Analysis of multi-wavelength measurements of diffusive properties via dispersion dependence of optical properties

Abstract. We present LIVAS (LIdar climatology of Vertical Aerosol Structure for space-based lidar simulation studies), a 3-D multi-wavelength global aerosol and cloud optical database, optimized to be used for future space-based lidar end-to-end simulations of realistic atmospheric scenarios as well as retrieval algorithm testing activities. The LIVAS database provides averaged profiles of aerosol optical properties for the potential spaceborne laser operating wavelengths of 355, 532, 1064, 1570 and 2050 nm and of cloud optical properties at the wavelength of 532 nm. The global database is based on CALIPSO observations at 532 and 1064 nm and on aerosol-type-dependent backscatter- and extinction-related Ångström exponents, derived from EARLINET (European Aerosol Research Lidar Network) ground-based measurements for the UV and scattering calculations for the IR wavelengths, using a combination of input data from AERONET, suitable aerosol models and recent literature. The required spectral conversions are calculated for each of the CALIPSO aerosol types and are applied to CALIPSO backscatter and extinction data corresponding to the aerosol type retrieved by the CALIPSO aerosol classification scheme. A cloud optical database based on CALIPSO measurements at 532 nm is also provided, neglecting wavelength conversion due to approximately neutral scattering behavior of clouds along the spectral range of LIVAS. Averages of particle linear depolarization ratio profiles at 532 nm are provided as well. Finally, vertical distributions for a set of selected scenes of specific atmospheric phenomena (e.g., dust outbreaks, volcanic eruptions, wild fires, polar stratospheric clouds) are analyzed and spectrally converted so as to be used as case studies for spaceborne lidar performance assessments. The final global data set includes 4-year (1 January 2008–31 December 2011) time-averaged CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) data on a uniform grid of 1° × 1° with the original high vertical resolution of CALIPSO in order to ensure realistic simulations of the atmospheric variability in lidar end-to-end simulations.

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LIVAS: a 3-D multi-wavelength aerosol/cloud climatology based on CALIPSO and EARLINET

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-15-2247-2015 ◽

2015 ◽

Vol 15 (2) ◽

pp. 2247-2304 ◽

Cited By ~ 5

Author(s):

V. Amiridis ◽

E. Marinou ◽

A. Tsekeri ◽

U. Wandinger ◽

A. Schwarz ◽

...

Keyword(s):

Optical Properties ◽

Volcanic Eruptions ◽

Retrieval Algorithm ◽

Uniform Grid ◽

Conversion Factors ◽

Multi Wavelength ◽

End To End ◽

532 Nm ◽

Aerosol Type ◽

Spectral Conversion

Abstract. We present LIVAS, a 3-dimentional multi-wavelength global aerosol and cloud optical climatology, optimized to be used for future space-based lidar end-to-end simulations of realistic atmospheric scenarios as well as retrieval algorithm testing activities. LIVAS database provides averaged profiles of aerosol optical properties for the potential space-borne laser operating wavelengths of 355, 532, 1064, 1570 and 2050 nm and of cloud optical properties at the wavelength of 532 nm. The global climatology is based on CALIPSO observations at 532 and 1064 nm and on aerosol-type-dependent spectral conversion factors for backscatter and extinction, derived from EARLINET ground-based measurements for the UV and scattering calculations for the IR wavelengths, using a combination of input data from AERONET, suitable aerosol models and recent literature. The required spectral conversion factors are calculated for each of the CALIPSO aerosol types and are applied to CALIPSO extinction and backscatter data correspondingly to the aerosol type retrieved by the CALIPSO aerosol classification scheme. A cloud climatology based on CALIPSO measurements at 532 nm is also provided, neglecting wavelength conversion due to approximately neutral scattering behavior of clouds along the spectral range of LIVAS. Averages of particle linear depolarization ratio profiles at 532 nm are provided as well. Finally, vertical distributions for a set of selected scenes of specific atmospheric phenomena (e.g., dust outbreaks, volcanic eruptions, wild fires, polar stratospheric clouds) are analyzed and spectrally converted so as to be used as case studies for space-borne lidar performance assessments. The final global climatology includes 4-year (1 January 2008–31 December 2011) time-averaged CALIPSO data on a uniform grid of 1×1 degree with the original high vertical resolution of CALIPSO in order to ensure realistic simulations of the atmospheric variability in lidar end-to-end simulations.

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Supplementary material to "Measurement and modeling of the multi-wavelength optical properties of uncoated flame-generated soot"

10.5194/acp-2018-306-supplement ◽

2018 ◽

Author(s):

Sara D. Forestieri ◽

Taylor M. Helgestad ◽

Andrew Lambe ◽

Lindsay Renbaum-Wolff ◽

Daniel A. Lack ◽

...

