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Lindkvist, Jesper, DoctorORCID iD iconorcid.org/0000-0002-5765-2806
Publications (10 of 13) Show all publications
Vorburger, A., Pfleger, M., Lindkvist, J., Holmström, M., Lammer, H., Lichtenegger, H. I. M., . . . Wurz, P. (2019). Three-Dimensional Modeling of Callisto's Surface Sputtered Exosphere Environment. Journal of Geophysical Research - Space Physics
Open this publication in new window or tab >>Three-Dimensional Modeling of Callisto's Surface Sputtered Exosphere Environment
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2019 (English)In: Journal of Geophysical Research - Space Physics, ISSN 2169-9380, E-ISSN 2169-9402Article in journal (Refereed) Epub ahead of print
Abstract [en]

We study the release of various elements from Callisto's surface into its exosphere by plasma sputtering. The cold Jovian plasma is simulated with a 3‐D plasma‐planetary interaction hybrid model, which produces 2‐D surface precipitation maps for magnetospheric H+, O+, O++, and S++. For the hot Jovian plasma, we assume isotropic precipitation onto the complete spherical surface. Two scenarios are investigated: one where no ionospheric shielding takes place and accordingly full plasma penetration is implemented (no‐ionosphere scenario) and one where an ionosphere lets virtually none of the cold plasma but all of the hot plasma reach Callisto's surface (ionosphere scenario). In the 3‐D exosphere model, neutral particles are sputtered from the surface and followed on their individual trajectories. The 3‐D density profiles show that whereas in the no‐ionosphere scenario the ram direction is favored, the ionosphere scenario produces almost uniform density profiles. In addition, the density profiles in the ionosphere scenario are reduced by a factor of ∼2.5 with respect to the no‐ionosphere scenario. We find that the Neutral Gas and Ion Mass Spectrometer, which is part of the Particle Environment Package on board the JUpiter ICy moons Explorer mission, will be able to detect the different sputter populations from Callisto's icy surface and the major sputter populations from Callisto's nonicy surface. The chemical composition of Callisto's exosphere can be directly linked to the chemical composition of its surface and will offer us information not only on Callisto's formation scenario but also on the building blocks of the Jupiter system.

National Category
Fusion, Plasma and Space Physics
Identifiers
urn:nbn:se:umu:diva-119795 (URN)10.1029/2019JA026610 (DOI)2-s2.0-85070838044 (Scopus ID)
Note

Originally included in thesis in manuscript form with title "3D-modeling of Callisto's exosphere caused by thermal plasma sputtering" by the authors Pfleger, Martin; Lindkvist, Jesper; Vorburger, Audrey; Holmström, Mats; Lichtenegger, Herbert I. M.; Lammer, Helmut; Wurz, Peter; Barabash, Stas.

Available from: 2016-04-27 Created: 2016-04-27 Last updated: 2019-08-27
Fatemi, S., Poirier, N., Holmström, M., Lindkvist, J., Wieser, M. & Barabash, S. (2018). A modelling approach to infer the solar wind dynamic pressure from magnetic field observations inside Mercury's magnetosphere. Astronomy and Astrophysics, 614, Article ID A132.
Open this publication in new window or tab >>A modelling approach to infer the solar wind dynamic pressure from magnetic field observations inside Mercury's magnetosphere
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2018 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 614, article id A132Article in journal (Refereed) Published
Abstract [en]

Aims: The lack of an upstream solar wind plasma monitor when a spacecraft is inside the highly dynamic magnetosphere of Mercury limits interpretations of observed magnetospheric phenomena and their correlations with upstream solar wind variations.

Methods: We used AMITIS, a three-dimensional GPU-based hybrid model of plasma (particle ions and fluid electrons) to infer the solar wind dynamic pressure and Alfvén Mach number upstream of Mercury by comparing our simulation results with MESSENGER magnetic field observations inside the magnetosphere of Mercury. We selected a few orbits of MESSENGER that have been analysed and compared with hybrid simulations before. Then we ran a number of simulations for each orbit (~30–50 runs) and examined the effects of the upstream solar wind plasma variations on the magnetic fields observed along the trajectory of MESSENGER to find the best agreement between our simulations and observations.

