Ingrid Mann - Profile on Academia.edu (original) (raw)
Papers by Ingrid Mann
The solar F-corona : calculations of the optical and infrared brightness of circumsolar dust
The brightness of the solar F-corona along the ecliptic is calculated in the visual and near-infr... more The brightness of the solar F-corona along the ecliptic is calculated in the visual and near-infrared spectral range and the results are discussed with respect to future observations. It is shown that dust particles close to the Sun have a strong influence on the corona brightness, which enables their investigation by remote sensing experiments. Comparison of model calculations with the observations indicates that the zodiacal dust cloud remains mainly undisturbed up to the beginning of a dust-free zone that amounts to about 5 solar radii (R ⊙ ). Calculations of visual brightness and polarization indicate a change of particle properties for a solar distance smaller than 20R ⊙ , which has to be proven by future experiments
Atmospheric Chemistry and Physics, 2021
Abstract. We present a detailed investigation of the formation of an additional sodium density pe... more Abstract. We present a detailed investigation of the formation of an additional sodium density peak at altitudes of 79–85 km below the main peak of the sodium layer based on sodium lidar and airglow imager measurements made at Ramfjordmoen near Tromso, Norway, on the night of 19 December 2014. The airglow imager observations of OH emissions revealed four passing frontal systems that resembled mesospheric bores, which typically occur in ducting regions of the upper mesosphere. For about 1.5 h, the lower-altitude sodium peak had densities similar to that of the main peak of the layer around 90 km. The lower-altitude sodium peak weakened and disappeared soon after the fourth front had passed. The fourth front had weakened in intensity by the time it approached the region of lidar beams and disappeared soon afterwards. The column-integrated sodium densities increased gradually during the formation of the lower-altitude sodium peak. Temperatures measured with the lidar indicate that ther...
Remote sensing of a comet at millimeter and submillimeter wavelengths from an orbiting spacecraft
Planetary and Space Science, 2007
... The submillimeter-wave subharmonic mixer utilizes integrated planar GaAs Schottky diodes in a... more ... The submillimeter-wave subharmonic mixer utilizes integrated planar GaAs Schottky diodes in a waveguide mount. Its local oscillator is a Gunn diode oscillator followed by a doubler with a planar diode varactor (Oswald et al., 1998). ...
Radiation pressure on porous micrometeoroids
Meteroids
Title: Radiation pressure on porous micrometeoroids. Authors: Kimura, H.; Mann, I. Publication: M... more Title: Radiation pressure on porous micrometeoroids. Authors: Kimura, H.; Mann, I. Publication: Meteroids 1998, editors: WJ Baggaley and V. Porubcan. ...
Analysis of Doppler shifts in the zodiacal light
Astronomy and Astrophysics, 1993
We present the theoretical Doppler shifts of the scattered solar light due to the interplanetary ... more We present the theoretical Doppler shifts of the scattered solar light due to the interplanetary dust particles moving in elliptical orbits, taking into account both Doppler components δλ 1 due to the instantaneous rate of change of the light path between the Sun and the particle and δλ 2 between the particle and the Earth. It is found that our simple model for maximum shifts along the line of sight (LOS) leads to a favorable Doppler shifts-dependence on an elongation angle to explain the previous measurements (e.g. Fried 1978). An introduction of the δλ 1 component along with a decrease of the ratio of radiation pressure force to gravity on the particle with decreasing solar distance plays an important role in fitting the theoretical Doppler shifts to the measurements
In a recent paper, Treumann and Baumjohann (2011) propose that the contribution of dust particles... more In a recent paper, Treumann and Baumjohann (2011) propose that the contribution of dust particles to the solar wind dynamic pressure can cause large compressions of the Earth's magnetopause and suggest that this occurs when Earth encounters meteoroid streams. In this paper we estimate the contribution from charged dust particles to the solar wind dynamical pressure, and we exclude that the dust associated to meteoroid streams can influence the extension of the magnetopause according to the proposed model. A sufficient coupling to the solar wind is only expected for so-called nanodust. However, the dynamic pressure of the nanodust is orders of magnitudes below that of the solar wind, making it unlikely that its variation can be observed in displacements of the magnetopause. We also discuss the equation that the authors use for estimating the extension of the Earth's magnetopause, and conclude that this is not applicable due to the large gyroradius of the nanodust. We finally note that an influence of dust on the extension of a magnetosphere might be quite possible in other astrophysical systems and based on other processes.
