Geomagnetism and Aeronomy最新文献

{"title":"Multi-Latitudinal PRN-Based GNSS-TEC Analysis of Ionospheric Perturbations during the 21 August 2017 Solar Eclipse","authors":"Devbrat Pundhir,&nbsp; Ashok Kumar","doi":"10.1134/S0016793226600165","DOIUrl":"10.1134/S0016793226600165","url":null,"abstract":"<p>The 21 August 2017 Great American solar eclipse provided a unique opportunity to examine ionospheric disturbances under rapid and controlled solar radiation reduction. In this study, GNSS-derived Total Electron Content (TEC) observations from three representative stations located at low latitude (BOGT), mid latitude (P398), and high latitude (NYAL) were analyzed to investigate the spatial and temporal characteristics of eclipse-induced plasma variability. Distinct TEC depletion was recorded at all stations during the eclipse interval, with the largest response over the low-latitude sector and comparatively weaker but more irregular changes at high latitudes. To identify short-term disturbances, detrended TEC residuals and continuous wavelet transform analyses were performed. The results revealed enhanced oscillatory activity near and after the maximum eclipse phase, with dominant periodicities in the range of 40–65 min. These signatures indicate the presence of medium-scale traveling ionospheric disturbances (TIDs), most likely generated by eclipse-driven atmospheric gravity waves (AGWs) and subsequent ionosphere-thermosphere coupling. The comparative multi-latitudinal analysis demonstrates that the eclipse response was strongly modulated by regional background ionization and latitude-dependent electrodynamic processes. This study highlights the capability of GNSS observations to capture both large-scale electron density depletion and mesoscale wave perturbations, providing valuable insight into transient ionospheric dynamics during sudden solar forcing events.</p>","PeriodicalId":55597,"journal":{"name":"Geomagnetism and Aeronomy","volume":"66 7","pages":"241 - 251"},"PeriodicalIF":0.5,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148927318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Relationship between Solar Wind Speed at Shock Arrival and Interplanetary Coronal Mass Ejections Start Time during Intense Geomagnetic Storms","authors":"Solomon Degefa Robi,&nbsp;Chigomezyo M. Ngwira,&nbsp;Teshome Dugassa Feyissa","doi":"10.1134/S0016793226600220","DOIUrl":"10.1134/S0016793226600220","url":null,"abstract":"&lt;p&gt;This study provides a comparative investigation of solar wind speed at shock arrival (V&lt;sub&gt;1&lt;/sub&gt;), solar wind speed at the interplanetary coronal mass ejection start time (V&lt;sub&gt;2&lt;/sub&gt;), and the minimum southward interplanetary magnetic field (IMF Bz) in relation to intense geomagnetic storms during solar cycle (SC) 24 and the early phase of SC 25 (2020–2023). Intense geomagnetic storms were selected using the criterion disturbance storm time (Dst) ≤ –100 nT. For each event, V&lt;sub&gt;1&lt;/sub&gt;, V&lt;sub&gt;2&lt;/sub&gt;, IMF Bz, and interplanetary coronal mass ejection (ICME) duration were analyzed to evaluate their relative contributions to geomagnetic storm intensity. Comparative statistical analyses were further performed across different phases of SC 24 and seasonal periods. The results show that geomagnetic storm intensity is controlled by the combined effects of solar wind speed, the magnitude and persistence of southward IMF Bz, and the duration of ICME–magnetosphere interaction. Several events characterized by moderate solar wind speeds produced intense geomagnetic storms when accompanied by prolonged southward IMF Bz and extended ICME durations, indicating that sustained solar wind–magnetosphere coupling is a key factor in storm development. Comparisons among events during the ascending, maximum, and descending phases of SC 24 revealed that longer ICME durations can produce stronger geomagnetic storms even under relatively weaker solar wind conditions. The analysis of early phase of SC 25 events further demonstrated that similar geomagnetic storm intensities may arise from different