Nonequilibrium Effects in Atmospheric Perturbations Caused by Solar Radiation Flux     

A.?B.?AndreevEmail author  V.?M.?Somsikov  S.?N.?Mukasheva  V.?I.?Kapytin  K.?A.?Nurgalieva 《Geomagnetism and Aeronomy》2018,58(1):106-112

The effects of atmospheric nonequilibrium in the generation of wave perturbations due to the solar radiation flux are studied. Equations of nonequilibrium thermodynamics are used to perform an assessment of the channels of solar energy transformation into the atmosphere for different altitudes. As a result of calculations of the dispersion relation for a nonequilibrium atmosphere, we consider how the flux of solar radiation changes the spectrum of natural atmospheric oscillations at different altitudes and for different solar activities. A qualitative relation between the results of wave spectra calculations and the data of ionosphere dynamics observations for different intensities of the solar radiation flux has been established.  相似文献   

Galactic Cosmic Ray Intensity in the Upcoming Minimum of the Solar Activity Cycle     

M.?B.?KrainevEmail author  G.?A.?Bazilevskaya  M.?S.?Kalinin  A.?K.?Svirzhevskaya  N.?S.?Svirzhevskii 《Geomagnetism and Aeronomy》2018,58(2):169-177

During the prolonged and deep minimum of solar activity between cycles 23 and 24, an unusual behavior of the heliospheric characteristics and increased intensity of galactic cosmic rays (GCRs) near the Earth’s orbit were observed. The maximum of the current solar cycle 24 is lower than the previous one, and the decline in solar and, therefore, heliospheric activity is expected to continue in the next cycle. In these conditions, it is important for an understanding of the process of GCR modulation in the heliosphere, as well as for applied purposes (evaluation of the radiation safety of planned space flights, etc.), to estimate quantitatively the possible GCR characteristics near the Earth in the upcoming solar minimum (~2019–2020). Our estimation is based on the prediction of the heliospheric characteristics that are important for cosmic ray modulation, as well as on numeric calculations of GCR intensity. Additionally, we consider the distribution of the intensity and other GCR characteristics in the heliosphere and discuss the intercycle variations in the GCR characteristics that are integral for the whole heliosphere (total energy, mean energy, and charge).  相似文献   

Natural and Anthropogenic Variations of the Concentrations of Iron,Copper, and Zinc in Water Streams of the Republic of Bashkortostan   总被引：1，自引：0，他引：1  

T.?B.?FashchevskayaEmail author  Yu.?G.?Motovilov  N.?B.?Shadiyanova 《Water Resources》2018,45(6):873-886

The natural and anthropogenic sources of iron, copper, and zinc in water streams in the Republic of Bashkortostan are considered. Statistical analysis of long-term hydrochemical monitoring data was used to establish the spatial year-to-year and annual regularities in metal concentrations in water streams. The acceptability of river water quality for different types of water use was estimated. The exceedance probabilities of metal MAC values in streams were evaluated.  相似文献   

Simulating the Propagation of Infrasonic Waves and Estimating the Energy of the Chelyabinsk Meteoroid Explosion Observed on February 15, 2013     

S.?N.?KulichkovEmail author  O.?Ye.?Popov  K.?V.?Avilov  I.?P.?Chunchuzov  O.?G.?Chkhetiani  A.?A.?Smirnov  V.?I.?Dubrovin  A.?A.?Mishenin 《Izvestiya Atmospheric and Oceanic Physics》2018,54(3):293-303

Results obtained from simulating the propagation of infrasonic waves from the Chelyabinsk meteoroid explosion observed on February 15, 2013, are given. The pseudodifferential parabolic equation (PDPE) method has been used for calculations. Data on infrasonic waves recorded at the IS31 station (Aktyubinsk, Kazakhstan), located 542.7 km from the likely location of the explosion, have been analyzed. Six infrasonic arrivals (isolated clearly defined pulse signals) were recorded. It is shown that the first “fast” arrival (F) corresponds to the propagation of infrasound in a surface acoustic waveguide. The rest of the arrivals (T1–T5) are thermospheric. The agreement between the results of calculations based on the PDPE method and experimental data is satisfactory. The energy E of the explosion has been estimated using two methods. One of these methods is based on the law of conservation of the acoustic pulse I, which is a product of the wave profile area S/2 of the signal under analysis and the distance to its source E _I [kt] = 1.38 × 10^–10 (I [kg/s])^1.482. The other method is based on the relation between the energy of explosion and the dominant period T of recorded signal E _T [kt] = 1.02 × (T [s]²/σ)^3/2, where σ is the dimensionless distance determining the degree of nonlinear effects during the propagation of sound along ray trajectories. According to the data, the explosion energy E _I,T ranges from 1.87 to 32 kt TNT.  相似文献   

Possible Mechanism for Damping of Electrostatic Instability Related to Inhomogeneous Distribution of Energy Density in the Auroral Ionosphere     

I.?V.?Golovchanskaya  B.?V.?Kozelov  A.?A.?ChernyshovEmail author  A.?A.?Ilyasov  M.?M.?Mogilevsky 《Geomagnetism and Aeronomy》2018,58(2):223-228

