Markku_inproceedings.bib

@inproceedings{2015EGUAnomaly,
  author = {{Alho}, M. and {Kallio}, E. and {Wedlund}, C.~S. and {Wurz}, P.},
  title = {{Interaction of Solar Wind and Magnetic Anomalies – Modelling from Moon to Mars}},
  booktitle = {EGU General Assembly Conference Abstracts},
  year = 2015,
  series = {EGU General Assembly Conference Abstracts},
  month = april,
  abstract = {{The crustal magnetic anomalies on both the Moon and Mars strongly affect the local plasma environment. On the
Moon, the impinging solar wind is decelerated or deflected when interacting with the magnetic field anomaly,
visible in the lunar surface as energetic neutral atom (ENA) emissions or as reflected protons, and may play a part
in the space weathering of the lunar soil. At Mars, the crustal magnetic fields have been shown to be associated
with, e.g., enhanced electron scale heights and modified convection of ionospheric plasma, resulting in the plasma
environment being dominated by crustal magnetic fields up to altitudes of 400km.
Our  previous  modelling  work  suggested  that  Hall  currents  are  a  dominant  feature  in  a  Moon-like  magnetic
anomaly interaction at scales at or below the proton inertial length. In this work we study the solar wind interaction
with  magnetic  anomalies  and  compare  the  plasma  environments  of  a  Moon-like  anomaly  with  a  Mars-like
anomaly by introducing an ionosphere and an exosphere to probe the transition from an atmosphere-less anomaly
interaction to an ionospheric one.
We  utilize  a  3D  hybrid  plasma  model,  in  which  ions  are  modelled  as  particles  while  electrons  form  a
charge-neutralizing massless fluid. The hybrid model gives a full description of ion kinetics and associated plasma
phenomena at the simulation region ranging from instabilities to possible reconnection. The model can thus be
used to interpret both in-situ particle and field observations and remotely-sensed ENA emissions. A self-consistent
ionosphere package for the model is additionally in development.}},
  url = {http://presentations.copernicus.org/EGU2015-11384_presentation.pdf}
}
@inproceedings{2015EGUSW,
  author = {{Dyadechkin}, S. and {Kallio}, E. and {Alho}, M. and {Wedlund}, C.~S. and {Erkaev}, N.},
  title = {{Acceleration of the solar wind in a spherical coordinate kinetic model}},
  booktitle = {EGU General Assembly Conference Abstracts},
  year = 2015,
  series = {EGU General Assembly Conference Abstracts},
  month = april,
  abstract = {{We have studied the acceleration of the solar wind protons by using a spherical coordinate kinetic hybrid model
(HYBs). The model treats ions as particles while electrons form a massless, charge neutralizing fluid. The model
includes the gravitation, the electron pressure and the jxB forces.
We  have  studied  a  magnetized  and  a  non-magnetized  solar  wind  cases  and  performed  simulations  for  dif-
ferent isothermal electron temperatures by using the same initial Maxwellian velocity distribution function for
protons. We show in the presentation of how the bulk velocity, the plasma density, the electric potential and the
velocity distribution function of protons depend on the radial distance from the Sun to several Astronomical Units.