Proceedings of the International Astronomical Union, 2015
After a little more than forty years of work related to the interplanetary plasma and the heliosp... more After a little more than forty years of work related to the interplanetary plasma and the heliosphere the IAU's Commission 49 was formally discontinued in 2015. The commission started its work when the first spacecraft were launched to measure the solar wind in–situ away from Earth orbit, both inward and outward from 1 AU. It now hands over its activities to a new commission during an era of space research when Voyager 1 measures in–situ the parameters of the local interstellar medium at the edge of the heliosphere. The commission will be succeeded by C.E3 with a similar area of responsibility but with more focused specific tasks that the community intends to address during the coming several years. This report includes a short description of the motivation for this commission and of the historical context. It then describes work from 2012 to 2015 during the present solar cycle 24 that has been the weakest in the space era so far. It gave rise to a large number of studies on sol...
Fractal aggregate analogues for near solar dust properties
ABSTRACT
Radiation pressure on dust aggregates in circumstellar disks
Physics and Chemistry of the Earth, Part C: Solar, Terrestrial & Planetary Science, 1999
... Radiation pressure on dust aggregates in circumstellar disks. H. Kimura a , Corresponding Aut... more ... Radiation pressure on dust aggregates in circumstellar disks. H. Kimura a , Corresponding Author Contact Information and I. Mann a. ...
Analysis of Doppler shifts in the zodiacal light
Astronomy and Astrophysics, 1993
We present the theoretical Doppler shifts of the scattered solar light due to the interplanetary ... more We present the theoretical Doppler shifts of the scattered solar light due to the interplanetary dust particles moving in elliptical orbits, taking into account both Doppler components δλ 1 due to the instantaneous rate of change of the light path between the Sun and the particle and δλ 2 between the particle and the Earth. It is found that our simple model for maximum shifts along the line of sight (LOS) leads to a favorable Doppler shifts-dependence on an elongation angle to explain the previous measurements (e.g. Fried 1978). An introduction of the δλ 1 component along with a decrease of the ratio of radiation pressure force to gravity on the particle with decreasing solar distance plays an important role in fitting the theoretical Doppler shifts to the measurements
Fractal aggregate analogues for near solar dust properties
ABSTRACT
Radiation pressure on dust aggregates in circumstellar disks
Physics and Chemistry of the Earth, Part C: Solar, Terrestrial & Planetary Science, 1999
... Radiation pressure on dust aggregates in circumstellar disks. H. Kimura a , Corresponding Aut... more ... Radiation pressure on dust aggregates in circumstellar disks. H. Kimura a , Corresponding Author Contact Information and I. Mann a. ...
Journal of Quantitative Spectroscopy and Radiative Transfer, 1998
We apply the discrete dipole approximation (DDA) to estimate the radiation pressure cross section... more We apply the discrete dipole approximation (DDA) to estimate the radiation pressure cross section for fluffy aggregates by computing the asymmetry parameter and the cross sections for extinction and scattering. The ballistic particle-cluster aggregate and the ballistic cluster-cluster aggregate consisting of either dielectric or absorbing material are considered to represent naturally existing aggregates. We show that the asymmetry parameter perpendicular to the direction of wave propagation is maximized where the wavelength is comparable to the aggregate size, which may be characterized by the area-equivalent radius or the radius of gyration rather than the volume-equivalent radius. The asymmetry parameter for the aggregate depends on the morphology of the particle, but not on the constituent material. Therefore, the dependence of the radiation pressure cross section on the material composition arises mainly from that of the extinction and scattering cross sections, in other words, the single-scattering albedo. We find that aggregates consisting of high-albedo material show a large deviation of radiation pressure from the direction of incident radiation. When the aggregates are illuminated by blackbody radiation, the deviation of the radiation pressure increases with increasing temperature of the blackbody. Since the parallel component of the radiation pressure cross section for the aggregates is smaller than that for the volume-equivalent spheres at the size parameter close to unity, the Planck-mean radiation pressure cross section for the aggregates having radius comparable to the effective wavelength of radiation shows a lower value, compared with the volume-equivalent sphere. Consequently, the slope of the radiation pressure force per mass of the particle as a function of particle mass shows a lower maximum for the aggregates than for compact spherical particles.
