A new method of inferring the size, number density, and charge of mesospheric dust from its in situ collection by the DUSTY probe

Abstract. We present a new method of analyzing measurements of mesospheric dust made with DUSTY rocket-borne Faraday cup probes. It can yield the variation in fundamental dust parameters through a mesospheric cloud with an altitude resolution down to 10 cm or less if plasma probes give the plasma density variations with similar height resolution. A DUSTY probe was the first probe that unambiguously detected charged dust and aerosol particles in the Earth's mesosphere. DUSTY excluded the ambient plasma by various biased grids, which however allowed dust particles with radii above a few nanometers to enter, and it measured the flux of charged dust particles. The flux measurements directly yielded the total ambient dust charge density. We extend the analysis of DUSTY data by using the impact currents on its main grid and the bottom plate as before, together with a dust charging model and a secondary charge production model, to allow the determination of fundamental parameters, such as dust radius, charge number, and total dust density. We demonstrate the utility of the new analysis technique by considering observations made with the DUSTY probes during the MAXIDUSTY rocket campaign in June–July 2016 and comparing the results with those of other instruments (lidar and photometer) also used in the campaign. In the present version we have used monodisperse dust size distributions.

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A new method to infer the size, number density, and charge of mesospheric dust from its in situ collection by the DUSTY probe

10.5194/amt-2018-222 ◽

2018 ◽

Author(s):

Ove Havnes ◽

Tarjei Antonsen ◽

Gerd Baumgarten ◽

Thomas W. Hartquist ◽

Alexander Biebricher ◽

...

Keyword(s):

Production Model ◽

Dust Particles ◽

Bottom Plate ◽

Charged Dust ◽

Fundamental Parameters ◽

Dust Charge ◽

Analysis Technique ◽

June July ◽

In Situ Collection ◽

The Impact

Abstract. We present a new extended method of analyzing measurements of mesospheric dust made with DUSTY rocket-borne Faraday cup probes. It yields the variation of fundamental dust parameters through a mesospheric cloud with an unrivalled altitude resolution down to 10 cm or less. A DUSTY probe was the first probe which unambiguously detected charged dust/aerosol particles in the Earth's mesosphere. DUSTY excluded the ambient plasma by various biased grids, which however allowed dust particles with radii above a few nanometer to enter, and it measured the flux of charged dust particles. The flux measurements directly yielded the total ambient dust charge density. We extend the analysis of DUSTY data by using the impact currents on its main grid and the bottom plate as before, together with a dust charging model and a secondary charge production model, to allow the determination of fundamental parameters, such as dust radius, charge number and total dust density. We demonstrate the utility of the new analysis technique by considering observations made with the DUSTY probes during the MAXIDUSTY rocket campaign in June–July 2016 and comparing the results with those of other instruments (Lidar and photometer) also used in the campaign.

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On the secondary charging effects and structure of mesospheric dust particles impacting on rocket probes

Annales Geophysicae ◽

10.5194/angeo-25-623-2007 ◽

2007 ◽

Vol 25 (3) ◽

pp. 623-637 ◽

Cited By ~ 30

Author(s):

O. Havnes ◽

L. I. Næsheim

Keyword(s):