The  derived  velocity  and  density  profiles  are  compared  with  those  of  the  Parker’s  solar  wind  model.  Finally,
extensions of the model and its applicability for a space weather modelling are discussed.}}
}
@inproceedings{2015EGUComet,
  author = {{Wedlund}, C.~S. and {Kallio}, E. and {Alho}, M. and {Dyadechkin}, S. and {Nilsson}, H. and {Stenberg-Wieser}, G. and {Béhar}, E. and {Gunell}, H. and {Holmström}, M.},
  title = {{A comet's tale: Role of charge exchange in the plasma environment of comet 67P/Churyumov-Gerasimenko}},
  booktitle = {EGU General Assembly Conference Abstracts},
  year = 2015,
  series = {EGU General Assembly Conference Abstracts},
  month = april,
  abstract = {{On 6 Aug. 2014, the Rosetta mission arrived in the vicinity of comet 67P/Churyumov-Gerasimenko (C-G) and started measuring its complex plasma environment, using notably the RPC-ICA ion spectrometer (Rosetta Plasma Consortium Ion Composition Analyser). A simple model of charge-exchange processes is first presented for He2+ and H+ solar wind ions that efficiently convert them into He+ ions (measured by RPC-ICA) and H energetic neutral atoms, respectively. In a second step, we present a new cometary hybrid plasma model, taking into account photoionisation, charge-exchange, electron impact ionisation and electron recombination, dedicated to the interpretation of RPC-ICA measurements. We use this global model to investigate in more detail the role of the water production rate and charge-exchange processes in the formation of plasma regions at comet 67P/C-G and for various heliocentric distances.}},
  url = {http://presentations.copernicus.org/EGU2015-10701_presentation.pdf}
}
@inproceedings{2014EGUGA..1612398M,
  author = {{McKenna-Lawlor}, S. and {Alho}, M. and {Kallio}, E. and {Jarvinen}, R. and 
	{Dyadechkin}, S. and {Wedlund}, C.~S.},
  title = {{A search for the effects exerted by a possible Martian intrinsic magnetic field on its SEP environment}},
  booktitle = {EGU General Assembly Conference Abstracts},
  year = 2014,
  series = {EGU General Assembly Conference Abstracts},
  volume = 16,
  month = may,
  eid = {12398},
  pages = {12398},
  abstract = {{Present-day Mars does not have a significant global intrinsic magnetic
field although it displays surface magnetic anomalies. In the past
'young Mars' may have had a strong intrinsic magnetic field. Induced
Martian magnetic fields affect the properties of Solar Energetic
Particles, (SEPs), near the planet. Recent Martian SEP environment
studies, made using self-consistent global plasma simulations
[McKenna-Lawlor et al. 2012; Kallio et al., 2012], have shown that piled
up magnetic fields in the Martian magnetosheath/magnetosphere affect the
behaviour of SEPs, resulting, for instance, in dramatic magnetic
shadowing. In these studies when correlating the simulations with in
situ measurements made by the SLED instrument aboard the Phobos
spacecraft, Mars was not assumed to have an intrinsic magnetic field,
which raises the question as to whether, and how, a residual Martian
intrinsic magnetic field may have contributed to affecting the disturbed
solar energetic particles (SEPs) recorded near the planet. In the
present work we have extended our hybrid modelling of SEPs by assuming
that Mars has an intrinsic magnetic field. Then, we compare a
non-magnetized Mars with a magnetized Mars in terms of SEP measurements.
We also discuss the consequences of the results, keeping in mind the
forthcoming in situ SEP instrument measurements which are scheduled to
start near Mars at the end of 2014 on-board the MAVEN spacecraft.
}},
  adsurl = {http://adsabs.harvard.edu/abs/2014EGUGA..1612398M},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}
@inproceedings{2014EGUGA..1610913A,
  author = {{Alho}, M. and {Jarvinen}, R. and {Kallio}, E. and {Wurz}, P. and 
	{Barabash}, S. and {Futaana}, Y.},
  title = {{Solar wind interaction with a lunar magnetic anomaly: Hybrid modelling results}},
  booktitle = {EGU General Assembly Conference Abstracts},
  year = 2014,
  series = {EGU General Assembly Conference Abstracts},
  volume = 16,
  month = may,
  eid = {10913},
  pages = {10913},
  abstract = {{New in situ plasma, neutral atom and magnetic field observations done by
recent lunar missions have revealed that the solar wind interaction with
the Moon is more complex and scientifically more interesting than
anticipated before. Especially, an unexpectedly high fraction of the
incident solar wind protons is reflected from the surface, and an even
larger fraction by the lunar magnetic anomalies. Such reflection has
been observed both by measuring deviated solar wind ion flow near the
magnetic anomalies and by observing decreased flux of energetic neutral
hydrogen atoms, H-ENAs, from the surface region of strong magnetic
anomalies. These processes affect the properties of plasma near the
lunar surface. In this work we study the solar wind interaction with a
lunar magnetic anomaly by a 3D hybrid model (HYB-Anomaly). In the hybrid
model, ions are modelled as particles while electrons form a charge
neutralizing massless fluid. The HYB-Anomaly model can also simulate
H-ENA productions when the solar wind protons hit against the surface.