Astronomy & Astrophysics, 2004
Solar-wind particles striking dust grains in orbit around the sun exert not only a repulsive forc... more Solar-wind particles striking dust grains in orbit around the sun exert not only a repulsive force on the grains, but also a drag force, called the plasma or pseudo Poynting-Robertson (PR) effect, which limits their dynamical lifetimes. To better understand the dynamical evolution of interplanetary dust, we study the momentum transfer from the solar wind to interplanetary dust taking into account the passage of impinging particles through the grains. The pseudo PR drag is one of the most important perturbations for the dynamics of interplanetary dust of any sizes. However, previous studies underestimated the lifetimes of small grains by overestimating the acting solar-wind forces. Our study also provides the velocity distribution of neutralized solar-wind particles after passage through a grain along with some implications for the generation of pickup ions by solar-wind interaction with dust grains.
Advances in Space Research, 2007
We study the radiation pressure on cometary dust over a wide size range in order to discuss the p... more We study the radiation pressure on cometary dust over a wide size range in order to discuss the properties of particles in cometary dust trails and meteor streams. Our model calculations utilize aggregates consisting of spherical monomers of 0.1 lm in radius as an analogue of cometary dust. We then estimate the radiation pressure on aggregates over a wide size range in order to discuss the properties of particles in cometary dust trails and meteor streams. We find that the influence of the radiation pressure force is stronger on large aggregates than on spherical particles of the same mass. Our study shows that aggregates on bound orbits in the solar system must have a fractal dimension close to three and that dust particles in observed cometary trails and meteor streams are more massive than previously estimated with spherical particles.
The Galileo spacecraft was the first man-made satellite of Jupiter, orbiting the planet between D... more The Galileo spacecraft was the first man-made satellite of Jupiter, orbiting the planet between December 1995 and September 2003. The spacecraft was equipped with a highly sensitive dust detector that monitored the jovian dust environment between approximately 2 and 370 R J (jovian radius R J = 71492 km). The Galileo dust detector was a twin of the one flying on board the Ulysses spacecraft. This is the tenth in a series of papers dedicated to presenting Galileo and Ulysses dust data. Here we present data from the Galileo dust instrument for the period January 2000 to September 2003 until Galileo was destroyed in a planned impact with Jupiter. The previous Galileo dust data set contains data of 2883 particles detected during Galileo's interplanetary cruise and 12978 particles detected in the jovian system between 1996 and 1999. In this paper we report on the data of additional 5389 particles measured between 2000 and the end of the mission in 2003. The majority of the 21250 particles for which the full set of measured impact parameters (impact time, impact direction, charge rise times, charge amplitudes, etc.) was transmitted to Earth were tiny grains (about 10 nm in radius), most of them originating from Jupiter's innermost Galilean moon Io. They were detected throughout the jovian system and the impact rates frequently exceeded 10 min −1. Surprisingly large impact rates up to 100 min −1 occurred in August/September 2000 when Galileo was far away (≈ 280 R J) from Jupiter, implying dust ejection rates in excess of 100 kg s −1. This peak in dust emission appears to coincide with strong changes in the release of neutral gas from the Io torus. Strong variability in the Io dust flux was measured on timescales of days to weeks, indicating large variations in the dust release from Io or the Io torus or both on such short timescales. Galileo has detected a large number of bigger micron-sized particles mostly in the region between the Galilean moons. A surprisingly large number of such bigger grains was measured in March 2003 within a 4-day interval when Galileo was outside Jupiter's magnetosphere at approximately 350 R J jovicentric distance. Two passages of Jupiter's gossamer rings in 2002 and 2003 provided the first actual comparison of in-situ dust data from a planetary ring with the results inferred from inverting optical images. Strong electronics degradation of the dust instrument due to the harsh radiation environment of Jupiter led to increased calibration uncertainties of the dust data.