Results: We show that, on average, the solar wind dynamic pressure for the selected orbits is slightly lower than the typical estimated dynamic pressure near the orbit of Mercury. However, we show that there is a good agreement between our hybrid simulation results and MESSENGER observations for our estimated solar wind parameters. We also compare the solar wind dynamic pressure inferred from our model with those predicted previously by the WSA-ENLIL model upstream of Mercury, and discuss the agreements and disagreements between the two model predictions. We show that the magnetosphere of Mercury is highly dynamic and controlled by the solar wind plasma and interplanetary magnetic field. In addition, in agreement with previous observations, our simulations show that there are quasi-trapped particles and a partial ring current-like structure in the nightside magnetosphere of Mercury, more evident during a northward interplanetary magnetic field (IMF). We also use our simulations to examine the correlation between the solar wind dynamic pressure and stand-off distance of the magnetopause and compare it with MESSENGER observations. We show that our model results are in good agreement with the response of the magnetopause to the solar wind dynamic pressure, even during extreme solar events. We also show that our model can be used as a virtual solar wind monitor near the orbit of Mercury and this has important implications for interpretation of observations by MESSENGER and the future ESA/JAXA mission to Mercury, BepiColombo.

Keywords
planets and satellites: terrestrial planets, methods: numerical, solar-terrestrial relations, solar wind, Sun: activity, magnetic fields
National Category
Fusion, Plasma and Space Physics
Identifiers
urn:nbn:se:umu:diva-147410 (URN)10.1051/0004-6361/201832764 (DOI)000436411500002 ()2-s2.0-85049600986 (Scopus ID)
Available from: 2018-05-03 Created: 2018-05-03 Last updated: 2018-09-28Bibliographically approved
Hamrin, M., Gunell, H., Lindkvist, J., Lindqvist, P.-A., Ergun, R. E. & Giles, B. L. (2018). Bow shock generator current systems: MMS observations of possible current closure. Journal of Geophysical Research - Space Physics, 123, 242-258
Open this publication in new window or tab >>Bow shock generator current systems: MMS observations of possible current closure
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2018 (English)In: Journal of Geophysical Research - Space Physics, ISSN 2169-9380, E-ISSN 2169-9402, Vol. 123, p. 242-258Article in journal (Refereed) Published
Abstract [en]

We use data from the first two dayside seasons of the Magnetospheric Multiscale (MMS) mission to study current systems associated with quasi‐perpendicular bow shocks of generator type. We have analyzed 154 MMS bow shock crossings near the equatorial plane. We compute the current density during the crossings and conclude that the component perpendicular to the shock normal (J⊥) is consistent with a pileup of the interplanetary magnetic field (IMF) inside the magnetosheath. For predominantly southward IMF, we observe a component Jn parallel (antiparallel) to the normal for GSM Y> 0 (<0), and oppositely directed for northward IMF. This indicates current closure across the equatorial magnetosheath, and it is observed for IMF clock angles near 0∘ and 180∘. To our knowledge, these are the first observational evidence for bow shock current closure across the magnetosheath. Since we observe no clear signatures of |J⊥| decreasing toward large |Y| we suggest that the main region of current closure is further tailward, outside MMS probing region. For IMF clock angles near 90∘, we find indications of the current system being tilted toward the north‐south direction, obtaining a significant Jz component, and we suggest that the current closes off the equatorial plane at higher latitudes where the spacecraft are not probing. The observations are complicated for several reasons. For example, variations in the solar wind and the magnetospheric currents and loads affect the closure, and Jn is distributed over large regions, making it difficult to resolve inside the magnetosheath proper.

National Category
Fusion, Plasma and Space Physics
Identifiers
urn:nbn:se:umu:diva-143055 (URN)10.1002/2017JA024826 (DOI)000425637600018 ()
Available from: 2017-12-14 Created: 2017-12-14 Last updated: 2018-06-09Bibliographically approved
Lindkvist, J., Hamrin, M., Gunell, H., Nilsson, H., Simon Wedlund, C., Kallio, E., . . . Karlsson, T. (2018). Energy conversion in cometary atmospheres: Hybrid modeling of 67P/Churyumov-Gerasimenko. Astronomy and Astrophysics, 616, Article ID A81.
Open this publication in new window or tab >>Energy conversion in cometary atmospheres: Hybrid modeling of 67P/Churyumov-Gerasimenko
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2018 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 616, article id A81Article in journal (Refereed) Published
Abstract [en]

Aims. We wish to investigate the energy conversion between particles and electromagnetic fields and determine the location where it occurs in the plasma environment of comets.

Methods. We used a hybrid plasma model that included photoionization, and we considered two cases of the solar extreme ultraviolet flux. Other parameters corresponded to the conditions of comet 67P/Churyumov-Gerasimenko at a heliocentric distance of 1.5 AU.