The magnetic anomaly has a surface strength of the order of 100nT,
producing an interaction region with length scales at or below proton
inertial length scales. We find an upward electric field responsible for
the deceleration of precipitating protons, which is consistent with
observed H-ENA features. In this presentation, we further discuss the
dependence of H-ENA emissions on the direction of the interplanetary
magnetic field.
}},
  adsurl = {http://adsabs.harvard.edu/abs/2014EGUGA..1610913A},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}
@inproceedings{2014EGUGA..16.7941K,
  author = {{Kallio}, E. and {Alho}, M. and {Alvarez}, F. and {Barabash}, S. and 
	{Dyadechkin}, S. and {Fernandes}, V. and {Futaana}, Y. and {Harri}, A.-M. and 
	{Haunia}, T. and {Heilimo}, J. and {Holmstr{\"o}m}, M. and {Jarvinen}, R. and 
	{Lue}, C. and {Makela}, J. and {Porjo}, N. and {Schmidt}, W. and 
	{Shahab}, F. and {Siili}, T. and {Wurz}, P.},
  title = {{Kinetic Modeling of the Lunar Dust-Plasma Environment}},
  booktitle = {EGU General Assembly Conference Abstracts},
  year = 2014,
  series = {EGU General Assembly Conference Abstracts},
  volume = 16,
  month = may,
  eid = {7941},
  pages = {7941},
  abstract = {{Modeling of the lunar dust and plasma environment is a challenging task
because a self-consistent model should include ions, electrons and dust
particles and numerous other factors. However, most of the parameters
are not well established or constrained by measurements in the lunar
environment. More precisely, a comprehensive model should contain
electrons originating from 1) the solar wind, 2) the lunar material
(photoelectrons, secondary electrons) and 3) the lunar dust. Ions
originate from the solar wind, the lunar material, the lunar exosphere
and the dust. To model the role of the dust in the lunar plasma
environment is a highly complex task since the properties of the dust
particles in the exosphere are poorly known (e.g. mass, size, shape,
conductivity) or not known (e.g. charge and photoelectron emission) and
probably are time dependent. Models should also include the effects of
interactions between the surface and solar wind and energetic particles,
and micrometeorites. Largely different temporal and spatial scales are
also a challenge for the numerical models. In addition, the modeling of
a region on the Moon - for example on the South Pole - at a given time
requires also knowledge of the solar illumination conditions at that
time, mineralogical and electric properties of the local lunar surface,
lunar magnetic anomalies, solar UV flux and the properties of the solar
wind. Harmful effects of lunar dust to technical devices and to human
health as well as modeling of the properties of the lunar plasma and
dust environment have been topics of two ESA funded projects L-DEPP and
DPEM. In the presentation we will summarize some basic results and
characteristics of plasma and fields near and around the Moon as studied
and discovered in these projects. Especially, we analyse three different
space and time scales by kinetic models: [1] the ''microscale'' region
near surface with an electrostatic PIC (ions and electrons are
particles) model, [2] the ''mesoscale'' region including lunar magnetic
anomalies and [3] the global scale Moon-solar wind interaction with
hybrid (ions as particles in massless electron fluid) models.
}},
  adsurl = {http://adsabs.harvard.edu/abs/2014EGUGA..16.7941K},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}
@inproceedings{2014EGUGA..16.4203W,
  author = {{Wedlund}, C.~S. and {Kallio}, E. and {Jarvinen}, R. and {Dyadechkin}, S. and 
	{Alho}, M.},
  title = {{A new self-consistent hybrid chemistry model for Mars and cometary environments}},
  booktitle = {EGU General Assembly Conference Abstracts},
  year = 2014,
  series = {EGU General Assembly Conference Abstracts},
  volume = 16,
  month = may,
  eid = {4203},
  pages = {4203},
  abstract = {{Over the last 15 years, a 3-D hybrid-PIC planetary plasma interaction
modelling platform, named HYB, has been developed, which was applied to
several planetary environment such as those of Mars, Venus, Mercury, and
more recently, the Moon. We present here another evolution of HYB
including a fully consistent ionospheric-chemistry package designed to
reproduce the main ions in the lower boundary of the model. This
evolution, also permitted by the increase in computing power and the
switch to spherical coordinates for higher spatial resolution
(Dyadechkin et al., 2013), is motivated by the imminent arrival of the
Rosetta spacecraft in the vicinity of comet 67P/Churyumov-Gerasimenko.