Annales Geophysicae Discussions
The electric and magnetic field instrument suite FIELDS on board the NASA Parker Solar Probe and ... more The electric and magnetic field instrument suite FIELDS on board the NASA Parker Solar Probe and the radio and plasma waves instrument RPWS on the ESA Solar Orbiter mission that explore the inner heliosphere are sensitive to signals generated by dust impacts. Dust impacts were observed using electric field antennas on spacecraft since the 1980s and the method was recently used with a number of space missions to derive dust fluxes. Here, we consider the details of dust impacts, subsequent development of the impact generated plasma and how it produces the measured signals. We describe empirical approaches to characterise the signals and compare to a qualitative discussion of laboratory simulations to predict signal shapes for spacecraft measurements in the inner solar system. While the amount of charge production from a dust impact will be higher near the sun than observed in the interplanetary medium before, the amplitude of pulses will be lower because of the different recovery behaviour that varies with the plasma environment. The photocurrent, that is expected to be higher near the Sun, is found to have moderate influence on the spacecraft potential. 1 Introduction The space missions Parker Solar Probe and Solar Orbiter explore the inner heliosphere and close vicinity of the Sun and carry antennas experiments that respond to dust impacts onto the spacecraft. Parker Solar Probe (Parker Probe) is a NASA mission that was launched in August 2018 and will explore the vicinity of the Sun at closest distance ~ 10 solar radii near the solar equator. The mission payload includes the electric and magnetic fields instrument suite FIELDS (Bale et al. 2016). Solar Orbiter is an ESA mission with a launch planned in 2020. It
The solar F-corona : calculations of the optical and infrared brightness of circumsolar dust
The brightness of the solar F-corona along the ecliptic is calculated in the visual and near-infr... more The brightness of the solar F-corona along the ecliptic is calculated in the visual and near-infrared spectral range and the results are discussed with respect to future observations. It is shown that dust particles close to the Sun have a strong influence on the corona brightness, which enables their investigation by remote sensing experiments. Comparison of model calculations with the observations indicates that the zodiacal dust cloud remains mainly undisturbed up to the beginning of a dust-free zone that amounts to about 5 solar radii (R ⊙ ). Calculations of visual brightness and polarization indicate a change of particle properties for a solar distance smaller than 20R ⊙ , which has to be proven by future experiments
Atmospheric Chemistry and Physics, 2021
Abstract. We present a detailed investigation of the formation of an additional sodium density pe... more Abstract. We present a detailed investigation of the formation of an additional sodium density peak at altitudes of 79–85 km below the main peak of the sodium layer based on sodium lidar and airglow imager measurements made at Ramfjordmoen near Tromso, Norway, on the night of 19 December 2014. The airglow imager observations of OH emissions revealed four passing frontal systems that resembled mesospheric bores, which typically occur in ducting regions of the upper mesosphere. For about 1.5 h, the lower-altitude sodium peak had densities similar to that of the main peak of the layer around 90 km. The lower-altitude sodium peak weakened and disappeared soon after the fourth front had passed. The fourth front had weakened in intensity by the time it approached the region of lidar beams and disappeared soon afterwards. The column-integrated sodium densities increased gradually during the formation of the lower-altitude sodium peak. Temperatures measured with the lidar indicate that ther...
Remote sensing of a comet at millimeter and submillimeter wavelengths from an orbiting spacecraft
Planetary and Space Science, 2007
... The submillimeter-wave subharmonic mixer utilizes integrated planar GaAs Schottky diodes in a... more ... The submillimeter-wave subharmonic mixer utilizes integrated planar GaAs Schottky diodes in a waveguide mount. Its local oscillator is a Gunn diode oscillator followed by a doubler with a planar diode varactor (Oswald et al., 1998). ...
