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Multi-Instrument Approach to Study Polarization Jet/SAID and STEVE
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS. 2024. Vol. 129. No. 11. Article e2024JA033222.
A. A. Sinevich, A. A. Chernyshov, Chugunin D. V., Klimenko M. V., Panchenko V. A., Yakimova G. A., Timchenko A. V., Miloch W. J., Mogilevsky M. M.
In this study, we employ a unique multi‐instrumental approach for a comprehensive examination of Polarization Jet (PJ) (or, another name, Subauroral Ion Drift (SAID)). A diverse set of data is used to assess the connection between the appearance of the inhomogeneous structure of PJ/SAID and its reflection in groundbased observations during geomagnetic activity. Our approach combines satellite (Defense Meteorological Satellite Program, NorSat‐1, Swarm) and ground‐based (ionosondes, magnetometers, GPS/GLONASS receivers) data, allowing us to study PJ/SAID in detail and compare satellite data with ground‐based measurements. We describe the characteristic patterns on ionograms that may indicate the presence of PJ/SAID and how ionosondes can be used to study PJ/SAID. Polarization Jet Strata and irregularities of plasma parameters can cause multiple reflections, which are visible in ionograms as F‐spread. The splitting of the F2 trace into two or more traces on ionograms may indicate the presence of PJ/SAID near the observation point. Data from GPS/GLONASS receivers in regions where PJ/SAID is observed enable the construction of local total electron content maps, visualizing how PJ/SAID is reflected in those maps. It is shown how the geomagnetic latitude of PJ/SAID changes during the geomagnetic activity. Furthermore, this case is notable because not only PJ/SAID but also STEVE (Strong Thermal Emission Velocity Enhancement) is observed at
subauroral latitudes in Northern Europe during the examined geomagnetic event.
Derkacheva A., Sakirkina M., Kraev G. et al., /. 2026.
Comprehensive data on natural hazards and their consequences are crucial for effective for risk assessment, adaptation planning, and emergency response. However, many countries face challenges with fragmented, inconsistent, and inaccessible data, particularly regarding local-scale events. To address this data gap in Russia, we developed an end-to-end processing pipeline that scrapes news from various online sources, ...
Added: April 28, 2026
Ponomarev A., Aleksandrov N., Plasma Physics Reports 2026 Vol. 52 No. 3 P. 367–378
An approximate method for calculating drift velocity and other kinetic coefficients of heavy ions
in a light gas is generalized to gaseous mixtures. Obtained equations are used to calculate the mobilities of
and ions, as well as rate constants for inelastic ion–molecule processes with these ions in helium with
small additions of O2 under an electric field. Calculated ...
Added: April 27, 2026
Domrin V. I., Malova H. V., V. Yu. Popov et al., Cosmic Research 2026 Vol. 64 No. 2 P. 238–252
During magnetospheric perturbations a relatively thin current sheet with thickness about several
proton gyroradii forms in the Earth’s magnetotail. In a framework of the kinetic model describing current
sheet thinning in the magnetotail, the processes of its formation are investigated depending on the normal
magnetic field magnitude which affects both the current sheet structure and particle dynamics within ...
Added: April 27, 2026
Tsareva O. O., Malova H. V., V. Yu. Popov et al., Plasma Physics Reports 2026 Vol. 52 No. 2 P. 179–185
The influence of asymmetry of plasma sources on the structure and spatial localization of a superthin
current sheet (STCS) supported by demagnetized electrons is studied using a self-consistent model. The
simulation takes into account the presence of a single plasma source in the northern hemisphere, which
makes the plasma flow asymmetric. It is demonstrated that the asymmetry of ...
Added: April 27, 2026
П.А.Беспалов, О.Н. Савина, Геомагнетизм и аэрономия 2025 Т. 65 № 5 С. 620–628
Several basic models of frequency dynamics in quasi-periodic VLF emissions with spectral form repetition
periods from 10 to 300 s are considered. In all cases, we are talking about manifestations of cyclotron instability
of electron radiation belts thet are well described within the framework of the plasma magnetospheric maser
theory based an the averaged self-consistent system of quasi-linear ...
Added: April 25, 2026
Bondarenko G.G., Fisher M. R., Kristya V. I., Bulletin of the Russian Academy of Sciences: Physics 2026 Vol. 90 No. 4 P. 572–576
A model of the cathode layer of a glow gas discharge with a thin dielectric film on a fraction of the
cathode’s working surface is formulated. It is shown that a glow discharge most rapidly transits to an arc discharge,
accompanied by a significant increase in discharge current density and a decrease in cathode voltage
drop, if the ...