Results. We find that a shock-like structure is formed upstream of the comet and acts as an electromagnetic generator, similar to the bow shock at Earth that slows down the solar wind. The Poynting flux transports electromagnetic energy toward the inner coma, where newly born cometary ions are accelerated. Upstream of the shock-like structure, we find local energy transfer from solar wind ions to cometary ions. We show that mass loading can be a local process with a direct transfer of energy, but also part of a dynamo system with electromagnetic generators and loads.

Conclusions. The energization of cometary ions is governed by a dynamo system for weak ionization, but changes into a large conversion region with local transfer of energy directly from solar wind protons for high ionization.

Place, publisher, year, edition, pages
EDP Sciences, 2018
Keywords
comets: individual: 67P/Churyumov-Gerasimenko, Sun: UV radiation, solar wind, methods: numerical, plasmas, acceleration of particles
National Category
Fusion, Plasma and Space Physics
Identifiers
urn:nbn:se:umu:diva-148207 (URN)10.1051/0004-6361/201732353 (DOI)000442541100001 ()
Funder
Swedish National Space Board, 201/15Swedish National Space Board, 112/13Swedish Research Council, 2015-04187
Available from: 2018-05-30 Created: 2018-05-30 Last updated: 2018-09-10Bibliographically approved
Behar, E., Tabone, B., Saillenfest, M., Henri, P., Deca, J., Lindkvist, J., . . . Nilsson, H. (2018). Solar wind dynamics around a comet: A 2D semi-analytical kinetic model. Astronomy and Astrophysics, 620, Article ID A35.
Open this publication in new window or tab >>Solar wind dynamics around a comet: A 2D semi-analytical kinetic model
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2018 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 620, article id A35Article in journal (Refereed) Published
Abstract [en]

Aims. We aim at analytically modelling the solar wind proton trajectories during their interaction with a partially ionised cometary atmosphere, not in terms of bulk properties of the flow but in terms of single particle dynamics.

Methods. We first derive a generalised gyromotion, in which the electric field is reduced to its motional component. Steady-state is assumed, and simplified models of the cometary density and of the electron fluid are used to express the force experienced by individual solar wind protons during the interaction.

Results. A three-dimensional (3D) analytical expression of the gyration of two interacting plasma beams is obtained. Applying it to a comet case, the force on protons is always perpendicular to their velocity and has an amplitude proportional to 1/r2. The solar wind deflection is obtained at any point in space. The resulting picture presents a caustic of intersecting trajectories, and a circular region is found that is completely free of particles. The particles do not lose any kinetic energy and this absence of deceleration, together with the solar wind deflection pattern and the presence of a solar wind ion cavity, is in good agreement with the general results of the Rosetta mission.

Conclusions. The qualitative match between the model and the in situ data highlights how dominant the motional electric field is throughout most of the interaction region for the solar wind proton dynamics. The model provides a simple general kinetic description of how momentum is transferred between these two collisionless plasmas. It also shows the potential of this semi-analytical model for a systematic quantitative comparison to the data.

Place, publisher, year, edition, pages
EDP Sciences, 2018
Keywords
comets: general, methods: analytical, plasmas
National Category
Astronomy, Astrophysics and Cosmology
Identifiers
urn:nbn:se:umu:diva-154349 (URN)10.1051/0004-6361/201832736 (DOI)000451249600003 ()
Available from: 2018-12-17 Created: 2018-12-17 Last updated: 2018-12-18Bibliographically approved
Gunell, H., Goetz, C., Wedlund, C. S., Lindkvist, J., Hamrin, M., Nilsson, H., . . . Holmström, M. (2018). The infant bow shock: a new frontier at a weak activity comet [Letter to the editor]. Astronomy and Astrophysics, 619, Article ID L2.
Open this publication in new window or tab >>The infant bow shock: a new frontier at a weak activity comet
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2018 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 619, article id L2Article in journal, Letter (Refereed) Published
Abstract [en]

The bow shock is the first boundary the solar wind encounters as it approaches planets or comets. The Rosetta spacecraft was able to observe the formation of a bow shock by following comet 67P/Churyumov-Gerasimenko toward the Sun, through perihelion, and back outward again. The spacecraft crossed the newly formed bow shock several times during two periods a few months before and after perihelion; it observed an increase in magnetic field magnitude and oscillation amplitude, electron and proton heating at the shock, and the diminution of the solar wind further downstream. Rosetta observed a cometary bow shock in its infancy, a stage in its development not previously accessible to in situ measurements at comets and planets.

