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Investigation by backscatter radar of artificial irregularities produced in ionospheric plasma heating experiments 总被引：1，自引：0，他引：1
N.V. Bakhmet'eva V.N. Bubukina Yu.A. Ignat'ev G.S. Bochkarev V.A. Eremenko V.V. Kol'tsov I.V. Krasheninnikov Yu.N. Cherkashin 《Journal of Atmospheric and Solar》1997,59(18):2257-2263
The artificial ionospheric turbulence occurs in the ionosphere illuminated by high power HF radio waves. There are a lot of irregularities stretched along the geomagnetic field in this region. The investigation of the artificially disturbed ionospheric region is based on the reception of back scattered signals (BSS) which permits the basic parameters of this region to be estimated and its inhomogeneous structure to be described.Experiments were carried out using ‘Sura’ heating facility in the frequency range of ? = 4.7–9 MHz (ordinary mode) with the effective radiated power Peff = 50–70 MW beamed vertically upwards. The most important dynamic and statistical BSS characteristics (the built-up time, the relaxation and autocorrelation times, the BSS amplitude spatial correlation function and power spectra) were measured using probe waves in the frequency range of that made it possible to obtain the basic parameters of the artificial irregularities. The model representation of a disturbed region in a form of a periodic structure gives a possibity to evaluate the scale of the structure, the whole size of the disturbance and its power and to calculate the main BSS characteristics. 相似文献
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Kinetic equations for ultrarelativistic particles with due account of gravitational interactions with massive particles in the Robertson-Walker universe are obtained. On the basis of an exact solution of the kinetic equations thus obtained, a conclusion is made as to the high degree of the uniformity of the relict radiation on scales whih are less than 10. 相似文献
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I. M. Chertok V. A. Slemzin S. V. Kuzin V. V. Grechnev O. I. Bugaenko I. A. Zhitnik A. P. Ignat'ev A. A. Pertsov 《Astronomy Reports》2004,48(5):407-417
We analyze large-scale solar activity following the eruption of a very powerful, geoeffective coronal mass ejection in the 23rd solar cycle, observed at 175, 284, and 304 Å on November 4, 2001, using data from the CORONAS-F/SPIRIT telescope. In particular, we have shown that the restructuring of the magnetic field above the eruption center was accompanied by the formation of a multicomponent post-eruptive arcade, which was observed in all three bands over many hours and had an extent of the order of 0.5R⊙. Two kinds of dimmings were observed, i.e., compact dimmings on either side of this arcade and channeled dimmings along some extended features beyond the active region. The intensity in the dimmings decreased by several tens of percent. The enhanced emission observed at the top of the post-eruptive arcade can be due to energy release in the course of magnetic reconnection high in the corona at the relaxation stage of the perturbed magnetic field to a new equilibrium state with a closed configuration. It can also be due to an enhanced emission measure because of the oblique direction of the line of sight crossing both loop tops and footpoint regions. The spatial coincidence of the main dimmings in lines corresponding to different temperatures indicates that a plasma outflow from the transition region and coronal structures with opened field lines are responsible for these dimmings. Variations in the plasma temperature associated with coronal mass ejections probably play an important role for some dimmings, which appear different in different lines. 相似文献
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A. Zhitnik K. A. Boyarchuk O. I. Bugaenko G. S. Ivanov-Kholodnyi A. P. Ignat'ev V. V. Krutov S. V. Kuzin A. V. Mitrofanov S. N. Oparin A. A. Pertsov V. A. Slemzin A. I. Stepanov 《Solar System Research》2003,37(4):296-301
We consider the effects of the absorption of solar XUV radiation by the Earth's atmosphere that were observed in the solar images obtained with the TEREK-K telescope onboard the Coronas-I satellite in May–June 1994 at low solar activity and with the SPIRIT instrumentation onboard the Coronas-F satellite in October–November 2001 at maximum solar activity. The solar images were recorded during the satellite occultation: in the 175- and 304-A spectral ranges onboard Coronas-I with the TEREK-K telescope and in the 175-, 304-, and 8.42-A ranges onboard Coronas-F with the SPIRIT instrumentation. Based on the XUV solar images obtained during atmospheric sounding, apart from the total absorption, we can determine the direction of the atmospheric density gradient and study the local absorption variations with altitude on spatial scales of less than 1 km. The described method can significantly supplement the data obtained in studies of the upper atmosphere by the methods of mass spectrometry, incoherent radar scattering, and the drag of orbital spacecraft. 相似文献
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I. A. Zhithik S. V. Kuzin I. I. Sobel'man O. I. Bugaenko A. P. Ignat'ev A. V. Mitrofanov S. N. Oparin A. A. Pertsov V. A. Slemzin N. K. Sukhodrev A. M. Urnov 《Solar System Research》2005,39(6):442-452