combinations of controlling parameters, highlighting compensating effects between solar wind speed, IMF Bz, and interaction duration. The statistical analysis showed that CME and halo CME (HCME) occurrence rates peaked during the solar maximum phase, whereas some of the most intense geomagnetic storms occurred during the descending phase of SC 24. This indicates that CME frequency alone is insufficient to explain geomagnetic storm intensity and that intrinsic CME properties and solar wind coupling efficiency play important roles in determining geoeffectiveness. Seasonal analysis revealed that intensity of geomagnetic activity peaks in autumn and decreases in summer, suggesting that storm occurrence varies with seasonal factors and the phase of the SC. The relationship between sunspot number and geomagnetic storm occurrence was found to be complex and non-linear, suggesting that sunspot number alone is not always a reliable indicator of geomagnetic storm activity. Overall, the results confirm that intense geomagnetic storms are governed by multiple interacting solar wind and interplanetary parameters rather than by a single controlling factor. The findings improve the understanding of CME geoeffectiveness and solar wind–magnetosphere coupling processes and provide useful insight for improving space weather forecasting and prediction of extreme geomagnetic storm events.&lt;","PeriodicalId":55597,"journal":{"name":"Geomagnetism and Aeronomy","volume":"66 5","pages":"181 - 194"},"PeriodicalIF":0.5,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148927482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of F10.7 Flux and Proton Intensity on Delayed Ionospheric TEC Responses at Low Latitudes during Geomagnetic Storms across Solar Cycles 23–25","authors":"H. S. Mohamed,&nbsp;Sampad Kumar Panda,&nbsp;O. M. Shalabiea,&nbsp;Christine Amory-Mazaudier,&nbsp;Hussein M. Farid,&nbsp;A. Mahrous","doi":"10.1134/S0016793226600207","DOIUrl":"10.1134/S0016793226600207","url":null,"abstract":"<p>There has been a growing interest in ionospheric delay as a crucial element in comprehending the impact of solar phenomena and geomagnetic storms on the ionosphere. This study investigates Total Electron Content (TEC) data collected from two International GNSS Service (IGS) stations: CUSV, Thailand (Geographic 13.74° N, 100.53° E), and COCO, Keeling Island (Geographic 12.19° S, 96.839° E). The investigation focuses on the geomagnetic storms during Solar Cycles (SC) 23, 24 and the early phase of Cycle 25. The ionospheric delay time is defined as the duration from the start of a geomagnetic storm to its peak effect on the deviation of TEC (DTEC) from the quiet time reference level. We found a relationship between the ionospheric delay time and the Disturbance Storm Time (Dst) index, with specific selection criteria applied to storm events to enhance the accuracy of this association. The lowest correlation is for COCO station during the declining phase of SC 23 with value 0.27 due to system errors and gaps. The Highest value is CUSV station during the Ascending phase SC 25 which is 0.89. High and statistically significant correlation values were observed across most cases and time periods, with the F10.7 flux imposing a direct influence on these relationships, which contradicts some prior research. Our research highlights the significant part that proton flux plays during these periods, as variations in logarithmic proton intensity across four distinct energy ranges (6.95, 16.40, 32.95, and 46 MeV) have influenced the correlation’s linearity and its association with F10.7 flux at different stages of the Solar Cycle. Linear correlation equations were developed for each time period, revealing a linear relationship between the DTEC and the logarithm of the proton intensity across the four specified energy ranges. We report that the Lyman-alpha irradiance affects the DTEC linearly, characterized by a good correlation coefficient. The average ionosphere delay time varied by time period; the shortest delay time was observed during the declining phase of Solar Cycle 24, and the longest was during the early part of the declining phase of Solar Cycle 23.