KOBV Portal

1

Online Resource

Hybrid-Vlasov modelling of nightside auroral proton precipitation during southward interplanetary magnetic field conditions

Grandin, Maxime ; Battarbee, Markus ; Osmane, Adnane ; [et al.]

Copernicus GmbH ; 2019

In: Annales Geophysicae Vol. 37, No. 5 ( 2019-09-10), p. 791-806

add to watchlist on the watchlist

Details

In: Annales Geophysicae, Copernicus GmbH, Vol. 37, No. 5 ( 2019-09-10), p. 791-806

Abstract: Abstract. Particle precipitation plays a key role in the coupling of the terrestrial magnetosphere and ionosphere by modifying the upper atmospheric conductivity and chemistry, driving field-aligned currents, and producing aurora. Yet quantitative observations of precipitating fluxes are limited, since ground-based instruments can only provide indirect measurements of precipitation, while particle telescopes aboard spacecraft merely enable point-like in situ observations with an inherently coarse time resolution above a given location. Further, orbit timescales generally prevent the analysis of whole events. On the other hand, global magnetospheric simulations can provide estimations of particle precipitation with a global view and higher time resolution. We present the first results of auroral (∼1–30 keV) proton precipitation estimation using the Vlasiator global hybrid-Vlasov model in a noon–midnight meridional plane simulation driven by steady solar wind with a southward interplanetary magnetic field. We first calculate the bounce loss-cone angle value at selected locations in the simulated nightside magnetosphere. Then, using the velocity distribution function representation of the proton population at those selected points, we study the population inside the loss cone. This enables the estimation of differential precipitating number fluxes as would be measured by a particle detector aboard a low-Earth-orbiting (LEO) spacecraft. The obtained differential flux values are in agreement with a well-established empirical model in the midnight sector, as are the integral energy flux and mean precipitating energy. We discuss the time evolution of the precipitation parameters derived in this manner in the global context of nightside magnetospheric activity in this simulation, and we find in particular that precipitation bursts of 〈1 min duration can be self-consistently and unambiguously associated with dipolarising flux bundles generated by tail reconnection. We also find that the transition region seems to partly regulate the transmission of precipitating protons to the inner magnetosphere, suggesting that it has an active role in regulating ionospheric precipitation.

Type of Medium: Online Resource

ISSN: 1432-0576

URL: Article

DOI: 10.5194/angeo-37-791-2019

DOI: 10.5194/angeo-37-791-2019-supplement

Language: English

Publisher: Copernicus GmbH

Publication Date: 2019

detail.hit.zdb_id: 1458425-6

Bookmarklink

Library	Location	Call Number	Volume/Issue/Year	Availability

Others were also interested in ...

Online Resource

Open Access Request

Availability (electronic / print)

Link to publisher

2

Online Resource

Magnetosheath jet properties and evolution as determined by a global hybrid-Vlasov simulation

Palmroth, Minna ; Hietala, Heli ; Plaschke, Ferdinand ; [et al.]

Copernicus GmbH ; 2018

In: Annales Geophysicae Vol. 36, No. 5 ( 2018-09-07), p. 1171-1182

add to watchlist on the watchlist

Details

In: Annales Geophysicae, Copernicus GmbH, Vol. 36, No. 5 ( 2018-09-07), p. 1171-1182

Abstract: Abstract. We use a global hybrid-Vlasov simulation for the magnetosphere, Vlasiator, to investigate magnetosheath high-speed jets. Unlike many other hybrid-kinetic simulations, Vlasiator includes an unscaled geomagnetic dipole, indicating that the simulation spatial and temporal dimensions can be given in SI units without scaling. Thus, for the first time, this allows investigating the magnetosheath jet properties and comparing them directly with the observed jets within the Earth's magnetosheath. In the run shown in this paper, the interplanetary magnetic field (IMF) cone angle is 30∘, and a foreshock develops upstream of the quasi-parallel magnetosheath. We visually detect a structure with high dynamic pressure propagating from the bow shock through the magnetosheath. The structure is confirmed as a jet using three different criteria, which have been adopted in previous observational studies. We compare these criteria against the simulation results. We find that the magnetosheath jet is an elongated structure extending earthward from the bow shock by ∼2.6 RE, while its size perpendicular to the direction of propagation is ∼0.5 RE. We also investigate the jet evolution and find that the jet originates due to the interaction of the bow shock with a high-dynamic-pressure structure that reproduces observational features associated with a short, large-amplitude magnetic structure (SLAMS). The simulation shows that magnetosheath jets can develop also under steady IMF, as inferred by observational studies. To our knowledge, this paper therefore shows the first global kinetic simulation of a magnetosheath jet, which is in accordance with three observational jet criteria and is caused by a SLAMS advecting towards the bow shock.

