A5059883955- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Geomagnetism and Paleomagnetism Studies
- Astro and Planetary Science
- Geophysics and Gravity Measurements
- Planetary Science and Exploration
- Earthquake Detection and Analysis
- Dust and Plasma Wave Phenomena
- Laser-induced spectroscopy and plasma
- Plasma Diagnostics and Applications
- Magnetic confinement fusion research
- Atmospheric Ozone and Climate
- Inertial Sensor and Navigation
- Space Satellite Systems and Control
- High-pressure geophysics and materials
- Solar Radiation and Photovoltaics
- Particle accelerators and beam dynamics
- Space Exploration and Technology
- Gamma-ray bursts and supernovae
- Spacecraft Design and Technology
- Atomic and Subatomic Physics Research
- GNSS positioning and interference
- Atomic and Molecular Physics
- Magnetic Field Sensors Techniques
- Semiconductor Quantum Structures and Devices
Charles University
2016-2025
Karlovac University of Applied Sciences
1998-2015
Deleted Institution
2010
Czech Technical University in Prague
2004
Slovak Academy of Sciences
1987-2002
Institute of Electrical Engineering of the Slovak Academy of Sciences
1995-2002
Royal Belgian Institute for Space Aeronomy
2001
Space Research Institute
1987-2001
Marshall Space Flight Center
2001
We present a comprehensive observational study of the magnetospheric response to an interplanetary magnetic field (IMF) tangential discontinuity, which first struck postnoon bow shock and magnetopause then swept past prenoon on July 24, 1996. Although unaccompanied by any significant plasma variation, discontinuity interacted with form hot flow anomaly (HFA), was observed Interball‐1 just upstream from shock. Pressures within Earthward HFA were depressed order magnitude, allowed briefly (∼7...
Abstract. We present multi spacecraft measurements in the magnetosheath (MSH) and solar wind (SW) by Interball, Cluster Polar, demonstrating that coherent structures with magnetosonic Mach number up to 3 – Supermagnetosonic Plasma Streams (SPS) generate transient anomalous boundary dynamics, which may cause substantial displacements of magnetospheric boundaries riddling peripheral layers. In this regard, for first time, we describe a direct plasma penetration into flank layers, is candidate...
We report THEMIS and Geotail observations of prolonged magnetopause (MP) expansions during long-lasting intervals quasi-radial interplanetary magnetic field (IMF) nearly constant solar wind dynamic pressure. The were global: the was located more than 3 RE ~7 outside its nominal dayside magnetotail locations, respectively. expanded states persisted several hours, just as long IMF conditions, indicating steady-state situations. For an observed pressure ~1.1-1.3 nPa, new equilibrium subsolar MP...
The present empirical models describing a location and shape of the magnetopause bow shock are based on statistical evaluation crossings. crossings usually identified by visual inspection plots or automatic methods which less reliable. We new method determination most probable boundary locations. is continuous plasma magnetic field measurements in regions visited sounding spacecraft (the solar wind, magnetosheath, magnetosphere) ratios these parameters to simultaneously monitored upstream...
Abstract The turbulent foreshock region upstream of the quasi‐parallel bow shock is dominated by waves and reflected particles that interact with each other create a large number different transients. structures enhanced magnetic field, Short Large Amplitude Magnetic Structures, density spikes named plasmoids are frequently observed. They one suggested sources transient flux enhancements or jets in magnetosheath. Using measurements Magnetospheric Multiscale Spacecraft (MMS) OMNI solar wind...
This study presents INTERBALL‐1, and MAGION‐4 observations of transient ion flux variations in the magnetosheath which cannot be related to similar changes solar wind observed by WIND GEOTAIL. The duration events varies from tens seconds a few minutes their amplitude can exceed background levels factor 2 or more. We use closely‐spaced INTERBALL‐1 satellites estimate that spatial dimensions are on order ∼ 1 R E . interaction foreshock discontinuities with bow shock is identified as possible...
Abstract. Two satellites of the INTERBALL project were launched on 3 August 1995. The main goals present paper are (1) to give a brief information about VDP plasma device onboard INTERBALL-1 satellite, (2) Faradays cup data taken in different magnetospheric regions and (3) expose first results two satellite measurements magnetopause motion. presented illustrate crossings as seen by when separated ~ 1000 km. This separation combined with Faraday's time resolution allows estimate velocity...
This Letter shows the first results from solar wind monitor onboard Spektr-R spacecraft which measures plasma moments with a time resolution of 31 ms. high-time allows us to make direct observations turbulence below ion kinetic length scales. We present examples frequency spectra density, velocity, and thermal velocity. Our study reveals that although these parameters exhibit same behavior at magnetohydrodynamic scale, their are remarkably different scale.
