Light scattering in combustion

Jones, Alan R.

doi:10.1007/3-540-37672-0_9

Cited by 19 publications

(11 citation statements)

References 172 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Light absorbing carbon aggregates formed in combustion processes typically have a fractal-like structure that can be modelled by the scaling relation (Jones, 2006)…”

Section: Morphological Propertiesmentioning

confidence: 99%

Modelling the optical and radiative properties of freshly emitted light absorbing carbon within an atmospheric chemical transport model

Kahnert

2010

Atmos. Chem. Phys.

View full text Add to dashboard Cite

Abstract. Light absorbing carbon (LAC) aerosols have a complex, fractal-like aggregate structure. Their optical and radiative properties are notoriously difficult to model, and approximate methods may introduce large errors both in the interpretation of aerosol remote sensing observations, and in quantifying the direct radiative forcing effect of LAC. In this paper a numerically exact method for solving Maxwell's equations is employed for computing the optical properties of freshly emitted, externally mixed LAC aggregates. The computations are performed at wavelengths of 440 nm and 870 nm, and they cover the entire size range relevant for modelling these kinds of aerosols. The method for solving the electromagnetic scattering and absorption problem for aggregates proves to be sufficiently stable and fast to make accurate multiple-band computations of LAC optical properties feasible. The results from the electromagnetic computations are processed such that they can readily be integrated into a chemical transport model (CTM), which is a prerequisite for constructing robust observation operators for chemical data assimilation of aerosol optical observations. A case study is performed, in which results obtained with the coupled optics/CTM model are employed as input to detailed radiative transfer computations at a polluted European location. It is found that the still popular homogeneous sphere approximation significantly underestimates the radiative forcing at top of atmosphere as compared to the results obtained with the aggregate model. Notably, the LAC forcing effect predicted with the aggregate model is less than that one obtains by assuming a prescribed mass absorption cross section for LAC.

show abstract

“…Light absorbing carbon aggregates formed in combustion processes typically have a fractal-like structure that can be modelled by the scaling relation (Jones, 2006)…”

Section: Morphological Propertiesmentioning

confidence: 99%

Modelling the optical and radiative properties of freshly emitted light absorbing carbon within an atmospheric chemical transport model

Kahnert

2010

Atmos. Chem. Phys.

View full text Add to dashboard Cite

show abstract

“…In this context optical methods have gained special importance as they allow for an in situ determination of central parameters, namely concentration and particle sizes. Apart from various light scattering and extinction approaches-for recent surveys see, e.g., Sorensen (2001) and Jones (2006)-laserinduced incandescence has evolved as a particularly attractive technique, as it requires comparatively little experimental effort and can also be applied in a two-dimensional, imaging approach. As the name implies, the method is based on rapid heating of nanoparticles by a short laser-pulse and the analysis of the resulting thermal radiation.…”

Section: Introductionmentioning

confidence: 99%

On heat conduction between laser-heated nanoparticles and a surrounding gas

Kuhlmann

Reimann

Will

2006

Journal of Aerosol Science

View full text Add to dashboard Cite

“…They can also limit atmospheric visibility and have a highly negative effect on human health [12]. Owing to the notoriously complex morphology of such particles [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30], theoretical modeling of their scattering and absorption properties is a highly nontrivial task and has often been based on approximate approaches with poorly defined accuracy and range of applicability. However, the growing need for much improved knowledge of BC and BC-containing aerosols and their climatic, ecological, and visibility effects imposes strict limitations on quantitative uncertainties in particle scattering and absorption properties entering optical characterization and remote sensing applications as well as atmospheric radiation budget computations [31][32][33][34][35][36][37][38][39][40][41][42].…”

Section: Introductionmentioning

confidence: 99%

T-matrix modeling of linear depolarization by morphologically complex soot and soot-containing aerosols

Mishchenko

Liu

Mackowski

2013

Journal of Quantitative Spectroscopy and Radiative Transfer

View full text Add to dashboard Cite

a b s t r a c tWe use state-of-the-art public-domain Fortran codes based on the T-matrix method to calculate orientation and ensemble averaged scattering matrix elements for a variety of morphologically complex black carbon (BC) and BC-containing aerosol particles, with a special emphasis on the linear depolarization ratio (LDR). We explain theoretically the quasi-Rayleigh LDR peak at side-scattering angles typical of low-density soot fractals and conclude that the measurement of this feature enables one to evaluate the compactness state of BC clusters and trace the evolution of low-density fluffy fractals into densely packed aggregates. We show that small backscattering LDRs measured with groundbased, airborne, and spaceborne lidars for fresh smoke generally agree with the values predicted theoretically for fluffy BC fractals and densely packed near-spheroidal BC aggregates. To reproduce higher lidar LDRs observed for aged smoke, one needs alternative particle models such as shape mixtures of BC spheroids or cylinders.Published by Elsevier Ltd.

show abstract

Light scattering in combustion

Cited by 19 publications

References 172 publications

Modelling the optical and radiative properties of freshly emitted light absorbing carbon within an atmospheric chemical transport model

Modelling the optical and radiative properties of freshly emitted light absorbing carbon within an atmospheric chemical transport model

On heat conduction between laser-heated nanoparticles and a surrounding gas

T-matrix modeling of linear depolarization by morphologically complex soot and soot-containing aerosols

Contact Info

Product

Resources

About