Type of Medium: Online Resource

ISSN: 1432-0576

URL: Article

DOI: 10.5194/angeo-36-1171-2018

DOI: 10.5194/angeo-36-1171-2018-supplement

Language: English

Publisher: Copernicus GmbH

Publication Date: 2018

detail.hit.zdb_id: 1458425-6

Bookmarklink

Library	Location	Call Number	Volume/Issue/Year	Availability

Others were also interested in ...

Online Resource

Open Access Request

Availability (electronic / print)

Link to publisher

3

Online Resource

Helium in the Earth's foreshock: a global Vlasiator survey

Battarbee, Markus ; Blanco-Cano, Xóchitl ; Turc, Lucile ; [et al.]

Copernicus GmbH ; 2020

In: Annales Geophysicae Vol. 38, No. 5 ( 2020-10-20), p. 1081-1099

add to watchlist on the watchlist

Details

In: Annales Geophysicae, Copernicus GmbH, Vol. 38, No. 5 ( 2020-10-20), p. 1081-1099

Abstract: Abstract. The foreshock is a region of space upstream of the Earth's bow shock extending along the interplanetary magnetic field (IMF). It is permeated by shock-reflected ions and electrons, low-frequency waves, and various plasma transients. We investigate the extent of the He2+ foreshock using Vlasiator, a global hybrid-Vlasov simulation. We perform the first numerical global survey of the helium foreshock and interpret some historical foreshock observations in a global context. The foreshock edge is populated by both proton and helium field-aligned beams, with the proton foreshock extending slightly further into the solar wind than the helium foreshock and both extending well beyond the ultra-low frequency (ULF) wave foreshock. We compare our simulation results with Magnetosphere Multiscale (MMS) Hot Plasma Composition Analyzer (HPCA) measurements, showing how the gradient of suprathermal ion densities at the foreshock crossing can vary between events. Our analysis suggests that the IMF cone angle and the associated shock obliquity gradient can play a role in explaining this differing behaviour. We also investigate wave–ion interactions with wavelet analysis and show that the dynamics and heating of He2+ must result from proton-driven ULF waves. Enhancements in ion agyrotropy are found in relation to, for example, the ion foreshock boundary, the ULF foreshock boundary, and specular reflection of ions at the bow shock. We show that specular reflection can describe many of the foreshock ion velocity distribution function (VDF) enhancements. Wave–wave interactions deep in the foreshock cause de-coherence of wavefronts, allowing He2+ to be scattered less than protons.

Type of Medium: Online Resource

ISSN: 1432-0576

URL: Article

DOI: 10.5194/angeo-38-1081-2020

Language: English

Publisher: Copernicus GmbH

Publication Date: 2020

detail.hit.zdb_id: 1458425-6

Bookmarklink

Library	Location	Call Number	Volume/Issue/Year	Availability

Others were also interested in ...

Online Resource

Open Access Request

Availability (electronic / print)

Link to publisher

4

Online Resource

Foreshock cavitons and spontaneous hot flow anomalies: a statistical study with a global hybrid-Vlasov simulation

Tarvus, Vertti ; Turc, Lucile ; Battarbee, Markus ; [et al.]