In this presentation we show the application of the new HYB-ionosphere
model to 1D and 2D hybrid simulations at Mars above 100 km altitude and
demonstrate that with a limited number of chemical reactions, good
agreement with 1D kinetic models may be found. This is a first
validation step before applying the model to the 67P/CG comet
environment, which, like Mars, is expected be rich in carbon oxide
compounds.
}},
  adsurl = {http://adsabs.harvard.edu/abs/2014EGUGA..16.4203W},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}
@article{2013AGUFM.P51E1763K,
  author = {{Kallio}, E.~J. and {Alho}, M. and {Jarvinen}, R. and {Dyadechkin}, S. and 
	{Wurz}, P. and {Barabash}, S.~V. and {Futaana}, Y.},
  title = {{Solar Wind-Lunar Magnetic Anomaly Interaction: Hybrid Model Simulations}},
  journal = {AGU Fall Meeting Abstracts},
  keywords = {6250 PLANETARY SCIENCES: SOLAR SYSTEM OBJECTS Moon, 6033 PLANETARY SCIENCES: COMETS AND SMALL BODIES Magnetospheres, 2753 MAGNETOSPHERIC PHYSICS Numerical modeling},
  year = 2013,
  month = dec,
  pages = {1763},
  abstract = {{The localized, crustal magnetic field on the Moon shows a complex
interaction with the impinging solar wind. The interaction includes
interesting and unique plasma physics processes when a small
magnetosphere-like field structure, commonly referred to as a
mini-magnetosphere, is formed above the magnetic anomaly. Because of the
small size of the interaction region, kinetic effects play an important
role in the interaction region. Recently, unique new particle and field
data have been obtained above the lunar magnetic anomalies by the
Chandrayaan-1 and Kaguya missions. In this work, we model a lunar
magnetic anomaly in the spatial scale of hundreds of kilometers with an
100nT surface field anomaly. We employ the 3D HYB hybrid plasma model
(HYB-Anomaly) developed at the Finnish Meteorological Institute, in
which ions are treated as fully kinetic macroparticles, with electrons
providing a massless, charge-neutralizing fluid. We study the properties
of particles and fields within the mini-magnetosphere, especially,
characteristic features of the electric field resulting from the
different motion of protons and electrons. We also analyze the response
of the mini-magnetosphere to the upstream solar wind parameters, such as
the direction of the interplanetary magnetic field. Finally,
Chandrayaan-1 particle observations are used for comparison.
}},
  adsurl = {http://adsabs.harvard.edu/abs/2013AGUFM.P51E1763K},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}
@article{2013EPSC....8..753J,
  author = {{Jarvinen}, R. and {Kallio}, E. and {Dyadechkin}, S. and {Wedlund}, C.~S. and 
	{Alho}, M.},
  title = {{Hybrid modelling studies of solar wind interactions at Venus and Mars}},
  journal = {European Planetary Science Congress 2013, held 8-13 September in London, UK. id.EPSC2013-753},
  year = 2013,
  month = sep,
  volume = 8,
  eid = {EPSC2013},
  pages = {753},
  abstract = {{We present hybrid modelling of solar wind interactions of unmagnetized
Solar System bodies and, more specifically, we discuss the solar wind
induced ion escape and the structure of induced magnetospheres at Venus
and at Mars. The modelling work is based on the HYB hybrid simulation
model family, which has been developed for over a decade at the Finnish
Meteorological Institute (FMI) and has been used to study plasma
environments of unmagnetized and weakly magnetized celestial objects. In
the hybrid approach ions are treated as particles moving under the
Lorentz force and self-consistently coupled to the electric and magnetic
field via Maxwell's equations while electrons form a massless,
charge-neutralizing fluid. Especially, the global HYB hybrid simulations
have been used to interpret in situ observations made by the ASPERA
plasma instruments on the Mars Express and the Venus Express missions.