We investigate the dependence of magnetopause location on interplanetary magnetic field (IMF) cone angle (the between IMF and solar wind velocity vectors) in a statistical study based ≈6500 crossings observed by five THEMIS spacecraft, both at dayside flanks. To remove other well‐known effects, we analyze difference radial distances those predicted an empirical model (scalable dynamic pressure B Z component). The results demonstrate systematic increase distance for directions, from ≈0.3 R E...
This paper presents a large statistical analysis of frequency spectra the solar wind density fluctuations in range 0.001–5 Hz (corresponding to spatial scales 100–5 × 105 km). The confirms that spectrum consists three segments divided by two breakpoints and each can be described power-law function with spectral index α. first segment corresponds MHD is followed plateau, third associated kinetic range. statistics show values slopes depend on fluctuations; their increasing amplitude leads...
The intermittency of density fluctuations in the solar wind at kinetic scales has been examined using high time resolution Faraday cup measurements from Spektr-R spacecraft. It was found that probability functions (PDFs) are highly non-Gaussian over this range, but do not show large changes shape with scale. These properties statistically similar to those magnetic and important understanding dynamics small scale turbulence wind. Possible explanations for behavior discussed.
ABSTRACT This paper analyzes solar wind power spectra of bulk and thermal speed fluctuations that are computed with a time resolution 32 ms in the frequency range 0.001–2 Hz. The analysis uses measurements Bright Monitor Solar Wind on board Spektr-R spacecraft limited to 570 km s −1 speed. statistics, based more than 42,000 individual spectra, show that: (1) speeds can be fitted by two power-law segments; (2) despite their large variations, parameters characterizing spectrum fits each...
Propagation of an interplanetary (IP) shock through the bow and magnetosheath is studied using numerical results a three‐dimensional MHD model magnetosheath. According to already published theoretical studies, fast forward passing would generate train new discontinuities including slow expansion wave, contact discontinuity, reversed shock. We have found that these particular propagate with similar velocities thus they cannot be distinguished in our calculations, we observe one discontinuity...
We present results from a new three‐dimensional empirical magnetopause model based on 15,089 crossings 23 spacecraft. To construct the model, we introduce Support Vector Regression Machine (SVRM) technique with systematic approach that balances smoothness fitting accuracy to produce reveals manner in which size and shape of depend upon various control parameters without any assumptions concerning analytical magnetopause. The fits data used modeling very accurately, can guarantee similar when...
This paper analyzes the distribution of different pressure components (dynamic, thermal, magnetic) in magnetosheath along Sun‐Earth line for northward and radial interplanetary magnetic field (IMF) orientations with motivation to explain an unusual location shape magnetopause often observed during intervals IMF. The analysis employs isotropic anisotropic MHD models, their results are compared statistical processing THEMIS observations. We have found that (1) temperature anisotropy controls...
The paper reviews the interaction of collisionless interplanetary (IP) shocks with turbulent solar wind. coexistence and turbulence plays an important role in understanding acceleration particles via Fermi mechanisms, geoeffectiveness highly disturbed sheaths following IP and, among others, nature fluctuations themselves. Although our knowledge physics upstream downstream shock regions has been greatly improved recent years, many aspects IP-shock/turbulence are still poorly known, for...
Abstract Magnetopause position is controlled mainly by the solar wind dynamic pressure and north‐south interplanetary magnetic field component these quantities are included in different empirical magnetopause models. We have collected about 50,000 of dayside crossings observed THEMIS course 2007–2019 compared with model prediction. The difference between predicted radial distance, R obs − mod used for quantifying model‐observation agreement. Its median values well cases up to ≈ 12 E all...
An intrinsic limitation of empirical models the magnetopause location is a predefined shape and assumed functional dependences on relevant parameters. We overcome this using machine learning approach (artificial neural networks), allowing us to incorporate general, purely data-driven dependences. For training testing developed network model, data set about 15,000 crossings identified in THEMIS A-E, Magion 4, Geotail, Interball-1 satellite subsolar region used. A cylindrical symmetry around...
Abstract. A number of magnetopause models have been developed in the course last three decades. We chosen seven them and tested using a fresh set crossings observed by Interball-1, Magion-4, Geotail satellites. The cover from subsolar region up to near-Earth tail (XGSE ~ - 20 RE ) all geomagnetic latitudes. Our study reveals that (1) difference between investigated is smaller than error prediction caused factors not included models, (2) dayside indented cusp region, (3) deepness indentation...