Grazing Incidence ◽

Dust Particles ◽

Bottom Plate ◽

Charged Dust ◽

Dust Layer ◽

Secondary Currents ◽

Positive Currents ◽

The Impact ◽

The Relationship ◽

Positively Charged

Abstract. The dust probe DUSTY, first launched during the summer of 1994 (flights ECT–02 and ECT–07) from Andøya Rocket Range, northern Norway, was the first probe to unambiguously detect heavy charged mesospheric aerosols, from hereon referred to as dust. In ECT–02 the probe detected negatively charged dust particles in the height interval of 83 to 88.5 km. In this flight, the lower grid in the detector (Grid 2) measures both positive and negative currents in various regions, and we find that the relationship between the current measurements of Grid 2 and the bottom plate can only be explained by influence from secondary charge production on Grid 2. In ECT–07, which had a large coning, positive currents reaching the top grid of the probe were interpreted as due to the impact of positively charged dust particles. We have now reanalyzed the data from ECT–07 and arrived at the conclusion that the measured positive currents to this grid must have been mainly due to secondary charging effects from the impacting dust particles. The grid consists of a set of parallel wires crossed with an identical set of wires on top of it, and we find that if the observed currents were created from the direct impact of charged dust particles, then they should be very weakly modulated at four times the rocket spin rate ωR. Observations show, however, that the observed currents are strongly modulated at 2ωR. We cannot reproduce the observed large modulations of the impact currents in the dust layer if the currents are due only to the transfer of the charges on the impacted dust particles. Based on the results of recent ice cluster impact secondary charging experiments by Tomsic (2003), which found that a small fraction of the ice clusters, when impacting with nearly grazing incidence, carried away one negative charge −1e, we have arrived at the conclusion that similar, but significantly more effective, charging effects must be predominantly responsible for the positive currents measured by the top grid in ECT–07 and their large rotational modulation at 2ωR. Since the secondary effect is dependent on the size of the impacting dust, this opens up for the possibility of mapping the relative dust sizes throughout a dust layer by comparing the observed direct and secondary currents.

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Future lunar missions and investigation of dusty plasma processes on the Moon

Journal of Plasma Physics ◽

10.1017/s0022377813000214 ◽

2013 ◽

Vol 79 (4) ◽

pp. 405-411 ◽

Cited By ~ 15

Author(s):

SERGEY I. POPEL ◽

LEV M. ZELENYI

Keyword(s):

Dusty Plasma ◽

Lunar Surface ◽

Dust Particles ◽

Maximum Height ◽

Charged Dust ◽

The Moon ◽

Plasma System ◽

Lunar Dust ◽

The Impact ◽

Dusty Plasma System

AbstractFrom the Apollo era of exploration, it was discovered that sunlight was scattered at the terminators giving rise to “horizon glow” and “streamers” above the lunar surface. Subsequent investigations have shown that the sunlight was most likely scattered by electrostatically charged dust grains originating from the surface. A renaissance is being observed currently in investigations of the Moon. The Luna-Glob and Luna-Resource missions (the latter jointly with India) are being prepared in Russia. Some of these missions will include investigations of lunar dust. Here we discuss the future experimental investigations of lunar dust within the missions of Luna-Glob and Luna-Resource. We consider the dusty plasma system over the lunar surface and determine the maximum height of dust rise. We describe mechanisms of formation of the dusty plasma system over the Moon and its main properties, determine distributions of electrons and dust over the lunar surface, and show a possibility of rising dust particles over the surface of the illuminated part of the Moon in the entire range of lunar latitudes. Finally, we discuss the effect of condensation of micrometeoriod substance during the expansion of the impact plume and show that this effect is important from the viewpoint of explanation of dust particle rise to high altitudes in addition to the dusty plasma effects.

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Mesospheric dust and its secondary effects as observed by the ESPRIT payload

Annales Geophysicae ◽

10.5194/angeo-27-1119-2009 ◽

2009 ◽

Vol 27 (3) ◽

pp. 1119-1128 ◽

Cited By ~ 5

Author(s):

O. Havnes ◽

L. H. Surdal ◽

C. R. Philbrick

Keyword(s):

