Session - Planetary Space Weather
Christina Plainaki, Iannis Dandouras, Maria Andriopoulou
The session welcomes papers on all aspects of the conditions in the Sun, solar wind and magnetospheric plasmas, at different
planetary systems of our Solar System, that can influence the performance and reliability of space-borne technological systems.
Focus will be given in cross-disciplinary issues, including: - the interaction of solar wind/magnetospheric plasmas with
planetary/satellite ionospheres and thick (e.g. at Jupiter, Saturn, Uranus, Mars, Venus, Titan) or tenuous (e.g. Ganymede,
Europa, Mercury, our Moon) atmospheres, including the generation of auroras - the satellite interactions with their
neutral environments and dust - the variability of the magnetospheric regions under different solar wind conditions -
the inter-comparisons of space weather conditions in different planetary environments Contributions addressing previous
(e.g. CHANDRAYAAN-1, KAGUYA), present (e.g. CASSINI, MARS EXPRESS, VENUS EXPRESS, ROSETTA, MAVEN, MESSENGER, VAN ALLEN PROBES)
and forthcoming (e.g. BEPI COLOMBO, JUICE, MMS) in situ observations are welcome. Abstracts on theoretical modeling and simulations
of planetary space weather conditions, possibly destined for end-users of space weather services, are extremely welcome.
Inter-comparisons and interpretation of measurements at different planetary systems and quantification of the possible effect
of the environment interactions on components and systems (e.g. radiation doze studies) are strongly encouraged.
Talks and First Class Posters
Thursday November 20, 09:00-13:00, auditorium Roger
Poster Viewing
Thursday November 20, 10:30-11:30, area in front of auditorium Roger
Talks and First Class Posters
Oral - invited |
9:00 am |
Energetic Particle Populations
and their Contribution to the Solar System Landscape |
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Crosby, N B |
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Belgian Institute for Space
Aeronomy |
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With interplanetary missions
orbiting or en route to selected targets in the Solar System (planets, moons
and asteroids), the effects of the space environment in the context of space
weather services are not anymore confined to near-Earth space. It is the
behaviour of the Sun that contributes primarily to defining the changing
space environment in the Solar System. However, predicting the target's local
space weather requires detailed knowledge of the target's characteristics,
for example, distance from the Sun, interplanetary magnetic field conditions,
is there a magnetosphere and/or atmosphere? Different types of energetic
particle populations characterize the Solar System landscape and are one of
the major concerns for potential future human interplanetary travel. They
provide challenges for scientists that work on the prediction of these
phenomena, as well as for engineers who design mitigation strategies for
spacecraft. The implications of these particle radiation environments on
interplanetary travel will be discussed in regard to their effects on
technology and humans, as well as current and envisioned mitigation
techniques. |
1 |
Invited poster |
9:20 AM |
Space weather at Uranus |
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Prangé, R1; Lamy, L1 |
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1LESIA,
Observatoire de Paris |
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Similarly to the Earth,
planetary magnetospheres of the solar system are sensitive to the solar wind
activity, which can be diagnosed by auroral emissions. This study is based on
multi-planet multi-wavelength observations of planetary aurorae throughout the
heliosphere, acquired along the propagation path of a series of consecutive
interplanetary shocks. The underlying motivation to track the shocks was to
increase the probability of detection of auroral emissions at Uranus. Despite
several Earth-based attempts in the past few years, at Far-UV (FUV) and
Near-IR (NIR) wavelengths, such emissions have never been unambiguously
re-observed since their discovery by Voyager 2 in 1986. Here, we present a
campaign of FUV observations of Uranus obtained in November 2011 with the
Hubble Space Telescope (HST) during active solar wind conditions. We
positively identify auroral signatures in several of these HST measurements,
together with some obtained in 1998, representing the first images of Uranus’
aurorae. We analyze their characteristics and discuss the implications for
the asymmetric Uranian magnetosphere and its highly variable interaction with
the solar wind flow from near-solstice (1986) to near-equinox (2011)
configurations. |
2 |
Invited poster |
9:25 AM |
Saturn’s Energetic Charged
Particle Radiation Environment: a Space Weather Perspective |
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Roussos, E1; Krupp , N1; Paranicas , C2; Mitchell , D G2; Krimigis , S M3 |
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1Max
Planck Institute for Solar System Research; 2Applied Physics Laboratory; 3Academy of Athens |
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Since the arrival of Cassini at
Saturn in July 2004, the energetic charged particle environment of the planet
has been continuously monitored by Cassini's MIMI/LEMMS instrument, a
double-headed particle telescope capable of detecting electrons between 20
keV and 10 MeV and ions between 20 keV and several hundred MeV (depending on
the species). A large number of statistical or single case studies
highlighted many space-weather related aspects of the environment, such as
average flux maps of electron and ion fluxes, variability time scales and
transient radiation belts. Overall, the harshest radiation environment at
Saturn is similar to the one that a spacecraft may typically encounter around
Ganymede’s orbit at Jupiter and is also less harsh than that of the Earth,
primarily due to the presence of numerous loss regions (moons, rings, neutral
cloud) and the alignment of the planetary magnetic and rotational equators.
The permanent MeV ion belts are relatively stable in intensity over both
short and long time scales, they reside only within the L-shell of Saturn's
moon Tethys (L=4.89) and comprise different sectors, each separated from the
other by an ion depleted region that is centered on an L-shell of one of the
planet's inner icy moons. Fluxes within these belts result from Galactic
Cosmic Ray secondaries and therefore vary weakly with the solar cycle.
Transient extensions of the ion belts beyond the orbit of Tethys may last
several months and occur only after the interaction of Saturn's magnetosphere
with an interplanetary, energetic solar wind event. These transient
extensions have no impact on the structure of the inner belts. The electron
radiation belts form a continuous structure with highly variable extension
and intensity from orbit to orbit. This variability appears to be controlled
by various factors, such as the arrival of corotating interaction regions at
Saturn, the EUV input to the Saturnian system and internal magnetospheric
dynamics making the modelling of these belts and the prediction of their
state a very challenging task. Besides that, considerable fluxes of mildly
relativistic electrons (few hundred keV to several MeV) are found in a broad
local time range beyond Titan’s orbit, suggesting that at least for
electrons, critical environments are not only restricted within the radiation
belts. This poster will summarize all aforementioned findings, together with
open questions, the limitations and the challenges of using LEMMS data for
space weather studies. |
3 |
Invited poster |
9:30 AM |
Space weather at Saturn
(invited) |
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Radioti, A1; Grodent, D1; Gérard, J-C1; Bonfond, B1 |
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1LPAP,
Université de Liège |
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Unlike to Earth, Saturn is a
fast rotator and its magnetosphere is dominated by fast planetary rotation
and internally driven processes. However, the interaction of the solar wind
with Saturn’s magnetosphere is not negligible and it is manifested among others
in the auroral region. The interplanetary magnetic field reconnects with the
dayside magnetopause at Saturn and results in enhancements in the auroral
emission accompanied by entry of significant amount of open flux in the
magnetosphere. The solar wind affects also the nightside magnetosphere.
