Global observations of the ionospheric total electron content (TEC) are used to analyze the development of a moderate geomagnetic storm on November 7, 2022. The effects of the storm in the American and European sectors are compared. Signatures of such large-scale ionospheric structures as storm enhanced density (SED) and tongues of ionization (TOIs) are detected during the storm.

Using the global total electron content data, the development of a moderate magnetic storm on November 7, 2022, is presented. The effects of the storm in the American and European sectors are compared. During the storm, manifestations in the ionosphere large-scale structures such as SED (storm enhanced density) and TOI (tongue of ionization) were detected.

In this report the occurrence of TEC fluctuations and their impact on the Precise Point Positioning (PPP) errors at high latitudes for November 4, 2021 geomagnetic storm is presented. We used GPS observations of polar Ny-Ålesund (MLAT, 76.6°) and auroral Tromsø (MLAT, 66.9°) stations. The fluctuation activity and intensity of fluctuations was evaluated by ROT/ROTI indexes. At both stations the periods of the most intense fluctuations occurrences in GPS data coincided with strong increases in AE index. There is good agreement in dependence of fluctuation intensity (ROTI) and positioning errors. At Ny-Ålesund the errors were reached 4 m against 16 cm at during quiet conditions. At TRO1 strong intensification fluctuations led to a dramatic increase PPP errors.

A statistical study is performed of the phase fluctuations of GPS signals and positioning errors at Ny-Ålesund (78.9° N, 11.9° E) and Tromsø (69.60° N, 19.20° E) for March, June, October, and December 2015. The strongest fluctuations occur around magnetic noon at Ny-Ålesund and magnetic midnight at Tromsø. The seasonal/diurnal course of fluctuations and positioning errors agree strongly.

—We present joint analysis of fluctuations in navigation signals, positioning errors, and their relationship to auroral disturbances occurred in March 2015. Using the precise point positioning (PPP) algorithm in the kinematic mode during the March 17, 2015, geomagnetic storm, we found anomalously large positioning errors of navigation measurements at auroral, subauroral, and mid-latitude stations in Europe.

Determination of the physical mechanisms of energy transfer from tropospheric disturbances to the ionosphere is one of the fundamental problems of atmospheric physics. Both regular events (passage of the solar terminator) and irregular ones (meteorological storms, earthquakes, solar eclipses, etc.) lead to such disturbances. This paper presents the results of observations of tropospheric and ionospheric disturbances during the passage of the solar terminator, solar eclipse, and meteorological storm. Lidar sounding shows that during the development of these events, regions are formed in the troposphere with a noticeable increase in the amplitudes of variations in density, pressure, and temperature with periods corresponding to acoustic and internal gravity waves (AWs and IGWs, respectively). Simultaneous satellite measurements demonstrate the response of the ionosphere to tropospheric disturbances. Based on the observational data for each of the events, the characteristic periods and the time and spatial scales of variations are determined. It is found that the response time of the ionosphere to tropospheric disturbances is 30–40 min. As a result of numerical modeling using the AtmoSym software package, it is shown that nonlinear and dissipative processes in the thermosphere lead to the formation of sources of secondary waves with periods longer than those of the primary AWs and IGWs propagating vertically upward from the troposphere into the thermosphere. The influence of tropospheric disturbances on the operation of global navigation satellite systems is also discussed.

We analyzed the occurrence of TEC fluctuations and an impact of auroral disturbances on the Precise Point Positioning (PPP) errors in European sector using GPS measurements of EPN network. Index AE was used as indicator of auroral activity. The fluctuation activity was evaluated by indexes ROT and ROTI. The positioning errors were determined using the GIPSY-OASIS software (http://apps.gdgps.net). The Precise Point Positioning is the processing strategy of the single receiver for GNSS observations that enables the efficient computation of the high-quality coordinates. For quiet conditions the algorithm provided for TRO1 stations daily average PPP errors less than 4-5 sm. The analysis indicated regular increasing positioning errors around MLT (22 UT) during March 2015. While raising the auroral activity it was observed increasing TEC fluctuation as well as positioning errors. In the report we discus also behavior PPP errors during super storm 17 March 2015. During storm at TRO1 the PPP errors reached more than 20 m. The increasing errors were observed on latitudes low than 52-54°N.

