_DS1.pdf
File Type:

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