Dramatic enhancements of the nightside-dawn auroral emissions have been
attributed to solar wind-induced auroral storms. Additionally, recent auroral
observations revealed the presence of a transpolar arc at Saturn, one of the
most spectacular auroral features at Earth, which could be possibly related
to solar wind driven tail reconnection. Finally, there is evidence of viscous
interaction of the solar wind with Saturn’s magnetosphere, which involves
magnetic reconnection on a small scale. |
4 |
Invited poster |
9:35 AM |
Space Weather Phenomena at the
Galilean Satellites |
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Cessateur, G1; Barthelemy, M2; Peinke, I2 |
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1PMOD/WRC;
2IPAG |
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In the framework of the JUICE
mission, characterization of Galilean satellites atmospheres is a priority.
Although Ganymede and Europa possess a faint atmosphere, their exosphere show
emissions features due to both solar UV flux as well as precipitating particles.
Using the atmospheric model proposed by Marconi (2006,2007), we have
developed a model of exospheric emissions by only considering primary
collisions. Two regions will be considered for Ganymede, a polar one mainly
dominated by oxygen, and an equatorial one with the predominance of water.
Model of Europa's atmosphere presents an uniform one dominated by oxygen.
Since Ganymede has its own magnetic field, the polar regions are mainly
affected by particle precipitations while in case of Europe, the whole
atmosphere has to be considered.
Comparison with direct observations such as local measurements from
Galileo (electronic density), or remote observations with the Hubble Space
Telescope in the UV (oxygen lines at 130.5 and 135.5 nm), shows a good
agreement which ensures us to provide reasonable constraints for the JUICE
mission. |
5 |
Invited poster |
9:40 AM |
Exoplanetary Exosphere Tails |
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Mura, A1; Di Mauro, Maria Pia1; Mangano, Valeria1; Plainaki, Chrstina1 |
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1INAF |
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We investigate the interaction
of stellar wind plasma with the exosphere and possibly with the planetary
magnetospheric environment of close-in exoplanets. Based on the present
knowledge of such planets and drawing on the analogy to solar system planets,
we use numerical models to simulate exospheric and magnetospheric
distributions of different particle populations, among which are neutral
sodium and ionised calcium and magnesium. We find that, for most species, the
atmospheric loss rate in such an extreme environment can be very high, so
that a neutral and an ionised tail of escaping particles will form. Depending
on the planetary composition we postulate the presence of a Mercury- like
tail, and of an extended magnetospheric distribution of ions. A parameter
study is also performed, tuning basic planetary quantities such as radius,
mass, temperature and distance. In this way, we calculate exospheric
quantities for a larger ensemble of possible exoplanets. |
6 |
Invited poster |
9:45 AM |
(Invited) Cosmic Ray
Interactions with the Venusian Atmosphere |
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Nordheim, T1; Dartnell, L2; Coates, A1; Jones, G1 |
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1University
College London; 2Space Research Centre, University of Leicester |
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The atmospheres of the
terrestrial planets are constantly exposed to solar and galactic cosmic rays,
the most energetic of which are capable of affecting deep atmospheric layers
through nuclear and electromagnetic particle cascades. The energy deposited by
these interactions is thought to be an important driver for atmospheric
chemistry and may possibly affect cloud microphysics, and in regions beneath
the penetration of ultraviolet radiation, cosmic rays are the primary
ionization agent. It is therefore crucial to quantify the amount of energy
deposited by cosmic rays in the atmosphere by altitude, as this is required
to estimate ionization and conductivity profiles. Detailed studies have considered the
propagation of cosmic rays in the atmospheres of Earth, Mars, Titan and the
Giant Planets. However, to date, only a few studies [1] [2] have considered
such interactions in the Venusian atmosphere, notably using Boltzmann
transport approximations. Using the capabilities of the Geant4 [3] particle
physics framework and Planetocosmics [4], we have carried out full Monte
Carlo modelling of the discrete interactions between atmospheric neutrals and
cosmic ray primary and secondary
particles. The primary cosmic ray
spectrum has been derived from the
CRÈME-2009 [5] engineering model at 1 AU
with scaling of the primary
fluxes to the Venusian orbit. Based on
this input spectrum we have simulated atmospheric energy deposition by cosmic
rays at solar minimum and maximum conditions as well as during solar
energetic particle events and computed cosmic ray ionization profiles between
0-100 km in the Venusian atmosphere. In future work we plan to apply these
results to investigations of electrical processes and radiation hazard in the
Venusian atmosphere. References [1]
Dubach, J., Whitten, R. and Sims, J.: The lower ionosphere of Venus,
Planetary and Space Science, Vol. 22, pp. 535-536, 1974. [2] Boroucki, W. J.,
Levin, Z., Whitten, R. C., Keesee, R.G., Capone, L. A., Toon, O. B. and
Dubach, J.: Predicted Electrical Conductivity between 0 and 80 km in the
Venusian Atmosphere, Icarus, Vol. 51, pp. 302-321, 1982. [3] Agostinelli, S.
J., et al.: GEANT4 – a simulation toolkit, Nucl. Instrum. Meth. Phys. Res. A,
Vol. 506, pp. 250-303, 2003. [4]
http://cosray.unibe.ch/~laurent/planetocosmics/ [5]
http://creme.isde.vanderbilt.edu/ |
7 |
Invited poster |
9:50 AM |
Solar Energetic Particles in the
Mercury Environment (Invited) |
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Laurenza, M |
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IAPS/INAF |
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Solar energetic particles (SEPs)
can enter and propagate in the Mercury environment, their penetration
depending mainly on the particle energy and the planetary magnetosphere
shape. A significant flux of energetic particles can reach and impact the
Mercury surface, produce secondary particles, X-ray fluorescence, and
possibly changes of Mercury’s exosphere (e.g., Leblanc et al., 2003, Plan.
Space Sci., 51, 339). The SEP interaction with Mercury’s environment is
studied through simulations of particle propagation in the Hermean magnetic
field, assuming a Toffoletto-Hill modified model (Massetti et al., 2007,
Space Sci., 55, 1557) and SEP energy spectra typical for Mercury location
(0.31 – 0.47 AU). In particular, cutoff rigidities, quantifying the shielding
effect of the Hermean magnetosphere, are computed for geometries of the Mercury’s
magnetosphere obtained as response to different solar wind conditions
(interplanetary magnetic field intensity and dynamic pressure). Moreover,
fluxes and tracks of primary and secondary particles are obtained at
different selected altitudes. Results allow to estimate the SEP effects and
their transmission through the Hermean magnetosphere, which represent key
aspects in Planetary Space Weather. |
Oral |
11:30 am |
Comparative Earth, Jupiter and
Saturn's Radiation Belts |
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Sicard-Piet, A1; Bourdarie, S1 |
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1ONERA |
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Since the 1990s ONERA/DESP has
worked on a physical model of the radiation belts, called Salammbô-3D. First
developed in the case of the Earth, it was later adapted to the giant
planets, Jupiter and Saturn. Salammbô model includes the main physical processes
that govern the particles of the radiation belts and are based on solving the
Fokker Planck equation. These models have been successfully compared to
measurements and, for the Jovian case, to radioastronomy images. From lessons
learned from these modelling activities we plan here to review the main
characteristics of radiation belts in the vicinity of magnetised body
illustrated with Earth, Jupiter and Saturn environment. We will show how the
same fundamental physical processes (radial diffusion, interactions with
exosphere and ionosphere-plasmasphere) lead to similarities between the three
sets of belts. Nevertheless we will emphasize the specificity of each planet.