Added: April 25, 2026
Кивалов С. Н., Fitzjarrald D., Boundary-Layer Meteorology 2018 Vol. 166 No. 2 P. 165–198
Cloud shadows lead to alternating light and dark periods at the surface, with
the most abrupt changes occurring in the presence of low-level forced cumulus clouds.
We examine multiyear irradiance time series observed at a research tower in a midlatitude
mixed deciduous forest (Harvard Forest, Massachusetts, USA: 42.53◦N, 72.17◦W) and one
made at a similar tower in a tropical ...
Added: April 24, 2026
Кивалов С. Н., Fitzjarrald D., Boundary-Layer Meteorology 2019 Vol. 173 No. 1 P. 1–52
We examine the physical and biological responses of forest canopies to step changes in light
caused by passing low cumulus clouds that intermittently block the direct solar beam. Using
data obtained at a tropical rainforest and at a midlatitude deciduous forest, we estimate the
course of sensible heat flux, net ecosystem exchange, evapotranspiration, and water-use efficiency in response ...
Added: April 24, 2026
Addressing effects of environment on eddy-covariance flux estimates at a temperate sedge-grass marsh
Кивалов С. Н., Dušek J., Czerný R. et al., Boundary-Layer Meteorology 2023 Vol. 186 P. 217–250
We examined the net-ecosystem-exchange (NEE)-based annual carbon-balance estimates
obtained from eddy-covariance (EC) measurements at an unmanaged sedge-grass marsh
ecosystem (Tˇreboˇn, Czech Republic, 49°1′ N, 14°46′ E), seeking methods to improve the EC
measurements in inhomogeneous environment. The data filtering procedure was developed
using three thresholds: (a) a stationarity test; (b) a stability u∗-threshold; and (c) a high relative
humidity RH-threshold. ...
Added: April 24, 2026
Кивалов С. Н., Лопес де Гереню В. О., Хорошаев Д. А. et al., Forests 2023 Vol. 14 No. 8 Article 1568
Soil respiration (SR) is a main component of the carbon cycle in terrestrial ecosystems,
and being strongly affected by changes in the environment, it is a good indicator of the ecosystem’s
ability to cope with climate change. This research aims to find better empirical SR models using
25-year-long SR monitoring in two forest ecosystems formed on sandy Entic ...
Added: April 24, 2026
Касицкий В. А., Кивалов С. Н., Лопес де Гереню В. О. et al., АгроЭкоИнфо 2025 Т. 5 Статья 517
Оценка дыхания почвы - одного из основных источников углекислого газа в атмосферу – необходима для корректного определения углеродного баланса в наземных экосистемах. Сравнение пульсационного и камерного методов измерения дыхания почвы, проведенные в березняке постагрогенном в регионе южного Подмосковья, показывает хорошую сопоставимость этих методов с коэффициентом детерминации R2=0.75 (p-value=7.546e-12). С учетом высокой пространственной и временной неоднородности ...
Added: April 24, 2026
Кивалов С. Н., Ecological Modelling 2024 Vol. 498 Article 110904
On certain kinds of cloudy days, many forested ecosystems exhibit enhanced carbon uptake and water-use efficiency-the cloudy-day forest flux anomaly. Using ensemble methods to analyze eddy-covariance fluxes, we have
diagnosed net ecosystem exchange (NEE) and water-use efficiency (WUE) of a temperate broadleaf forest and a
tropical evergreen forest as they responded to natural fluctuating-light regimes. Here we ...
Added: April 24, 2026
Кивалов С. Н., Курганова И. Н., Быховец С. С. et al., Soil Systems 2025 Vol. 9 No. 1 Article 9010025
Carbon dioxide (CO₂) efflux from soil (or soil respiration, SR) is one of the most important yet variable characteristics of soil. When evaluating large areas, CO₂ efflux modeling serves as a viable alternative to direct measurements. This research aims to identify site-specific differences and their effects on empirical CO₂ efflux modeling. The experimental data from ...
Added: April 24, 2026
Zadkov V., Plasmonics 2026 Vol. 21 P. 1503–1512
Plasmonic nanostructures typically exhibit shifts in their resonant wavelength in response to changes in the refractive index of the surrounding medium. This limits their applications in scenarios requiring stable optical resonances. Here we present a metallic-dielectric hybrid metasurface that exhibits stable multi-wavelength resonance even if the refractive index of its surrounding varies. To quantitatively evaluate the stability of ...
