A5060583480- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Geomagnetism and Paleomagnetism Studies
- Earthquake Detection and Analysis
- Atmospheric Ozone and Climate
- Complex Systems and Time Series Analysis
- Atmospheric and Environmental Gas Dynamics
- Geophysics and Gravity Measurements
- Magnetic confinement fusion research
- Atmospheric chemistry and aerosols
- Chaos control and synchronization
- Oceanographic and Atmospheric Processes
- Astro and Planetary Science
- Plasma Diagnostics and Applications
- Theoretical and Computational Physics
- Lightning and Electromagnetic Phenomena
- Statistical Mechanics and Entropy
- Meteorological Phenomena and Simulations
- Dark Matter and Cosmic Phenomena
- Atmospheric aerosols and clouds
- Astrophysics and Cosmic Phenomena
- Atomic and Subatomic Physics Research
- GNSS positioning and interference
- Methane Hydrates and Related Phenomena
- Geophysics and Sensor Technology
Polar Geophysical Institute
2016-2025
RWTH Aachen University
2023
Space Research Institute
2016
Russian Academy of Sciences
1994-2015
Kazan Scientific Center
2012
UiT The Arctic University of Norway
2007-2008
The measurements of chorus emissions by four closely separated Cluster spacecraft provide important information concerning the generation mechanism. They confirm such properties wave source as their strong localization near equatorial cross section a magnetic flux tube, an almost parallel average wave-vector direction with respect to geomagnetic field, and energy pointing outward from region. Inside this region, discovered temporal spatial variations in amplitude correlation scale lengths...
Abstract We report on simultaneous spacecraft and ground‐based observations of quasiperiodic VLF emissions related energetic‐electron dynamics. Quasiperiodic in the frequency range 2–6 kHz were observed during a substorm 25 January 2013 by Van Allen Probe‐A station Northern Finland. The detected signals near geomagnetic equator night sector at L = 3.0–4.2 when it was inside plasmasphere. During satellite motion toward higher latitudes, time interval between elements decreased from 6 min to 3...
Chorus emissions are generated by a nonlinear mechanism involving wave‐particle interactions with energetic electrons. Discrete chorus wave packets narrowband tones usually rising (sometimes falling) in frequency. We investigate frequency sweep rates of measured the Wideband data (WBD) instrument onboard Cluster spacecraft. In particular, we study relationship between and plasma density WHISPER active sounder. have observed increasing values rate for decreasing densities. compared our...
The spatial structure of polar auroras is described by the fractal dimension glow fluctuations and its anisotropy from direction. estimated slope in logarithmic axes spectrum range 1.5–50 km, obtained through discrete wavelet transformation intensity fluctuation using Daubechies wavelets order 5. variability structures characterized variation over time. statistics these characteristics are presented according to data ground-based all-sky camera Polar Geophysical Institute Apatity for...
We demonstrate the turbulent properties of high‐latitude electric and magnetic fluctuations, observed by low‐altitude polar‐orbiting Dynamic Explorer 2 (DE2) satellite, means spectrum analysis examination probability density function (PDF) fluctuations. To gain insight into origin underlying turbulence, we calculate field patterns from DE2 observations under different IMF conditions compare them with associated Birkeland field‐aligned currents (FACs). A clear similarity these two groups...
Some of the most significant observational indications self‐organized critical (SOC) behavior in magnetosphere are scale‐free statistical distributions nighttime auroral emission regions as depicted by Ultraviolet Imager (UVI) onboard POLAR spacecraft [ Uritsky et al. , 2002 ]. Here, we report results from a similar study ground‐based optical observations. Individual active have been detected and analyzed using spatiotemporal technique methods appropriate for quantifying SOC models....
Abstract. We present a detailed study of chorus emissions in the magnetosphere detected on board Magion 5, when satellite was not far from magnetic equator. determine frequency sweep rate more than 8500 electromagnetic VLF elements. These results are compared with backward wave oscillator (BWO) regime generation. Comparison BWO model shows: (i) There is correlation between rates and amplitudes. The increases amplitude, accordance expectations model; (ii) growth rate, estimated accord that...
The dependence of the frequency spectrum individual chorus elements on position observation point in and near generation region is analyzed using recent Cluster data obtained two different geomagnetically active days. source night‐side localized multicomponent measurements wave electric magnetic fields. We have revealed that lacks lower frequencies at center region. One possible explanation this effect provided by applying backward oscillator model to these data. According model, determined...