In the Earth case, the lower magnetic field intensity leads to strong
dynamics while in the Jupiter and Saturn cases, there is a strong influence
of dust particles and moons. |
Oral |
11:50 am |
Space Environment Effects inside
a Comet Coma: ROSINA/DFMS Measurements onboard Rosetta |
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De Keyser, J1; Dhooghe , F1; Maggiolo, R1; Gunell, H1; Altwegg, K2; Calmonte, U2; Fuselier, S3; Hässig , M3; Berthelier, J -J4; Mall, U5; Gombosi, T6; Fiethe, B7 |
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1Belgian
Institute for Space Aeronomy; 2Physikalisches Institut, University of Bern; 3Southwest Research
Institute; 3Southwest
Research Institute; 4LATMOS/IPSL, Université Versailles Saint-Quentin; 5Max-Planck-Institut für
Sonnensystemforschung; 6University of Michigan; 7Institute of Computer and Network Engineering, TU Braunschweig |
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As a comet approaches the Sun,
it develops a cometary coma. A fully developed comet coma is a diamagnetic
cavity from which the interplanetary magnetic field is excluded. The
environment inside the coma is determined by three factors. First, solar
illumination of the nucleus is responsible for the sublimation of the
volatile material on the nucleus surface. Since the resulting gas is not
gravitationally bound, it escapes and engulfs the spacecraft in the vicinity
of the nucleus. Second, solar ultraviolet radiation initiates photo-chemical
reactions in this gas. Further reactions produce a whole range of neutral and
ionized species that reach the spacecraft. Finally, as volatiles on the
nucleus sublimate, ice and dust grains are released and dragged along with
the flow. ESA’s Rosetta spacecraft is examining the environment of comet
67P/Churyumov-Gerasimenko. The ROSINA instrument package is one of the eleven
instruments onboard Rosetta, and ROSINA performs in-situ coma measurements
using a pressure sensor COPS and the two complementary mass spectrometers
RTOF and DFMS. The double focusing mass spectrometer DFMS has a high mass
resolution and sensitivity and was designed for coma studies. This
contribution discusses DFMS measurements and model simulations of the coma
environment. The roles of the neutral gas composition, the ionized fraction,
and the dust component, and some of their effects on the spacecraft will be
addressed. |
Oral - invited |
12:05 pm |
Solar Variability Effects on the
Martian Atmosphere (invited) |
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González-Galindo, F1; Lopez-Valverde, M A1; Forget, F2; Chaufray, J-Y3; Millour, E2 |
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1Instituto
de Astrofísica de Andalucía, CSIC; 2Laboratoire de Météorologie Dynamique, CNRS; 3LATMOS, CNRS |
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Recent studies (Valeille et al.,
2009; Yagi et al., 2012) show a strong influence of the temperatures and
densities in the upper atmosphere of Mars over the exospheric densities and
the rate of atmospheric escape from the planet. A good understanding of the
long-term evolution of the Martian atmosphere requires thus to identify the
different sources of variability of the upper atmosphere. Different
observations (Forbes et al., 2006, 2008; Nielsen et al. 2006) probe that the
Mars' thermosphere/ionosphere system is affected by the variability of the UV
solar flux, in the medium-long term (11-year solar cycle) and in shorter
timescales (solar rotation, solar flares). However, Global Climate Models
(GCMs) used to simulate the Martian upper atmosphere often use strongly
simplified schemes for the 11-year solar cycle (usually just three solar
scenarios, corresponding to solar minimum, solar average and solar maximum
conditions), and they usually neglect the short-term solar variability,
keeping the solar flux constant during the simulated time. We will present the new scheme incorporated
into the Mars GCM developed at the Laboratoire de Météorologie Dynamique
(LMD-MGCM) in order to take into account the observed day-to-day variability
of the UV solar flux. The LMD-MGCM (Forget et al., 1999, González-Galindo et
al. 2009, 2013) is the only ground-to-exosphere Martian GCM, so it includes
in a natural way the coupling with the lower atmosphere, known to have a
strong impact on the upper atmosphere (e.g. Withers and Pratt, 2013). Using
this improved version of the LMD-MGCM, we have simulated the variability of
the Martian upper atmosphere during 8 Martian Years (MY24 to MY31),
corresponding to about 15 terrestrial years (that is, covering more than one
solar cycle). An analysis of the results of these simulations show important
effects of the 11 year solar cycle. The inter-annual variability of the
temperatures in the upper thermosphere ranges from about 50 K during the
aphelion season to up to 150 K during perihelion. The seasonal variability of
the temperatures within a given Martian year due to the eccentricity of the
Martian orbit is significantly modified by the variability of the solar flux
within the year. The solar rotation is also clearly felt in the thermosphere,
with temperature variations of up to 30 K. Also the composition of the upper
atmosphere is modified by the solar variability. In particular the simulated electron
densities present a significant solar cycle variability, and they also
respond to the solar rotation, in agreement with observations (Nielsen et
al., 2006). References: -Forbes et
al., Science, 312, 1366-1368 (2006) -Forbes et al., Geophys. Res. Lett., 35,
L01201 (2008) -Forget et al., J. Geophys. Res. 104, 24155-24175 (1999)
-González-Galindo et al., J. Geophys. Res., 114, pp. 4001+ (2009)
-González-Galindo et al., J. Geophys. Res., 118, pp. 2105-2123 (2013) -Nielsen
et al., Space Sci. Rev., 126, 373-388, (2006) -Valeille et al., J. Geophys.
Res. 114, pp. 11005+ (2009) -Withers and Pratt, Icarus, 225, 378-389 (2013)
-Yagi et al., Icarus 221, pp. 682-693 (2012)
Acknowledgemnt: Francisco González-Galindo is funded by a CSIC JAE-Doc
contract financed by the European Social Fund |
Oral |
12:25 pm |
SEP, GCR, and Energetic Ion
Precipitation in the Martian Atmosphere and their Impact on Human Exploration |
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Gronoff, G1; Norman, R2; Simon Wedlund, C3; Mertens, C2 |
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1SSAI/NASA
LaRC; 2NASA
LaRC; 3Aalto
University |
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Proton and more generally ion
precipitation has an impact in the energy balance of planetary upper
atmospheres. The accurate computation of the ionization and excitation is
difficult, a difficulty stemming from charge-exchange reactions and
neutralisations altering the nature of the initial beam between ion and an
energetic neutral atom. Both ion and ENA are capable of ionizing and exciting
the ambient neutral species, while the secondary electron created by the
first ionization is capable of ionizing the neutral medium in return. In
addition, for protons of higher energy (as in Solar Energetic Particle (SEP)
events, or for the Galactic Cosmic Rays (GCR)), relativistic effects must be
taken into account. The effect of heavier ion precipitating in the Martian
atmosphere, such as High-Z GCR, has to be studies in more details since
secondary particles responsible to high biological radiation damages like
neutron can be created very efficiently.
