Впериоды магнитосферных суббурь зарегистрированы одновременные возмущения полного электронного содержания и горизонтальной компоненты геомагнитного поля в диапазоне периодов Рс6, возникающие в интервалы взаимодействия магнитосферы Земли с турбулентной оболочкой магнитных облаков. Вейвлет анализ возмущений межпланетного магнитного поля, скорости и плотности плазмы солнечного ветра свидетельствует о существовании в межпланетной среде колебаний с такими же периодами.

The efficiency of the previously developed algorithm for predicting extreme solar flares from their geomagnetic precursors has been tested on the example of a series of class X flares recorded on September 6, 2017. Over the past few years, these events of the solar flare activity are seen as the most intense. The algorithm consists in comparing the total histograms of the normalized number of synchronization moments for oscillations of long-period pulsations in the horizontal component of the geomagnetic field with extreme solar flare events in the intervals preceding them. The result of the algorithm is that extrema of histograms were detected a few days before the development of intense solar flares and can be considered as markers of the expected extreme flare activity. The study confirms the possibility of using the previously proposed algorithm for a short-term forecast of solar flare activity.

The phenomena accompanying the event of synchronous night-time ionospheric and geomagnetic disturbances, marked in globally magnetospecific quiet-time on the base of the mid-latitude Kazan station minute data, are analyzed. The dynamic and wavelet spectra comparison for studied disturbances showed coinciding features of the simultaneous disturbances for layer F2 critical frequency and H, D, Z geomagnetic field components. Therefore it was possible to assume their magnetosonic nature and establish the characteristic periods of observed magnetosonic ULF disturbances in the range of 35-50 minutes. The spatial analysis of noted magnetosonic disturbances with use of geomagnetic data obtained at stations located at different latitudes and longitudes toward to Kazan station demonstrated the isotropy of founded magnetosonic waves. This allows classifying them as fast magnetosonic disturbances. It is shown that the studied event occurs under substorm development conditions. The causes establishment of intramagnetospheric magnetohydrodynamic (MHD) disturbance is an important goal of solar-terrestrial physics. The appearance of magnetosound disturbances in the magnetosphere-ionospheric medium is commonly associated with development of geomagnetic storm. MHD disturbances in the magnetosphere and ionospheric conductive layers can also be associated however with other high-energy processes. In studies [Barkhatova et al., 2009; Barkhatova et al., 2015], for example, magnetosound type waves, generated by an eastward electrojet and earthquakes of large magnitude were detected. At the same time in addition to geomagnetic field disturbances, synchronous disturbances in ionospheric conductive layer F2 in the ULF range were observed. The present study is devoted to the analysis of phenomena accompanying the event of synchronous night time ionospheric and geomagnetic disturbances, detected in the globally magneto-quiet time at the midvertical sounding data and data of geomagnetic field H, D, and Z components with a minute resolution for the interval September 1-4, 2014. The coinciding features of F2 layer critical frequency and the geomagnetic field components simultaneous disturbances as a result of dynamic spectra and wavelet patterns comparison of studied disturbance for September 3, 2014 were found. For other days (1, 2 and 4 September) in the night time region (+ 3 GMT) there is no pronounced ionospheric disturbance. Fig. 1 shows the critical frequency foF2 and the geomagnetic field H component wavelet spectra for Kazan station, received for September 3, 2014 during the night time interval (00.00 to 02.00 UT). The black arrows show the maxima coincidence of ionospheric and geomagnetic field H component disturbances for the interval 01.17 01.55 UT. The best coincidence of considered disturbances was noted for periods from 15 to 30 minutes. The fact of simultaneous disturbances for foF2 and the geomagnetic field components coincide allow us to assume their magnetosound nature. The question of relation for considered disturbances to SMS (slow magnetosound), more likely associated to geomagnetic field force line, or to an isotropic FMS (fast magnetosound) type can be solved by spatial analysis of disturbance wavelet spectra received at stations with different latitudes and longitudes from Kazan. The data of 51.87 E), Hel (54.61 N, 18.82 E), San Fernando (36.67 N, 5.50 W). The coincidence of spectral maxima for Kazan station critical frequency and geomagnetic field H component at the magneto-conjugated observatory Port Alfred (southern hemisphere) for the analyzed frequency range is established for the studied time interval. This indicates the connection of studied wave phenomenon to the corresponding geomagnetic force line. The comparison of the disturbance spectral features for the critical frequency over Kazan with disturbances of geomagnetic field H, D components at other stations located in a large latitudinal-longitude region also showed cases of analyzed spectral features coincidence. Such isotropic behavior for studied magnetosound waves makes it possible to classify them as fast magnetosound disturbances. The search for a possible source of considered night time mid-latitude synchronous ionospheric and geomagnetic disturbances required the study of outer magnetospheric processes. During the case of foF2 disturbances in Kazan, disturbances of the interplanetary magnetic field Bz component (Bz IMF) were detected in the same frequency range. So it was established that the long-period oscillations of Bz IMF find their manifestation in the ionosphere and geomagnetic field components. Fig. 2 shows the wavelet spectra of the foF2 critical frequency at Kazan station (upper panel) and Bz IMF component for the considered time interval. Synchronization of geomagnetic and ionospheric disturbances on the substorm process background 98 A study of time behavior for the Solar wind concentration shows that in the time period up to 00.45 UT (+3 GMT Kazan) its higher values are observed with a further decrease and reaching the minimum value at 01.00 UT. For the interval 01.00 02.00 UT, there is a general increase in the Solar wind velocity, which persists throughout the interval. Figure 1. Wavelet spectra of F2 layer critical frequency (the first panel from the top) and geomagnetic field H component (second panel) for September 3, 2014. The black arrows indicate a correspondence between the spectra maximums for foF2 and the H component disturbances. Figure 2. Wavelet spectra of the ionospheric layer F2 critical frequency and interplanetary magnetic field Bz component disturbances for September 3, 2014. The arrows indicate areas of the spectral singularities coincidence for foF2 critical frequency and IMF Bz component. O.M. Barkhatova et al. 99 In addition, during ~ 01.00 UT, the values of IMF Bz component change from small negative to positive values. Such situation, according to [Barkhatov et al., 2017; Morley and Freeman, 2007], correspond to the substorm development. Note that the considered time interval corresponds to the night-time magnetosphere sector, within the westward electrojet (AL) is localized. Its dynamic shows that during this time there really is a bay-like disturbance preceded a non-disturbed period (AL ~ -20 nT). Fig. 3 shows the dynamics of the Solar wind parameters and the AL index. Black vertical lines indicate the coincidence of foF2 and geomagnetic field H component spectral features at Kazan station. The performed results demonstrate the possibility of synchronous ionospheric and geomagnetic disturbances existence in the class of Pi3 pulsations (periods of 15-30 min) at medium latitudes for local nighttime in the global geomagnetic non-disturbed conditions. The magnetosound nature of observed disturbances is demonstrated by comparing of foF2 critical frequency over the Kazan station and geomagnetic field component spectral patterns over a large spatial region including high, middle and low latitudes. The revealed magnetosound disturbances can be generated by the instability of westward electrojet. At the same time, these electrojet participates in substorm process as an element of a large-scale three-dimensional current system a substorm current wedge. During the substorm development, the extended magnetic force lines of geomagnetic tail are subjected to ULF vibration by disturbed magnetized Solar wind. It makes possible to explain such low frequencies of observed disturbances in comparison with resonant MHD oscillations under quiet conditions. Thus, the noted synchronization of ionospheric and magnetic disturbances gives reason for believing that detected disturbances have a magnetosound nature and are associated with substorm activity. Acknowledgements. -05-35-00084 and the Ministry of for provided Kazan ionospheric vertical sounding data. Figure 3. Interplanetary magnetic field component Bx, By, Bz plots (left panel), Solar wind velocity and concentration (right panel) for September 3, 2014. Vertical black lines indicate the coincidence of foF2 and H component spectral features at Kazan station.

