Technical Note: Optical properties of desert aerosol with non-spherical mineral particles: data incorporated to OPAC

Koepke, Peter; Gasteiger, Josef; Heß, Michael

doi:10.5194/acp-15-5947-2015

Cited by 103 publications

(110 citation statements)

References 46 publications

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“…In this example, we illustrate the effect of the cutoff for the desert aerosol type from OPAC at RH = 0 % (Koepke et al, 2015). Figure 7 illustrates various aerosol properties as a function of the cutoff radius r max .…”

Section: Effect Of Cutoff At Maximum Sizementioning

confidence: 99%

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MOPSMAP v1.0: a versatile tool for the modeling of aerosol optical properties

Gasteiger

Wiegner²

2018

Geosci. Model Dev.

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Abstract. The spatiotemporal distribution and characterization of aerosol particles are usually determined by remotesensing and optical in situ measurements. These measurements are indirect with respect to microphysical properties, and thus inversion techniques are required to determine the aerosol microphysics. Scattering theory provides the link between microphysical and optical properties; it is not only needed for such inversions but also for radiative budget calculations and climate modeling. However, optical modeling can be very time-consuming, in particular if nonspherical particles or complex ensembles are involved.In this paper we present the MOPSMAP package (Modeled optical properties of ensembles of aerosol particles), which is computationally fast for optical modeling even in the case of complex aerosols. The package consists of a data set of pre-calculated optical properties of single aerosol particles, a Fortran program to calculate the properties of userdefined aerosol ensembles, and a user-friendly web interface for online calculations. Spheres, spheroids, and a small set of irregular particle shapes are considered over a wide range of sizes and refractive indices. MOPSMAP provides the fundamental optical properties assuming random particle orientation, including the scattering matrix for the selected wavelengths. Moreover, the output includes tables of frequently used properties such as the single-scattering albedo, the asymmetry parameter, or the lidar ratio. To demonstrate the wide range of possible MOPSMAP applications, a selection of examples is presented, e.g., dealing with hygroscopic growth, mixtures of absorbing and non-absorbing particles, the relevance of the size equivalence in the case of nonspherical particles, and the variability in volcanic ash microphysics.The web interface is designed to be intuitive for expert and nonexpert users. To support users a large set of default settings is available, e.g., several wavelength-dependent refractive indices, climatologically representative size distributions, and a parameterization of hygroscopic growth. Calculations are possible for single wavelengths or user-defined sets (e.g., of specific remote-sensing application). For expert users more options for the microphysics are available. Plots for immediate visualization of the results are shown. The complete output can be downloaded for further applications. All input parameters and results are stored in the user's personal folder so that calculations can easily be reproduced. The web interface is provided at https://mopsmap.net (last access: 9 July 2018) and the Fortran program including the data set is freely available for offline calculations, e.g., when large numbers of different runs for sensitivity studies are to be made.

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Section: Effect Of Cutoff At Maximum Sizementioning

confidence: 99%

“…We use the desert aerosol type of OPAC (Koepke et al, 2015). Prolate spheroids with the aspect ratio distribution of Kandler et al (2009) are assumed for the mineral components and spherical particles for the WASO component (RH = 0 %).…”

Section: Effect Of Refractive Index Variabilitymentioning

confidence: 99%

MOPSMAP v1.0: a versatile tool for the modeling of aerosol optical properties

Gasteiger

Wiegner²

2018

Geosci. Model Dev.

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“…4 of Dubovik et al (2002b) and Fig. 2 of Koepke et al (2015), both of which indicate that up to a scattering angle of ∼ 80 • there is very little difference in the phase functions (at 870 and 550 nm, respec- At ∼ 120 • is the maximum underestimation of the spherical phase function with respect to the non-spherical values, which may lead to a corresponding overestimation of the AOD, especially apparent in Fig. 10a; simultaneously, the SEVIRI scattering angles are at their highest (Fig.…”

Section: Intercomparisons Between Retrievalsmentioning

confidence: 99%

Satellite retrievals of dust aerosol over the Red Sea and the Persian Gulf (2005–2015)

et al. 2017

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Abstract. The inter-annual variability of the dust aerosol presence over the Red Sea and the Persian Gulf is analysed over the period [2005][2006][2007][2008][2009][2010][2011][2012][2013][2014][2015]. Particular attention is paid to the variation in loading across the Red Sea, which has previously been shown to have a strong, seasonally dependent latitudinal gradient. Over the 11 years considered, the July mean 630 nm aerosol optical depth (AOD) derived from the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) varies between 0.48 and 1.45 in the southern half of the Red Sea. In the north, the equivalent variation is between 0.22 and 0.66. The temporal and spatial pattern of variability captured by SEVIRI is also seen in AOD retrievals from the MODerate Imaging Spectroradiometer (MODIS), but there is a systematic offset between the two records. Comparisons of both sets of retrievals with ship-and land-based AERONET measurements show a high degree of correlation with biases of < 0.08. However, these comparisons typically only sample relatively low aerosol loadings. When both records are stratified by AOD retrievals from the Multi-angle Imaging SpectroRadiometer (MISR), opposing behaviour is revealed at high MISR AODs (> 1), with offsets of +0.19 for MODIS and −0.06 for SEVIRI. Similar behaviour is also seen over the Persian Gulf. Analysis of the scattering angles at which retrievals from the SEVIRI and MODIS measurements are typically performed in these regions suggests that assumptions concerning particle sphericity may be responsible for the differences seen.

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“…MACC has been evaluated to perform significantly better than the "Kinne" [47] GADS/OPAC [48,49] and HAC-v1 climatology [50], see [51] for details.…”

Section: Input On Atmospheric Statementioning

confidence: 99%

Digging the METEOSAT Treasure—3 Decades of Solar Surface Radiation

et al. 2015

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Solar surface radiation data of high quality is essential for the appropriate monitoring and analysis of the Earth's radiation budget and the climate system. Further, they are crucial for the efficient planning and operation of solar energy systems. However, well maintained surface measurements are rare in many regions of the world and over the oceans. There, satellite derived information is the exclusive observational source. This emphasizes the important role of satellite based surface radiation data. Within this scope, the new satellite based CM-SAF SARAH (Solar surfAce RAdiation Heliosat) data record is discussed as well as the retrieval method used. The SARAH data are retrieved with the sophisticated SPECMAGIC method, which is based on radiative transfer modeling. The resulting climate data of solar surface irradiance, direct irradiance (horizontal and direct normal) and clear sky irradiance are covering 3 decades. The SARAH data set is validated with surface measurements of the Baseline Surface Radiation Network (BSRN) and of the Global Energy and Balance Archive (GEBA). Comparison with BSRN data is performed in order to estimate the accuracy and precision of the monthly and daily means of solar surface irradiance.The SARAH solar surface irradiance shows a bias of 1.

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Technical Note: Optical properties of desert aerosol with non-spherical mineral particles: data incorporated to OPAC

Cited by 103 publications

References 46 publications

MOPSMAP v1.0: a versatile tool for the modeling of aerosol optical properties

MOPSMAP v1.0: a versatile tool for the modeling of aerosol optical properties

Satellite retrievals of dust aerosol over the Red Sea and the Persian Gulf (2005–2015)

Digging the METEOSAT Treasure—3 Decades of Solar Surface Radiation

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