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11.
The emergence of photospheric magnetic fields and the dynamics of the associated pattern of vertical motions in a developing active region are studied based on SOHO/MDI data. Objects were selected for which complete time series of data were available, so as to make it possible to determine the onset time of the magnetic-field emergence at the surface and tracing the formation of the first pores. The active regions studied originated near the central meridian. The total area of sunspots in these regions exceeded 100 millionths of the hemisphere at the maximum of active region evolution. A generalized evolutionary scenario is constructed for the magnetic field and vertical motions in the emerging active region. An asymmetry in the Doppler velocities is noted at an early stage of the active-region development, which corresponds to a matter flow from the leading to the trailing end of the emerging Ω-shaped tube. A direct relationship is found between the matter-downflow velocity in the area of the pore development and the growth in the strength of the longitudinal magnetic field. 相似文献
12.
V. M. Grigoryev L. V. Ermakova I. I. Salakhutdinova A. I. Khlystova 《Geomagnetism and Aeronomy》2009,49(7):823-829
The dynamics of the magnetic field and velocity field during the birth and an early development stage of a major active region
is studied. SOHO MDI longitudinal-component magnetograms, Dopplergrams, and continuum images are used. The presence of an
enhanced material upflow in the photosphere during the passing of the top of the magnetic flux loop, forming the active region,
is revealed. The maximum upflow velosity is 2 km/s and the maximum size of the upflow area exceeds 20000 km. The lifetime
of the upflow is about two hours. The undulating form of the magnetic flux tubes crossing the photosphere is confirmed. A
structural-analysis technique is used to show that the trailing polarity field at the formation stage of the active region
is more highly structured than the leading polarity field. 相似文献
13.
In this paper the magnetic flux distribution of bipolar active regions at the sunspot development stage is analyzed. It is shown that the ratio of the total sunspot area in an active region to the maximum one can be used as a characteristic of the development phase. Such a procedure allows combining the data attributed to different active regions for studying evolutionary changes. The expressions describing the evolution of magnetic flux distribution of bipolar active region were obtained and their interpretation with rise and descent of loop like magnetic flux tube leading to active region formation was justified. 相似文献
14.
O. S. Ermakova S. A. Ermakov Yu. I. Troitskaya 《Izvestiya Atmospheric and Oceanic Physics》2007,43(1):86-94
The evolution of a turbulent layer excited by standing surface parametric waves is studied experimentally. The time dependence of the depth of the turbulized region is obtained. It is found that the thikness of the layer is described by a nonlinear dependence as distinguished from the previously obtained theoretical results. The dynamics of turbulent-layer embedding is described on the basis of a semiempirical theory and the assumption that the outer scale of turbulence is constant. Satisfactory agreement with experimental data is obtained. In the context of the proposed model, a relationship is found between the quantities characterizing the turbulence and surface waves. The dependence of the steepness of surface waves on the acceleration of the bottom is obtained experimentally. The data obtained in this study can be used for estimation of turbulence generation during a submarine earthquake. 相似文献
15.
16.
Air Pollution Studies in Central Russia (Tver and Yaroslavl Regions) Using the Moss Biomonitoring Technique and Neutron Activation Analysis 总被引：1，自引：0，他引：1
E. V. Ermakova M. V. Frontasyeva S. S. Pavlov E. A. Povtoreiko E. Steinnes Ye N. Cheremisina 《Journal of Atmospheric Chemistry》2004,49(1-3):549-561
Data of 34 elements, including heavy metals, halogens, rare earth elements, U, and Th in 139 moss samples, collected in Central Russia in 2000–2002 in the Tver and Yaroslavl regions and in the northern part of the Moscow region, are presented. Factor analysis with VARIMAX rotation was applied to identify possible sources of the elements determined in the mosses. The seven resulting factors represent crust, vegetation and anthropogenic components. Some of the factors were interpreted as being associated with ferrous smelters (Fe, Zn, Sb, Ta); combination of non-ferrous smelters and other industries (Mn, Co, Mo, Cr, Ni, W); an oil-refining plant, and oil combustion at the thermal power plant (V, Ni). The geographical distribution patterns of the factor scores are also presented. Dependency equations of elemental content in mosses versus distance from the source were derived. 相似文献
17.
The complex active region NOAA 9672 is studied when it was near the central meridian, from October 21–26, 2001. At that time, there was an emergence of new magnetic flux, with the ongoing formation of a filament. The dynamics of the magnetic field are studied in order to search for their possible manifestations in the filament structure, using SOHO MDI magnetograms, SOHO EIT and TRACE filtergrams in the 171 Å line, and Hα filtergrams available via the Internet. Our earlier conclusion that filaments form at the boundaries of supergranules near polarity-inversion lines is confirmed. The conclusion of Chae that sinistral filaments have positive magnetic helicity is also confirmed. New information about magnetic-field decay processes is obtained. The direction of motion of the magnetic poles and their relative positions suggest that the axial field of a filament forms as a result of either reconnection of cancelling magnetic poles, or emergence of horizontal magnetic-flux tubes. 相似文献
18.
O. S. Ermakova Yu. A. Mal’kov D. A. Sergeev Yu. I. Troitskaya 《Izvestiya Atmospheric and Oceanic Physics》2009,45(6):791-798
This is an experimental study of the mixing induced by coincident surface waves in a liquid. The main mechanism leading to
the emergence of mixing was shown to be the middle currents generated by coincident waves. The regime of these currents strongly
depends on the amplitude of surface waves. For waves of near-critical amplitudes, an intense turbulization of middle currents
is observed. Patterns of the velocity field were obtained using the Particle Imaging Velocimetry (PIV) technique for different
amplitudes of surface waves. The results obtained can be used to estimate mixing in the near-surface oceanic layer. 相似文献
19.
Ermakova G. S. Gorelits O. V. Zhbakov K. K. Zemlyanov I. V. Milyutina I. Yu. 《Water Resources》2022,49(4):616-629
Water Resources - The results of studies of extreme floods in Crimean rivers in the summer of 2021 are presented. Analytical and historical generalization is made for the problem of the adverse... 相似文献
20.
Structural magnetic elements observed in sunspot penumbrae are employed as indicators of motions occurring in and around penumbrae. The analysis presented here is base on SDO/HMI continuum images and magnetograms of the line-of-sight field obtained for the active region NOAA 11117. In a first approximation, the penumbral magnetic fields can be considered alternating spines and interspine filaments. In the plane of the sky, spines are thin radial elements with higher field strengths and lower magnetic-field inclinations compared with those in surrounding areas. It is confirmed that spines first appear as protrusions of the umbra magnetic fields visible in magnetograms, and then develop simultaneously with the growth of the penumbra. The departure of magnetic elements from penumbrae as a result of the detachment of the ends of spines begin 1–1.5 h after the spine formation. Inmature penumbrae, magnetic elements emerge fairly often, and the departure of groups of field elements sometimes generates structures resembling moving ribbons. The velocities of magnetic elements that have separated from spines are a factor of two to three lower than those of elements that have separated from inter-spine filaments. The results obtained agree well with an “uncombed” model for the penumbral magnetic fields. 相似文献