Copernicus GmbH ; 2021

In: Annales Geophysicae Vol. 39, No. 5 ( 2021-10-14), p. 911-928

add to watchlist on the watchlist

Details

In: Annales Geophysicae, Copernicus GmbH, Vol. 39, No. 5 ( 2021-10-14), p. 911-928

Abstract: Abstract. The foreshock located upstream of Earth's bow shock hosts a wide variety of phenomena related to the reflection of solar wind particles from the bow shock and the subsequent formation of ultra-low-frequency (ULF) waves. In this work, we investigate foreshock cavitons, which are transient structures resulting from the non-linear evolution of ULF waves, and spontaneous hot flow anomalies (SHFAs), which are thought to evolve from cavitons as they accumulate suprathermal ions while being carried to the bow shock by the solar wind. Using the global hybrid-Vlasov simulation model Vlasiator, we have conducted a statistical study in which we track the motion of individual cavitons and SHFAs in order to examine their properties and evolution. In our simulation run where the interplanetary magnetic field (IMF) is directed at a sunward–southward angle of 45∘, continuous formation of cavitons is found up to ∼11 Earth radii (RE) from the bow shock (along the IMF direction), and caviton-to-SHFA evolution takes place within ∼2 RE from the shock. A third of the cavitons in our run evolve into SHFAs, and we find a comparable amount of SHFAs forming independently near the bow shock. We compare the properties of cavitons and SHFAs to prior spacecraft observations and simulations, finding good agreement. We also investigate the variation of the properties as a function of position in the foreshock, showing that transients close to the bow shock are associated with larger depletions in the plasma density and magnetic field magnitude, along with larger increases in the plasma temperature and the level of bulk flow deflection. Our measurements of the propagation velocities of cavitons and SHFAs agree with earlier studies, showing that the transients propagate sunward in the solar wind rest frame. We show that SHFAs have a greater solar wind rest frame propagation speed than cavitons, which is related to an increase in the magnetosonic speed near the bow shock.

Type of Medium: Online Resource

ISSN: 1432-0576

URL: Article

DOI: 10.5194/angeo-39-911-2021

Language: English

Publisher: Copernicus GmbH

Publication Date: 2021

detail.hit.zdb_id: 1458425-6

Bookmarklink

Library	Location	Call Number	Volume/Issue/Year	Availability

Others were also interested in ...

Online Resource

Open Access Request

Availability (electronic / print)

Link to publisher

5

Online Resource

CME Magnetic Structure and IMF Preconditioning Affecting SEP Transport

Palmerio, Erika ; Kilpua, Emilia K. J. ; Witasse, Olivier ; [et al.]

American Geophysical Union (AGU) ; 2021

In: Space Weather Vol. 19, No. 4 ( 2021-04)

add to watchlist on the watchlist

Details

In: Space Weather, American Geophysical Union (AGU), Vol. 19, No. 4 ( 2021-04)

Abstract: We analyze the May 11, 2012 coronal mass ejections (CME) and the May 17, 2012 solar energetic particle (SEP) event through the inner heliosphere The May 11 CME appeared to rotate rapidly upon eruption and then considerably during its interplanetary propagation The May 11 CME provided direct magnetic connectivity for the efficient transport of SEPs from the May 17 event

Type of Medium: Online Resource

ISSN: 1542-7390 , 1542-7390

URL: Article

DOI: 10.1029/2020SW002654

Language: English

Publisher: American Geophysical Union (AGU)

Publication Date: 2021

detail.hit.zdb_id: 2131880-3

Bookmarklink

Library	Location	Call Number	Volume/Issue/Year	Availability

Others were also interested in ...

Online Resource

Open Access Request

Availability (electronic / print)

Link to publisher

6

Online Resource

Hybrid-Vlasov simulation of auroral proton precipitation in the cusps: Comparison of northward and southward interplanetary magnetic field driving

Grandin, Maxime ; Turc, Lucile ; Battarbee, Markus ; [et al.]