The phenomena which accompany synchronization of night-time ionospheric and geomagnetic disturbances in an ULF range with periods 35–50 min near the mid-latitude station Kazan during a global magnetically quiet period have been analyzed. The comparison between dynamic spectra and wavelet patterns of these disturbances has revealed that spectral features of simultaneous disturbances of the F2-layer critical frequency and H, D, Z geomagnetic field components are similar. By studying spectral features of the F2-layer critical frequency over Kazan and disturbances of the H and D geomagnetic field components at magnetic stations which differ from Kazan station in longitude and latitude, we have established that the disturbances considered belong to the class of fast magnetosonic waves. The analysis of solar wind parameters, interplanetary magnetic field (IMF), and values of the auroral index AL in the period under study has shown that this event is associated with IMF Bz component disturbances and occurs during substorm development.

The pattern of ionospheric activity along the meridional and latitudinal directions in the middle latitudes was analyzed based on the previously suggested IAI index. The contribution of the solar and geophysical factors that largely control the midlatitude ionosphere and the general level of the ionospheric disturbance were established. Changes in the ionospheric activity traced along a meridian from lower to higher latitudes in the interval from 35° to 50° N were quantified. Based on the obtained results, a method is suggested for calculating a correction of the IAI index, which makes it possible to estimate IAI at any desired latitude from the values of this index at a particular station. A neural network approach is developed for prompt diagnosis and forecasting of the state of the midlatitude ionosphere in terms of the IAI index from the level of the solar-geophysical activity. The optimal configuration of the neural network and the most efficient input parameters, which provide the maximum (75%) efficiency of the neural network forecasts of the IAI index, are determined.