Radiation pressure on porous micrometeoroids
Meteroids
Title: Radiation pressure on porous micrometeoroids. Authors: Kimura, H.; Mann, I. Publication: M... more Title: Radiation pressure on porous micrometeoroids. Authors: Kimura, H.; Mann, I. Publication: Meteroids 1998, editors: WJ Baggaley and V. Porubcan. ...
Analysis of Doppler shifts in the zodiacal light
Astronomy and Astrophysics, 1993
We present the theoretical Doppler shifts of the scattered solar light due to the interplanetary ... more We present the theoretical Doppler shifts of the scattered solar light due to the interplanetary dust particles moving in elliptical orbits, taking into account both Doppler components δλ 1 due to the instantaneous rate of change of the light path between the Sun and the particle and δλ 2 between the particle and the Earth. It is found that our simple model for maximum shifts along the line of sight (LOS) leads to a favorable Doppler shifts-dependence on an elongation angle to explain the previous measurements (e.g. Fried 1978). An introduction of the δλ 1 component along with a decrease of the ratio of radiation pressure force to gravity on the particle with decreasing solar distance plays an important role in fitting the theoretical Doppler shifts to the measurements
In a recent paper, Treumann and Baumjohann (2011) propose that the contribution of dust particles... more In a recent paper, Treumann and Baumjohann (2011) propose that the contribution of dust particles to the solar wind dynamic pressure can cause large compressions of the Earth's magnetopause and suggest that this occurs when Earth encounters meteoroid streams. In this paper we estimate the contribution from charged dust particles to the solar wind dynamical pressure, and we exclude that the dust associated to meteoroid streams can influence the extension of the magnetopause according to the proposed model. A sufficient coupling to the solar wind is only expected for so-called nanodust. However, the dynamic pressure of the nanodust is orders of magnitudes below that of the solar wind, making it unlikely that its variation can be observed in displacements of the magnetopause. We also discuss the equation that the authors use for estimating the extension of the Earth's magnetopause, and conclude that this is not applicable due to the large gyroradius of the nanodust. We finally note that an influence of dust on the extension of a magnetosphere might be quite possible in other astrophysical systems and based on other processes.
Proceedings of the International Astronomical Union, 2015
After a little more than forty years of work related to the interplanetary plasma and the heliosp... more After a little more than forty years of work related to the interplanetary plasma and the heliosphere the IAU's Commission 49 was formally discontinued in 2015. The commission started its work when the first spacecraft were launched to measure the solar wind in–situ away from Earth orbit, both inward and outward from 1 AU. It now hands over its activities to a new commission during an era of space research when Voyager 1 measures in–situ the parameters of the local interstellar medium at the edge of the heliosphere. The commission will be succeeded by C.E3 with a similar area of responsibility but with more focused specific tasks that the community intends to address during the coming several years. This report includes a short description of the motivation for this commission and of the historical context. It then describes work from 2012 to 2015 during the present solar cycle 24 that has been the weakest in the space era so far. It gave rise to a large number of studies on sol...
Fractal aggregate analogues for near solar dust properties
ABSTRACT
Radiation pressure on dust aggregates in circumstellar disks
Physics and Chemistry of the Earth, Part C: Solar, Terrestrial & Planetary Science, 1999
... Radiation pressure on dust aggregates in circumstellar disks. H. Kimura a , Corresponding Aut... more ... Radiation pressure on dust aggregates in circumstellar disks. H. Kimura a , Corresponding Author Contact Information and I. Mann a. ...
