Figure - available from: Pure and Applied Geophysics
This content is subject to copyright. Terms and conditions apply.
Source publication
A global study is made of the response of the total electron content of the ionosphere (TEC) to the geomagnetic storm occurred on 22 June 2015 (one of the strongest geomagnetic storms of the current Solar Cycle 24). Using data from 44 sites, a hemispheric comparison is made by considering high latitudes (> 50°), middle latitudes (30°–50°) and low l...
Similar publications
In this study, the variations of topside ionospheric irregularities during 24 geomagnetic storms with Dst < -50 nT in 2015 were examined through an algorithm specifically designed to detect a significant level of ionospheric irregularities. The algorithm was developed through the use of several parameters derived from the topside total electron con...
This study for the first time presents an investigation into the exploitation of multi‐Global Navigation Satellite System (GNSS) observations (Global Positioning System, Globalnaya Navigazionnaya Sputnikovaya Sistema, Galileo, and BeiDou) to characterize ionospheric plasma irregularities, based on the rate of change of total electron content index...
The ionospheric response of two geomagnetic storms of 2016 occurred during spring equinox (5-8 March, 2016) and autumn equinox (12-15 October, 2016) is investigated using the total electron content (TEC) data derived from Global Positioning System (GPS) receivers located in the equatorial ionization anomaly (EIA) crest regions at northern hemispher...
Global Navigation Satellite System (GNSS)–based Earthquake (EQ) anomalies in the ionosphere and troposphere provide explicit evidences to study the coupling between seismic events, atmosphere, and ionosphere in epicentral breeding regions consequent to the EQ day in the preparation period. EQs are still not predicted, but the space-based EQ anomali...
We have studied the behaviour of ionospheric Total Electron Content (TEC) at a mid latitude station Usuda (36.13 0 N, 138.36 0 E), Japan during intense geomagnetic storms which were observed during 23 solar cycle (1998-2006). For the present study we have selected 47 intense geomagnetic storms (Dst ≤-100nT), for the given period, which were then ca...
Citations
... The geomagnetic storms of June 2015 have gained attention from numerous space scientists, such as [42][43][44][45][46][47]. Astafyeva et al. (2017Astafyeva et al. ( , 2018) employed a multi-instrument to study the 22-23 June 2015 geomagnetic storms and observed the effect of eastward PPMEF, which caused short-lived positive ionospheric storms during the day, and the eastward DDEF caused long-lived positive ionospheric storms on the nightside of the main phase and the early stage of the recovery phase. ...
... Astafyeva et al. (2017Astafyeva et al. ( , 2018) employed a multi-instrument to study the 22-23 June 2015 geomagnetic storms and observed the effect of eastward PPMEF, which caused short-lived positive ionospheric storms during the day, and the eastward DDEF caused long-lived positive ionospheric storms on the nightside of the main phase and the early stage of the recovery phase. Mansilla et al. (2018) [47] also studied the same storm globally and observed increased total electron content (TEC) at high latitudes before the storm's main phase, significant asymmetry in TEC response between the middle and low latitudes of the Northern and Southern Hemispheres, and TEC decrease at equatorial latitudes. The prolonged TEC enhancements closely correlated with an increase in the O/N 2 ratio; however, TEC decreases are not linked to reductions in the O/N 2 ratio, unlike concurrent decrease in electron density. ...
... Astafyeva et al. (2017Astafyeva et al. ( , 2018) employed a multi-instrument to study the 22-23 June 2015 geomagnetic storms and observed the effect of eastward PPMEF, which caused short-lived positive ionospheric storms during the day, and the eastward DDEF caused long-lived positive ionospheric storms on the nightside of the main phase and the early stage of the recovery phase. Mansilla et al. (2018) [47] also studied the same storm globally and observed increased total electron content (TEC) at high latitudes before the storm's main phase, significant asymmetry in TEC response between the middle and low latitudes of the Northern and Southern Hemispheres, and TEC decrease at equatorial latitudes. The prolonged TEC enhancements closely correlated with an increase in the O/N 2 ratio; however, TEC decreases are not linked to reductions in the O/N 2 ratio, unlike concurrent decrease in electron density. ...
