DOI: 10.1002/2017JD027362
Scopus记录号: 2-s2.0-85041119995
论文题名: The Complex Refractive Index of Volcanic Ash Aerosol Retrieved From Spectral Mass Extinction
作者: Reed B.E. ; Peters D.M. ; McPheat R. ; Grainger R.G.
刊名: Journal of Geophysical Research: Atmospheres
ISSN: 2169897X
出版年: 2018
卷: 123, 期: 2 起始页码: 1339
结束页码: 1350
语种: 英语
英文关键词: aerosol optical properties
; complex refractive index
; mass extinction spectra
; Rayleigh CDE model
; scattering theory
; volcanic ash
Scopus关键词: aerosol
; extinction coefficient
; Mie theory
; optical property
; particle size
; radiative transfer
; Rayleigh number
; refractive index
; size distribution
; spectrometer
; volcanic aerosol
; volcanic ash
英文摘要: The complex refractive indices of eight volcanic ash samples, chosen to have a representative range of SiO2 contents, were retrieved from simultaneous measurements of their spectral mass extinction coefficient and size distribution. The mass extinction coefficients, at 0.33–19 μm, were measured using two optical systems: a Fourier transform spectrometer in the infrared and two diffraction grating spectrometers covering visible and ultraviolet wavelengths. The particle size distribution was measured using a scanning mobility particle sizer and an optical particle counter; values for the effective radius of ash particles measured in this study varied from 0.574 to 1.16 μm. Verification retrievals on high-purity silica aerosol demonstrated that the Rayleigh continuous distribution of ellipsoids (CDEs) scattering model significantly outperformed Mie theory in retrieving the complex refractive index, when compared to literature values. Assuming the silica particles provided a good analogue of volcanic ash, the CDE scattering model was applied to retrieve the complex refractive index of the eight ash samples. The Lorentz formulation of the complex refractive index was used within the retrievals as a convenient way to ensure consistency with the Kramers-Kronig relation. The short-wavelength limit of the electric susceptibility was constrained by using independently measured reference values of the complex refractive index of the ash samples at a visible wavelength. The retrieved values of the complex refractive indices of the ash samples showed considerable variation, highlighting the importance of using accurate refractive index data in ash cloud radiative transfer models. ©2018. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/114645
Appears in Collections: 气候减缓与适应
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作者单位: Atmospheric, Oceanic and Planetary Physics, University of Oxford, Oxford, United Kingdom; RAL Space, STFC Rutherford Appleton Laboratory, Harwell, United Kingdom; COMET, Atmospheric, Oceanic and Planetary Physics, University of Oxford, Oxford, United Kingdom
Recommended Citation:
Reed B.E.,Peters D.M.,McPheat R.,et al. The Complex Refractive Index of Volcanic Ash Aerosol Retrieved From Spectral Mass Extinction[J]. Journal of Geophysical Research: Atmospheres,2018-01-01,123(2)