Charge Density ◽

Lower Layer ◽

Bound Water ◽

Impact Angle ◽

Dust Particles ◽

Height Range ◽

Dust Layer ◽

Water Ice ◽

Dust Charge ◽

The Impact

Abstract. The dust detector on the ESPRIT rocket detected two extended dust/aerosol layers during the launch on 1 July 2006. The lower layer at height ~81.5–83 km coincided with a strong NLC and PMSE layer. The maximum dust charge density was ~−3.5×109 e m−3 and the dust layer was characterized by a few strong dust layers where the dust charge density at the upper edges changed by factors 2–3 over a distance of ≲10 m, while the same change at their lower edges were much more gradual. The upper edge of this layer is also sharp, with a change in the probe current from zero to IDC=−10−11 A over ~10 m, while the same change at the low edge occurs over ~500 m. The second dust layer at ~85–92 km was in the height range of a comparatively weak PMSE layer and the maximum dust charge density was ~−108 e m−3. This demonstrates that PMSE can be formed even if the ratio of the dust charge density to the electron density P=NdZd /n_e≲0.01. In spite of the dust detector being constructed to reduce possible secondary charging effects from dust impacts, it was found that they were clearly present during the passage through both layers. The measured secondary charging effects confirm recent results that dust in the NLC and PMSE layers can be very effective in producing secondary charges with up to ~50 to 100 electron charges being rubbed off by one impacting large dust particle, if the impact angle is θi≳20–35°. This again lends support to the suggested model for NLC and PMSE dust particles (Havnes and Næsheim, 2007) as a loosely bound water-ice clump interspersed with a considerable number of sub-nanometer-sized meteoric smoke particles, possibly also contaminated with meteoric atomic species.

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On the possibility of dust acoustic waves over sunlit lunar surface

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stab495 ◽

2021 ◽

Vol 503 (3) ◽

pp. 3965-3974 ◽

Cited By ~ 1

Author(s):

S K Mishra

Keyword(s):

Acoustic Waves ◽

Phase Speed ◽

Wave Dispersion ◽

Dust Particles ◽

Charged Dust ◽

Charge Fluctuation ◽

Dynamical Equations ◽

Ultralow Frequency ◽

Dust Charge ◽

Dust Acoustic

ABSTRACT The photoelectron sheath and floating fine positively charged dust particles constitute two-component dusty plasma in the sunlit lunar regolith’s vicinity. By including the charge fluctuation into photoelectron–dust dynamics, the lunar exospheric plasma is proposed to support the propagation of long-wavelength dust acoustic (DA) modes. Using the standard approach based on the dynamical equations for continuity, momentum, plasma potential, and dust charging along with Fowler's treatment of photoemission and non-Maxwellian nature of the sheath photoelectrons, the wave dispersion is derived. The dust charge variation modifies the usual DA wave dispersion and excites the ultralow frequency modes that propagate with sufficiently low phase speed. Such ultralow frequency modes are predicted as pronounced for smaller values of dust charge and sheath potential. The DA wave dispersion is also depicted as sensitive to the photoelectrons’ energy distribution within the sheath. The quantitative estimates suggest that the nominal exospheric plasma may exhibit DA waves propagating with frequencies of the order of unity.

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Intercontinental Transport and Climatic Impact of Saharan and Sahelian Dust

Advances in Meteorology ◽

10.1155/2012/157020 ◽

2012 ◽

Vol 2012 ◽

pp. 1-14 ◽

Cited By ~ 8

Author(s):

N'Datchoh Evelyne Touré ◽

Abdourahamane Konaré ◽

Siélé Silué

Keyword(s):