In this work, the transport of H+/H in the upper atmosphere of Mars is
presented in the form of a coupled system of equations that can be solved
analytically. Ionization due to proton and heavy ion precipitation from GCR
or SEP events are investigated by the Aeroplanet/Planetocosmics and
NAIRAS/HZETRN models. These results are analyzed in the frame of the human
exploration of the Martian surface. |
Oral - invited |
12:40 pm |
Plasma-surface interactions at
Mercury and their implications to space weather |
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Milillo, A1; Orsini, S1; Mura, A1; Mangano , V1; Massetti, S1; De Angelis, E1; Plainaki, C1 |
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1INAF/IAPS |
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The proximity of Mercury to the
Sun makes this planet a particularly interesting subject for extreme
environmental conditions. Mercury’s plasma environment is driven by a weak
internal global magnetic field that supports a small magnetosphere. The
plasma coexists with the planet’s exosphere and strongly interacts with the
surface. In fact, Mercury’s environment is a complex and highly coupled
system where solar wind, magnetosphere, exosphere and surface are linked by
interaction processes producing material and energy exchange. In particular,
different mechanisms compete in the Hermean environment for the exosphere
generation and erosion, depending by external conditions (the Sun distance
and activity, interplanetary dust distribution, etc…) and by planet surface
characteristics (surface illumination and composition, etc…), so that a kind
of space weather as in the Earth’s case can be depicted. Observations of exosphere and plasma
environment of Mercury are paradigm of the environments of planets close to
its parent star, providing important clues in planetary evolution. Recently, big efforts in ground-based
observations provided interesting results, but they are limited to just a few
exospheric species, mostly Na. The NASA MESSENGER mission (launched in March
2004) is providing observations on the exospheric distribution of already
observed species, like Na and Ca, as well as new species as Mg. Differences
in spatial distributions for different species suggest different release
mechanisms. Waiting for more detailed observations by the ESA-JAXA
BepiColombo mission, it is of crucial importance to perform accurate and
comprehensive simulations in order to maximize the science return. We present an updated view of the
plasma-surface interactions at Mercury and exosphere generation processes,
trying to identify the key observations needed to get a comprehensive
investigation. |
More posters
8 |
poster |
09:55 |
Statistical Analysis of
Earth-Based Na Exosphere Observations of Mercury Correlated with in-Situ
Magnetic Field Measurements by MESSENGER |
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Mangano, V1; Massetti, S1; Milillo, A1; Orsini, S1; Plainaki, C1; Leblanc, F2 |
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1INAF;
2LATMOS/IPSL |
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The exosphere of Mercury is a
tenuous collisionless cloud of gas surrounding the planet, and it derives
from the many interactions occurring among the exposed surface, the
interplanetary medium (Solar wind, photons and meteoroids) and the planetary
and interplanetary magnetic fields.
The action of solar photons through the process of resonant scattering
(acting on exospheric Na) is particularly efficient at Mercury; for this
reason Na, though not the major species of Mercury’s exosphere, has often
been used as a tracer of the dynamics of the whole exospheric environment. In
particular, its recurrent observation through the years often showed a
peculiar two-peak pattern, with two peaks occurring at mid-latitude regions,
in a position that may be easily related to the magnetic cusp footprints of
Mercury. In fact, due to a weak
intrinsic magnetic field, Mercury’s magnetosphere is strongly coupled with
the Interplanetary Magnetic Field and its wide magnetospheric cusp areas are
expected to allow a direct precipitation of the solar wind plasma on the
dayside high-latitudes. A correlation between IMF orientation and Na emission
features is likely to exist. An Earth-based campaign of observation of the Na
exosphere of Mercury is carried out by a French-Italian team at the THEMIS
telescope in the Canary Islands since 2007. The use of a solar telescope
allowed day-long observations and high resolution imaging. In addition to
this, the magnetometer MAG onboard MESSENGER spacecraft is orbiting around
Mercury since March 2011, and up to 3 years of contemporary data of global
exospheric Na mapping and in-situ measurements of the IMF B-field are now
available. By using THEMIS and MAG data, we performed a simple statistical
analysis to check if the supposed correlation between IMF orientation and
exospheric morphology, evidenced through the Na emission features, exists or
not. |
9 |
poster |
09:57 |
Solar wind Turbulence at 0.72 AU
and the Response of the Venus Magnetosheath |
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Teodorescu, E1; Echim, M2; Munteanu, C3; Zhang, T4; Barabash, S5; Budnik, E6; Fedorov, A6 |
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1Institute
of Space Science; 2Belgian Institute for Space Aeronomy, Bruxelles; Institute of
Space Science, Magurele-Bucharest, Romania; 3Institute of Space Science, Magurele-Bucharest; University of
Bucharest; University of Oulu, Finland; 4Space Research Institute; 5Institute of Space Physics, Kiruna; 6Research Institute in Astrophysics and Planetology, Toulouse |
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Venus Express (VEX) provides a
unique set of measurements in the solar wind at approximately 0.72 AU from
the Sun while orbiting planet Venus. We correlate information provided by two
of VEX instruments, Venus Express Magnetometer (MAG) and Analyser of Space
Plasma and Energetic Atoms (ASPERA) to investigate the turbulent behavior of
the magnetic field fluctuations for both fast or slow solar wind. We also
investigate the turbulent state of the magnetosheath in response to the
upstream turbulence. We analyze MAG-VEX data at 1 Hz resolution collected
between 2007 and 2009, during the minimum phase of the solar cycle.. We
identified 550 time intervals when VEX is in the solar wind out of which 118
correspond to fast solar wind. The
power spectral densities (PSD) are computed for Bx, By, Bz, B, B^{2}, and
parallel and perpendicular components of B. We also calculate the spectral
index through linear fits to the PSD in log-log space and perform a
statistical analysis of the spectral indices. We observe a dependence of the
spectral index with the velocity of the solar wind and a slight difference in
power content between parallel and perpendicular components of the magnetic
field. Preliminary results on a higher order analysis method, computation of
Probability Density Functions (PDF), and implications for intermittent
turbulence are also discussed.
