Past, present, and future of global aerosol climatologies derived from satellite observations: A perspective

Mishchenko, Michael I.; Geogdzhayev, Igor V.; Cairns, Brian; Carlson, Barbara E.; Chowdhary, Jacek; Lacis, Andrew A.; Liu, Li; Rossow, William B.; Travis, Larry D.

doi:10.1016/j.jqsrt.2007.01.007

Cited by 119 publications

(85 citation statements)

References 78 publications

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“…There is also growing evidence that Saharan dust outbreaks may be reducing Atlantic hurricane activity (Evan et al, 2006;Wu, 2007). Yet significant gaps in the understanding of its role exist, in terms of both global and regional influences on weather and climate (Andreae et al, 2005;Haywood et al, 2005;Myhre et al, 2003;Yu et al, 2006;Mishchenko et al, 2007). Consequently, much effort has been directed at the development Correspondence to: Z.…”

Section: Introductionmentioning

confidence: 99%

“…However, existing satellite instruments can not be able to resolve the non-uniqueness problem associated with passive aerosol retrievals (Chowdhary et al, 2001;Mishchenko et al, 2007). In this context, polarimetry has much to offer, because multispectral, multiangle polarization measurements can uniquely recover many relevant aerosol parameters (Chowdhary et al, 2002;Boesche et al, 2006;.…”

Section: Introductionmentioning

confidence: 99%

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Alignment of atmospheric mineral dust due to electric field

et al. 2007

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Abstract. Optical polarimetry observations on La Palma, Canary Islands, during a Saharan dust episode show dichroic extinction indicating the presence of vertically aligned particles in the atmosphere. Modelling of the extinction together with particle orientation indicates that the alignment could have been due to an electric field of the order of 2 kV/m. Two alternative mechanisms for the origin of the field are examined: the effect of reduced atmospheric conductivity and charging of the dust layer, the latter effect being a more likely candidate. It is concluded that partial alignment may be a common feature of Saharan dust layers. The modelling indicates that the alignment can significantly alter dust optical depth. This "Venetian blind effect" may have decreased optical thickness in the vertical direction by as much as 10% for the case reported here. It is also possible that the alignment and the electric field modify dust transport.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Alignment of atmospheric mineral dust due to electric field

et al. 2007

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“…Hasekamp and Landgraf, 2007;Lebsock et al, 2007) or cloud structure (Ferlay et al, 2010). Even for dedicated aerosol sounders, however, a consolidated view on the global distribution of aerosol properties is not yet achieved (Mishchenko et al, 2007), underlining the complexity in general, not withstanding its impact on trace gas retrievals. Any improvement in aerosol retrieval capabilities will, thus, improve both our understanding of the impact of aerosols in the climate system and reduce systematic biases in trace gas retrievals.…”

Section: Frankenberg Et Al: Multi-angle Hyperspectral Retrievalsmentioning

confidence: 99%

Aerosol information content analysis of multi-angle high spectral resolution measurements and its benefit for high accuracy greenhouse gas retrievals

et al. 2012

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Abstract. New generations of space-borne spectrometers for the retrieval of atmospheric abundances of greenhouse gases require unprecedented accuracies as atmospheric variability of long-lived gases is very low. These instruments, such as GOSAT and OCO-2, typically use a high spectral resolution oxygen channel (O 2 A-band) in addition to CO 2 and CH 4 channels to discriminate changes in the photon path-length distribution from actual trace gas amount changes. Inaccurate knowledge of the photon path-length distribution, determined by scatterers in the atmosphere, is the prime source of systematic biases in the retrieval. In this paper, we investigate the combined aerosol and greenhouse gas retrieval using multiple satellite viewing angles simultaneously. We find that this method, hitherto only applied in multi-angle imagery such as from POLDER or MISR, greatly enhances the ability to retrieve aerosol properties by 2-3 degrees of freedom. We find that the improved capability to retrieve aerosol parameters significantly reduces interference errors introduced into retrieved CO 2 and CH 4 total column averages. Instead of focussing solely on improvements in spectral and spatial resolution, signal-to-noise ratios or sampling frequency, multiple angles reduce uncertainty in space based greenhouse gas retrievals more effectively and provide a new potential for dedicated aerosols retrievals.

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“…It is generally recognized in the atmospheric science community that soot aerosols released from low temperature fuel combustion processes play a significant role in the radiation of Earth's atmosphere by scattering and absorbing both solar and terrestrial radiation (Sorensen 2001;Kolokolova et al 2006;Mishchenko et al 2007). Modeling the radiative impact of soot clusters in a manageable way in climate models is therefore an important matter.…”

Section: Introductionmentioning

confidence: 99%

The Influence of Water Coating on the Optical Scattering Properties of Fractal Soot Aggregates

Liu

Panetta

Yang

2012

Aerosol Science and Technology

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The effect of water coating of constituent monomers on the optical single-scattering properties of fractal soot aggregates is investigated numerically using core-mantle theory and approximations involving two effective medium theories. A cluster-cluster aggregation algorithm is used to numerically generate fractal aggregates, and the core-mantle Generalized Multi-particle Mie (GMM) method is used to compute the exact single-scattering properties of soot aggregates with water-coated monomers. Comparisons are then made with results obtained using approximations that combine either the GMM method or the Rayleigh-Debye-Gans (RDG) method with either the Maxwell-Garnett or the Bruggeman effective medium approximation (a total of four approximation methods). The optical properties calculated are the extinction and absorption cross sections, the single-scattering albedo, and the phase matrix of water-coated fractal aggregates; these calculations are done for two wavelengths, 0.628 µm and 1.1 µm. Water coating of the fractal aggregates is shown to increase the extinction and absorption cross sections, the single-scattering albedo, and forward scattering, but decrease backward scattering. The combination GMM + Maxwell-Garnett gives approximations that are quite good over a range of coating thicknesses and aggregate size. The combination GMM + Bruggeman performs less well, overestimating the extinction and absorption cross sections and underestimating the single-scattering albedo. In the case of RDG, the better combination is with the Bruggeman approximation, but the errors involved are greater than with the GMM + MaxwellGarnett combination. Results from simple idealized calculations indicate that the differences between results with the MaxwellGarnett and Bruggeman approximations should be even larger in cases of aerosol cores that are less absorptive than soot.

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Past, present, and future of global aerosol climatologies derived from satellite observations: A perspective

Cited by 119 publications

References 78 publications

Alignment of atmospheric mineral dust due to electric field

Alignment of atmospheric mineral dust due to electric field

Aerosol information content analysis of multi-angle high spectral resolution measurements and its benefit for high accuracy greenhouse gas retrievals

The Influence of Water Coating on the Optical Scattering Properties of Fractal Soot Aggregates

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