A5025881946- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Geomagnetism and Paleomagnetism Studies
- Earthquake Detection and Analysis
- Astro and Planetary Science
- Dust and Plasma Wave Phenomena
- Magnetic confinement fusion research
- Plasma Diagnostics and Applications
- Astrophysics and Cosmic Phenomena
- Laser-induced spectroscopy and plasma
- Physics of Superconductivity and Magnetism
- Complex Systems and Time Series Analysis
- Solar Radiation and Photovoltaics
- Fluid Dynamics and Turbulent Flows
- Gamma-ray bursts and supernovae
- Atmospheric Ozone and Climate
- Electron and X-Ray Spectroscopy Techniques
- Atomic and Subatomic Physics Research
- High-pressure geophysics and materials
- Oceanographic and Atmospheric Processes
- Quantum, superfluid, helium dynamics
- Nonlinear Dynamics and Pattern Formation
- Electrical Contact Performance and Analysis
- Skin Diseases and Diabetes
- Diabetes Management and Education
Gentofte Hospital
2024
Centrum Badań Kosmicznych
2010-2023
Polish Academy of Sciences
2010-2023
Ollscoil na Gaillimhe – University of Galway
2023
University of Zielona Góra
2013-2021
Swedish Institute of Space Physics
2004-2014
Military University of Technology in Warsaw
2012
National Cheng Kung University
2009
KTH Royal Institute of Technology
1997
Goddard Space Flight Center
1997
Abstract. Highlights are presented from studies of the electric field data various regions along Cluster orbit. They all point towards a very high coherence for phenomena recorded on four spacecraft that separated by few hundred kilometers structures over whole range apparent frequencies 1 mHz to 9 kHz. This presents completely new opportunities study spatial-temporal plasma magnetosphere out solar wind. A probe environment was constructed CLUSTER experiment now produces unprecedented...
High‐resolution particle measurements obtained from the VIKING spacecraft have provided interesting new observations of accelerated and heated plasma on auroral field lines. We present upward ion electron beams conies which indicate that acceleration/heating process is so variable many different physical processes to be taken into account. As a consequence this variability classification scheme will adopted.
We present Viking observations of energetic electrons and ions which move upward along the magnetic field lines with energies same order magnitude. The field‐aligned particles are associated a strong broadband low‐frequency turbulence in electric downward Birkeland currents. suggest that both accelerated by time‐varying component. component accelerating is experienced as quasi‐static while they remain height‐limited acceleration region. For fluctuating wave has only small translational...
A revised analysis of Freja observations shows that events interpreted previously as broadband turbulence in the frequency domain, f ∼1–500 Hz represent fact dispersive Alfvén waves (DAW) covering a wide range wave vectors k ⟂ . satellite's motion through broad Δk , low frequency, ω < ci Alfvénic structures makes them appear at (Doppler) frequencies Δω = v s · satellite reference frame. The identification is made with measured ratio δ E /δ B fluctuations which consistent theoretical...
A generalized model for one-dimensional magnetosonic structures of large amplitude in space plasmas is presented. The verified with multipoint measurements on Cluster satellites the magnetosheath and boundary layer under conditions plasma beta (plasma/magnetic pressure) between 0.1-10. We demonstrate good agreement observations wave trains, which represent increases magnetic field density 2-5 times ambient values, or local decreases (holes) by approximately (50-80)%. Theoretically derived...
Multiresolution wavelet analysis of magnetic field, electric and plasma density records taken on Freja during strong auroral events shows evidence for cavity Alfvén resonators in the topside ionosphere. The (or transverse) consist standing perpendicular wave modes which are trapped inside cavities different scales. smallest size have widths comparable to electron skin depth, λ s = 2π c / ω pe , presumably associated with resonance cones waves launched by a magnetospheric source. (ARCs) carry...
Experimental evidence is provided for the existence of slow-mode magnetosonic solitons in col-lisionless plasma at magnetopause boundary layer. The were detected by fleet Cluster spacecraft dusk flank magnetosphere as magnetic field depressions (up to 85%) accom-panied with enhancement density and temperature a factor 2. propagate 250 km/s respect satellites have perpendicular size 1000-2000 km, which few ion inertial scale lengths. comparison numerical solutions theoretical model shows...
Deep, very narrow magnetic-field-aligned density depletions were observed by the Freja spacecraft during auroral oval crossings. These cavities have perpendicular width of order electron skin depth $c/{\ensuremath{\omega}}_{\mathrm{pe}}$ and are associated with low-frequency electromagnetic perturbations discrete structures. We demonstrate here that these likely produced ponderomotive force inertial Alfv\'en waves.