</p>","PeriodicalId":55597,"journal":{"name":"Geomagnetism and Aeronomy","volume":"66 5","pages":"162 - 180"},"PeriodicalIF":0.5,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148927481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MLP-Based FPGA Model for Ionospheric TEC Prediction over a Low-Latitude Region during G3 and G4 Geomagnetic Storms that Occurred in 2026 and Comparison with IRI-2020 Model","authors":"J. Eindhumathy,&nbsp;C. Vennila,&nbsp;R. Mukesh,&nbsp;S. Kiruthiga","doi":"10.1134/S0016793226600311","DOIUrl":"10.1134/S0016793226600311","url":null,"abstract":"<p>This study investigates ionospheric Total Electron Content (TEC) anomalies before, during, and after two geomagnetic storm periods in 2026 over a low-latitude region. Apart from the TEC anomaly analysis, this paper investigates the performance of a hardware-accelerated multi-layer perceptron (MLP) based Field Programmable Gate Array (FPGA) model coupled with an AdamW optimizer for predicting TEC during storm periods January 19, .2026 to January 21, 2026 and March 22, 2026, using TEC data obtained from the BAKO station, along with solar and geomagnetic indices such as SSN, F10.7, Dst, Ap, and KP obtained from the Omniweb which capture the primary physical drivers of ionospheric variability. Multiple statistical parameters, including RMSE, MAE, <i>R</i>², MAPE, SMAPE, and NRMSE, were used to assess the performance of the MLP-based FPGA model. Performance evaluation parameters indicate that the developed model achieves an RMSE of 3.43 TECU, an MAE of 2.69 TECU, a MAPE of 20.03% and an <i>R</i>² of 0.96 during the January 2026 storm. Similarly, the model achieves an RMSE of 4.37 TECU, an MAE of 3.43 TECU, a MAPE of 21.35% and an <i>R</i>² of 0.97 during the March 2026 storm. The proposed MLP-FFNN (Feed-Forward Neural Network) architecture was validated against a Gated Recurrent Unit (GRU) model, demonstrating higher predictive accuracy while avoiding the heavy DSP and memory overhead of recurrent gating mechanisms. The MLP-FFNN model effectively captures TEC variability, especially under disturbed ionospheric conditions. This hardware architecture utilizes a sequential Multiply-Accumulate (MAC) state machine combined with Q16.16 fixed-point BRAM (Block Random Access Memory) Look-Up Tables for a non-linear activation function. This highly efficient design achieves real-time inference latency of 0.44–0.45 ms while consuming merely 2% of the available DSP slices and less than 0.3 Watts of power. Across the two events, noticeable TEC, solar and geomagnetic deviations were observed during both storm periods. The findings highlight the potential of integrating an AI algorithm with ultra-efficient physical hardware to predict TEC for low-latency space weather forecasting.</p>","PeriodicalId":55597,"journal":{"name":"Geomagnetism and Aeronomy","volume":"66 6","pages":"223 - 239"},"PeriodicalIF":0.5,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148927483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PRN-Wise Investigation of Storm-Time GNSS S4 Scintillations and Wave-Like Ionospheric Structures over Agra during Solar Cycle 25","authors":"Dhananjali Singh,&nbsp;Vijay Janyani,&nbsp;Rajendra Prasad Yadav,&nbsp;Devbrat Pundhir,&nbsp; Swati,&nbsp;Nitin Dubey","doi":"10.1134/S0016793226600189","DOIUrl":"10.1134/S0016793226600189","url":null,"abstract":"<p>This study investigates storm-time ionospheric scintillation variability over Agra, India, using GNSS-derived S4 index observations during 2024–2025 under Solar Cycle 25 conditions. PRN-wise analysis revealed enhanced scintillation activity mainly during post-sunset and nighttime hours (1700–2300 UT), with strong scintillation events (S₄ ≥ 0.6) observed during severe geomagnetic disturbances. Two major geomagnetic storms, namely the May 2024 superstorm and the November 2025 G5 storm, were analyzed using Dst and Kp indices. The May 2024 event exhibited comparatively stronger scintillation activity with peak S₄ values approaching 1.2, whereas the November 