We discuss the recent results of our hybrid simulation studies of the
solar wind interaction with Venus and Mars as well as the newest
developments of our hybrid simulation model.
}},
  url = {http://meetings.copernicus.org/epsc2013},
  adsurl = {http://adsabs.harvard.edu/abs/2013EPSC....8..753J},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}
@article{2013EPSC....8..724K,
  author = {{Kallio}, E. and {Jarvinen}, R. and {Alho}, M. and {Dyadechkin}, S.
	},
  title = {{Solar wind interaction with a lunar magnetic anomaly: Hybrid modelling studies}},
  journal = {European Planetary Science Congress 2013, held 8-13 September in London, UK. id.EPSC2013-724},
  year = 2013,
  month = sep,
  volume = 8,
  eid = {EPSC2013},
  pages = {724},
  abstract = {{Recent lunar missions have shown that the solar wind interaction with
the Moon is complex and scientifically more interesting than anticipated
before, as shown by new in situ plasma, neutral atom and magnetic field
observations. Especially, an unexpectedly high fraction of the incident
solar wind protons is reflected from the surface, and an even larger
fraction by the lunar magnetic anomalies. This effect has been observed
both by measuring deviated solar wind ion flow near the magnetic
anomalies and by observing decreased flux of energetic neutral hydrogen
atoms, H-ENAs, from the surface region of strong magnetic anomalies.
These processes affect the properties of plasma near the lunar surface.
In this work we continue [1] to study the solar wind interaction with a
lunar magnetic anomaly by a 3D hybrid model (HYB-Anomaly). In the hybrid
model ions are modelled as particles while electrons form a charge
neutralizing massless fluid. The hybrid model also includes energetic
neutral hydrogen atoms, HENAs, which are formed in charge exchange
processes on the lunar surface when solar wind protons hit against it.
In the presentation we analyse, based on the HYB model, properties of
plasma near the lunar surface, its modification by a lunar magnetic
anomaly and the reflected flux of ions and H-ENAs, which serves as
messengers for the interaction processes at the surface.
}},
  url = {http://meetings.copernicus.org/epsc2013},
  adsurl = {http://adsabs.harvard.edu/abs/2013EPSC....8..724K},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}
@inproceedings{2013EGUGA..15.5268K,
  author = {{Kallio}, E. and {Jarvinen}, R. and {Dyadechkin}, S. and {Alho}, M. and 
	{Wurz}, P. and {Barabash}, S.},
  title = {{Modelling of the solar wind interaction with a lunar magnetic anomaly at macro and micro scales}},
  booktitle = {EGU General Assembly Conference Abstracts},
  year = 2013,
  series = {EGU General Assembly Conference Abstracts},
  volume = 15,
  month = apr,
  eid = {EGU2013},
  pages = {5268},
  abstract = {{Recent lunar missions have shown that the solar wind interaction with
the Moon is complex and scientifically more interesting than anticipated
before, as shown by new in situ plasma, neutral atom and magnetic field
observations. Especially, an unexpectedly high fraction of the incident
solar wind protons is reflected from the surface, and an even larger
fraction by the lunar magnetic anomalies. This effect has been observed
both by measuring deviated solar wind ion flow near the magnetic
anomalies and by observing decreased flux of energetic neutral hydrogen
atoms, H-ENAs, from the surface region of strong magnetic anomalies.
These ''macro scale'' processes affect the properties of plasma near the
lunar surface. Consequently, also physical processes at ''micro scales''
within the Debye sheath layer, where the electric potential of the
surface and near surface region are controlled by photoelectrons and
solar wind particles, are affected.  In this work we study the solar
wind interaction with a lunar magnetic anomaly by two numerical kinetic
simulation models: (1) a 3D hybrid model (HYB-Anomaly) to study macro
scale processes and (2) a full kinetic 1D and 2D Particle-in-cell (PIC)
model to study micro scale processes. In the hybrid model ions are
modelled as particles while electrons form a charge neutralizing
massless fluid. The hybrid model also includes energetic neutral
hydrogen atoms, H-ENAs, which are formed in charge exchange processes on
the lunar surface when solar wind protons hit against it. In the PIC
simulations both ions and electrons are modelled as particles. In the
presentation we discuss, based on these models, properties of plasma
near the lunar surface, its modification by a lunar magnetic anomaly and
the reflected flux of ions and H-ENAs, which serves as messengers for
the interaction processes at the surface.