We demonstrate that satellite observations of intense transverse ion energization could be explained by stochastic heating on short perpendicular wavelength electrostatic waves and structures produced the decay dispersive Alfvén (DAW). This mechanism is related to chaotization orbits which leads strong when electric field gradient fulfills inequality ∂Ex/∂x > ΩB0 (here Ω gyrofrequency B0 ambient magnetic field). also show energy source for this process provided from dissipation Poynting flux...
Based on Magnetospheric Multiscale (MMS) observations from the Earth's bow shock, we have identified two plasma heating processes that operate at quasi-perpendicular shocks. Ions are subject to stochastic in a process controlled by function $\chi_j = m_j q_j^{-1} B^{-2}\mathrm{div}(\mathbf{E}_\perp)$ for particles with mass $m_j$ and charge $q_j$ electric magnetic fields $\mathbf{E}$ $\mathbf{B}$. Test particle simulations employed identify parameter ranges bulk acceleration of tail...
The analysis of the wave content inside a perpendicular bow shock indicates that heating ions is related to Lower-Hybrid-Drift (LHD) instability, and electrons Electron-Cyclotron-Drift (ECD) instability. Both processes represent stochastic acceleration caused by electric field gradients on electron gyroradius scales, produced two instabilities. Stochastic single particle mechanism where large break adiabatic invariants expose particles direct DC- wave-fields. controlled function $\chi =...
ABSTRACT The analysis of four-point measurements by the NASA Magnetospheric Multiscalespacecraft reveals that formation quasi-parallel shocks is consistent with counter-streaming ion–ion resonant right-handed instability. occurs between incoming solar wind and a diffuse hot ion population moving upstream. It found onset instability initiated 30 s period oscillations, which steepen to shorter wavelengths higher frequencies. turbulent cascade in electric field ranges from 0.01 Hz few kHz....
Multiscale structure of field‐aligned currents and plasma density records are analyzed with multiresolution wavelet technique. We show that measured by Freja in the auroral region have a spectrum scales from ∼ 500 km down to about hundred meters. The intensity has maximum ∼100–300 μAm −2 at subkilometer scales. locations small‐scale (corresponding presumably discrete structures) is not coincident neither strong macroscopic gradients, nor most intense large‐scale currents. These structures...
High time resolution data collected by the Freja spacecraft in topside ionosphere ( h ∼ 1500 km) reveal that “low‐frequency turbulence” observed commonly below ion gyrofrequency consists of a large number coherent plasma structures which represent intense field‐aligned currents j ‖ 30 − 300 μAm −2 ) accompanied density depletions (cavities). The electromagnetic fluctuations are identified with inertial electron Alfvén waves (IEAW) at perpendicular wavelengths ≲6 km. singularly strong...
We have analyzed complete spectrum of waves (0–4 MHz) and electron distributions during events modulated Langmuir observed by Freja in the topside polar ionosphere. Modulated are with amplitudes 1–1000 mV/m association beams electrons energies 50–5000 eV streaming through cold ionospheric plasma. find overwhelming evidence for interactions ( L ) lower hybrid LH waves. The consistent parametric decay beam induced ↝ ′ + as well scattering on preexisting ′). These at all wave ∼ 1 – 1000 but...
We present a detailed analysis of magnetic bubbles observed by the Polar satellite in high‐latitude magnetopause boundary. The which represent holes or strong depressions (up to 98%) ambient field are filled with heated solar wind plasma elements and vicinity currents possibly near reconnection site. analyze wave modes frequency range 0‐30 Hz at (bubble) layer conclude that broadband waves this most likely spatial turbulence kinetic Alfvén (KAW), Doppler‐shifted higher frequencies (in frame)...
A family of quantitative magnetospheric models is used to determine the cusp position in ionosphere and analyze field topology around outer cusp. It demonstrated that “cusp proper” (∼1° × 2 hours), observed particle precipitation patterns, can be defined as footprint magnetopause current layer with lines connected interplanetary medium via a normal magnetic component. wider local time extent cleft (∼8–16 hours MLT) associated low‐latitude boundary between X GSM = 0 20 R E downtail extending...
Electric field, magnetic auroral imager and particle observations obtained on the Viking satellite for one dusk‐dawn crossing through polar cusp, are used to illustrate a new promising technique derive “instantaneous” pictures of high‐latitude electrodynamics. Global electric field distributions calculated using as input UV‐imager data distribution in situ measurements electrodynamical parameters along orbit, which combined with measured average field‐aligned currents (Region 1 2)...