Place, publisher, year, edition, pages
EDP Sciences, 2018
Keywords
comets: general, comets: individual: 67P/Churyumov-Gerasimenko, plasmas, shock waves
National Category
Astronomy, Astrophysics and Cosmology Fusion, Plasma and Space Physics
Identifiers
urn:nbn:se:umu:diva-153545 (URN)10.1051/0004-6361/201834225 (DOI)000449276800001 ()
Funder
Swedish National Space Board, 201/15
Available from: 2018-11-22 Created: 2018-11-22 Last updated: 2018-11-22Bibliographically approved
Gunell, H., Maggiolo, R., Nilsson, H., Stenberg Wieser, G., Slapak, R., Lindkvist, J., . . . De Keyser, J. (2018). Why an intrinsic magnetic field does not protect a planet against atmospheric escape [Letter to the editor]. Astronomy and Astrophysics, 614, Article ID L3.
Open this publication in new window or tab >>Why an intrinsic magnetic field does not protect a planet against atmospheric escape
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2018 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 614, article id L3Article in journal, Letter (Refereed) Published
Abstract [en]

The presence or absence of a magnetic field determines the nature of how a planet interacts with the solar wind and what paths are available for atmospheric escape. Magnetospheres form both around magnetised planets, such as Earth, and unmagnetised planets, like Mars and Venus, but it has been suggested that magnetised planets are better protected against atmospheric loss. However, the observed mass escape rates from these three planets are similar (in the approximate (0.5–2) kg s−1 range), putting this latter hypothesis into question. Modelling the effects of a planetary magnetic field on the major atmospheric escape processes, we show that the escape rate can be higher for magnetised planets over a wide range of magnetisations due to escape of ions through the polar caps and cusps. Therefore, contrary to what has previously been believed, magnetisation is not a sufficient condition for protecting a planet from atmospheric loss. Estimates of the atmospheric escape rates from exoplanets must therefore address all escape processes and their dependence on the planet’s magnetisation.

Keywords
Planets and satellites: magnetic fields, Planets and satellites: atmospheres, plasmas
National Category
Fusion, Plasma and Space Physics
Research subject
Space and Plasma Physics; Space Physics
Identifiers
urn:nbn:se:umu:diva-148205 (URN)10.1051/0004-6361/201832934 (DOI)000435753000001 ()2-s2.0-85049562755 (Scopus ID)
Available from: 2018-05-30 Created: 2018-05-30 Last updated: 2018-11-26Bibliographically approved
Lindkvist, J., Holmström, M., Fatemi, S., Wieser, M. & Barabash, S. (2017). Ceres interaction with the solar wind. Geophysical Research Letters, 44(5), 2070-2077
Open this publication in new window or tab >>Ceres interaction with the solar wind
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2017 (English)In: Geophysical Research Letters, ISSN 0094-8276, E-ISSN 1944-8007, Vol. 44, no 5, p. 2070-2077Article in journal (Refereed) Published
Abstract [en]

The solar wind interaction with Ceres is studied for a high water vapor release from its surface using a hybrid model including photoionization. We use a water vapor production rate of 6 kg/s, thought to be due to subsurface sublimation, corresponding to a detection on 6 March 2013 by the Herschel Space Observatory. We present the general morphology of the plasma interactions, both close to Ceres and on a larger scale. Mass loading of water ions causes a magnetic pileup region in front of Ceres, where the solar wind deflects up to 15 ∘ and slows down by 15%. The global plasma interaction with Ceres is not greatly affected by the source location of water vapor nor on gravity, only on the production rate of water vapor. On a global scale, Ceres has a comet-like interaction with the solar wind with observable perturbations farther than 250 Ceres radii downstream of the body.

National Category
Fusion, Plasma and Space Physics
Research subject
Space and Plasma Physics
Identifiers
urn:nbn:se:umu:diva-119797 (URN)10.1002/2016GL072375 (DOI)000398183700003 ()
Funder
Swedish National Space Board
Available from: 2016-04-27 Created: 2016-04-27 Last updated: 2018-06-07Bibliographically approved
Simon Wedlund, C., Alho, M., Gronoff, G., Kallio, E., Gunell, H., Nilsson, H., . . . Miloch, W. J. (2017). Hybrid modelling of cometary plasma environments: I. Impact of photoionisation, charge-exchange and electron ionisation on bow shock and cometopause at 67P/Churyumov-Gerasimenko. Astronomy and Astrophysics, 604, Article ID A73.
Open this publication in new window or tab >>Hybrid modelling of cometary plasma environments: I. Impact of photoionisation, charge-exchange and electron ionisation on bow shock and cometopause at 67P/Churyumov-Gerasimenko
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2017 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 604, article id A73Article in journal (Refereed) Published
Abstract [en]

