Optical properties of a polydispersion of small charged cosmic dust particles

Abstract. Aerosol chemical and optical properties are extensively investigated for the first time over the Paris Basin in July 2000 within the ESQUIF project. The measurement campaign offers an exceptional framework to evaluate the performances of the chemistry-transport model CHIMERE in simulating concentrations of gaseous and aerosol pollutants, as well as the aerosol-size distribution and composition in polluted urban environments against ground-based and airborne measurements. A detailed comparison of measured and simulated variables during the second half of July with particular focus on 19 and 31 pollution episodes reveals an overall good agreement for gas-species and aerosol components both at the ground level and along flight trajectories, and the absence of systematic biases in simulated meteorological variables such as wind speed, relative humidity and boundary layer height as computed by the MM5 model. A good consistency in ozone and NO concentrations demonstrates the ability of the model to reproduce the plume structure and location fairly well both on 19 and 31 July, despite an underestimation of the amplitude of ozone concentrations on 31 July. The spatial and vertical aerosol distributions are also examined by comparing simulated and observed lidar vertical profiles along flight trajectories on 31 July and confirm the model capacity to simulate the plume characteristics. The comparison of observed and modeled aerosol components in the southwest suburb of Paris during the second half of July indicates that the aerosol composition is rather correctly reproduced, although the total aerosol mass is underestimated by about 20%. The simulated Parisian aerosol is dominated by primary particulate matter that accounts for anthropogenic and biogenic primary particles (40%), and inorganic aerosol fraction (40%) including nitrate (8%), sulfate (22%) and ammonium (10%). The secondary organic aerosols (SOA) represent 12% of the total aerosol mass, while the mineral dust accounts for 8%. The comparison demonstrates the absence of systematic errors in the simulated sulfate, ammonium and nitrates total concentrations. However, for nitrates the observed partition between fine and coarse mode is not reproduced. In CHIMERE there is a clear lack of coarse-mode nitrates. This calls for additional parameterizations in order to account for the heterogeneous formation of nitrate onto dust particles. Larger discrepancies are obtained for the secondary organic aerosols due to both inconsistencies in the SOA formation processes in the model leading to an underestimation of their mass and large uncertainties in the determination of the measured aerosol organic fraction. The observed mass distribution of aerosols is not well reproduced, although no clear explanation can be given.

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Observations of Saharan dust microphysical and optical properties from the Eastern Atlantic during NAMMA airborne field campaign

Atmospheric Chemistry and Physics ◽

10.5194/acp-11-723-2011 ◽

2011 ◽

Vol 11 (2) ◽

pp. 723-740 ◽

Cited By ~ 57

Author(s):

G. Chen ◽

L. D. Ziemba ◽

D. A. Chu ◽

K. L. Thornhill ◽

G. L. Schuster ◽

...

Keyword(s):