The main results of the SPIRIT experiment on imaging spectroscopy of the Sun in the soft X-ray and extreme vacuum UV range are presented. The results were obtained onboard the CORONAS-F satellite, which has been operating since July 2001. More than 40 thousand observation sessions were performed during the experiment. About a million solar images and spectra (more than 250 Gb of information) were obtained, including monotemperature images of the solar atmosphere in six spectral regions, corresponding to temperatures from 0.05 to 2 MK; full-Sun spectral images (spectroheliograms) in more than 150 lines (177–207 Å and 285–335 Å, T from ～0.05 to 20 MK); images of the full Sun in the monochrome Mg XII line (8.42 Å, T ～ 10 MK); images of the solar corona at a distance of up to five solar radii; continuous series (up to 20 days long) of observations with high time resolution (40–100 s); observations of the flare dynamics, including the preflare, initial, and main phases, with a resolution of 7 s, and data on the absorption of X-ray and XUV solar radiation in the upper atmosphere of the Earth. The study was performed for the maximum of the 11-year solar activity cycle and for its decrease phase. 相似文献
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I. M. Chertok V. V. Grechnev V. A. Slemzin S. V. Kuzin O. I. Bugaenko I. A. Zhitnik A. P. Ignat'ev A. A. Pertsov J.-P. Delaboudiniere 《Solar System Research》2005,39(6):462-469
We briefly overview results of our study of the large-scale solar activity associated with coronal mass ejections (CMEs). The observational material is constituted with data of the SPIRIT telescope aboard the CORONAS-F satellite in the three EUV channels 175, 284, and 304 Å. In particular, we consider a powerful geoeffective event of November 4, 2003, which was not observed by the SOHO/EIT telescope, a series of extremely powerful events of October 2003, and an event of November 18, 2003, with filament eruption. The efficiency of combined analysis of the SPIRIT and EIT data is demonstrated. The analysis confirms the coincidence of many dimmings in different spectral channels, including coronal lines with different excitation temperatures and the transition-region line, as well as the global character and homology of dimmings in recurrent events. The higher cadence SPIRIT observations at 304 Å reveal a slowly propagating large-scale darkening probably caused by absorption of emission in the dense, cold plasma of an eruptive filament. 相似文献
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V. A. Slemzin S. V. Kuzin I. A. Zhitnik J.-P. Delaboudiniere F. Auchere A. N. Zhukov R. Van der Linden O. I. Bugaenko A. P. Ignat'ev A. V. Mitrofanov A. A. Pertsov S. N. Oparin A. I. Stepanov A. N. Afanas'ev 《Solar System Research》2005,39(6):489-500
The SPIRIT complex onboard the CORONAS-F satellite has routinely imaged the Sun in the 171, 175, 195, 284, and 304 Å spectral bands since August 2001. The complex incorporates two telescopes. The Ritchey-Chretien telescope operates in the 171, 195, 284, and 304 Å bands and has an objective similar to that of the SOHO/EIT instrument. The Herschel telescope obtains solar images synchronously in the 175 and 304 Å bands with two multilayer-coated parabolic mirrors. The SPIRIT program includes synoptic observations, studies of the dynamics of various structures on the solar disk and in the corona up to 5 solar radii, and coordinated observations with other spaceborne and ground-based telescopes. In particular, in the period 2002–2003, synoptic observations with the SPIRIT Ritchey-Chretien telescope were coordinated with regular 6-hour SOHO/EIT observations. Since June 2003, when EIT data were temporarily absent (SOHO keyholes), the SPIRIT telescope has performed synoptic observations at a wavelength of 175 A. These data were used by the Solar Influence Data Analysis Center (SIDC) at the Royal Observatory of Belgium for an early space weather forecast. We analyze the photometric and spectral parameters of the SPIRIT and EIT instruments and compare the integrated (over the solar disk) EUV fluxes using solar images obtained with these instruments during the CORONAS-F flight from August 2001 through December 2003. 相似文献
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Bogomolov A. V. Denisov Yu. I. Kuznetsov S. N. Lisin D. V. Logachev Yu. I. Morozov O. V. Myagkova I. N. Svertilov S. I. Zhitnik I. A. Ignat'ev A. P. Oparin S. N. Pertsov A. A. Stepanov A. I. Tindo I. P. 《Solar System Research》2003,37(2):112-120
The first results of the experiment with the SPR-N hard X-ray (20–100 keV) polarimeter onboard the Coronas-F observatory (the experiment started on August 15, 2001) are presented. Hard X-ray radiation was detected from several solar flares. The spectral and temporal parameters were determined and the polarization was estimated. Comparison with the GOES observations of thermal X-ray radiation shows that hard X-ray bursts occur at the growth phase of the thermal radiation and that they are associated with the bremsstrahlung of energetic electrons precipitating into the solar atmosphere. 相似文献
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