EDP Sciences ; 2020

In: Journal of Space Weather and Space Climate Vol. 10 ( 2020), p. 51-

add to watchlist on the watchlist

Details

In: Journal of Space Weather and Space Climate, EDP Sciences, Vol. 10 ( 2020), p. 51-

Abstract: Particle precipitation is a central aspect of space weather, as it strongly couples the magnetosphere and the ionosphere and can be responsible for radio signal disruption at high latitudes. We present the first hybrid-Vlasov simulations of proton precipitation in the polar cusps. We use two runs from the Vlasiator model to compare cusp proton precipitation fluxes during southward and northward interplanetary magnetic field (IMF) driving. The simulations reproduce well-known features of cusp precipitation, such as a reverse dispersion of precipitating proton energies, with proton energies increasing with increasing geomagnetic latitude under northward IMF driving, and a nonreversed dispersion under southward IMF driving. The cusp is also found more polewards in the northward IMF simulation than in the southward IMF simulation. In addition, we find that the bursty precipitation during southward IMF driving is associated with the transit of flux transfer events in the vicinity of the cusp. In the northward IMF simulation, dual lobe reconnection takes place. As a consequence, in addition to the high-latitude precipitation spot associated with the lobe reconnection from the same hemisphere, we observe lower-latitude precipitating protons which originate from the opposite hemisphere’s lobe reconnection site. The proton velocity distribution functions along the newly closed dayside magnetic field lines exhibit multiple proton beams travelling parallel and antiparallel to the magnetic field direction, which is consistent with previously reported observations with the Cluster spacecraft. In both runs, clear electromagnetic ion cyclotron waves are generated in the cusps and might further increase the calculated precipitating fluxes by scattering protons to the loss cone in the low-altitude cusp. Global kinetic simulations can improve the understanding of space weather by providing a detailed physical description of the entire near-Earth space and its internal couplings.

Type of Medium: Online Resource

ISSN: 2115-7251

URL: Article

DOI: 10.1051/swsc/2020053

Language: English

Publisher: EDP Sciences

Publication Date: 2020

detail.hit.zdb_id: 2628166-1

Bookmarklink

Library	Location	Call Number	Volume/Issue/Year	Availability

Others were also interested in ...

Online Resource

Open Access Request

Availability (electronic / print)

Link to publisher

7

Online Resource

Alterations of tactile and anatomical spatial representations of the hand after stroke

Dupin, Lucile ; Gerardin, Eloïse ; Térémetz, Maxime ; [et al.]

Elsevier BV ; 2024

In: Cortex Vol. 177 ( 2024-08), p. 68-83

add to watchlist on the watchlist

Details

In: Cortex, Elsevier BV, Vol. 177 ( 2024-08), p. 68-83

Type of Medium: Online Resource

ISSN: 0010-9452

URL: Article

DOI: 10.1016/j.cortex.2024.04.015

RVK:

XA 10000

Language: English

Publisher: Elsevier BV

Publication Date: 2024

detail.hit.zdb_id: 2080335-7

SSG: 12

SSG: 5,2

SSG: 5,21

Bookmarklink

Library	Location	Call Number	Volume/Issue/Year	Availability

Others were also interested in ...

Online Resource

Open Access Request

Availability (electronic / print)

Link to publisher

8

Online Resource

Quasi‐Parallel Shock Reformation Seen by Magnetospheric Multiscale and Ion‐Kinetic Simulations

Johlander, Andreas ; Battarbee, Markus ; Turc, Lucile ; [et al.]

American Geophysical Union (AGU) ; 2022

In: Geophysical Research Letters Vol. 49, No. 2 ( 2022-01-28)

add to watchlist on the watchlist

Details

In: Geophysical Research Letters, American Geophysical Union (AGU), Vol. 49, No. 2 ( 2022-01-28)

Abstract: We present observations of the four MMS spacecraft crossing Earth's bow shock seemingly in the reverse order The observations, supported by an ion‐kinetic simulation, reveal that short‐large amplitude magnetic structures cause the shock to reform These multispacecraft signatures can be used in the future to identify shock reformation

Type of Medium: Online Resource

ISSN: 0094-8276 , 1944-8007

URL: Article

DOI: 10.1029/2021GL096335

Language: English

Publisher: American Geophysical Union (AGU)

Publication Date: 2022

detail.hit.zdb_id: 2021599-X

detail.hit.zdb_id: 7403-2

SSG: 16,13

Bookmarklink

Library	Location	Call Number	Volume/Issue/Year	Availability

Others were also interested in ...

Online Resource

Open Access Request

Availability (electronic / print)

Link to publisher

9

Online Resource

A possible source mechanism for magnetotail current sheet flapping

Juusola, Liisa ; Pfau-Kempf, Yann ; Ganse, Urs ; [et al.]