}},
  adsurl = {http://adsabs.harvard.edu/abs/2013EGUGA..15.5268K},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}
@inproceedings{2013EGUGA..15.3040M,
  author = {{McKenna-Lawlor}, S. and {Kallio}, E. and {Fram}, R.~A. and 
	{Alho}, M. and {Jarvinen}, R. and {Dyadechkin}, S. and {Wedlund}, C.~S. and 
	{Zhang}, T. and {Collinson}, G.~A. and {Futaana}, Y.},
  title = {{High energy particles at Mars and Venus: Phobos-2, Mars Express and Venus Express observations and their interpretation by hybrid model simulations}},
  booktitle = {EGU General Assembly Conference Abstracts},
  year = 2013,
  series = {EGU General Assembly Conference Abstracts},
  volume = 15,
  month = apr,
  eid = {EGU2013},
  pages = {3040},
  abstract = {{Mars and Venus can both be reached by Solar Energetic Particles (SEPs). 
Such high energy particles (protons, multiply charged heavy ions,
electrons) penetrate the upper atmospheres of Mars and Venus because, in
contrast to Earth, these bodies do not have a significant, global,
intrinsic magnetic field to exclude them. One especially well
documented, complex and prolonged SEP took in place in early 1989 (Solar
Cycle 23) when the Phobos-2 spacecraft was orbiting Mars. This
spacecraft had a dedicated high energy particle instrument onboard
(SLED), which measured particles with energies in the keV range up to a
few tens of MeV. There was in addition a magnetometer as well as solar
wind plasma detectors onboard which together provided complementary data
to support contemporaneous studies of the background SEP environment.
Currently, while the Sun is displaying maximum activity (Solar Cycle
24), Mars and Venus are being individually monitored by instrumentation
flown onboard the Mars Express (MEX) and Venus Express (VEX) spacecraft.
Neither of these spacecraft carry a high energy particle instrument but
their Analyzer of Space Plasmas and Energetic Atoms (ASPERA) experiments
(ASPERA-3 on MEX and ASPERA-4 on VEX), can be used to study SEPs
integrated over E {\ge} \~{}30 MeV which penetrate the instrument hardware
and form background counts in the plasma data. In the present work we
present  SEP events measured at Mars and Venus based on Phobos-2, 1989
data and  on, more recent, MEX and VEX (identified from particle
background) observations. We further introduce numerical global SEP
simulations of the measured events based on 3-D self-consistent hybrid
models (HYB-Mars and HYB-Venus).  Through comparing the in situ SEP
observations with these simulations, new insights are provided into the
properties of the measured SEPs as well as into how their individual
planetary bow shocks and magnetospheres affect the characteristics of
their ambient Martian and Venusian SEP environments.
}},
  url = {http://www.aspera-3.org/EGU2013_McKenna-Lawlor.pdf},
  adsurl = {http://adsabs.harvard.edu/abs/2013EGUGA..15.3040M},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}
@article{2012AGUFM.P43D1939K,
  author = {{Kallio}, E. and {Dyadechkin}, S. and {Jarvinen}, R. and {Wurz}, P. and 
	{Barabash}, S. and {Rantala}, A. and {Alho}, M.},
  title = {{Kinetic effects on Lunar plasma environment on global scale, mesoscale and microscale}},
  journal = {AGU Fall Meeting Abstracts},
  keywords = {[5421] PLANETARY SCIENCES: SOLID SURFACE PLANETS / Interactions with particles and fields, [6025] PLANETARY SCIENCES: COMETS AND SMALL BODIES / Interactions with solar wind plasma and fields},
  year = 2012,
  month = dec,
  pages = {D1939},
  abstract = {{Recent Lunar missions have shown that the solar wind interaction with
the Moon is complex and scientifically more interesting than anticipated
before, as shown by new in situ plasma, neutral atom and magnetic field
observations. Especially, an unexpectedly high fraction of the incident
solar wind protons is reflected from the surface, and even larger
fraction by the Lunar magnetic anomalies. This effect has been observed
both by measuring deviated solar wind flow near the magnetic anomalies
and by observing decreased flux of energetic neutral hydrogen atoms,
ENAs, from the surface region of strong magnetic anomalies. These ''macro
scale'' processes affect the properties of plasma near the Lunar surface.