This study investigated the impact of the June 2015 geomagnetic storms on the Brazilian equatorial and low-latitude ionosphere by analyzing various data sources, including solar wind parameters from the advanced compositional explorer satellite (ACE), global positioning satellite vertical total electron content (GPS-VTEC), geomagnetic data, and validation of the SAMI2 model-VTEC with GPS-VTEC. The effect of geomagnetic disturbances on the Brazilian longitudinal sector was examined by applying multiresolution analysis (MRA) of the maximum overlap discrete wavelet transform (MODWT) to isolate the diurnal component of the disturbance dynamo (Ddyn), DP2 current fluctuations from the ionospheric electric current disturbance (Diono), and semblance cross-correlation wavelet analysis for local phase comparison between the Sq and Diono currents. Our findings revealed that the significant fluctuations in DP2 at the Brazilian equatorial stations (Belem, dip lat: −0.47 • and Alta Floresta, dip lat: −3.75 •) were influenced by IMF Bz oscillations; the equatorial electrojet also fluctuated in tandem with the DP2 currents, and dayside reconnection generated the field-aligned current that drove the DP2 current system. The short-lived positive ionospheric storm during the main phase on 22 June in the Southern Hemisphere in the Brazilian sector was caused by the interplay between the eastward prompt penetration of the magnetospheric convection electric field and the westward disturbance dynamo electric field. The negative iono-spheric storms that occurred during the recovery phase from 23 to 29 June 2015, were attributed to the westward disturbance dynamo electric field, which caused the downward E × B drift of the plasma to a lower height with a high recombination rate. The comparison between the SAMI2 model-VTEC and GPS-VTEC indicates that the SAMI2 model underestimated the VTEC within magnetic latitudes of −9 • to −24 • in the Brazilian longitudinal sector from 6 to 17 June 2015. However, it demonstrated satisfactory agreement with the GPS-VTEC within magnetic latitudes of −9 • to 10 • from 8 to 15 June 2015. Conversely, the SAMI2 model overestimated the VTEC between ±10 • magnetic latitudes from 16 to 28 June 2015. The most substantial root mean square error (RMSE) values, notably 10.30 and 5.48 TECU, were recorded on 22 and 23 June 2015, coinciding with periods of intense geomagnetic disturbance.
... The second global study of the response of the ionospheric TEC during the geomagnetic storm on 22 June 2015 shows the following results: (a) before the main phase of the considered geomagnetic storm, increases in TEC at high latitudes were obtained; (b) there was a difference in the TEC response at mid and low latitudes in the Northern Hemisphere and the Southern Hemisphere and decreases at equatorial latitudes. The author explains the observed ionospheric response of the equatorial and low latitudes during the main phase of the storm with the influence of these areas by Prompt Penetration Electric Fields [39]. turbance dynamo effect was already in effect, competing with the PPEF and reducing them. ...
... The second global study of the response of the ionospheric TEC during the geo magnetic storm on 22 June 2015 shows the following results: (a) before the main phase o the considered geomagnetic storm, increases in TEC at high latitudes were obtained; (b there was a difference in the TEC response at mid and low latitudes in the Northern Hemisphere and the Southern Hemisphere and decreases at equatorial latitudes. The author explains the observed ionospheric response of the equatorial and low latitudes during the main phase of the storm with the influence of these areas by Prompt Penetra tion Electric Fields [39]. ...
In the present paper, the response of the ionospheric Total Electron Content (TEC) at low latitudes during several geomagnetic storms occurring in different seasons of the year is investigated. In the analysis of the ionospheric response, the following three geomagnetic events were selected: (i) 23–24 April 2023; (ii) 22–24 June 2015 and (iii) 16 December 2006. Global TEC data were used, with geographic coordinates recalculated with Rawer’s modified dip (modip) latitude, which improved the accuracy of the representation of the ionospheric response at low and mid-latitudes. By decomposition of the zonal distribution of the relative deviation of the TEC values from the hourly medians, the spatial distribution of the anomalies, the dependence of the response on the local time and their evolution during the selected events were analyzed. As a result of the study, it was found that the positive response (i.e., an increase in electron density relative to quiet conditions) in low latitudes occurs at the modip latitudes 30° N and 30° S. An innovative result related to the observed responses during the considered events is that they turn out to be relatively stationary. The longitude variation in the observed maxima changes insignificantly during the storms. Depending on the season, there is an asymmetry between the two hemispheres, which can be explained by the differences in the meridional neutral circulation in different seasons.