Climate Model ◽

Regional Climate ◽

Dust Emission ◽

Dust Particles ◽

Boreal Summer ◽

Climatic Impact ◽

North East ◽

June July August ◽

June July ◽

The Impact

The Sahara and Sahel regions of Africa are important sources of dust particles into the atmosphere. Dust particles from these regions are transported over the Atlantic Ocean to the Eastern American Coasts. This transportation shows temporal and spatial variability and often reaches its peak during the boreal summer (June-July-August). The regional climate model (RegCM 4.0), containing a module of dust emission, transport, and deposition processes, is used in this study. Saharan and Sahelian dusts emissions, transports, and climatic impact on precipitations during the spring (March-April-May) and summer (June-July-August) were studied using this model. The results showed that the simulation were coherent with observations made by the MISR satellite and the AERONET ground stations, within the domain of Africa (Banizoumba, Cinzana, and M’Bour) and Ragged-point (Barbados Islands). The transport of dust particles was predominantly from North-East to South-West over the studied period (2005–2010). The seasonality of dust plumes’ trajectories was influenced by the altitudes reached by dusts in the troposphere. The impact of dusts on climate consisted of a cooling effect both during the boreal summer and spring over West Africa (except Southern-Guinea and Northern-Liberia), Central Africa, South-America, and Caribbean where increased precipitations were observed.

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PROFIL KERAGAMAN VEGETASI EKOSISTEM MANGROVE DI DESA TAMUKU KABUPATEN LUWU UTARA

Jurnal Pendidikan Teknologi Pertanian ◽

10.26858/jptp.v5i0.8564 ◽

2019 ◽

Vol 5 ◽

pp. 104

Author(s):

Suhendra Purnawan ◽

Subari Yanto ◽

Ernawati S.Kaseng

Keyword(s):

Survey Methods ◽

Mangrove Ecosystem ◽

Line Transect ◽

Mangrove Forests ◽

Vegetation Diversity ◽

Line Transect Survey ◽

Analysis Technique ◽

Mangrove Vegetation ◽

Data Collection Technique ◽

The Impact

This study aims to describe the profile of vegetation diversity in the mangrove ecosystem in Tamuku Village, Bone-Bone-Bone District, North Luwu Regency. This research is a qualitative research using survey methods. The data collection technique uses the Quadrant Line Transect Survey technique. The data analysis technique uses the thinking flow which is divided into three stages, namely describing phenomena, classifying them, and seeing how the concepts that emerge are related to each other. The results of this study are the profile of mangrove vegetation in Tamuku Village, which is still found 16 varieties of true mangrove vegetation and 7 varieties of mangrove vegetation joined in the coastal area of Tamuku Village, Bone-Bone District, North Luwu Regency, South Sulawesi. The condition of mangrove vegetation in Tamuku Village is currently very worrying due to human activities that cause damage such as the project of normalization of flow, opening of new farms, disposal of garbage, water pollution due to chemicals, and exploitation of mangrove forests for living needs. The impact is ecosystem damage and reduced vegetation area as a place to grow and develop mangroves.

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Pengungkapan Corporate Social Responsibility (CSR) dan Kinerja Keuangan Perusahaan dengan Pengungkapan Anti Korupsi sebagai Variabel Moderasi

Akmenika: Jurnal Akuntansi dan Manajemen ◽

10.31316/akmenika.v16i2.393 ◽

2019 ◽

Vol 13 (2) ◽

Author(s):

Arief Hidayatullah Khamainy ◽

Dessy Novitasari Laras Asih

Keyword(s):

Regression Analysis ◽

Financial Performance ◽

Stock Exchange ◽

Linear Regression Analysis ◽

Sampling Technique ◽

Analysis Technique ◽

Study Population ◽

Csr Disclosure ◽

Corporate Social ◽

The Impact

The research was carried out to find the influence of training material and methods of training toward workability. The study was conducted respectively from an employee of PD BPR Bantul Yogyakarta. The purpose of this research is expected to be useful for stakeholders in seeing CSR disclosure in the company in testing and analyzing its effect on the company's financial performance and with the presence of anti-corruption exposure, whether it will strengthen the impact of CSR disclosure on the company's financial performance. The study population in this study were all mining companies registered on the Indonesia Stock Exchange in 2016-2018 with a total of 63 companies. The research sample was taken using a random sampling technique that was calculated by the Slovin formula so that 54 samples were obtained for analysis. Linear Regression Analysis and Moderation Regression Analysis were chosen as the analysis technique used in this study. The results show that CSR disclosure does not affect the company's financial performance, and anti-corruption disclosure does not affect the relationship between the two.

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