排序方式： 共有17条查询结果，搜索用时 271 毫秒
1.
2.
Solar flare films obtained on the TRACE spacecraft with a resolution of 1″ in the 160-nm (CIV) band with a frame separation of 2 s are examined. It has been indicated that the flare scenario is determined by the dynamics of numerous structures of about 1000 km in diameter. The fractal nature of the flare is confirmed. A self-organized criticality (SOC) mechanism is proposed to explain the flare formation and development. The most probable source of the flare energy is considered to be the chain of three-dimensional solitons. 相似文献
3.
J. Hanasz R. Schreiber H. de Feraudy M. M. Mogilevsky T. V. Romantsova 《Annales Geophysicae》1998,16(9):1097-1104
Intense auroral kilometric radiation (AKR) is being frequently observed with POLRAD from the Auroral Probe (Interball-2). Observations of the abrupt upper frequency cutoffs (UFCs) in the spectra of AKR are reported. The UFCs can be observed at a frequency range from 300 to 700 kHz, corresponding to AKR generation altitudes from approximately 4800 to 2100 km, and are distributed in magnetic local time (MLT) hours similarly to the AKR events, with a maximum at 1 h MLT. The observed frequency extent of the UFCs is 12 kHz, and is often determined by the instrumental resolution (4 kHz). It is suggested that the UFC may be associated with an abrupt switching on of the generation mechanism, when the electron density becomes sufficiently low inside a plasma depletion at an altitude where the ratio of fpe/fce crosses some threshold value. The steepness of the UFCs can imply a non-linear process of generation. The estimated distance of the e-folding field aligned wave amplification is between 3 and 8 km. The UFCs are sometimes, though very seldom (10%), accompanied by narrow band (less than 4 kHz) ridges of radiation observed at the cutoff frequency. They are smoothly drifting in frequncy for several minutes. The power density of radiation in the ridge can be up to 2 orders of magnitude stronger than in the accompanying wide band emission of AKR. The ridge at UFC can imply either energy concentration at the source bottom, or focusing, if specific conditions for the escape of the radiation are assumed. 相似文献
4.
A statistical analysis of the auroral kilometric radiation (AKR) measurements in the POLRAD experiment on the INTERBALL-2 satellite has revealed a dependences of the size and location of the AKR generation region on geomagnetic activity: the generation region rises upward and expands with increasing magnetic disturbances. Based on our two-year measurements, we found seasonal AKR intensity variations: the AKR maximum and minimum are observed in winter and summer, respectively. The seasonal variations and the dependence of the spectrum on geomagnetic activity are assumed to have a common physical nature—the background-plasma density variations in the region of the AKR source attributable to plasma flows from the ionosphere into the magnetosphere. 相似文献
5.
The discreteness of the time series of the solar-related geophysical phenomena is justified. The balance of the formation and decomposition (neglecting diffusion) of fractal elements during the evolution of the equilibrium systems as applied to the heliophysical and geomagnetic phenomena is the original position in this case. The discreteness properties of the spatial-temporal characteristics of solar activity are simply justified based on a fractal analysis. The performed calculations in the solar wind medium in the near-Earth space make it possible to classify the fluxes depending on their fractal dimension. The possible mechanism by which high-speed solar wind streams are generated is also briefly discussed in the scope of the fractal paradigm. 相似文献
6.
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
7.
G. S. Ivanov-Kholodny E. I. Mogilevsky V. Ye. Chertoprud 《Geomagnetism and Aeronomy》2006,46(2):139-145
Using the data of 1960–1999 on solar magnetic fields on the source surface and the Higuchi method, the fractal dimension of changes in the solar magnetic field energy at various heliolatitudes and in different time intervals is analyzed. The fractal dimension obtained on a moving 1-year interval displays substantial time variations. The 11-year cycle, which dominates at high latitudes, and quasi-biennial variations (QBVs), which dominate at low latitudes and are similar to QBVs of solar activity indices, are traced in these variations. Thus, solar QBVs that appear in all heliomagnetic activity indices are also present in the fractal structure of the solar magnetic field variations. 相似文献
8.
P. Mogilevsky 《Physics and Chemistry of Minerals》2007,34(3):201-214
The regular solid solution model has been applied to solid solubility in the monazite–xenotime systems and is verified against
the available experimental data for LaPO4–YPO4 and CePO4–YPO4 systems. The model is then used to predict the miscibility gaps in a number of other monazite–xenotime systems. The implications
for prospective two-phase monazite–xenotime fiber coatings for applications in ceramic matrix composites (CMCs) are discussed.
相似文献
| P. MogilevskyEmail: |
9.
A. A. Chernyshov D. V. Chugunin M. M. Mogilevsky I. L. Moiseenko A. A. Ilyasov V. V. Vovchenko S. A. Pulinets M. V. Klimenko I. E. Zakharenkova A. V. Kostrov M. E. Gushchin S. V. Korobkov 《Geomagnetism and Aeronomy》2016,56(1):72-79
Permanent variation in parameters affecting the key characteristics of the auroral ionosphere hinders the creation of a sufficiently accurate model for practical application within classical approaches describing quasi-stationary phenomena. The fractal approach for describing the properties of plasma in the auroral region has the following advantages: the results are versatile and the emergence of self-similar structures is nature-independent. Due to the self-similarity and fractality of ionospheric structures, it will suffice to have a few measurements within a characteristic scale; therefore, it is necessary to obtain a series of simultaneous measurements at intervals of tens of meters to tens of kilometers to describe the spatial and temporal distribution of inhomogeneities in the ionospheric plasma. Small and relatively low-cost satellites (the socalled cubesats) are supposed to be used to check whether the fractal approach can be applied to study the inhomogeneous structure of the ionosphere, including with artificial heating. The satellites should be located at different distances from each other to span the scales ranging from the inertial length of electrons to the inertial length of O+ ions. For each satellite, it is supposed to measure the variations in plasma density and electric and magnetic fields. 相似文献
10.
Chugunin D. V. Chernyshov A. A. Moiseenko I. L. Viktorov M. E. Mogilevsky M. M. 《Geomagnetism and Aeronomy》2020,60(5):538-546
Geomagnetism and Aeronomy - A method is proposed for the study of the height–time characteristics of physical processes in the region of auroral electron acceleration. Auroral kilometer... 相似文献