... This research paper delves into the examination of how the ionosphere in the Brazilian equatorial and low-latitude regions reacted to geomagnetic storms that took place in June 2015. The specific storms examined are those that occurred on 22-23 and 25 June 2015, which were induced by the combination of a coronal mass ejection (CME) and a high-speed solar wind stream (HSSWs) [24][25][26][27]. Additionally, the geomagnetic storm occurring on June 8, 2015, was primarily instigated by HSSWs. ...
... In another study on the ionospheric response to the June 22-23, 2015 geomagnetic storm, Mansilla (2018) [26] examined the Global Navigation Satellite System (GNSS) receivers to analyze the Total Electron Content (TEC) and observed TEC depletion at midlatitude stations. But at the equatorial and low latitude stations during the storm's main phase, the enhancements in TEC due to eastward prompt penetration electric field of the under shielding of the R1 region field-aligned current. ...
... In another study on the ionospheric response to the June 22-23, 2015 geomagnetic storm, Mansilla (2018) [26] examined the Global Navigation Satellite System (GNSS) receivers to analyze the Total Electron Content (TEC) and observed TEC depletion at midlatitude stations. But at the equatorial and low latitude stations during the storm's main phase, the enhancements in TEC due to eastward prompt penetration electric field of the under shielding of the R1 region field-aligned current. ...
This study investigates the impact of geomagnetic storms that occurred on June 8, 22-23, and 25, 2015, on the ionosphere in the low-latitude and equatorial regions of Brazil. By examining various data sources, such as solar wind parameters from the ACE satellite, GPS vertical total electron content (VTEC), magnetometer data, and the SAMI2 model, we aimed to simulate the effects of storms on the ionosphere in these regions. Two methods were employed to separate DP2 and Disturbance dynamo (Ddyn) from the ionospheric disturbance current (Diono). Our analysis revealed a positive (negative) ionospheric storm in the VTEC during the main phase (recovery) of the June 22-23 and 25 storms. This observation can be attributed to the combined impact of the eastward prompt penetration of the magnetospheric convection electric field (westward disturbance dynamo electric field) and changes in the storm-time thermospheric [O]/[N_2] ratio based on the GUVI satellite imagery. Notably, the westward disturbance dynamo exhibited a significant amplitude on June 23 in Belem. The amplitude of the D_dyn at Belem (dip lat: - 0.47˚) was greater than that at Alta Floresta (dip lat: - 3.75˚) due to intensified cowling conductivity in Belem. Furthermore, we found that the SAMI2 model provided more accurate results when we replaced the default ExB drift with the vertical drift calculated from the ground-based magnetometer, enabling us to simulate the effect of the westward DDEF on VTEC during daytime.
... However, as shown in Table 2, the storm time ionospheric responses to the 20th December storm were 2.05TECU enhancement at RABT and −1.43TECU depletion at SUTM. This result and the response to the initial storm of 23rd June at SUTM agrees with reports that early morning and nighttime onset have negative responses (Mansilla 2018;Prölss 1995;Balan and Rao 1990) but contrary to results at RABT. In other words, the storm onset as well as peak time and the hemispheric location of ionospheric stations are important in determining the storm-time ionospheric responses. ...