2025 storm showed a broader distribution of weak-to-moderate scintillation events. Continuous Wavelet Transform (CWT) analysis identified dominant periodicities ranging from 20 to 180 min, indicating the presence of multi-scale wave-like ionospheric structures and traveling ionospheric disturbances. The results suggest that storm-time electrodynamic processes, including prompt penetration electric fields and post-sunset plasma instabilities, significantly enhanced low-latitude plasma irregularities during disturbed geomagnetic conditions. The study demonstrates a strong coupling between geomagnetic storm intensity and GNSS scintillation variability over the Indian low-latitude region.</p>","PeriodicalId":55597,"journal":{"name":"Geomagnetism and Aeronomy","volume":"66 5","pages":"147 - 161"},"PeriodicalIF":0.5,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148927389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Predicting the Magnitude of Upcoming Powerful Earthquakes by Integrating LAI Anomalies Gathered by Remote Sensing Satellites: The Case of Kamchatka–Russia Earthquake (July 29, 2025; Mw = 8.8)","authors":"Mehdi Akhoondzadeh","doi":"10.1134/S0016793225600213","DOIUrl":"10.1134/S0016793225600213","url":null,"abstract":"<p>At 2324:52 UTC (local time = UTC + 1200) on July 29, 2025, an earthquake (Mw = 8.8) as the most powerful earthquake worldwide since the 2011 magnitude 9.1 Tohoku event in Japan and ranking among the ten largest quakes recorded globally since 1900, struck east of Petropavlovsk-Kamchatsky, Russia (52.512° N, 160.324° E, depth ~35 km). Also following the earthquake of the Kamchatka Peninsula, at least seven volcanoes including Klyuchevskoy and Krasheninnikov on July 30 and August 3, respectively erupted. This study analyzed time series variations of 47 parameters derived from 14 independent precursors including surface and air temperature, Outgoing Longwave Radiation (OLR), carbon monoxide (CO), Sulfur dioxide (SO₂), ozone, Methane, GPS-Total Electron Content (TEC), electron density (Ne), electron temperature (Te), and magnetic scalar and vector components (B, Bx, By, Bz), collected from satellite observations between June 1 and August 5, 2025, to identify possible seismic and volcanic anomalies in the Lithosphere Atmosphere Ionosphere (LAI) system around the location of the mentioned event. Next, an attempt was made to estimate the earthquake magnitude by integrating the detected LAI anomalies using two theories: Fuzzy Inference System (FIS) and Dempster-Shaffer (DS). Clear LAI anomalies were observed in the period of about 30 days before to 7 days after the earthquake, and the possible LAIC (LAI Coupling) mechanism was discussed. Also, the earthquake magnitude was estimated with reasonable accuracy in the days before the event. The coincidence of the main earthquake, foreshocks, and aftershocks with volcanic activities in the region acknowledges the occurrence of some LAI anomalies. The results of this study, in continuation of previous studies, emphasize that in a very large percentage of powerful earthquakes (Mw &gt; 7.5), the observation of LAI anomalies is inevitable.</p>","PeriodicalId":55597,"journal":{"name":"Geomagnetism and Aeronomy","volume":"66 6","pages":"195 - 222"},"PeriodicalIF":0.5,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148927317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prediction of VTEC Based on NavIC/GPS Data by Using Machine Learning Algorithms and Comparison with IRI Models","authors":"R. Mukesh,&nbsp;T. Senthilkumaran,&nbsp;A. Muruganandham,&nbsp;S. Kiruthiga,&nbsp;S. Karthick","doi":"10.1134/S0016793226600293","DOIUrl":"10.1134/S0016793226600293","url":null,"abstract":"<p>Total Electron Content (TEC) is utilized for the estimation of Ionospheric delay. Accurate prediction of TEC helps correct errors in position estimation using range measurements. TEC is influenced by several factors, such as location, time, solar radiation, geomagnetic index, and season. In this research, machine learning algorithms such as DeepAR, DLinear, and FFNN are used to forecast the Vertical