Particle Size ◽

Optical Properties ◽

Dust Particle ◽

Saharan Dust ◽

Dust Particles ◽

Small Range ◽

Size Distributions ◽

Particle Size Distributions ◽

Field Campaign ◽

Sahara Dust

Abstract. As part of the international project entitled "African Monsoon Multidisciplinary Analysis (AMMA)", NAMMA (NASA AMMA) aimed to gain a better understanding of the relationship between the African Easterly Waves (AEWs), the Sahara Air Layer (SAL), and tropical cyclogenesis. The NAMMA airborne field campaign was based out of the Cape Verde Islands during the peak of the hurricane season, i.e., August and September 2006. Multiple Sahara dust layers were sampled during 62 encounters in the eastern portion of the hurricane main development region, covering both the eastern North Atlantic Ocean and the western Saharan desert (i.e., 5–22° N and 10–35° W). The centers of these layers were located at altitudes between 1.5 and 3.3 km and the layer thickness ranged from 0.5 to 3 km. Detailed dust microphysical and optical properties were characterized using a suite of in-situ instruments aboard the NASA DC-8 that included a particle counter, an Ultra-High Sensitivity Aerosol Spectrometer, an Aerodynamic Particle Sizer, a nephelometer, and a Particle Soot Absorption Photometer. The NAAMA sampling inlet has a size cut (i.e., 50% transmission efficiency size) of approximately 4 μm in diameter for dust particles, which limits the representativeness of the NAMMA observational findings. The NAMMA dust observations showed relatively low particle number densities, ranging from 268 to 461 cm−3, but highly elevated volume density with an average at 45 μm3 cm−3. NAMMA dust particle size distributions can be well represented by tri-modal lognormal regressions. The estimated volume median diameter (VMD) is averaged at 2.1 μm with a small range of variation regardless of the vertical and geographical sampling locations. The Ångström Exponent assessments exhibited strong wavelength dependence for absorption but a weak one for scattering. The single scattering albedo was estimated at 0.97 ± 0.02. The imaginary part of the refractive index for Sahara dust was estimated at 0.0022, with a range from 0.0015 to 0.0044. Closure analysis showed that observed scattering coefficients are highly correlated with those calculated from spherical Mie-Theory and observed dust particle size distributions. These values are generally consistent with literature values reported from studies with similar particle sampling size range.

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Nanodust detection with Cassini CDA - Implications for DESTINY+ and Interstellar Probe

10.5194/egusphere-egu21-3198 ◽

2021 ◽

Author(s):

Ralf Srama ◽

Jon K. Hillier ◽

Sean Hsu ◽

Sascha Kempf ◽

Masanori Kobayashi ◽

...

Keyword(s):

High Resolution ◽

Impact Ionization ◽

Cosmic Dust ◽

Hypervelocity Impact ◽

Dust Particles ◽

Interstellar Space ◽

Mass Spectrometers ◽

High Resolution Mass ◽

Resolution Mass

The Cosmic Dust Analyzer (CDA) onboard Cassini characterized successfully the dust environment at Saturn from 2004 to 2017. Besides the study of Saturn&#8217;s E ring and its interaction with the embedded moons, CDA detected nanoparticles in the outer Saturn system moving on unbound orbits and originating primarily from Saturn&#8217;s E-ring. Although the instrument was built to detect micron and sub-micron sized particles, nano-sized grains were detected during the flyby at early Jupiter and in the outer environment at Saturn. Fast dust particles with sizes below 10 nm were measured by in-situ impact ionization and mass spectra were recorded. What are the limits of in-situ hypervelocity impact detection and what can be expected with current high-resolution mass spectrometers as flown onboard the missions DESTINY+ or EUROPA? Is the sensitivity of Dust Telescopes sufficient to detect nano-diamonds in interstellar space? This presentation summarizes the current experience of in-situ dust detectors and gives a prediction for future missions. In summary, current Dust Telescopes with integrated high-resolution mass spectrometers are more sensitive than the CASSINI Cosmic Dust Analyzer.

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2.2.4 Lunar Soil Movement Registered by the Apollo 17 Cosmic Dust Experiment

International Astronomical Union Colloquium ◽

10.1017/s0252921100051757 ◽

1976 ◽

Vol 31 ◽

pp. 233-237 ◽

Cited By ~ 2

Author(s):

Otto E. Berg ◽

Henry Wolf ◽

John Rhee

Keyword(s):

Lunar Surface ◽

Lunar Soil ◽

Cosmic Dust ◽

Dust Particles ◽

The Moon ◽

Normal Impact ◽

Soil Movement ◽

Impact Parameters

In December, 1973, a Lunar Ejecta and Meteorites (LEAM) experiment was placed in the Taurus-Littrow area of the moon by the Apollo 17 Astronauts. Objectives of the experiment were centered around measurements of impact parameters of cosmic dust on the lunar surface. During preliminary attempts to analyze the data it became evident that the events registered by the sensors could not be attributed to cosmic dust but could only be identified with the lunar surface and the local sun angle. The nature of these data coupled with post-flight studies of instrument characteristics, have led to a conclusion that the LEAM experiment is responding primarily to a flux of highly charged, slowly moving lunar surface fines. Undoubtedly concealed in these data is the normal impact activity from cosmic dust and probably lunar ejecta, as well. This paper is based on the recognition that the bulk of events registered by the LEAM experiment are not signatures of hypervelocity cosmic dust particles, as expected, but are induced signatures of electrostatically charged and transported lunar fines.

