A5014786377- Ionosphere and magnetosphere dynamics
- Geomagnetism and Paleomagnetism Studies
- Solar and Space Plasma Dynamics
- Astro and Planetary Science
- Earthquake Detection and Analysis
- Magnetic Field Sensors Techniques
- Geophysics and Sensor Technology
- High-pressure geophysics and materials
- Planetary Science and Exploration
- earthquake and tectonic studies
- Advanced Fiber Optic Sensors
- Solar Radiation and Photovoltaics
- Non-Invasive Vital Sign Monitoring
- Magnetic confinement fusion research
- Cyclone Separators and Fluid Dynamics
- Laser-Plasma Interactions and Diagnostics
- Tropical and Extratropical Cyclones Research
Charles University
2008-2022
Goddard Space Flight Center
2014-2018
Both heliophysics and planetary physics seek to understand the complex nature of solar wind's interaction with system obstacles like Earth's magnetosphere, ionospheres Venus Mars, comets. Studies this objective are frequently conducted help single or multipoint in situ electromagnetic field particle observations, guided by predictions both local global numerical simulations, placed context observations from far extreme ultraviolet (FUV, EUV), hard X-ray, energetic neutral atom imagers (ENA)....
Abstract We present the ion distribution functions in foreshock upstream of terrestrial bow shock obtained with Vlasiator, a new hybrid‐Vlasov simulation geared toward large‐scale simulations Earth's magnetosphere ( http://vlasiator.fmi.fi ). They are compared measured by multispacecraft Time History Events and Macroscale Interactions during Substorms (THEMIS) mission. The known types distributions well reproduced model. show that Vlasiator reproduces decrease backstreaming beam speed...
Abstract Results from 2.5‐D electromagnetic hybrid simulations show the formation of field‐aligned, filamentary plasma structures in magnetosheath. They begin at quasi‐parallel bow shock and extend far into These exhibit anticorrelated, spatial oscillations density ion temperature. Closer to shock, magnetic field variations associated with temperature may also be present. Magnetosheath (MFS) form primarily sheath; however, they quasi‐perpendicular occur over a wide range solar wind Alfvénic...
Abstract We present simultaneous Time History of Events and Macroscale Interactions during Substorms observations plasma parameters upstream in the solar wind downstream magnetosheath (MSH) from 2007 to 2008. discuss connection foreshock (FSH) processes magnetospheric disturbances transmission mechanisms MSH. In 60% analyzed cases, MSH was strongly influenced by FSH. analyze results as a function location, time scale, spatial orientation observed structures, prevailing interplanetary...
In the present statistical study, we discuss a probability of simultaneous observations same sign magnetic field B Z component in solar wind and magnetosheath. The analysis is based on 5 min data from four spacecraft (Interball‐1, IMP 8, Cluster, THEMIS) operating different phases cycle Their measurements are compared with Wind interplanetary (IMF) observations, other available upstream monitors (ACE, THEMIS B, OMNI database) tested for some sets. We can conclude that magnetosheath...
The magnetosheath is occupied with a variety of low‐frequency fluctuations from different sources. Among them, the bow shock and dominantly foreshock processes are often considered as their major contributors. We use distant (Wind) close (Geotail) interplanetary magnetic field monitors compare measurements simultaneous observations within dawn (Time History Events Macroscale Interactions During Substorms (THEMIS)) dusk (Cluster) magnetosheath. have found that coherent (10 −4 –10 −3 Hz)...
Abstract. Magnetosheath parameters are usually described by gasdynamic or magnetohydrodynamic (MHD) models but these cannot account for one of the most important sources magnetosheath fluctuations – foreshock. Earlier statistical processing a large amount observations has shown that magnetic field and plasma flow downstream quasiparallel shock much larger than those at opposite flank. These studies were based on single spacecraft thus they could not provide full information propagation...
The magnetosheath is characterized by a variety of low‐frequency fluctuations, but their features and sources are different. Taking advantage multipoint magnetic field measurements the Cluster spacecraft, we present statistical study to reveal properties waves. We compute cross‐correlation coefficients strengths as measured pairs spacecraft determine correlation length discuss relationship between upstream parameters well its connection with wave mode frequency power spectrum. In interval...
The crossing of the termination shock (TS) by Voyager 2 in 2007 at 84 AU allows a comparison fluctuations different heliosheath regions. Letter concentrates on MHD waves that exhibit significant correlation between magnetic field strength and plasma density. correlations both quantities were computed hr time intervals frequency range 1 × 10−4 to 4 10−3 Hz. We separate data into two regions with behavior; post-TS region many crossings current sheet unipolar where direction remains nearly...
Abstract The magnetopause is treated as a boundary where the pressure of incoming solar wind balanced by geomagnetic field and plasma inside often neglected. However, published studies balance at reveal an excess magnetosheath pressure. Moreover, our survey about 50,000 THEMIS crossings shows that 1% them exhibits even larger magnetic in than magnetosphere. A subsequent analysis observed subsolar region under southward interplanetary dense cold ion population important component total...
Abstract We present the results of a 2.5‐D (2‐D in space and 3‐D currents electromagnetic fields) hybrid simulation run for foreshock wave activity during an interval radial interplanetary magnetic field (IMF). The predicts nonlinear waves expansion connection with development cavitons formation compressional boundary. Fluctuations ion velocity component are associated fronts corresponding to small normal angles oscillate around 0 far upstream region. At distances closer bow shock, these...
Summary form only given. We present the ion distribution functions in terrestrial foreshock, simulated by hybrid-Vlasov model called Vlasiator and observed THEMIS Cluster spacecraft. In description, function is propagated up to three spatial velocity dimensions electrons are modelled as a massless charge-neutralising fluid. was used self-consistently bow shock foreshock regions ecliptic plane (two spatial, dimensions). The simulations were run for tens of gyroperiods over hundreds inertial...