Copernicus GmbH ; 2018

In: Annales Geophysicae Vol. 36, No. 4 ( 2018-07-27), p. 1027-1035

add to watchlist on the watchlist

Details

In: Annales Geophysicae, Copernicus GmbH, Vol. 36, No. 4 ( 2018-07-27), p. 1027-1035

Abstract: Abstract. The origin of the flapping motions of the current sheet in the Earth's magnetotail is one of the most interesting questions of magnetospheric dynamics yet to be solved. We have used a polar plane simulation from the global hybrid-Vlasov model Vlasiator to study the characteristics and source of current sheet flapping in the center of the magnetotail. The characteristics of the simulated signatures agree with observations reported in the literature. The flapping is initiated by a hemispherically asymmetric magnetopause perturbation, created by subsolar magnetopause reconnection, that is capable of displacing the tail current sheet from its nominal position. The current sheet displacement propagates downtail at the same pace as the driving magnetopause perturbation. The initial current sheet displacement launches a standing magnetosonic wave within the tail resonance cavity. The travel time of the wave within the local cavity determines the period of the subsequent flapping signatures. Compression of the tail lobes due to added flux affects the cross-sectional width of the resonance cavity as well as the magnetosonic speed within the cavity. These in turn modify the wave travel time and flapping period. The compression of the resonance cavity may also provide additional energy to the standing wave, which may lead to strengthening of the flapping signature. It may be possible that the suggested mechanism could act as a source of kink-like waves that have been observed to be emitted from the center of the tail and to propagate toward the dawn and dusk flanks.

Type of Medium: Online Resource

ISSN: 1432-0576

URL: Article

DOI: 10.5194/angeo-36-1027-2018

Language: English

Publisher: Copernicus GmbH

Publication Date: 2018

detail.hit.zdb_id: 1458425-6

Bookmarklink

Library	Location	Call Number	Volume/Issue/Year	Availability

Others were also interested in ...

Online Resource

Open Access Request

Availability (electronic / print)

Link to publisher

10

Online Resource

Cavitons and spontaneous hot flow anomalies in a hybrid-Vlasov global magnetospheric simulation

Blanco-Cano, Xochitl ; Battarbee, Markus ; Turc, Lucile ; [et al.]

Copernicus GmbH ; 2018

In: Annales Geophysicae Vol. 36, No. 4 ( 2018-08-08), p. 1081-1097

add to watchlist on the watchlist

Details

In: Annales Geophysicae, Copernicus GmbH, Vol. 36, No. 4 ( 2018-08-08), p. 1081-1097

Abstract: Abstract. In this paper we present the first identification of foreshock cavitons and the formation of spontaneous hot flow anomalies (SHFAs) with the Vlasiator global magnetospheric hybrid-Vlasov simulation code. In agreement with previous studies we show that cavitons evolve into SHFAs. In the presented run, this occurs very near the bow shock. We report on SHFAs surviving the shock crossing into the downstream region and show that the interaction of SHFAs with the bow shock can lead to the formation of a magnetosheath cavity, previously identified in observations and simulations. We report on the first identification of long-term local weakening and erosion of the bow shock, associated with a region of increased foreshock SHFA and caviton formation, and repeated shock crossings by them. We show that SHFAs are linked to an increase in suprathermal particle pitch-angle spreads. The realistic length scales in our simulation allow us to present a statistical study of global caviton and SHFA size distributions, and their comparable size distributions support the theory that SHFAs are formed from cavitons. Virtual spacecraft observations are shown to be in good agreement with observational studies.

Type of Medium: Online Resource

ISSN: 1432-0576

URL: Article

DOI: 10.5194/angeo-36-1081-2018

DOI: 10.5194/angeo-36-1081-2018-supplement

Language: English

Publisher: Copernicus GmbH

Publication Date: 2018

detail.hit.zdb_id: 1458425-6

Bookmarklink

Library	Location	Call Number	Volume/Issue/Year	Availability

Others were also interested in ...

Online Resource

Open Access Request

Availability (electronic / print)

Link to publisher

Kooperativer Bibliotheksverbund

Berlin Brandenburg