Satellite observations show that the electrostatic instability, which is expected to occur in most cases due to an inhomogeneous energy density caused by a strongly inhomogeneous transverse electric field (shear of plasma convection velocity), occasionally does not develop inside nonlinear plasma structures in the auroral ionosphere, even though the velocity shear is sufficient for its excitation. In this paper, it is shown that the instability damping can be caused by out-of-phase variations of the electric field and field-aligned current acting in these structures. Therefore, the mismatch of sources of free energy required for the wave generation nearly nullifies their common effect.  相似文献   

Characteristics of the Energetic Electron Precipitation and Magnetospheric Conditions in 1994     

G.?A.?BazilevskayaEmail author  M.?S.?Kalinin  M.?B.?Krainev  V.?S.?Makhmutov  A.?K.?Svirzhevskaya  N.?S.?Svirzhevsky  Yu.?I.?Stozhkov  B.?B.?Gvozdevsky 《Geomagnetism and Aeronomy》2018,58(4):483-492

The problem of the rapid depletion and saturation of the Earth’s outer radiation belt with energetic electrons is one of the central problems in the physics of the magnetosphere. The precipitation into the atmosphere and the escape of electrons from the magnetosphere are competing reasons for the depletion of the radiation belt. Long-term measurements of energetic electron precipitation (EEP) in the atmosphere in the experiment of the Lebedev Physical Institute (LPI) can be used to study the relative role of these phenomena. High fluence values of relativistic electrons in the outer belt is a necessary condition for EEP observation; however, the relation of the EEP rate to the condition of the belt is ambiguous, which is shown by the example of observations in 1994.  相似文献   

Once More about Deep Caucasus Earthquakes     

A.?A.?GodzikovskayaEmail author 《Seismic Instruments》2018,54(3):327-339

The upper crustal location of the foci of the Spitak earthquake of December 7, 1988, and its aftershocks is proved. It is demonstrated that the seismological network in Armenia and Georgia allowed unequivocal focal depth identification based on the kinematic data. The waveforms of all the Spitak earthquakes are typical of sources in the upper crust. It is noted that up to now, mantle earthquakes in the Caucasus have only been revealed in the Terek–Sunzha depression.  相似文献   

Determination of Supermassive Black Hole Spins Based on the Standard Shakura–Sunyaev Accretion Disk Model and Polarimetric Observations     

V.?L.?Afanasiev  Yu.N.?GnedinEmail author  M.Yu.?Piotrovich  S.?D.?Buliga  T.?M.?Natsvlishvili 《Astronomy Letters》2018,44(6):362-369

Based on spectropolarimetry for 47 type 1 active galactic nuclei observed with the 6-m BTA telescope, we have estimated the spins of the supermassive black holes at the centers of these galaxies. We have determined the spins based on the standard Shakura–Sunyaev accretion disk model. About 70% of the investigated active galactic nuclei are shown to have Kerr supermassive black holes with a dimensionless spin greater than 0.9.  相似文献   

Critical Latitude in Tidal Dynamics Using the Kara Sea as an Example     

B.?A.?KaganEmail author  E.?V.?Sofina  A.?A.?Timofeev 《Izvestiya Atmospheric and Oceanic Physics》2018,54(2):206-212

It is well known that, within the linear nonviscous equations of tidal dynamics, the amplitudes of oscillations of the barotropic and baroclinic tidal velocity components unlimitedly increase when approaching the critical latitude. It is also known that the linear equations of tidal dynamics with a constant and specified vertical eddy viscosity indicate the occurrence of significant tidal velocity shears in the near-bottom layer, which are responsible for increasing the baroclinic tidal energy dissipation, the turbulent kinetic energy, and the thickness of the bottom boundary layer. The first circumstance—the growth of the amplitudes of oscillations of the barotropic and baroclinic tidal velocity components—is due to the elimination in the original equations of small terms, which are small everywhere except for the critical latitude zone. The second circumstance—the occurrence of significant tidal velocity shears—is due to the fact that internal tidal waves, which induce the dissipation of the baroclinic tidal energy and the diapycnal diffusion, are either not taken into account or described inadequately. It is suggested that diapycnal diffusion can lead to the degeneration (complete or partial) of tidal velocity shears, with all the ensuing consequences. The aforesaid is confirmed by simulation results obtained using the QUODDY-4 high-resolution three-dimensional finite-element hydrostatic model along the 66.25° E section, which passes in the Kara Sea across the critical latitude.  相似文献   

Effect of Electron Precipitations on the Effective Recombination Coefficient     

Zh.?V.?DashkevichEmail author  V.?E.?Ivanov 《Geomagnetism and Aeronomy》2018,58(2):290-293

The results of an analysis of the possible effect of auroral electron fluxes on the effective recombination coefficient α_eff in the ionosphere are presented. It is shown that the α_eff value in the E-region of the ionosphere is determined mainly by the physical-chemical properties of the medium. In the F1-layer of the ionosphere, the effective recombination coefficient becomes dependent on both the value of the energy flux and the type of the energy spectrum of the auroral electron flux.  相似文献