Consequently, also physical processes at ''micro scales'' within the Debye
sheath layer, where the electric potential of the surface and near
surface region are controlled by photoelectrons and solar wind
particles, are affected. In this work we introduce two numerical kinetic
simulation models developed to study the solar wind interaction with the
Moon: (1) a hybrid model (HYB-Moon) to study macro scale processes and
(2) a full kinetic PIC model to study micro scale processes. Both models
are part of the HYB planetary plasma modelling platform developed at the
Finnish Meteorological Institute. In the hybrid model ions are modelled
as particles while electrons form a charge neutralizing massless fluid.
In the Particle-in-cell (PIC) simulation both ions and electrons are
modelled as particles. In the presentation we show results based on
these models. A schematic illustration of plasmas and fields which
affect the lunar dust-plasma environment near the lunar surface:
photoelectrons (e-hf), solar wind electrons (e-sw) and ions (H+sw), dust
electrons (e-dust), dust particles (q dust), electric field (E) and
magnetic field. Because of the non-zero magnetic field associated with
the interplanetary magnetic field (Bsw), electric currents in the plasma
and the lunar magnetic anomalies, the charged particle follow gyromotion
around the magnetic field. The electric field contains the convective
electric field of the solar wind (Esw) and the electric field associated
with the charge separation within the potential sheath and possible also
within magnetic anomalies. The length scale of the potential sheath is
the Debye length (lamda D). See Kallio et al., ''Kinetic effects on Lunar
plasma environment on global scale, mesoscale and microscale'' (PSS,
2012, submitted) for details.
}},
  adsurl = {http://adsabs.harvard.edu/abs/2012AGUFM.P43D1939K},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}
@inproceedings{2012epsc.conf..339K,
  author = {{Kallio}, E. and {Jarvinen}, R. and {Dyadechkin}, S. and {Wurz}, P. and 
	{Barabash}, S. and {Rantala}, A. and {Alho}, M.},
  title = {{Modelling of the solar wind interaction with the Moon: Magnetic anomaly region and Debye sheath layer near the surface}},
  booktitle = {European Planetary Science Congress 2012},
  year = 2012,
  month = sep,
  eid = {EPSC2012},
  pages = {339},
  abstract = {{The recent lunar missions have shown that the solar wind interaction
with the Moon is more complex than anticipated before and scientifically
highly interesting, as shown by new in situ plasma, neutral atom and
magnetic field observations. Especially, an unexpectedly high fraction
of the incident solar wind protons is reflected from the surface, and
even larger fraction at the location of lunar magnetic anomalies. This
effect has been observed both by measuring deviated solar wind flow near
the magnetic anomalies and by observing decreased flux of energetic
neutral hydrogen atoms, H-ENAs, from the surface region of strong
magnetic anomalies [1, 2, 3]. These global scale processes affect the
properties of plasma near the lunar surface. Consequently, also physical
processes at much smaller spatial scale, within the Debye sheath layer,
where the electric potential of the surface and near surface region are
controlled by photoelectrons and solar wind particles, are affected. In
this work we use two numerical kinetic simulation models developed to
study the solar wind interaction with the Moon: (1) a local 3-D hybrid
model (HYBMoon) to study a plasma region near lunar magnetic anomaly and
(2) a full kinetic 1-D electrostatic Particle-In-Cell PIC model (HYB-es)
to study the Debye layer a few meters above the surface. Both models are
part of the HYB planetary plasma modelling platform developed at the
Finnish Meteorological Institute. In the hybrid model ions are modelled
as particles while electrons form a charge neutralizing massless fluid.
In the PIC simulation both ions and electrons are modelled as particles.