We studied the responses of the ionosphere over the southern and northern African sector. A RINEX formatted TEC data obtained from the global positioning system (GPS) was used to study the impact of geomagnetic storms of 23rd June and 20th December on a South African station, SUTM (33.97°N, 6.84°W) and a Moroccan station, RABT (32.41°S, 38.75°E). The storms which occurred in summer and winter (solstice months) were quantified using the Dst data from World Data Center, Kyoto, Japan. The results showed obvious hemispheric and seasonal influences on ionospheric responses to the geomagnetic storms. The substorm-time responses of the ionosphere were always positive across the stations and seasons. This is a result of increased particle and energy depositions occasioned by the proton density (PD). The rates of energy and particles intensifications during substorms were higher in the summer storm event than in winter for both stations. In other words, there was no hemispheric asymmetry observed. In addition to the storm onset time, its peak time and hemispheric location are crucial in storm-time ionospheric responses. Local timing of the orientations of the prompt penetration and disturbance dynamo electric fields during northward interplanetary magnetic fields determined the nature of ionospheric responses in the day and night sides. These results contribute to our understanding of the dynamics and complexities of the ionosphere over African mid latitude ionosphere.
... The main phase was caused by the increase in the magnetospheric ring current, which ended at approximately 05:00 UT on the 23rd. The recovery phase was due to the decay of the ring current by the collision process (Mansilla, 2018). In Figure 8, the RMSE increased during the initial and main phases, while its peak occurred later than the Dst index minimum. ...
Total electron content (TEC), as one of the most valuable ionosphere parameters, has many variation characteristics. The TEC has specific characteristics at a given time, suggesting that the global TEC morphology distribution is maintained for a period. We consider the global ionosphere map (GIM) to be the actual ionospheric electron density integration, predict the GIM by a previous period in a geomagnetic latitude and local time (LT) coordinate system, and compare the differences between these two GIMs. The objective of this research is to find the morphological properties of global TEC in the geomagnetic latitude and LT coordinate system, reveal ionospheric behavior and predict TEC using an uncomplicated method. The GIM data for a solar cycle (2009–2020) are used to find the error characteristics and prediction performance of TEC in this coordinate. The equatorial ionization anomaly is the dominant error region. This error shows diurnal and seasonal variations and has a strong correlation with solar activity. The prediction error of this method is smaller than that of the International Reference Ionosphere (IRI) model, especially in high solar activity years. The root mean square error of the 3‐hr prediction is 6.53 in 2014 and 2.02 TECU in 2019, and it is 28.5% smaller than that of IRI on average for 2009–2020.
... php? id= res3-2013). Lanzerotti et al. (1990) This concept is based on the following experimental evidences (Troshichev et al. 2014Troshichev and Sormakov 2015, 2018, 2019a, 2019b: (1) the PC index responds to changes of the solar wind electric field (EKL), the EKL increase being followed by the PC growth with the delay time ΔΤ ~ 12-20 min; ...
... The investigations of ionospheric storms have shown that during the first few hours of a geomagnetic storm, the PPEF penetrates both the dayside and nightside ionosphere (Astafyeva et al. 2016;Correia et al. 2017;Mansilla 2018). The normal eastward dawn-to-dusk electric field on the dayside is reinforced by the PPEF, which lifts the equatorial ionospheric plasma to higher altitudes and latitudes, forming the dayside ionospheric superfountain (DIS) effect (Tsurutani et al. 2004). ...
... On the nightside during the main phase of the storm, from middle to high latitudes the westward dawn-to-dusk electric fields are dominated by the dynamo disturbance, causing a downward plasma drift, which increases the recombination process and decreases the electron density. This mechanism was identified in the geomagnetic storms that occurred on 26 September 2011 (Correia et al. 2017), and 22-23 June 2015 (Astafyeva et al. 2016;Mansilla 2018). The studies showed that during these storms the ionosphere is highly structured and dynamic as a consequence of solar wind coupling with the magnetosphere-ionosphere system, suggesting a combination of effects associated with PPEFs and disturbance dynamo processes. ...
The Antarctic and Arctic regions are Earth's open windows to outer space. They provide unique opportunities for investigating the troposphere–thermosphere–ionosphere–plasmasphere system at high latitudes, which is not as well understood as the mid- and low-latitude regions mainly due to the paucity of experimental observations. In addition, different neutral and ionised atmospheric layers at high latitudes are much more variable compared to lower latitudes, and their variability is due to mechanisms not yet fully understood. Fortunately, in this new millennium the observing infrastructure in Antarctica and the Arctic has been growing, thus providing scientists with new opportunities to advance our knowledge on the polar atmosphere and geospace. This review shows that it is of paramount importance to perform integrated, multi-disciplinary research, making use of long-term multi-instrument observations combined with ad hoc measurement campaigns to improve our capability of investigating atmospheric dynamics in the polar regions from the troposphere up to the plasmasphere, as well as the coupling between atmospheric layers. Starting from the state of the art of understanding the polar atmosphere, our survey outlines the roadmap for enhancing scientific investigation of its physical mechanisms and dynamics through the full exploitation of the available infrastructures for radio-based environmental monitoring.