Research supported by the European Community’s Seventh Framework
Programme (FP7/2007-2013) under grant agreement no 313038/STORM, and a grant
of the Romanian Ministry of National Education, CNCS – UEFISCDI, project
number PN-II-ID-PCE-2012-4-0418. |
10 |
poster |
09:59 |
Nitrogen Ion TRacing Observatory
(NITRO): Toward understanding the Earth-Vernus-Mars Difference of N/O Ratio |
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Yamauchi, M1; Dandouras, I2; Reme, H2 |
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1Swedish
Institute of Space Physics; 2Institut de Recherche en Astrophysique et Planetologie (IRAP),
CNRS/Université de Toulouse |
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Nitrogen is a key element for
life as an inevitable part of the amino acid and protein, and its oxidation
state (NH3 or N2 or NOx) in the ancient atmosphere is one of the key factors
that determine the difficulty in forming amino acid without biological processes. In this sense, the history of planetary N/O
ratio of one of the controlling factor for life-environment. While nitrogen is abundant on the Earth
(the amount in the soil, crust, and ocean are small compared to the
atmospheric amount) and on Venus (only 3% but pressure is 90 times of the
Earth, resulting in three times as the Earth), Martian atmosphere has very
little nitrogen, about only 0.01% of the Earth or Venus (with 10% of
planetary mass). This contrasts the
oxygen abundance, which is found in all three planets (Martian case, it is
now believed to exist in the crust as oxidized rocks because the observed
escape rate is equivalent only 10 m deep water). Considering the fact that nitrogen
molecule with triple chemical binding is much more difficult to be
dissociated/ionized than oxygen molecule with double chemical binding,
absence of the nitrogen only on the Mars is a mystery, while this absence
might explain the absence of life at the present knowledge. From these viewpoints, it is important to
understand the dynamic of nitrogen ions at different solar conditions as
compared to oxygen ion dynamics or proton dynamics for whatever the
planet. However, nearly no such
observation exists at low energy less than keV, except very little
observations for thermal nitrogen. One
reason for lack of such measurement is difficulty in separating hot N+ from
hot O+ even with the modern instruments, causing past instruments on board
magnetospheric missions not targeting such separation but rather targeting
higher temporal and spatial resolutions.
With recent improvement of mass-separating ion analyser, it is now
most likely possible to separate O+ and N+ by masking H+ and He++ and by limiting
the angular coverage to minimize the contamination. To realize such measurements, we consider
two options: (1) single spacecraft mission with minimum instrumentation to
detect hot nitrogen ions of missing energy range from 50 eV to 10 keV in the
past missions for all planets; and (2) multi-spacecraft terrestrial mission
at high inclination orbits to make a comprehensive understanding of the
dynamics of nitrogen ions in the magnetosphere. The second option consists of three
spacecraft, two mid-altitude satellites for in-situ measurement with gradient
information (by the second spacecraft), and one low-altitude satellite for
outward remote sensing to obtain line-of-sight integration information. Instrumentation for such a mission also
benefits studies on the inner magnetosphere, substorms, and basic plasma
physics such as ion energization. |
11 |
poster |
10:01 |
The Blue and Green Aurorae of
the Red Planet. |
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Lilensten, J1; Bernard, D2; Barthélémy, M3; Gronoff, G4; Simon, C5 |
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1CNRS;
2CNRS /
IPAG; 3UJF /
IPAG; 4NASA
LaRC; 5Aalto
University, School of Electrical Engineering, Department of Radio Science and
Engineering |
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|
The upper atmosphere of Mars is
a laboratory for better understanding the planetary atmosphere evolution, and
is an example of the interaction of a planet with a weak intrinsic magnetic
field with the solar wind. In that context, several space missions were
launched to study the Martian environment and its aurorae, notably ESA's Mars
Express discovered the first aurora-like structures, and more recently NASA's
MAVEN, which is dedicated to understand the atmospheric escape. However, none
of the existing missions have a visible spectrometer for the observation of
the upper atmosphere and the aurora. In this work, we simulate the visible
aurora at Mars both with an experimental setting called Planeterrella, and
with the numerical ionosphere simulation Aeroplanets. We show that the electron impact on CO2
produces strong blue emissions which are due to the Fox-Duffendack-Barker
bands. The modeling of the electron transport at Mars shows that both these
blue emissions and the emissions of the green line of atomic oxygen may be
observable during extreme solar events.
The UV aurorae at Mars have a counterpart in the visible which should
be observed in the right conditions. The absence of visible spectrometers
dedicated to these observations onboard existing space missions and the
location of the different Martian rovers, far from the vertically aligned
crustal magnetic field lines of Mars, have prevented so far the observations
of such an aurora. The exo-Mars/Trace Gas Orbiter mission will carry a
visible spectrometer which could be used to detect these visible events. |
12 |
poster |
10:03 |
Multipoint Imaging and In Situ
Observations of Coronal Mass Ejections in June and July 2012 |
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Moestl, C1; Rollett, T1; Boakes, P2; Farrugia, C J3; Temmer, M2; Lugaz, N3; Liewer, P4 |
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1Space
Research Institute, Austrian Academy of Sciences; 2University of Graz; 3University of New Hampshire; 4Jet Propulsion Laboratory |
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We investigate the evolution of
coronal mass ejections (CMEs) in the ecliptic plane by modeling STEREO/HI
observations in combination with in situ solar wind plasma and magnetic field
data (Venus Express, MESSENGER, Wind). During June and July 2012, high solar
activity was coinciding with Venus and Mercury passing the Sun-Earth line. We
approximate the CME front with a new method using an elliptical shape for
conversion of elongation, as measured by HI, to distance from the Sun. The
results constrain the global shape and kinematics of ICMEs during the
propagation from the Sun to Earth, aiding in predicting their arrival time
and speed with increased accuracy. Multipoint in situ observations of the
ICMEs also reveal insights into the 3D structure of their interior magnetic
flux ropes, which are the main drivers of strong geomagnetic storms at Earth. |
13 |
poster |
10:05 |
Vlasiator Simulations of Ion
Foreshock |
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Vainio, R1; Palmroth, M2; Kempf, Y2; Ganse, U3; von Alfthan, S2; Afanasiev, A1; Hoilijoki, S2 |
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1University
of Turku; 2Finnish
Meteorological Insititute, Helsinki; 3University of Helsinki |
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Accurate characterization of
planetary space weather should often be based on the plasma kinetic theory.
The Finnish Meteorological Institute's Vlasiator is the world’s first code to
capture large simulation volumes using a kinetic theory with accuracy that
can be compared to spacecraft measurements. Since it directly solves the
Vlasov equation for ions, Vlasiator is numerically noiseless. Vlasiator
presents ion kinetics in 6-dimensional (6D) phase space embedded in a
self-consistent solution of electromagnetic fields in the 3D ordinary space.