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Investigation of optical glass characteristics under the influence of space factors

Computer Optics ◽

10.18287/2412-6179-2019-43-5-803-809 ◽

2019 ◽

Vol 43 (5) ◽

pp. 803-809

Author(s):

М.P. Kalaev ◽

А.М. Telegin ◽

K.E. Voronov ◽

Jiang Lixiang ◽

Jiao Jilong

Keyword(s):

Experimental Study ◽

Optical Properties ◽

High Speed ◽

Optical Glass ◽

Outer Space ◽

Characteristic Size ◽

Dust Particles ◽

Spectral Transmittance ◽

Ability To Work ◽

High Speed Flows

The paper describes a DF-OPTICS device that the present authors designed for the experimental study of changes in the optical properties of a glass whose surface is exposed to high-speed flows of micron-sized dust particles. The device allows the scattering indicatrix and the spectral transmittance to be automatically measured at each point of the sample with a 0.5-mm increment. Advantages of the developed device include small dimensions and the ability to work in vacuum, allowing it to be used in an accelerator chamber to simulate outer space factors. Experimental results for the K-8 glass put in a microparticle accelerator and bombarded by an aluminum powder PAP-1 with a characteristic size of 1-3 µm and speeds of 2-8 km / s are presented. The device makes it possible to measure the change of the spectral transmittance of transparent materials in the UV and RGB regions with an accuracy of 0.005%, which exceeds the sensitivity of some known spectrophotometers.

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Aerosol chemical and optical properties over the Paris area within ESQUIF project

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-6-401-2006 ◽

2006 ◽

Vol 6 (1) ◽

pp. 401-454 ◽

Cited By ~ 3

Author(s):

A. Hodzic ◽

R. Vautard ◽

P. Chazette ◽

L. Menut ◽

B. Bessagnet

Keyword(s):

Optical Properties ◽

Secondary Organic Aerosols ◽

Organic Aerosols ◽

Dust Particles ◽

Aerosol Size Distribution ◽

Aerosol Composition ◽

Aerosol Mass ◽

Coarse Mode ◽

Paris Area ◽

Flight Trajectories

Abstract. Aerosol chemical and optical properties are extensively investigated for the first time over the Paris Basin in July 2000 within the ESQUIF project. The measurement campaign offers an exceptional framework to evaluate the performances of the chemistry-transport model CHIMERE in simulating concentrations of gaseous and aerosol pollutants, as well as the aerosol-size distribution and composition in polluted urban environment against ground-based and airborne measurements. A detailed comparison of measured and simulated variables during the second half of July with particular focus on 19 and 31 pollution episodes reveals an overall good agreement for gas-species and aerosol components both at the ground level and along flight trajectories, and the absence of systematic biases in simulated meteorological variables such as wind speed, relative humidity and boundary layer height as computed by the MM5 model. A good consistency in ozone and NO concentrations demonstrates the ability of the model to reproduce fairly well the plume structure and location both on 19 and 31 July, despite an underestimation of the amplitude of ozone concentrations on 31 July. The spatial and vertical aerosol distributions are also examined by comparing simulated and observed lidar vertical profiles along flight trajectories on 31 July and confirmed the model capacity to simulate the plume characteristics. The comparison of observed and modeled aerosol components in the southwest suburb of Paris during the second half of July indicated that the aerosol composition is rather correctly reproduced, although the total aerosol mass is underestimated of about 20%. The simulated Parisian aerosol is dominated by primary particulate matter that accounts for anthropogenic and biogenic primary particles (40%) and inorganic aerosol fraction (40%) including nitrate (8%), sulfate (22%) and ammonium (10%). The secondary organic aerosols (SOA) represent 12% of the total aerosol mass, while the mineral dust accounts for 8%. The comparison demonstrated the absence of systematic errors in the simulated sulfate, ammonium and nitrates total concentrations. However for nitrates the observed partition between fine and coarse mode is not reproduced. In CHIMERE there is a clear lack of coarse-mode nitrates. This calls for additional parameterizations in order to account for the heterogeneous formation of nitrate onto dust particles. Larger discrepancies are obtained for the secondary organic aerosols due to both inconsistencies in the SOA formation processes in the model leading to an underestimation of their mass and large uncertainties in the determination of the measured aerosol organic fraction. The observed mass distribution of aerosols is not well reproduced, although no clear explanation can be given.

