Vol 63, No 3 (2023)

The results of experiments on radio sounding of near the Sun plasma by the signals of the Mars
Express Mars satellite are presented. In the region of heliocentric distances of the proximate point of the line
of sight of 8–13 solar radii, frequency fluctuations of transmission radio signals were measured. During the
experiments sharp increases in the variance of frequency fluctuations were recorded on both the eastern and
western limbs. In measurements near the Earth’s orbit on the Wind spacecraft in adjacent periods with a delay
of 5–17 days, increases in the proton concentration and magnetic field strength were recorded at 7–15 times the
background values. A comparison between the data related to the inner and near-Earth solar wind indicates that
the observed disturbances are associated with the same region of the solar corona rotating with the Sun

Анализируются доплеровские наблюдения авроральной электроструи норвежским радаром STARE в течение одного солнечного оборота, предшествовавшего сильной магнитной буре. При этом наименьшая частота резонансного ультранизкочастотного поглощения определяется как частота ступенчатого падения спектральной плотности мощности наблюдаемого сигнала. В свою очередь, ч-астота ступенчатого падения спектральной плотности мощности определяется посредством решения минимальной вариационной задачи, которая наилучшим образом (метод наименьших квадратов) вписывает ступенчатую модель средней спектральной мощности в профиль спектральной плотности мощности реальных наблюдений. Последовательное сжатие спектрального окна, в котором решается вариационная задача, позволяет построить диаграммы решений минимальной задачи на плоскости частота – мощность резонансного поглощения. С помощью таких диаграмм выделены высокочастотная и низкочастотная ветви резонансного ультранизкочастотного поглощения. Обнаружено, что в слабовозмущенных условиях изменчивость резонансного ультранизкочастотного поглощения обусловлена, в первую очередь, вариациями мощности поглощения в обеих ветвях.

A neural network forecast of substorms caused by the impact of solar wind plasma flows on the
Earth’s magnetosphere has been performed. For this, recurrent neural network models were created based on
physical cause-and-effect relationships of the dynamics of high-latitude geomagnetic activity (according to
the AL index) with the parameters of the interplanetary magnetic field (IMF) and solar wind plasma (SWP).
Two parameters are used as input sequences: the bz-component of the IMF and the integral parameter
Σ[NV2], taking into account the prehistory of the process of pumping the kinetic energy of the solar wind into
the magnetosphere, where N and V are the plasma density and solar wind velocity, respectively. The forecast
of the AL index according to SWP and IMF for 10 min, etc. with 10 min discreteness individually by an individual
artificial neural network (ANN) for each point corresponding to the dynamics of the AL index was
completed. This means that the prediction of a continuous series of values AL index is achieved by a parallel
running of the ANN package. The number of ANNs in the package is determined by the duty cycle of the
required predictive series of the AL index, while taking 90 min of the history of input parameters in each of
the networks into account provides a prediction of the values AL index with an accuracy of ~80%

Analysis of geomagnetic and ionospheric activity is performed for 541 disturbed days during spotless
Sun (Kp > 3.0) from 1995 to 2021. Variations of the global ionospheric indices WU (positive disturbances
of total electron content), WL (negative disturbances), their range WE and the planetary index Wp are analyzed.
The source W-index characterizes a measure of deviation of the instant total electron content from the
quiet median varying from −4 to +4 with a step 1, and the global indices WU, WL, WE, Wp are derived from
the global maps GIM-TEC of Jet Propulsion Laboratory, JPL. Investigation of the seasonal dependence has
revealed two levels of the ionosphere disturbances: the low disturbance of the ionosphere during 1996‒1998
and 2018‒2021 and the high disturbance during 2004‒2010 and 2016‒2017. The seasonal ionosphere variations
are different for two sets of the data. The seasonal variations of the solar wind velocity Vsw near the Earth
orbit are first identified for the 1st data set displaying the peaks at the equinoxes similar to variations of the
Kp-index. The 2nd set of the high disturbance of the ionosphere refers to the epoch of transition from the high
solar activity SA to low SA characterized by the total restructuring of the physical conditions on the Sun

The results of experimental studies of electric field disturbances generated by sources of an ionospheric
origin in the coastal zones of the White and Barents seas are presented. The data recording was performed
by geophysical stations GI-MTS-1. The horizontal electric field was recorded by telluric lines ~50 m
long. The Ex component was set orthogonally to the coastline in the direction from the shore, and the Еy
component was directed along the coastline. In the coastal strip of the sea–land contact, a zone of anomalous
increase in the amplitude of ULF variations (F < 1 Hz) of the Ex component adjacent to the water’s edge was
revealed. An additional narrow zone of anomalous amplification of the ULF variations of the electric field is
observed at a distance of ~30 m from the water’s edge. The coastal effect reaches its maximum near the
water’s edge in the coastal zone and decreases with distance from the seashore

This article presents the results of a study of the thermal regime of the lithosphere under the Taimyr
Peninsula and adjacent territories (70°–80° N, 80°–115° E) based on geomagnetic data. Spectral analysis of
the lithospheric geomagnetic field given by the EMAG2v3 model was performed using the centroid method.
The calculations we performed showed that the minimum depths of the top boundary of lithospheric magnetic
sources (<2.5 km) are typical for the entire Taimyr fold belt and the considered part of the Siberian Platform,
and the maximum (>6 km) for the North Kara Basin. The position of the top boundary of the magnetically
active layer of the lithosphere above the bottom of the sedimentary layer under the Yenisei-Khatanga
and Khatanga-Lena basins can be associated with the widespread intrusion of basalt traps into the sedimentary
layer. The minimum depths of the bottom boundary of lithospheric magnetic sources (<36 km) are confined
to the Eurasian Basin and neighboring territories of the Laptev Sea shelf and the islands of the Severnaya
Zemlya archipelago, which indicates the greatest heating of the lithosphere under them within the
region under consideration. The depth of the bottom boundary reaches maximum values (≥48 km) under the
Yenisei-Khatanga and North Kara basins and the Siberian Platform, indicating the existence of the cold and,
accordingly, thick lithosphere here, which is confirmed by other independent geophysical data

The source material for the number of Wolf numbers is both archival records of disparate observations
and regular observatory observations. Many researchers rely on a series of Wolf numbers, including
restored data of archival records, although the properties and characteristics of the restored and reliable parts
of the series differ significantly. The parameters of the restored part itself are also contradictory. Naturally,
matching the properties of the reconstructed and reliable series will smooth the contradictions and expand
the array of more reliable data. Taking the relationship between the characteristics of significant cycles into
account, options for group correction of the average values of cycles I–IX are presented. Since local data
residuals play a lesser role when comparing extended fragments, by relying on the integral estimates of these
fragments (without detailing the conditions for their formation) we obtained more weighted interval estimates.
The parameters of intervals (groups of cycles) of a reliable series serve as the basis for correction.