Local and global tests show that the simulation is physically and technically
mature enough to be run in a massively parallel setup. The resolution
employed in our latest runs enables us to consider dispersive effects in the
foreshock and magnetosheath. Therefore, we also consider the inclusion of the
Hall term in the Ohm's law. Vlasiator
has been applied to a semi-global setup including the shock front
encompassing Earth’s magnetic field and its surroundings. The simulations
reproduce many well-known foreshock features that are in quantitative
agreement with spacecraft observations. We study in particular the formation
of the ULF waves and their consequences at the edge of the shock surrounding
the Earth's magnetic field. We also use the newly developed post-processing
tracer particle technique to identify the origin of ion populations in the
foreshock and the magnetosheath. While the present runs are performed on
Earth’s parameters, Vlasiator is a potential tool for simulating at least the
Hermean magnetosphere, as well. The aim of this paper is to present the
potential of Vlasiator as a tool aiding planetary space weather modeling in
the future. |
14 |
poster |
10:07 |
Electromagnetic Particle-in-Cell
Simulations of the Solar Wind Interaction with Lunar Magnetic Anomalies |
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Deca, J1; Divin, A2; Lapenta, G1; Lembège, B3; Markidis, S4; Horányi , M5 |
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1KU
Leuven; 2Swedish
Institute of Space Physics; 3Université de Versailles à Saint Quentin; 4KTH Royal Institute of
Technology; 5University
of Colorado |
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We present the first
three-dimensional fully kinetic and electromagnetic simulations of the solar
wind interaction with lunar crustal magnetic anomalies (LMAs). Using the
implicit particle-in-cell code iPic3D, we confirm that LMAs may indeed be
strong enough to stand off the solar wind from directly impacting the lunar
surface forming a mini-magnetosphere, as suggested by spacecraft observations
and theory. In contrast to earlier MHD and hybrid simulations, the fully
kinetic nature of iPic3D allows to investigate the space charge effects and
in particular the electron dynamics dominating the near-surface lunar plasma
environment. We describe the general picture of the interaction of a dipole
model centred just below the lunar surface under various solar wind and
plasma conditions and focus on the kinetic effects. It is shown that the
configuration is dominated by electron motion, because the LMA scale size is
small with respect to the gyroradius of the solar wind ions. Driven by strong
pressure anisotropies, the mini-magnetosphere is also unstable over time,
leading to only temporal shielding of the surface underneath. Our work opens
new frontiers of research toward a deeper understanding of LMAs and is
ideally suited to be compared with field or particle observations from
spacecraft such as Kaguya (SELENE), Lunar Prospector or ARTEMIS. The ability
to evaluate the implications for future lunar exploration as well as lunar
science in general hinges on a better understanding of LMAs. This research has received funding from the
European Commission’s FP7 Program with the grant agreement SWIFF (project
2633430, swiff.eu) and EHEROES (project 284461, www.eheroes.eu). The
simulations were conducted on the computational resources provided by the
PRACE Tier-0 project 2011050747 (Curie supercomputer). This research was
supported by the Swedish National Space Board, Grant No. 136/11. JD has
received support through the HPC-Europa2 visitor programme (project
HPC08SSG85) and the KuLeuven Junior Mobility Programme Special Research Fund. |
15 |
poster |
10:09 |
Solar System Plasma Turbulence
and Intermittency over the Solar Cycle from in-Situ Measurements in the
Heliosphere and Planetary Environments |
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Echim, M1; Wawrzaszek, A2; Macek, W2; Yordanova, E3; Mursula, K4; Virtanen, I4; Vaisanen, P4; Teodorescu, E5; Munteanu, C5; Voitcu, G5; Voeroes, Z6; Narita, Y6; Dwivedi, N6; Bruno, R7; Consolini, G7; Pallochia, G7; Marcucci, M F7; Kovacs, P8; Lamy, H9; Voitenko, Y9 |
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1BIRA-IASB;
2CBK Warsaw;
3IRF Sweden;
4U Oulu; 5ISS-INFLPR; 6IWF Graz; 7INAF-IAPS; 8ELGI; 9BIRA-IASB |
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In the framework of the European
FP7 project STORM (“Solar system plasma Turbulence: Observations,
inteRmittency and Multifractals”) we analyze the properties of turbulence in
various regions of the solar system, for the minimum and respectively maximum
of the solar activity. The main scientific objective of STORM is to advance
the understanding of the turbulent energy transfer, intermittency and
multifractals in space plasmas. Specific analysis methods are applied on
magnetic field and plasma data provided by Ulysses, Venus Express and
Cluster, as well as other solar system missions (e.g. Giotto, Cassini). We
provide an overview of the properties of turbulence derived from Power
Spectral Densities (PSD) and Probability Density Functions (PDFs) computed in
the solar wind (from Ulysses, Cluster, Venus Express) and at the interface of
planetary magnetospheres with the solar wind (from Venus Express, Cluster).
Ulysses provides data in the solar wind between 1992 and 2008, out of the
ecliptic, at radial distances ranging between 1.3 and 5.4 AU. We selected
only those Ulysses data that satisfy a consolidated set of selection criteria
able to identify "pure" fast and slow wind. We analyzed Venus
Express data close to the orbital apogee, in the solar wind, at 0.72 AU, and
in the Venus magnetosheath. We investigated Cluster data in the solar wind
(for time intervals not affected by planetary ions effects), the
magnetosheath and few crossings of other key magnetospheric regions (cusp,
plasma sheet). We organize our PSD and PDFs results in three solar wind data
bases (one for the solar maximum, 1999-2001, two for the solar minimum,
1997-1998 and respectively, 2007-2008), and two planetary databases (one for
the solar maximum, 2000-2001, that includes PSD and PDFs obtained in the
terrestrial magnetosphere, and one for the solar minimum, 2007-2008, that
includes PSD and PDFs obtained in the terrestrial and Venus magnetospheres
and magnetosheaths). In addition to investigating the properties of turbulence
for the minimum and maximum of the solar cycle we also analyze the
similarities and differences between fast and slow wind turbulence. We
emphasize the importance of our data survey and analysis in the context of
understanding the solar wind turbulence, the exploitation of data bases and
as a first step towards developing a (virtual) laboratory for studying solar
system plasma turbulence. Research
supported by the European Community’s Seventh Framework Programme
(FP7/2007-2013) under grant agreement no 313038/STORM, and a grant of the
Romanian Ministry of National Education, CNCS –UEFISCDI, project number
PN-II-ID-PCE-2012-4-0418. |
16 |
poster |
10:11 |
Numerical Simulations of
Solar-Wind Comet interactions based on
Implicit Particle-In cell/Monte Carlo Method |
|
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Jiang, W1; Amaya, J1; Lapenta, G1 |
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1Katholieke
Universiteit Leuven |
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|
The interaction of the solar
wind with comets has been a hot research topic for a long time. The new
ROSETTA mission offers a unique opportunity to study the plasma activity
during the solar-wind comet interaction. In order to better understand the
interaction process, and in particular to study the transition from the
collisionless outer coma to the collision-dominated inner coma, it is
necessary to couple gas and plasma dynamics in a comprehensive,
self-consistent way. Based on the
code iPIC3D[1], we have used he implicit Particle-In cell/Monte Carlo
(PIC/MC) method to study this process self-consistently, including both the
kinetic and the collisional treatment of cometary electrons, ions with
molecules. We consider the charged particles H+,, H2O+, O-, and electrons,
and the neutral molecules of H and O. Two dimensional cases are considered.