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Compositional Indicators for a Dynamical Barrier within Saturn’s E-ring

10.5194/epsc2021-146 ◽

2021 ◽

Author(s):

Lenz Nölle ◽

Frank Postberg ◽

Sascha Kempf ◽

Jon Hillier ◽

Nozair Khawaja ◽

...

Keyword(s):

Salt Concentration ◽

Mass Spectra ◽

Space Science ◽

Cosmic Dust ◽

Dust Particles ◽

Equilibrium Potential ◽

Surface Charges ◽

Geophysical Research ◽

Water Ice ◽

Plasma Sputtering

Abstract Mass spectra from the Cosmic Dust Analyzer (CDA) [1] onboard the Cassini spacecraft revealed the existence of different compositional types of icy dust particles in Saturn&#8217;s E-ring. Most of these &#181;m to sub-&#181;m water ice grains were ejected from the cryo-volcanoes at the southern polar region of Enceladus and carry different constituents, for example organic compounds or salts [2-5]. These particles are subject to ongoing plasma sputtering during their lifetime in the E-ring [6,7]. Recent modelling of the dynamics of E-ring particles has shown that, in the region between the orbital distances of Dione and Rhea, the outwards migration of a proportion of the E-ring dust slows down and almost comes to a halt [8]. Due to the minimum of the V-shaped electrostatic grain equilibrium potential [9] and a polarity reversal of the dust surface charges [10], the semi-major axes of the dust particles&#8217; orbits actually stop growing, forcing the particles to spend a significant part of their lifetime at this distance from Saturn. Therefore, this phenomenon should allow plasma sputtering to operate much longer on the dust particles residing in this region, potentially resulting in detectable alterations to the dust particle properties, e.g. particle composition and size, in this region. Here we present the discovery of a new population of grains within the E ring, which show signs of compositional alteration, best explained by plasma sputtering. The radial frequency distribution of these grains shows a distinct accumulation in the region between the orbits of Dione and Rhea, and may provide evidence of prolonged residence there. Analyses of CDA mass spectra of the grains, interpreted via comparison with laboratory Laser&#8208;Induced Liquid Beam Ion Desorption (LILBID) [11] analogue experiments, indicate the particles to be very salt-rich water ice. In comparison to the previously reported salt-rich particle types, generated from Enceladus&#8217; subsurface ocean [3,4] this new population must possess a far higher salt concentration to explain its observed spectral appearance. We propose that the increase in salt concentration arises from sputtering-induced removal of water from less salty oceanic grains (Type 3) [3,4], during their extended time in the region between Dione and Rhea. This population may therefore represent the first confirmation of the proposed dynamical barrier within Saturn&#8217;s E-ring. References [1] Srama, R. et al., The Cassini Cosmic Dust Analyzer, Space Science Reviews, 114, 465-518, 2004. [2] Hillier, J. et al., The composition of Saturn&#8217;s E ring, Mon. Not. R. Astron. Soc., 377, 1588&#8211;1596, 2007 [3] Postberg, F. et al., The E-ring in the vicinity of Enceladus II. Probing the moon&#8217;s interior-The composition of E-ring particles, Icarus, 193, 438-454, 2008. [4] Postberg, F. et al., Sodium salts in E-ring ice grains from an ocean below the surface of Enceladus, Nature, 459, 1098-1101, 2009. [5] Postberg, F. et al., A salt-water reservoir as the source of a compositionally stratified plume on Enceladus, Nature, 474, 620&#8211;622, 2011 [6] Jurac, S. et al., Saturn&#8217;s E Ring and Production of the Neutral Torus, Icarus, 149, 384&#8211;396, 2001 [7] Johnson, R. E. et al., Sputtering of ice grains and icy satellites in Saturn&#8217;s inner magnetosphere, Planetary and Space Science, 56, 1238&#8211;1243, 2008 [8] Kempf & Beckmann, Dynamics and long-term evolution of Saturn's E ring particles (in prep.) [9] Mitchell, C. J. et al., Tenuous ring formation by the capture of interplanetary dust at Saturn, JOURNAL OF GEOPHYSICAL RESEARCH, 110, 2005 [10] Kempf, S. et al., The electrostatic potential of E ring particles, Planetary and Space Science, 54, 999-1006, 2006 [11] Klenner, F. et al., Analogue spectra for impact ionization mass spectra of water ice grains obtained at different impact speeds in space, Rapid Commun Mass Spectrom., 33, 1751&#8211;1760, 2019