Magnetogravity activity during the preparation of four strong (M > 6.5) earthquake with epicenters at medium (35–40° N) and low (10° S–10° N) latitudes is detected. For this purpose a comparison of simultaneous disturbances at dynamic spectra of ionospheric layers Es, E, F2 critical frequencies and geomagnetic field X, Y, Z components was performed. It was found that the greatest number of magnetogravity events noted in epicenters vicinity takes place at two days before the considered earthquakes. Evaluation of dynamic spectra intensity level which was obtained by data from magnetic stations located around the epicenter, allows to identify the magnetogravity waves (MGW) propagation direction with least damping. In most cases they coincide with geomagnetic field direction. Attention is paid to ionospheric wind influence for low-frequency MGW mode.

Synchronous disturbances of ionospheric (layers F2, E, and Es) electron density and the geomagnetic field components during the intervals of strong earthquakes (exceeding 6.5 on the Richter magnitude scale) (8 January 2006 and 17 July 2006 off the west coast of Indonesia) have been detected. These disturbances are supposed to be related to the formation of magnetogravity waves (MGWs) during the development of high energy geophysical events. The enhancement of MGW activity takes place two days before and after the quake. On the day of the event MGWs are not registered except for the passage of acoustic-gravity waves. The existence of MGWs is analytically confirmed by the dispersion analysis under conditions of the horizontal geomagnetic field (near-equatorial regions) and the finite ionospheric conductivity.

It was observed earlier [Bystrov et al, 1979] that a few days before the expansion of a Solar flare can be observed long-period (20 minutes or more) geomagnetic pulsations in the components of the geomagnetic field of groundbased observatories. In [Smirnova, 2010] showed that indeed for 2-3 days before the Solar flare enhancement of long-period pulsations of H-component of the geomagnetic field in comparison with quiet periods is observed. There is also pointed out that the correlation coefficient of the spectral density of X-ray radiation and the horizontal component of the magnetic field can reach 93%. This allowed the claim on the effect of the spectral composition of ionizing radiation from the Sun to pre-flare spectrum of growing geomagnetic fluctuations. Unfortunately, this conclusion on the consideration of a narrow range of oscillation periods for one event of extreme flare is based. In addition calculated the correlation coefficient is not accurately set moments of synchronization of processes on terrestrial observatories. A major factor limiting consideration of direct communication fluctuations of Solar ionizing radiation and geomagnetic pulsations is the inertia of the ionosphere [Barkhatov et al., 2004] is observed. In our study using large experimental data, which includes data from 20 extreme X-ray flares is performed by wavelet analysis of geomagnetic pulsations at different scales within a five-day interval before each flare. Feature of the data is the use of wavelet-skeleton technology allows maximum eliminate uncertainty in the interpretation of results. The study aims to establish the possibility of using evidence obtained synchronization skeletons as precursors of a powerful Solar flares. It is necessary to test the hypothesis of the electromagnetic impact of Solar radiation on the physical processes in the Earth's magnetosphere. The study was performed with minute data for the horizontal component of the geomagnetic field of six observatories Leirvogur, Valentia, Kanoya, Hatizyo, Kakioka, Memambetsu in a wide range of coordinates (latitude geom. 31-64) derived from the resource http://wdc.kugi.kyoto-u.ac.jp. Were analyzed in simultaneous minute data about the power of X-rays and the data on the Solar wind the flow velocity, density, the magnitude of the IMF granted resource http://spidr.ngdc.noaa.gov/spidr. The study of each case included a flare interval of observations containing 4.5 days (6480 min) before register the flare and 0.3 days (500 minutes) after register. Thus, each analyzed interval contains 6980 minutes of simultaneous observations of the geomagnetic field, parameters of the solar wind and the power of X-rays. The main criteria for the selection of such events was magnetically quiet environment for the entire five-day observation period (|Dst| 10-4 W/m). According to these criteria, 20 flares were analyzed according to the catalog http://vso.nso.edu/cgi/catalogui. The date of the analyzed flares of class X: 07.09.2005, 16.07.2004, 02.11.2003, 28.10.2003, 19.10.2001, 23.07.2002, 13.12.2001, 17.03.2003, 26.02.2004, 07.11.2004, 24.09.2001, 03.08.2002, 06.04.2001, 28.12.2001, 21.04.2002, 31.10.2002, 09.06.2003, 15.06.2003, 13.08.2004, 30.10.2004.