Analysis of Doppler shifts in the zodiacal light
Astronomy and Astrophysics, 1993
We present the theoretical Doppler shifts of the scattered solar light due to the interplanetary ... more We present the theoretical Doppler shifts of the scattered solar light due to the interplanetary dust particles moving in elliptical orbits, taking into account both Doppler components δλ 1 due to the instantaneous rate of change of the light path between the Sun and the particle and δλ 2 between the particle and the Earth. It is found that our simple model for maximum shifts along the line of sight (LOS) leads to a favorable Doppler shifts-dependence on an elongation angle to explain the previous measurements (e.g. Fried 1978). An introduction of the δλ 1 component along with a decrease of the ratio of radiation pressure force to gravity on the particle with decreasing solar distance plays an important role in fitting the theoretical Doppler shifts to the measurements
Fractal aggregate analogues for near solar dust properties
ABSTRACT
Radiation pressure on dust aggregates in circumstellar disks
Physics and Chemistry of the Earth, Part C: Solar, Terrestrial & Planetary Science, 1999
... Radiation pressure on dust aggregates in circumstellar disks. H. Kimura a , Corresponding Aut... more ... Radiation pressure on dust aggregates in circumstellar disks. H. Kimura a , Corresponding Author Contact Information and I. Mann a. ...
Journal of Quantitative Spectroscopy and Radiative Transfer, 1998
We apply the discrete dipole approximation (DDA) to estimate the radiation pressure cross section... more We apply the discrete dipole approximation (DDA) to estimate the radiation pressure cross section for fluffy aggregates by computing the asymmetry parameter and the cross sections for extinction and scattering. The ballistic particle-cluster aggregate and the ballistic cluster-cluster aggregate consisting of either dielectric or absorbing material are considered to represent naturally existing aggregates. We show that the asymmetry parameter perpendicular to the direction of wave propagation is maximized where the wavelength is comparable to the aggregate size, which may be characterized by the area-equivalent radius or the radius of gyration rather than the volume-equivalent radius. The asymmetry parameter for the aggregate depends on the morphology of the particle, but not on the constituent material. Therefore, the dependence of the radiation pressure cross section on the material composition arises mainly from that of the extinction and scattering cross sections, in other words, the single-scattering albedo. We find that aggregates consisting of high-albedo material show a large deviation of radiation pressure from the direction of incident radiation. When the aggregates are illuminated by blackbody radiation, the deviation of the radiation pressure increases with increasing temperature of the blackbody. Since the parallel component of the radiation pressure cross section for the aggregates is smaller than that for the volume-equivalent spheres at the size parameter close to unity, the Planck-mean radiation pressure cross section for the aggregates having radius comparable to the effective wavelength of radiation shows a lower value, compared with the volume-equivalent sphere. Consequently, the slope of the radiation pressure force per mass of the particle as a function of particle mass shows a lower maximum for the aggregates than for compact spherical particles.
Astronomy & Astrophysics, 2004
Solar-wind particles striking dust grains in orbit around the sun exert not only a repulsive forc... more Solar-wind particles striking dust grains in orbit around the sun exert not only a repulsive force on the grains, but also a drag force, called the plasma or pseudo Poynting-Robertson (PR) effect, which limits their dynamical lifetimes. To better understand the dynamical evolution of interplanetary dust, we study the momentum transfer from the solar wind to interplanetary dust taking into account the passage of impinging particles through the grains. The pseudo PR drag is one of the most important perturbations for the dynamics of interplanetary dust of any sizes. However, previous studies underestimated the lifetimes of small grains by overestimating the acting solar-wind forces. Our study also provides the velocity distribution of neutralized solar-wind particles after passage through a grain along with some implications for the generation of pickup ions by solar-wind interaction with dust grains.
Advances in Space Research, 2007
We study the radiation pressure on cometary dust over a wide size range in order to discuss the p... more We study the radiation pressure on cometary dust over a wide size range in order to discuss the properties of particles in cometary dust trails and meteor streams. Our model calculations utilize aggregates consisting of spherical monomers of 0.1 lm in radius as an analogue of cometary dust. We then estimate the radiation pressure on aggregates over a wide size range in order to discuss the properties of particles in cometary dust trails and meteor streams. We find that the influence of the radiation pressure force is stronger on large aggregates than on spherical particles of the same mass. Our study shows that aggregates on bound orbits in the solar system must have a fractal dimension close to three and that dust particles in observed cometary trails and meteor streams are more massive than previously estimated with spherical particles.