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The Optical Properties of Interplanetary Dust

International Astronomical Union Colloquium ◽

10.1017/s0252921100066707 ◽

1991 ◽

Vol 126 ◽

pp. 163-170 ◽

Cited By ~ 1

Author(s):

P.L. Lamy ◽

J.M. Perrin

Keyword(s):

Optical Properties ◽

Light Scattering ◽

Phase Function ◽

Interplanetary Dust ◽

Dust Particles ◽

Local Enhancement ◽

Zodiacal Light ◽

Laboratory Results

AbstractAfter briefly evaluating the observations of the Zodiacal Light and F-corona, we review the laboratory results on the light scattering by dust particles and the various theories which have been recently proposed. We then discuss the optical properties of the dust with emphasis on the phase function, the polarization, the color, the albedo and the local enhancement in the Gegenschein.

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Java application for the superposition T-matrix code to study the optical properties of cosmic dust aggregates

Computer Physics Communications ◽

10.1016/j.cpc.2014.04.019 ◽

2014 ◽

Vol 185 (9) ◽

pp. 2369-2379 ◽

Cited By ~ 6

Author(s):

P. Halder ◽

A. Chakraborty ◽

P. Deb Roy ◽

H.S. Das

Keyword(s):

Optical Properties ◽

Cosmic Dust ◽

Java Application ◽

T Matrix

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Study of Cosmic Dust Particles on Board LDEF and MIR Space Station

International Astronomical Union Colloquium ◽

10.1017/s0252921100066380 ◽

1991 ◽

Vol 126 ◽

pp. 11-14

Author(s):

J.C. Mandeville

Keyword(s):

Size Distribution ◽

Good Accuracy ◽

Space Station ◽

Cosmic Dust ◽

Orbital Debris ◽

Dust Particles ◽

Chemical Identification ◽

Near Earth Space ◽

Solid Objects ◽

Long Duration

AbstractInterplanetary and near-earth space contains solid objects whose size distribution continuously covers the interval from submicron sized particles to km sized asteroids or comets. Two French experiments partly devoted to the detection of cosmic dust have been flown recently in space. One on the NASA Long Duration Exposure Facility (LDEF), and one on the Soviet MIR Space Station. A variety of sensors and collecting devices will make possible the study of cosmic particles after recovery of exposed material. Flux mass distribution is expected to be derived from craters counts, with a good accuracy. Remnants of particles, suitable for chemical identification are expected to be found within stacked foil detectors. Discrimination between extraterrestrial particles and man-made orbital debris will be possible.

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