Open AccessSensitivity of multiangle imaging to the optical and microphysical properties of biomass burning aerosols
Author(s) -
Chen WeiTing,
Kahn Ralph A.,
Nelson David,
Yau Kevin,
Seinfeld John H.
Publication year - 2008
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2007jd009414
Subject(s) - aeronet , aerosol , spectroradiometer , environmental science , effective radius , remote sensing , albedo (alchemy) , single scattering albedo , atmospheric sciences , atmosphere (unit) , satellite , meteorology , reflectivity , optics , physics , geology , astrophysics , art , astronomy , galaxy , performance art , art history
The treatment of biomass burning (BB) carbonaceous particles in the Multiangle Imaging SpectroRadiometer (MISR) Standard Aerosol Retrieval Algorithm is assessed, and algorithm refinements are suggested, based on a theoretical sensitivity analysis and comparisons with near‐coincident AERONET measurements at representative BB sites. Over the natural ranges of BB aerosol microphysical and optical properties observed in past field campaigns, patterns of retrieved Aerosol Optical Depth (AOD), particle size, and single scattering albedo (SSA) are evaluated. On the basis of the theoretical analysis, assuming total column AOD of 0.2, over a dark, uniform surface, MISR can distinguish two to three groups in each of size and SSA, except when the assumed atmospheric particles are significantly absorbing (mid‐visible SSA ∼0.84), or of medium sizes (mean radius ∼0.13 μ m); sensitivity to absorbing, medium‐large size particles increases considerably when the assumed column AOD is raised to 0.5. MISR Research Aerosol Retrievals confirm the theoretical results, based on coincident AERONET inversions under BB‐dominated conditions. When BB is externally mixed with dust in the atmosphere, dust optical model and surface reflection uncertainties, along with spatial variability, contribute to differences between the Research Retrievals and AERONET. These results suggest specific refinements to the MISR Standard Aerosol Algorithm complement of component particles and mixtures. They also highlight the importance for satellite aerosol retrievals of surface reflectance characterization, with accuracies that can be difficult to achieve with coupled surface‐aerosol algorithms in some higher AOD situations.