In the presentation we will show results based on these models.
}},
  adsurl = {http://adsabs.harvard.edu/abs/2012epsc.conf..339K},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}
@inproceedings{2012EGUGA..14.1509M,
  author = {{McKenna-Lawlor}, S. and {Kallio}, E. and {Alho}, M. and {Jarvinen}, R. and 
	{Afonin}, V.},
  title = {{Comparisons between in situ measurements of the magnetic shadowing of high energy ions at Mars and hybrid model simulations, using contemporary particle and field measurements to define the upstream interplanetary conditions}},
  booktitle = {EGU General Assembly Conference Abstracts},
  year = 2012,
  series = {EGU General Assembly Conference Abstracts},
  volume = 14,
  editor = {{Abbasi}, A. and {Giesen}, N.},
  month = apr,
  pages = {1509},
  abstract = {{Energetic particle data recorded by the SLED instrument aboard Phobos-2
while in circular orbit about Mars in March, 1989 showed the presence of
magnetic shadowing.  A 3-D, self consistent, hybrid model (HYB-Mars)
supplemented by test particle simulations was developed to study the
response of the Martian plasma environment to solar disturbances and to
interpret, in particular, the SLED observations. The magnetic and
electric fields, as well as the properties of high energy ions, present
at Mars under conditions of extreme solar disturbance can be derived
from HYB-Mars. Our initial study [McKenna-Lawlor et al., EPS 2011, in
press] showed that the HYB-Mars model predicted an already
well-documented plasma phenomenon at the planet, namely 'sw-flow
shadowing (identified in the measurements of the ASPERA (plasma)
experiment aboard Phobos-2). HYB further, importantly, predicted the
occurrence of magnetic shadowing which is qualitatively similar to that
recorded by SLED. The simulations in addition suggested that the
configuration of a magnetic shadow depends on the pertaining solar wind
density and velocity, and on the magnitude and direction of the
interplanetary magnetic field.   The present work presents a more
detailed study where plasma and magnetic field inputs to the HYB model
come from measurements made aboard Phobos-2 contemporaneously with the
SLED observations.  In this way it is possible to realistically match
the upstream interplanetary conditions with the configuration of the
magnetic shadow recorded at various energies in the SLED data. 
One-to-one comparisons between the SLED observations and simulated high
energy H+ fluxes will be presented in this context and similarities and
differences between the observations and simulations discussed.
}},
  adsurl = {http://adsabs.harvard.edu/abs/2012EGUGA..14.1509M},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}
@inproceedings{2011epsc.conf..462M,
  author = {{McKenna-Lawlor}, S. and {Kallio}, E. and {Jarvinen}, R. and 
	{Alho}, M. and {Afonin}, V.~V.},
  title = {{Magnetic shadowing of high energy ions at Mars: Comparison of SLED/Phobos-2 observations and hybrid model simulations}},
  booktitle = {EPSC-DPS Joint Meeting 2011},
  year = 2011,
  month = oct,
  pages = {462},
  abstract = {{Energetic particle data recorded by the SLED instrument aboard Phobos-2
while in circular orbit about Mars in March, 1989 showed the presence of
magnetic shadowing. A 3-D, self-consistent, hybrid model (HYB-Mars)
supplemented by test particle simulations has been developed to study
the response of the Martian plasma environment to the solar disturbances
concerned and to interpret the SLED observations. During Extreme Solar
Events, the magnetic and electric fields as well as the properties of
high energy ions present at Mars can be derived from HYB-Mars. It has
already been shown [1] that the hybrid modeling results in magnetic
shadowing which is qualitatively similar to that recorded by SLED at
Mars while demonstrating in addition that the size of the shadow
decreases with the energy of the ions in the range analyzed (50 keV to
3.2 MeV). In this presentation the initial qualitative study outlined
above has been extended to provide a more quantitative analysis by
comparing the observed and the simulated fluxes of high energy ions at
Mars during Extreme Flaring.
}},
  adsurl = {http://adsabs.harvard.edu/abs/2011epsc.conf..462M},
  adsnote = {Provided by the SAO/NASA Astrophysics Data System}
}

This file was generated by bibtex2html 1.98.