An analysis is performed of fluctuations in navigation signals in the Arctic due to the auroral disturbance of September 27, 2019. Anomalous 3D positioning errors over European auroral stations were detected during this event. It is shown that strong positioning errors were caused by the navigation signals crossing intense discrete forms of the aurora.

В работе дано сопоставление проявления фазовых флуктуаций GPS-сигналов и их воздействия на точность позиционирования на полярной NYA1 и авроральной TRO1 станциях для ноября 2012г. Представлен детальный анализ особенностей и различий ионосферных эффектов на обсуждаемых станциях во время конкретных геофизических условий.

The features of the annular solar eclipse of June 21, 2020, in variations of the ionospheric total electron content (TEC) were analyzed using GPS observations of the IGS network of China. It is noted that the ionospheric effects of annular eclipses have been much less studied than the effects of total or partial solar eclipses. Based on the analysis of diurnal TEC variations for the selected GPS stations, it was found that the effect of this eclipse had the form of a TEC depression with a minimum close to the maximum phase of the eclipse at the observation station. The eclipse effect was found to be more clear in TEC variations along individual satellites passes, which had the form of a trough-like depression. It is shown that the major component in the magnitude decrease and delay of the TEC minimum relative to the maximum eclipse phase is the magnitude of the eclipse for a particular station. This follows from the high correlation between these parameters and the magnitude of the eclipse. The delay varies from several minutes to tens of minutes, depending on the magnitude of the eclipse. The maximum value of the TEC decrease reached ~4–6 TECU. To analyze the spatiotemporal behavior of the TEC, the IONEX files with a 15-min resolution were used. It was found that the maximum TEC depression was consistent with the trajectory and position of the eclipse shadow on the Earth’s surface.

Since 1964, the Kaliningrad branch of Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation, Russian Academy of Sciences (IZMIRAN) has been conducting regular observations of the parameters of the lower atmosphere, ionosphere, and variations in the Earth’s magnetic field. The base of the measuring equipment, located in Ulyanovka village, Kaliningrad region (54° N, 20° E) consists of ionosonde for the vertical sounding of the ionosphere; two-frequency GPS/GLONASS receivers, which are used to determine the total electron content in the ionosphere; magnetic variation stations for the continuous recording of variations of the three components of the Earth’s magnetic field vector and calculating the local K-index; and a weather station. The simultaneous observations of variations in the magnetic field, as well as the ionospheric and meteorological parameters in the same observatory, offer a wide range of opportunities to study the atmospheric-ionospheric relations. This article provides a brief description of all the tools, provides a method for transmitting and storing the time series of measured parameters, and also presents examples of using these data for various geophysical studies.

The manifestation of the most powerful flares of class X9.3 and X8.2 recorded on September 6 and 10, 2017, respectively, in the total electronic content (TEC) of the ionosphere, are analyzed. GPS observations at midlatitude stations located in the conditions of an illuminated ionosphere were used as the initial data. The ionospheric response was determined from phase measurements of the TEC value along satellite flights over the observation station. A high linear correlation was found between the amplitude of the increase in TEC (ΔТЕС) during flares and the zenith angle of the Sun for longitudinally spaced stations. For the class-X9.3 flare, ΔТЕС exceeded 3 TECU, while for the X8.2 flare, the amplitude was almost two times smaller. It is shown that this is mainly due to the different positions of flares on the solar disk. The spatiotemporal response of the ionosphere to flares was analyzed with TEC maps with a time resolution of 5 min. Errors in navigation measurements that are caused by the effects of solar flares are identified and evaluated.

Проанализированы проявления фазовых флуктуаций GPS сигналов и их связи с авроральными возмущениями за период с 1 декабря 2015 по1 января 2016 года. Были использованы GPS наблюдения авроральных, субавроральных и среднеширотных станций Европейского региона. Путем прямых сопоставлений авроральной возмущенности (AE индекс) и проявления флуктуаций показана тесная связь этих событий в их временном развитии.