Context. The ESA/Rosetta mission made it possible to monitor the plasma environment of a comet, from near aphelion to perihelion conditions. To understand the complex dynamics and plasma structures found at the comet, a modelling effort must be carried out in parallel. Aims. Firstly, we present a 3D hybrid model of the cometary plasma environment including photoionisation, solar wind charge exchange, and electron ionisation reactions; this model is used in stationary and dynamic conditions (mimicking the solar wind variations), and is thus especially adapted to a weakly outgassing comet such as 67P/Churyumov-Gerasimenko, the target of the ESA/Rosetta mission. Secondly, we use the model to study the respective effects of ionisation processes on the formation of the dayside macroscopic magnetic and density boundaries upstream of comet 67P in perihelion conditions at 1.3 AU. Thirdly, we explore and discuss the effects of these processes on the magnetic field line draping, ionisation rates, and composition in the context of the Rosetta mission. Methods. We used a new quasi-neutral hybrid model, originally designed for weakly magnetised planetary bodies, such as Venus, Mars, and Titan, and adapted here to comets. Ionisation processes were monitored individually and together following a probabilistic interaction scheme. Three-dimensional paraboloid fits of the bow shock surface, identified for a magnetosonic Mach number equal to 2, and of the cometopause surface, were performed for a more quantitative analysis. Results. We show that charge exchange and electron ionisation play a major role in the formation of a bow shock-like structure far upstream, while photoionisation is the main driver at and below the cometopause boundary, within 1000 km cometocentric distance. Charge exchange contributes to 42% of the total production rate in the simulation box, whereas production rates from electron ionisation and photoionisation reach 33% and 25%, respectively. We also discuss implications for Rosetta's observations, regarding the detection of the bow shock and the cometopause.

Keywords
comets: general, comets: individual: 67P/Churyumov-Gerasimenko, solar wind, plasmas, methods: numerical
National Category
Fusion, Plasma and Space Physics
Identifiers
urn:nbn:se:umu:diva-135371 (URN)10.1051/0004-6361/201730514 (DOI)000408480100077 ()
Funder
Swedish National Space Board
Available from: 2017-05-24 Created: 2017-05-24 Last updated: 2018-06-09Bibliographically approved
Khurana, K. K., Fatemi, S., Lindkvist, J., Roussos, E., Krupp, N., Holmström, M., . . . Dougherty, M. K. (2017). The role of plasma slowdown in the generation of Rhea's Alfvén wings. Journal of Geophysical Research - Space Physics, 122(2), 1778-1788
Open this publication in new window or tab >>The role of plasma slowdown in the generation of Rhea's Alfvén wings
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2017 (English)In: Journal of Geophysical Research - Space Physics, ISSN 2169-9380, E-ISSN 2169-9402, Vol. 122, no 2, p. 1778-1788Article in journal (Refereed) Published
Abstract [en]

Alfvén wings are known to form when a conducting or mass-loading object slows down a flowing plasma in its vicinity. Alfvén wings are not expected to be generated when an inert moon such as Rhea interacts with Saturn's magnetosphere, where the plasma impacting the moon is absorbed and the magnetic flux passes unimpeded through the moon. However, in two close polar passes of Rhea, Cassini clearly observed magnetic field signatures consistent with Alfvén wings. In addition, observations from a high-inclination flyby (Distance > 100 R Rh ) of Rhea on 3 June 2010 showed that the Alfvén wings continue to propagate away from Rhea even at this large distance. We have performed three-dimensional hybrid simulations of Rhea's interaction with Saturn's magnetosphere which show that the wake refilling process generates a plasma density gradient directed in the direction of corotating plasma. The resulting plasma pressure gradient exerts a force directed toward Rhea and slows down the plasma streaming into the wake along field lines. As on the same field lines, outside of the wake, the plasma continues to move close to its full speed, this differential motion of plasma bends the magnetic flux tubes, generating Alfvén wings in the wake. The current system excited by the Alfvén wings transfers momentum to the wake plasma extracting it from plasma outside the wake. Our work demonstrates that Alfvén wings can be excited even when a moon does not possess a conducting exosphere.

National Category
Fusion, Plasma and Space Physics
Research subject
Space and Plasma Physics
Identifiers
urn:nbn:se:umu:diva-131165 (URN)10.1002/2016JA023595 (DOI)000397022900025 ()
Funder
Swedish National Space Board
Available from: 2017-02-07 Created: 2017-02-07 Last updated: 2018-06-09Bibliographically approved
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Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-5765-2806

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