Resolving Size Distribution of Black Carbon Internally Mixed With Snow: Impact on Snow Optical Properties and Albedo

Abstract We develop a stochastic aerosol‐snow albedo model that explicitly resolves size distribution of aerosols internally mixed with various snow grains. We use the model to quantify black carbon (BC) size effects on snow albedo and optical properties for BC‐snow internal mixing. Results show tha...

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Bibliographic Details
Main Authors: Cenlin He, Kuo‐Nan Liou, Yoshi Takano
Format: Article
Language:English
Published: Wiley 2018-03-01
Series:Geophysical Research Letters
Subjects:
Online Access:https://doi.org/10.1002/2018GL077062
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Summary:Abstract We develop a stochastic aerosol‐snow albedo model that explicitly resolves size distribution of aerosols internally mixed with various snow grains. We use the model to quantify black carbon (BC) size effects on snow albedo and optical properties for BC‐snow internal mixing. Results show that BC‐induced snow single‐scattering coalbedo enhancement and albedo reduction decrease by a factor of 2–3 with increasing BC effective radii from 0.05 to 0.25 μm, while polydisperse BC results in up to 40% smaller visible single‐scattering coalbedo enhancement and albedo reduction compared to monodisperse BC with equivalent effective radii. We further develop parameterizations for BC size effects for application to climate models. Compared with a realistic polydisperse assumption and observed shifts to larger BC sizes in snow, respectively, assuming monodisperse BC and typical atmospheric BC effective radii could lead to overestimates of ~24% and ~40% in BC‐snow albedo forcing averaged over different BC and snow conditions.
ISSN:0094-8276
1944-8007