... From the RMS statistics in To further verify the effectiveness of EAS-ROTI model in PPP, 386 IGS tracking stations datasets during another severe storm on 23 June 2015 are also used to perform the PPP experiments. The minimum geomagnetic index Dst of this geomagnetic storm is −200 nT, which is also a severe storm (Mansilla, 2018). Using multi-instrumental observations, Cherniak et al. (2019) clearly reported that this severe storm induced large-scale EPBs in the African sector with a localized zone of about 20° and in the American sector with a longitudinal range of around 100°. ...
For global navigation satellite system (GNSS), ionospheric disturbances caused by the geomagnetic storm can reduce the accuracy and reliability of precision point positioning (PPP). At present, common stochastic models in GNSS PPP, such as the elevation angle stochastic (EAS) model or carrier‐to‐noise power‐density ratio (C/N0 $C/{N}_{\mathit{0}}$) based SIGMA‐ε $\varepsilon $ model, do not properly consider storm effects on GNSS measurements. To mitigate severe storm effects on GNSS PPP, this study further implements the rate of total electron content index (ROTI) parameter into the EAS model referred to as the EAS‐ROTI model. This model contains two operations. The first one is to adjust variance of GNSS measurements using ROTI observations on EAS model. The second one is to determine the ratio of the priori variance factor between pseudorange and carrier phase measurements during severe storm conditions. The performance of EAS‐ROTI model is verified by using a large number of international GNSS service stations datasets on 17 March and 23 June in 2015. Experimental results indicate that on a global scale, the EAS‐ROTI model improves the PPP accuracy in 3D direction by approximately 12.9%–14.7% compared with the EAS model, and by about 24.8%–45.9% compared with the SIGMA‐ε $\varepsilon $ model.
... Several studies have reported that geomagnetic storms induce ionospheric disturbances, presented by statistical analyses and different case studies [8][9][11][12][13]. For example, Mansilla and Zossi [12] reported VTEC enhancement at equatorial and low latitude regions due to PPEF during the main phase of the storm on north side of the magnetic equator. ...
... Several studies have reported that geomagnetic storms induce ionospheric disturbances, presented by statistical analyses and different case studies [8][9][11][12][13]. For example, Mansilla and Zossi [12] reported VTEC enhancement at equatorial and low latitude regions due to PPEF during the main phase of the storm on north side of the magnetic equator. Moreover, some studies mainly focused on storm-time ionospheric variations on global level and specifically emphasized on different morphological characteristics of the storm in ionosphere. ...
... High magnetic field values are developed immediately over low latitude stations after the SSC during main and recovery phases in South American sector. Mansilla and Zossi [12] reported small negative ionospheric responses at equator sector during main phase, which is in good agreement with the results in this paper and concluded that VTEC depletion was caused by PPEF. Moreover, Macho et al. [24] reported daytime VTEC enhancements at low latitudes in the beginning of main phase storm, which occurred during local afternoon, and this enhancement were attributed to the effect of PPEF. ...