Added: April 22, 2026
Shchur L., Antonov D., Burovski E., International Journal of Bifurcation and Chaos in Applied Sciences and Engineering 2026 P. 1–9
We present a simple model that simulates the possible influence of one society on another. Specifically, two societies evolve deterministically according to the well-known Nowak-May spatial game with the addition of mutual influence through connections that reflect the current states of the societies. This may be related to the influence of a global information resource ...
Added: April 20, 2026
Qin X., Deng Y., Shchur L. et al., / Series arXiv "math". 2026. No. 2603.02962.
We perform a Monte Carlo analysis of the Ising model on many three-dimensional lattices. By means of finite-size scaling we obtain the critical points and determine the scaling dimensions. As expected, the critical exponents agree with the three-dimensional Ising universality class for all models. The irrelevant field, as revealed by the correction-to-scaling amplitudes, appears to ...
Added: April 20, 2026
Pilé I., Deng Y., Shchur L., / Series arXiv "math". 2026. No. 2604.10254.
We investigate the spatial overlap of successive spin configurations in Markov chain Monte Carlo simulations using the local Metropolis algorithm and the Svendsen-Wang and Wolff cluster algorithms. We examine the dynamics of these algorithms for two models in different universality classes: the Ising model and the Potts model with three components. The overlap of two ...
Added: April 20, 2026
G.V.Klink, Semenkov I. N., Enchilik P. R., Science of the Total Environment 2025 Vol. 998 Article 180219
Natural regeneration of forest soils affected by agricultural practices is a common phenomenon in many regions worldwide, particularly in boreal ecosystems. Affecting soil quality, the partitioning of extractable fractions of heavy metals and metalloids (HMMs) is not studied during natural regeneration. The following stages of natural regeneration after plowing have been identified in the Smolenskoye ...
Added: April 19, 2026
Chernyshov A., Klimenko M. V., Nosikov I. A. et al., Advances in Space Research 2025 P. 1–26
In the subauroral zone at the boundary of the auroral oval in the evening and night hours duringgeomagnetic disturbances, a narrow (about 1º-2º) and extended structure (several hours in longitude) isformed. It is known as a polarization jet (PJ) or the sub-auroral ion drift (SAID). The PJ/SAID is a fastwestward ion drift and is one ...
Added: May 19, 2025
Kotova D. S., Sinevich A., Chernyshov A. et al., Scientific Reports 2025 Vol. 15 No. 3458
In the subauroral zone at the boundary of the auroral oval in the evening and night hours during geomagnetic disturbances, a narrow (about 1°–2°) and extended structure (several hours in longitude) is formed. It is known as a polarization jet (PJ) or the subauroral ion drift (SAID). The PJ/SAID is a fast westward ion drift ...
Added: January 29, 2025
Sinevich A., Chernyshov A., Чугунин Д. В. et al., Известия РАН. Серия физическая 2024 Т. 88 № 3 С. 438–444
Results are presented from a study of the internal small-scale structure of the polarization jet/SAID using data from different satellites. The minimum size of irregularities and the typical internal composition of a stratified subauroral ion drift (SSAID) are confirmed. A two-peak structure is found that contains two large strata of the polarization jet/SAID. A shift ...
Added: January 29, 2025
Sinevich A., Chernyshov A., Чугунин Д. В. et al., Геомагнетизм и аэрономия 2023 Т. 63 № 6 С. 764–774
The results of a study of the small-scale internal structure of a polarization jet/SAID (Subauroral Ion Drift) based on satellite data using the wavelet transform of ionospheric plasma parameters are presented. The minimum sizes of small-scale temperature and electron density irregularities are determined. Most likely, any polarization jet/SAID is stratified, as follows from the sample ...
Added: January 29, 2025
Sinevich A., Chernyshov A., Чугунин Д. В. et al., Космические исследования 2021 Т. 59 № 6 С. 489–497
In this work, we study the spatial structure of the polarization jet based on data from the NorSat-1 and Swarm ionospheric satellites during a geomagnetic storm. A comparative analysis of the electron density and temperature dependence on the invariant latitude is carried out simultaneously according to measurements of the NorSat-1 and Swarm C satellites during ...
Added: January 29, 2025
Sinevich A., Chernyshov A., Чугунин Д. В. et al., Солнечно-земная физика 2021 Т. 7 № 1 С. 21–33
In this work, we study the small-scale structure of a polarization jet in the subauroral region during the April 20, 2018 geomagnetic storm. We report measurement results of plasma parameters inside the polarization jet with a maximum sampling rate of up to 1 kHz, obtained with Langmuir probes installed on the NorSat-1 microsatellite. The study ...
Added: January 28, 2025