Physical and chemical processes similar to Rubin et.al [2] are included in
our model. Photoionization and photo-dissociation are included with a
prescribed rate. We added to the model 12 electron-neutral collision
processes, including attachment, excitation and ionization. Two ionic
collision processes, including charge exchange and momentum transfer, are
imposed through the Monte Carlo method [3], using the cross sections given by
LXCat [4]. Recombination processes between the electrons and ions are also
considered with temperature dependent recombination rate. The neutral gas is
imposed using an analytic formula, which includes the neutral depleting
effect. The simulations are
performed at different distances between the sun and the comet. We observe a
clear transition from the solar wind proton-dominated flow to a plasma population
primarily consisting of relatively cold cometary heavy ions. The position of
the cometopause is well predicted by the model. Density, temperature profiles
and the spatial dependent electron energy distribution functions are
calculated self consistently. The plasma properties in the coma strongly rely
on the solar-wind and photon properties, as well as the comet outgassing
characteristics. This work has
received funding from the European Union’s Seventh Programme for Research,
Technological Development and Demonstration under Grant Agreement No. 610476
- Project DEEP-ER (www.deep-er.eu). W. Jiang gratefully acknowledge the
Belgian Federal Science Policy Office and the China Scholarship Council for
financial support. [1] S. Markidis,
et.al. Mathematics and Computers in Simulation. 80(7), 1509, 2010. [2] M. Rubin, et.al. The Astrophysical
Journal, 781,86, 2014. [3] K. Nanbu.
Plasma Science, IEEE Transactions on 28 97, 2000 [4] www.lxcat.net/ |
17 |
poster |
10:13 |
Solar Wind Interaction with the
Magnetosphere of Jupiter : Impact on the Magnetopause and the Aurorae |
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Bonfond, B1; Grodent, D1; Gérard, J-C1; Radioti, A1; Kivelson, M2; Khurana, K2; Delamere, P3; Stauffer, B3 |
|
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1Université
de Liège; 2University
of California - Los Angeles; 3University of Alaska Fairbanks |
|
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|
The outcome of the interaction
between the solar wind and the Jovian magnetic field bears many differences
compared to the Earth's case. At Earth, the solar wind is the major particle
and energy source in the magnetosphere. At Jupiter, the tremendous volcanism
on the moon Io is the main plasma source and Jupiter's rapid rotation
(relative to its size) is the main energy source for the particles populating
its magnetosphere. Combined with a weaker solar wind pressure and a larger
Alfvén Mach number as the distance from the Sun increases, all these
parameters modify the relative importance of large scale Dungey reconnection
and viscous interaction at the magnetopause. In order to study these
differences, here we present a statistical analysis of magnetopause waves and
flux tube event on the Jovian magnetopause, based on in-situ measurement from
the spacecraft that flew-by or orbited around Jupiter. Moreover, variations
of the solar wind have significant impact on the Jovian magnetospheric
current systems and such changes reflect on the aurora. In this presentation,
we will also review the recent findings concerning the aurora at Jupiter and
their relationship with the solar wind. |
18 |
poster |
10:15 |
Jovian Plasma - Moon
Interactions at the Galilean Satellites |
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|
|
Plainaki, C1; Milillo, A1; Massetti, S1; Mura, A1; Jia, X2; Saur, J3; Orsini, S1; Mangano, V1; De Angelis, E1; Rispoli, R1; Lazzarotto, F1 |
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1INAF-IAPS;
2University
of Michigan; 3Universität
zu Köln |
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The exospheres of Jupiter's
moons Europa and Ganymede are mixtures of different species among which
sputtered H2O and H2 dominate in the highest altitudes and O2, formed mainly
by radiolysis of ice and subsequent release of the produced molecules, prevail
at lower altitudes. Several observations have demonstrated that these neutral
environments are formed mainly through the interaction of the Jovian plasma
with the moons' icy surfaces. Given the variable environment conditions (i.e.
plasma, UV, surface heating etc.) at the Galilean moons, the exospheres of
Ganymede and Europa result to be spatially and temporally non-uniform.
Therefore, the neutral environment variability at these moons constitutes a
direct evidence of space weather phenomena in the Jupiter system. In the present study we investigate
Europa's exospheric H2O and O2 characteristics under the external conditions
that are likely in the Jupiter's magnetospheric environment, applying the
Europa Global model of Exospheric Outgoing Neutrals (EGEON, Plainaki et al.,
2012). The H2O and O2 exospheres of Jupiter’s moon Ganymede are simulated
through the application of a 3-D Monte Carlo modeling technique that takes
into consideration the combined effect in the exosphere generation of the
main surface release processes (i.e. sputtering, sublimation and radiolysis)
and the surface precipitation of the energetic ions of Jupiter’s
magnetosphere. We discuss the modeled water and oxygen densities at both
Galilean satellites and we compare them, a posteriori, with the analysis
results from observations. We show that in view of future missions to the
Jovian system, it is important to describe the variability of the exospheric
environment around the Galilean moons, due to space weather driven by plasma
and/or the UV radiation. |
19 |
poster |
10:17 |
Radiation Shielding for an
Instrument in the Jovian Environment |
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Rispoli, R1; Plainaki, C1; Milillo, A1; Orsini, S1; De Angelis, E1; Kieft, P2 |
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1INAF/IAPS;
2University
of Nottingham |
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|
Jovian environment includes
intense, energetic and highly penetrating electron and ion populations.
Energetic particles can cause radiation damage to electronic components and
materials, resulting in increased detector noise, part failures such as
leakage current due to total dose effects, power glitches probably due to
arcing dielectrics, Cerenkov and Florescence radiation in optical elements,
oscillator frequency shifts, and other effects. Energetic electrons can
penetrate thin shields and build up static charge in internal dielectric
materials such as cable and other insulation, circuit boards, and on
ungrounded metallic parts. These components can be subsequently discharged,
generating electromagnetic interference. In this view, the extreme radiation
environment at Jupiter can be a primary source of spacecraft problems.
Therefore, while designing potential future missions to the giant planet and
to its satellites, accurate estimates of the space weather conditions that
characterize the regions of the external Solar System are necessary.
Specifically, a quantitative evaluation of the radiation dose received by the
spacecraft (s/c) is of significant importance. Jupiter's magnetosphere is a
unique plasma laboratory in our solar system and presents a paradigm of a gas
giant system with a fast rotating plasma disk. The trapped populations in the
radiation belts include energetic protons and electrons. Data from the
Galileo spacecraft have quantified the intense radiation belt that exists
inward of the orbit of Jupiter’s satellite Ganymede (at r ~ 15 RJ).
Specifically, Jun et al. (2005), using the Galileo Energetic Particles
Detector (EPD) data, estimated that the flux of ~11 MeV electrons increases
by roughly 2 orders of magnitude inward from Ganymede’s orbit to Europa’s (at
r ~ 9.4 RJ). However, the Galilean satellites co-located with this radiation
belt, do not receive the full radiation dose that characterizes their
surroundings. For example, Ganymede’s internal magnetic field reduces the
access of charged particles to the surface and as a result, the radiation in
the moon’s vicinity is reduced. Although the dominant contribution to the
radiation environment at Jupiter comes from the energetic electrons and the
magnetospheric charged particles, s/c problems can be caused also due to
sporadic Solar Particle Events (SPEs) and to Galactic Cosmic Rays (GCR)
access to the Jovian magnetosphere.