The ionospheric storm time responses during August 2018 are investigated over South American region using multiple observables, for example, Global Navigation Satellite System (GNSS) derived Vertical Total Electron Content (VTEC) from International GNSS Service (IGS), magnetic field data, geomagnetic indices, Global Ionospheric Maps (GIMs), Thermospheric Mass Density (TMD), and [O/N2] ratio measurement. Strong ionospheric and upper-atmospheric disturbances affected the ionospheric variables with long duration, during the storm recovery phase and following after. First, daytime VTEC (9:0020:00 UT) presented variations of > 15 TECU during days 25 to 30 of August 2018 in low and middle latitudes of South America, this after sudden storm commencement (SSC). Furthermore, nighttime (21:00-24:00 and 00:00-05:00 UT) VTEC presented low values (5<TECU<7) in mid-latitude region after SSC event during the main phase, followed by high values (>8 TECU) in the recovery phase. Second, the ionospheric values during the storm main phase and following after, at low-and mid-latitudes, caused the Equatorial Ionization Anomaly (EIA) to expand due to Prompt Penetration Electric Field (PPEF). Furthermore, VTEC enhancements are likely to occur few hours after the SSC of 25 August 2018, while enhancements of Thermospheric Mass Density (TMD) and [O/N2] ratio started to appear later on 26 and 27 of August 2018.
... In June 2015, coronal mass ejections (CMEs) towards the Earth (one main and several small ejections) occurred on the Sun. This event was recorded by spacecraft (three satellites Swarm A, B, and C; ACE (Advanced Composition Explorer) spacecraft), and ionospheric stations (Reiff et al., 2016;Baker et al., 2016;Astafyeva et al., 2016Astafyeva et al., , 2017Mansilla, 2018;Yasyukevich et al., 2020). The approach of the main CME to the Earth's magnetosphere and its interaction with the shock wave was expected at ~1836 UT on June 22, 2015, after a weaker shock at ~0540 UT (Reiff et al., 2016). ...
The results of ~100 sessions of sounding of the Earth’s high-latitude (>65° N) ionosphere performed on June 22–23, 2015, at a GPS carrier frequency of f1 = 1575.42 MHz (L1 range, wavelength of ~19.0 cm) in the FORMOSAT-3/COSMIC radio occultation experiment are analyzed. The coronal plasma ejections that reached the Earth’s magnetosphere during this time period provoked a strong magnetic storm of the G4 class (G4 = Kp – 4), which caused significant fluctuations in radio wave parameters on ionospheric sounding paths: navigation (GPS) satellites—low-orbit (FORMOSAT-3/COSMIC) satellites. Ionospheric disturbances in the characteristics of radio waves are shown to be caused by both geomagnetic conditions and the activity of powerful X-ray flares during measurements. A search for the absorption of decimeter radio waves (wavelength of ~19 cm) at a GPS carrier frequency of f1 = 1545.42 MHz was carried out. Based on the results of the FORMOSAT-3/COSMIC data analysis, an integral absorption of ~3 dB of decimeter radio waves was detected for the first time on the sounding paths in the D and E regions of the Earth’s high-latitude ionosphere.
... A few studies have made use of satellites in investigating the ionospheric response during geomagnetic storm, such as, Nazarkov et al. justified the formation of ring current induced by solar wind pressure by utilizing Van Allen Probes (VAP) [12] and Astafyeva et al. discovered a significant rise in electron density in the summer hemisphere which are most probably related to various physical mechanisms [13]. In June 2015, Global Navigation Satellite System (GNSS) receivers were also used to examine the change in Total Electron Content (TEC) during an intense storm [14]. ...
In a severe geomagnetic storm on 8th September 2017, the Kp index reached 8+ along with the interplanetary magnetic field (IMF) reaching 34 nT with the maximum Bz of-30 nT. There is a possibility that the storm started as a result of a Coronal Mass Ejection. This study is aimed to examine the effects of the G4 storm by analyzing the geomagnetic induced current (GIC) pattern with respect to geomagnetic parameters; solar wind speed, Bz, AE-index and SYM-H. As a substitute for measuring the pattern of GIC, we used time derivative horizontal component magnetic field (dH/dt). The selected stations are Barrow (Brw), Alaska station and Nurmijarvi (Nur), Finland station for high and middle latitude respectively. In conclusion, it is found that GIC was more actively triggered at high latitude compared to the middle as Brw station recorded its peak of 368.67 nT/s while Nur station obtained 202.59 nT/s. GIC was significant at midnight and at noon until late evening which corresponds to fluctuations of geomagnetic parameters. As a result of the G4 storm, N Mohamad Ansor et al. 200 northern lights covered up the skies of several US states and Finland with greenish lights brightening up.