Abstract. Using data from WIND spacecraft, we investigated the difference in substorm bulge development during different types of solar wind flow: recurrent streams (RS), corotating interaction regions (CIR), magnetic clouds (MC), and region with undisturbed (Sheath). The RS/CIR MC/Sheath structures were examined for periods December 1996–July 1997; January 2000–December 2000; October 2001. All available auroral substorms observed by Ultra Violet Imager onboard Polar spacecraft these...
Abstract. Whistler-mode chorus is a structured wave emission observed in the Earth's magnetosphere frequency range from few hundreds of Hz to several kHz. We investigate packets using high-resolution measurements recorded by WBD instrument on board four Cluster spacecraft. A night-side event during geomagnetically disturbed conditions analyzed. identify lower and upper frequencies for large number individual inside source region. how these observations are related central position which has...
We compare scaling properties of electric fields measured by the low‐altitude polar‐orbiting Dynamics Explorer 2 satellite in auroral zone and polar cap under interplanetary magnetic field (IMF) southward conditions. The techniques logscale diagrams (LDs) probability density function (PDF) are applied to demonstrate scale‐free structure fluctuations on scales from 0.5 km 256 both regions. It is shown that while amplitudes much smaller than zone, characteristics two domains basically same. To...
Fractal geometry is used to describe the spatial structure of ionospheric conductivity. Topological values fractal dimension and connectivity index, characterizing Pedersen Hall conductivities on nightside auroral zone, are analytically obtained. Restrictions imposed conductivity analyzed in terms percolation currents. It shown that observed scaling for fluctuations electric field glow region well within limitations by critical condition The multiple arc structures corresponds estimates...
Inhomogeneities of plasma density and non-uniform electric fields are compared as possible sources a sort electrostatic ion cyclotron waves that can be identified with broadband extremely low frequency turbulence in the topside auroral ionosphere. Such excited by inhomogeneous energy-density-driven instability. To gain deeper insight generation these waves, computational modeling is performed various parameters. It demonstrated inhomogeneities give rise to this instability even absence...
Abstract. Routine observations of the aurora are conducted in Apatity by a set five cameras: (i) all-sky TV camera Watec WAT-902K (1/2"CCD) with Fujinon lens YV2.2 × 1.4A-SA2; (ii) two monochromatic cameras Guppy F-044B NIR HF25HA-1B (1:1.4/25 mm) for 18° field view and glass filter 558 nm; (iii) color F-044C DF6HA-1B (1:1.2/6 67° view. The observational complex is aimed at investigating spatial structure aurora, its scaling properties, vertical distribution rayed forms. were installed on...
A Pulsating Aurora Imaging Photometers Stereoscopic System (PAIPS) is suggested and described in the paper. The system based on two lens telescopes with a matrix of multianode photomultiplier tubes as photodetectors placed high latitude observatories Polar Geophysical Institute. Telescopes provide simultaneous observations large volume atmosphere at altitudes range 50–100 km temporal resolution (up to 2.5 μs) spatial about 2 km. This novel for pulsating aurora study aimed determine energies...
Abstract We report a detailed analysis of explosive local magnetic field line stretching just before dipolarization observed by one Time History Events and Macroscale Interactions during Substorms (THEMIS) satellites the pseudo‐breakup followed substorm 6 January 2008. At end growth phase, this satellite (THEMIS‐C) was located at r ~ 6.3 R E near convection boundary 10 keV electrons. Penetration hot electron plasma sheet to region trapped energetic ions precondition for onset in premidnight...
Abstract. We examine the effectiveness of nonuniform, quasistatic, transverse electric fields that are often observed in auroral region destabilization inhomogeneous energy-density-driven (IEDD) waves. Specifically, IEDD dispersion relation Ganguli et al. (1985a, b) is evaluated for an field structure by FAST satellite ionosphere at 1000 km altitude. The background field-aligned current, plasma density and ion composition derived from observations. Other input parameters adopted calculations...
Abstract The temporal modulations of magnetospheric chorus waves are one the candidates for explaining quasiperiodic precipitation energetic electrons causing pulsating aurora (PsA). To confirm fully direct association between PsA and chorus, an extended interval (~1 hr) simultaneously observed by Arase satellite a ground‐based all‐sky imager in Apatity, Kola Peninsula, Russia was examined. In particular, region high correlation continuously tracked within field view imager. result showed...