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Geomagnetism and Aeronomy - A model of the medium of the ionosphere and magnetosphere, including the distributions of the concentrations and temperatures, collision frequencies, and magnetic field...  相似文献   
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Geomagnetism and Aeronomy - The climatological features and behavior of the parameters B0_Neh_I, B1_Neh_I found from N(h) profiles calculated by the curves from the virtual heights during...  相似文献   
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The insufficiently known phenomenon of MF-wave propagation from the Earths surface through the magnetosphere (guiding) to the conjugate hemisphere and back to the transmitter has been experimentally studied. Computer modelling fulfilled on the basis of ray tracing showed that guiding was possible only from area of the main ionospheric trough. The effect of MF guiding is most useful for the diagnostics of the plasmapause, poleward edge of the trough, the diffuse precipitation boundary and so on.  相似文献   
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A comparison of the total electron content (TEC) of the ionosphere calculated using different correcting multipliers in the IRI2007 model with experimental data indicates that this model, which is not empirical with respect to the TEC, does not adequately reflect the quantitative and qualitative features of the TEC behavior. The situation can be improved by using new empirical models of the critical frequency and equivalent thickness of the ionosphere and new methods for determining the TEC.  相似文献   
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The method of correcting the daytime vertical profiles of electron plasma frequency in the low ionosphere from International Refererence Ionosphere (IRI) model in accordance with the measured data of the virtual heights and absorption of signal radiowaves (method А1) reflected from the bottom of E-region at vertical sounding (VS) is presented. The method is based on the replacement of the IRI model profile by an approximation of analytical dependence with parameters determined according to VS data and partially by the IRI model. The method is tested by the results of four joint ground-based and rocket experiments carried out in the 1970s at midlatitudes of the European part of Russia upon the launches of high-altitude geophysical rockets of the Vertical series. It is shown that the consideration of both virtual reflection heigths and absorption makes it possible to obtain electron density distributions that show the best agreement with the rocket measurements made at most height ranges in the D- and E-regions. In additional, the obtained distributions account more adequately than the IRI model for the contributions of D- and E-regions to absorption of signals reflected above these regions.  相似文献   
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We report methane concentrations in the bottom water layer and the upper layer of bottom sediments and the results of acoustic explorations of methane seeps on the shelf bordering the continental slope of the Sea of Japan region, in which electromagnetic Schumann’s resonance oscillations were earlier recorded at continental-slope water depths of 500, 1000, and 2000 m. The occurrence of Schumann’s resonances at such great depths is explained by an increase (a factor of more than 25) in the electrical resistivity of a ~ 2000 m thick sediment layer with the pore space largely filled with free methane. A new method is proposed for determining the depth of the sources of anomalous concentrations of methane in bottom sediments or in the bottom water layer on a deep shelf. The method is based on recording Schumann’s resonances during measurements of the natural electric field at a series of increasing depths in areas bordering the continental slope.  相似文献   
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A study of simultaneous groundbased observations of I.P.D.P. (intervals of pulsation of diminishing period) magnetic field fluctuation events and satellite observations of energetic protons have been performed. Some of our results are as follows. (1) The region of I.P.D.P. occurrence is always located equatorward of the isotropic proton precipitation. (2) The I.P.D.P. generation is not connected with the poleward leap of the aurora and the poleward expansion of the precipitating protons. (3) In the evening to afternoon sector enhanced pitch angle scattering is found near L = 4 during I.P.D.P. events, earlier shown to be associated with ion cyclotron resonance. (4) I.P.D.P. events seem to be associated with increased fluxes of (40–60) keV protons injected during substorms near the plasmapause in the equatorial plane.In order to explain the observations we invoke the following model: at substorm onset ring current protons are injected deep into the nightside magnetosphere covering a certain region in L and L.T., with the inner edge of the proton population following McIlwain's injection boundary. The protons drift azimuthally westward and generate ion cyclotron waves in a certain L interval at or inside the plasmapause. By taking into account the shape and position of the plasmapause and the injection boundary, the exterrt and position of the wave generating region can be determined. The frequency-time dispersion of the I.P.D.P. is largely attributed to the L-dependent drift velocity of protons in a narrow energy band. The model is able to explain the observations during several individual events. Also, the model predicts the general trends that have been found by statistical analysis of I.P.D.P. events and accounts for the constant frequency observed by satellites during I.P.D.P. events.  相似文献   
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Summary The elements of the VLF chorus, observed simultaneously at a ground station and satellite in polar orbit, can be used to determine the differences in the arrival times of waves and their dependence on latitude. Mostly does not change practically over a wide range of latitudes, however, in some cases it may increase appreciably at low value of L. Model computations of the propagation time, based on the assumption that the source of the chorus is located close to the equatorial plane, have indicated the possibility of explaining the increase in at low latitudes by the presence of a step in the electron density profile close to this plane.
a¶rt;u m a u a um nmu nun um nm n¶rt;um amu u nu¶rt;a ma a u u um auum (L). um a a m ¶rt;uana um, m a a¶rt;am aum uu a a L-a. am anmau n¶rt;nuu amua umua naam m um uu a uu uma auu mnu an¶rt;uu m mauu amua nmu.
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