The Galileo spacecraft was the first man-made satellite of Jupiter, orbiting the planet between D... more The Galileo spacecraft was the first man-made satellite of Jupiter, orbiting the planet between December 1995 and September 2003. The spacecraft was equipped with a highly sensitive dust detector that monitored the jovian dust environment between approximately 2 and 370 R J (jovian radius R J = 71492 km). The Galileo dust detector was a twin of the one flying on board the Ulysses spacecraft. This is the tenth in a series of papers dedicated to presenting Galileo and Ulysses dust data. Here we present data from the Galileo dust instrument for the period January 2000 to September 2003 until Galileo was destroyed in a planned impact with Jupiter. The previous Galileo dust data set contains data of 2883 particles detected during Galileo's interplanetary cruise and 12978 particles detected in the jovian system between 1996 and 1999. In this paper we report on the data of additional 5389 particles measured between 2000 and the end of the mission in 2003. The majority of the 21250 particles for which the full set of measured impact parameters (impact time, impact direction, charge rise times, charge amplitudes, etc.) was transmitted to Earth were tiny grains (about 10 nm in radius), most of them originating from Jupiter's innermost Galilean moon Io. They were detected throughout the jovian system and the impact rates frequently exceeded 10 min −1. Surprisingly large impact rates up to 100 min −1 occurred in August/September 2000 when Galileo was far away (≈ 280 R J) from Jupiter, implying dust ejection rates in excess of 100 kg s −1. This peak in dust emission appears to coincide with strong changes in the release of neutral gas from the Io torus. Strong variability in the Io dust flux was measured on timescales of days to weeks, indicating large variations in the dust release from Io or the Io torus or both on such short timescales. Galileo has detected a large number of bigger micron-sized particles mostly in the region between the Galilean moons. A surprisingly large number of such bigger grains was measured in March 2003 within a 4-day interval when Galileo was outside Jupiter's magnetosphere at approximately 350 R J jovicentric distance. Two passages of Jupiter's gossamer rings in 2002 and 2003 provided the first actual comparison of in-situ dust data from a planetary ring with the results inferred from inverting optical images. Strong electronics degradation of the dust instrument due to the harsh radiation environment of Jupiter led to increased calibration uncertainties of the dust data.
Annales Geophysicae Discussions
The electric and magnetic field instrument suite FIELDS on board the NASA Parker Solar Probe and ... more The electric and magnetic field instrument suite FIELDS on board the NASA Parker Solar Probe and the radio and plasma waves instrument RPWS on the ESA Solar Orbiter mission that explore the inner heliosphere are sensitive to signals generated by dust impacts. Dust impacts were observed using electric field antennas on spacecraft since the 1980s and the method was recently used with a number of space missions to derive dust fluxes. Here, we consider the details of dust impacts, subsequent development of the impact generated plasma and how it produces the measured signals. We describe empirical approaches to characterise the signals and compare to a qualitative discussion of laboratory simulations to predict signal shapes for spacecraft measurements in the inner solar system. While the amount of charge production from a dust impact will be higher near the sun than observed in the interplanetary medium before, the amplitude of pulses will be lower because of the different recovery behaviour that varies with the plasma environment. The photocurrent, that is expected to be higher near the Sun, is found to have moderate influence on the spacecraft potential. 1 Introduction The space missions Parker Solar Probe and Solar Orbiter explore the inner heliosphere and close vicinity of the Sun and carry antennas experiments that respond to dust impacts onto the spacecraft. Parker Solar Probe (Parker Probe) is a NASA mission that was launched in August 2018 and will explore the vicinity of the Sun at closest distance ~ 10 solar radii near the solar equator. The mission payload includes the electric and magnetic fields instrument suite FIELDS (Bale et al. 2016). Solar Orbiter is an ESA mission with a launch planned in 2020. It