Moreover, secondary radiation generated by the interaction of primary
radiation with s/c materials is an additional potential source for satellite
problems. For this harsh environment a Jupiter space mission requests
accurate radiation analysis. This work presents a shielding strategy for an
instrument proposed for JUICE (Jupiter Icy Moons Explorer) payload. The
received total ionizing dose levels for critical component of the instrument
have been calculated through the FASTRAD 3.3.0.0, complete engineering
software developed for 3D radiation shielding analyses. The results of this
study constitute a necessary starting point in the design and development of
any instrument to be functioning inside Jupiter's system in a compatible mode
with the planet's space weather conditions. |
20 |
poster |
10:19 |
Study of the Photoelectron
Emission from the Surface of Cluster Spacecraft |
|
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Andriopoulou, M1; Nakamura, R1; Torkar, K1 |
|
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1Space
Reseach Institute, Austrian Academy of Sciences |
|
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|
A sunlit spacecraft that orbits
in tenuous plasma regions will be positively charged due to the
photoelectrons that escape from its surface. The spacecraft potential can be
then determined by the equilibrium of the acting currents, which in this
case, are the photoelectron current and the current of the ambient electrons.
The photoelectron emission is also expected to be variable with the solar
cycle. In this work we use plasma and spacecraft potential data from the
Cluster satellites to derive the photoelectron current profiles as a function
of the spacecraft potential. In order to derive more accurate results, we
focus at periods where the separation between the Cluster spacecraft was
minimum. These profiles can then be used for helping to reconstruct the
spacecraft potential measurements from the spacecraft potential measurements
at which active spacecraft potential control (ion emitters) is applied. Such
reconstruction can allow more accurate electron density estimations obtained
from spacecraft potential measurements, regardless of the fact that active
spacecraft potential control is applied. The results of this work will be of
useful for the upcoming Multiscale Magnetospheric Mission (MMS) mission. |
21 |
poster |
10:21 |
IMPEx/FMI-HWA Planetary
Simulations Database and Matlab Tools for Easy Access |
|
|
|
Laitinen, T1; Häkkinen, L1; Kallio, E2; Schmidt, W3; Jarvinen, R4; Haunia, T1; Khodachenko, M5; Al-Ubaidi, T5; Topf, F5; Scherf, M5; Génot, V6; Gangloff, M6; Modolo, R3; Hess, S3; Alexeev, I7; Mukhametdinova, L7; Belenkaya, E7; Budnik, E6; Bourrel, N6; Penou, E3; Renard, B3; André, N3 |
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1Finnish
Meteorological Institute; 2School of Electrical Engineering, Aalto University; 3LATMOS/CNRS, Université
de Versailles Saint Quentin; 4Finnish Meteorological Institute / presently at: LASP,
University of Colorado; 5Space Research Institute, Austrian Academy of Sciences; 6IRAP/CNRS, Université
Paul Sabatier; 7SINP, Skobeltsyn Institute of Nuclear Physics, Moscow State
University |
|
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|
The FP-7 SPACE project IMPEx
(Integrated Medium for Planetary Exploration) is building a web-based
research environment for planetary plasma science, aiming to facilitate
comparison of in situ measurements and computational models. Several
observational and simulation databases with common metadata standards provide
datasets that can be combined, compared and visualised with online tools or
downloaded for analysis with personal favourite software. The Finnish Meteorological Institute’s
(FMI) Hybrid Web Archive (HWA) contains simulations of the plasma
environments of several Solar System objects, such as Venus and Mars,
modelled with the HYB hybrid code. HWA
also includes the GUMICS Earth Archive, which contains simulations of the
Earth’s magnetosphere performed with Europe's only global magnetohydrodynamic
code GUMICS-4 (Grand Unified Magnetosphere–Ionosphere Coupling Simulation).
The simulations can be examined online at http://hwa.fmi.fi/beta/. HWA
implements the IMPEx data access protocol, allowing downloading of the
simulation data via a SOAP-based web service interface. In this presentation we illustrate the use
of the IMPEx / FMI-HWA web services directly from the Matlab command line,
using a Matlab function package written for this purpose. The freely
available package includes functions for specifying sets of points in space,
e.g. on a surface or along a spacecraft trajectory, for retrieving simulation
data at the specified points and for reading the data into Matlab
variables. IMPEx home:
http://impex-fp7.oeaw.ac.at |
22 |
poster |
10:23 |
Magnetospheric Modes and
Magnetic Reconnection. |
|
|
|
Hubert, B1; Milan, S2; Cowley, S2 |
|
|
|
1University
of Liège; 2University
of Leicester |
|
|
|
We combine imaging of the proton
aurora from the SI12-IMAGE instrument with measurement of the ionospheric
convection from the SuperDARN radar network to analyze the cycle of magnetic
flux opening and closure of the Earth magnetosphere. Interaction between the
solar wind and the Earth geomagnetic environment causes a reconfiguration of
the magnetic field that connects the interplanetary magnetic field (IMF) to
the geomagnetic field. This reconnection process produces open magnetic field
lines (i.e. field lines of the magnetosphere that close through the
interplanetary medium) that are dragged to the magnetotail by the solar wind
flow, where they eventually reconnect again, back to a closed topology. The SI12 imaging of the Doppler-shifted
Lyman-α emission of the proton aurora is used to estimate the location of the
boundary separating open and closed field lines at ionospheric altitude. We
then estimate the open magnetic flux
of the Earth magnetosphere, encircled by this boundary. The rate of
reconnection causing a variation of the open magnetic flux can be expressed
as a voltage in application of Faraday’s law. This voltage is measured along
the open/closed field line boundary determined from the imaging data. The
electric field associated with the voltage has two origins: motion of the
boundary and the ionospheric field. We use the ionospheric electric field
deduced from ionospheric convection measurement from the SuperDARN to
estimate the reconnection voltage at the magnetopause (flux opening) and in
the magnetotail (flux closure) accounting for the motion of the open/closed
field line boundary determined from the SI12 images. The method is applied
during substorms, steady geomagnetic convection intervals, sawtooth events
and geomagnetic storms. These different intervals are characterized by
different values of open flux and reconnection rates, as a result of
different coupling between the solar wind and the geomagnetic environment. We
interpret these differences as different dynamic modes of the magnetospheric
system. Shock-induced flux closure events are also presented, as an
exceptional situation that differs from the modes presented above. |
23 |
poster |
10:25 |
Theoretical Model of CR
Forbush-Decrease and Precursors Effects |
|
|
|
Dorman, L |
|
|
|
Israel Cosmic Ray and Space
Wearther Center of Tel Aviv University, Israel Space Agency and Golan
Research Institute, Israel; IZMIRAN, Russia |
|
|
|
The understanding of the
mechanism of CR Forbush decrease and precursor effects is important for
forecasting of the great magnetic storms by using on-line one hour CR
observation data. We consider in details the situation with CR distribution
inside CME and how it changed with time. We suppose that shock wave before
CME is semi-transpired and the coefficient of transparence depends from the
CR particles rigidity. One differential equation determined the change of CR
intensity inside CME by the particle energy decrease in the expanding volume
and by exchange with CR particles outside the CME. The other differential
equation determined the outside CR particles drift acceleration by
interaction with the shock wave before CME (this effect gives increase of CR
intensity before magnetic storm sudden commencement) as well as exchange with
CR particles inside the CME along the IMF lines (what gives the decrease of
CR intensity before the start of magnetic storm on the Earth). We calculate
also the expected CR anisotropy. Obtained results we compare with observation
data. |
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