Keyword(s):

Optical Properties ◽

Multi Wavelength ◽

Supplementary Material

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Optical properties and mineralogical composition of different Saharan mineral dust samples: a laboratory study

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-6-2897-2006 ◽

2006 ◽

Vol 6 (2) ◽

pp. 2897-2922 ◽

Cited By ~ 6

Author(s):

C. Linke ◽

O. Möhler ◽

A. Veres ◽

Á. Mohácsi ◽

Z. Bozóki ◽

...

Keyword(s):

Optical Properties ◽

Cross Sections ◽

Mineral Dust ◽

Mineralogical Composition ◽

Dust Sample ◽

Single Scattering ◽

Saharan Dust ◽

Multi Wavelength ◽

Oxide Phases ◽

Aerosol Chamber

Abstract. In aerosol chamber experiments optical properties of airborne mineral dust samples of defined size distribution were measured. Extinction coefficients (bext) and mass specific extinction cross sections (σext) were determined for Saharan dust samples from different locations. The results for σext were not very sensitive to the type of dust and varied at λ=550 nm between 3.3±0.4 m2 g−1 and 3.7±0.4 m2 g−1. The absorption coefficients (babs) and mass specific absorption cross sections (σabs) were determined with a novel multi-wavelength photo-acoustic absorption spectrometer (PAS). Between λ=266 nm and λ=1064 nm the derived single scattering albedos (SSA) ranged from 0.63±0.04 to 0.99±0.01. Additionally the chemical and mineralogical composition of the dust samples was analysed with special regard to the iron oxide phases hematite and goethite. At λ=266 nm the mineral dust sample without any detectable iron oxides showed a significantly higher SSA compared to the sample with a hematite content of 0.6 wt-%.

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Photoacoustic and nephelometric spectroscopy of aerosol optical properties with a supercontinuum light source

Atmospheric Measurement Techniques ◽

10.5194/amt-6-3501-2013 ◽

2013 ◽

Vol 6 (12) ◽

pp. 3501-3513 ◽

Cited By ~ 37

Author(s):

N. Sharma ◽

I. J. Arnold ◽

H. Moosmüller ◽

W. P. Arnott ◽

C. Mazzoleni

Keyword(s):

Optical Properties ◽

Light Source ◽

Wavelength Dependence ◽

Common Salt ◽

Design Development ◽

Aerosol Optical Properties ◽

Scattering Coefficients ◽

Aerosol Absorption ◽

Multi Wavelength

Abstract. A novel multi-wavelength photoacoustic-nephelometer spectrometer (SC-PNS) has been developed for the optical characterization of atmospheric aerosol particles. This instrument integrates a white light supercontinuum laser with photoacoustic and nephelometric spectroscopy to measure aerosol absorption and scattering coefficients at five wavelength bands (centered at 417, 475, 542, 607, and 675 nm). These wavelength bands are selected from the continuous spectrum of the laser (ranging from 400–2200 nm) using a set of optical interference filters. Absorption and scattering measurements on laboratory-generated aerosol samples were performed sequentially at each wavelength band. To test the instrument we measured the wavelength dependence of absorption and scattering coefficients of kerosene soot and common salt aerosols. Results were favorably compared to those obtained with a commercial 3-wavelength photoacoustic and nephelometer instrument demonstrating the utility of the SC light source for studies of aerosol optical properties at selected wavelengths. Here, we discuss instrument design, development, calibration, performance and experimental results.

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Spectroscopic Ellipsometry Studies of Tb-doped SiO2 Thin Films

MRS Proceedings ◽

10.1557/proc-0997-i07-14 ◽

2007 ◽

Vol 997 ◽

Author(s):

Zhe Chuan Feng ◽

Yia Chung Chang ◽

Ting Kai Li

Keyword(s):

Thin Films ◽

Refractive Index ◽

Optical Properties ◽

Layer Thickness ◽

Wavelength Range ◽

Spectroscopic Ellipsometry ◽

Thickness Variation ◽

Multi Wavelength

AbstractThe optical properties of Tb-doped SiO2 films have been studied from multi-wavelength spectroscopic ellipsometry (SE) measurements performed over the 250–1100 nm wavelength range. The SE modeling carried out with care to adhere as much to the ellipsometric fitting qualities. The refractive index dispersions, the layer thickness, and the lateral thickness variation of the films are given and discussed regarding the optical constitution of these films and the ellipsometric validity of these parameters

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