Publication Date:
2017-10-05
Description:
Scattering and absorption characteristics of water cloud droplets containing black carbon (BC) inclusions are calculated at a visible wavelength of by a combination of ray-tracing and Monte Carlo techniques. In addition, Lorenz–Mie calculations are performed assuming that the same amount of BC particles are mixed with water droplets externally. The results show that it is unlikely under normal conditions that BC aerosols can modify scattering and absorption properties of cloud droplets in any significant way except for geographical locations very close to major sources of BC. The differences in the single-scattering co-albedo and asymmetry parameter between BC-fraction-equivalent internal and external mixtures are negligibly small for normal black carbon loadings, which makes possible the use of the much simpler external mixing model in radiative transfer modeling irrespective of the actual form of mixing. For a fixed amount of BC internally mixed with cloud droplets, the absorption is maximal when the effective radius of the BC inclusions is about 0.05–.
Type:
Article
,
PeerReviewed
Format:
text
DOI:
10.1016/S0022-4073(01)00232-1
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