TEC. The developed algorithms are evaluated using L5- and S-band pseudorange measurements from an operational NavIC receiver at ACS College of Engineering (ACSCE), Bangalore, India. In order to assess the algorithms, NavIC TEC for the ACSCE station is predicted and analyzed. The NRMSE of DeepAR is 0.0.225, MASE is 1.468 and SMAPE is 18%. The FFNN yielded an NRMSE of 0.136, SMAPE of 9.51% and MASE of 0.839. The DLinear provides an NRMSE of 0.157, MASE of 0.961 and SMAPE of 11.57%. Apart from this, the VTEC predicted by the DeepAR, FFNN, and DLinear algorithms are compared with the IRI-2016 and IRI-2020 models, and it is found that FFNN gives better results compared to DeepAR, DLinear, IRI-2020, and IRI-2020.</p>","PeriodicalId":55597,"journal":{"name":"Geomagnetism and Aeronomy","volume":"66 7","pages":"252 - 261"},"PeriodicalIF":0.5,"publicationDate":"2026-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148927319","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Warming of the Mesosphere-Lower Thermosphere over the Equatorial Region during the Geomagnetic Superstorm of 10–11 May 2024 and Its Teleconnection with the Polar Region-Auroral Oval","authors":"Navin Parihar,&nbsp;Govind Narayanan Kunnath,&nbsp;Anand Kumar Singh,&nbsp;Rahul Rawat,&nbsp;Shailendra Saini,&nbsp;Prasant Kumar Tiwari,&nbsp;Ashok Priyadarshan Dimri","doi":"10.1134/S001679322660013X","DOIUrl":"10.1134/S001679322660013X","url":null,"abstract":"<p>We report, here, the warming of the mesosphere-lower thermosphere (MLT) region over the equatorial region in the Indian subcontinent during the geomagnetic superstorm of May 10–11, 2024 (Dst ~ –412 nT and SYM-H ~ –518 nT) using Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) temperature measurements. A comparative study of vertical temperature profiles between 90 and 110 km on 11 May with that of control profile and 09 May (a neighbouring quiet day) reveals an increase in temperature beyond 96 ± 2 km over 15° S–15° N. We found this warming to increase with increasing height, and the temperature enhancement exceeded ~30–45 K near 108–109 km. Slight lowering of the mesopause altitude was noted. An extension of this comparative study over higher latitude bins showed similar warming of the MLT region. Supported with existing reports on auroral observations during this superstorm and expansion of auroral oval, the warming in latitudes greater than 30° appears to a direct consequence of Joule and auroral heating; whereas, the warming within ±30° latitude could be a manifestation of the superstorm-induced changes in global wind circulation and associated redistribution of deposited energy.</p>","PeriodicalId":55597,"journal":{"name":"Geomagnetism and Aeronomy","volume":"66 3","pages":"111 - 122"},"PeriodicalIF":0.5,"publicationDate":"2026-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148909706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ionospheric Storms as a Hazard to Aircraft: A Comprehensive Analysis of Risks for Navigation, Communication, and Surveillance","authors":"K. A. Ivanova","doi":"10.1134/S0016793226600281","DOIUrl":"10.1134/S0016793226600281","url":null,"abstract":"&lt;p&gt;Modern aviation has achieved unprecedented levels of safety, efficiency, and capacity through the pervasive integration of satellite-dependent technologies. Global Navigation Satellite Systems (GNSS) have become the cornerstone of area navigation, precision approach, and landing operations. Automatic Dependent Surveillance–Broadcast (ADS‑B) provides real‑time aircraft tracking to air traffic control, while High‑Frequency (HF) communication remains a critical backup over remote oceanic and polar regions. Collectively, these systems have enabled the transition to performance‑based navigation and the modernization of air traffic management. However, this technological dependence engenders a new and often underestimated vulnerability: all three systems rely on the propagation of radio waves through the ionosphere - a dynamic, plasma environment that is subject to abrupt and severe disturbances under enhanced solar activity. Ionospheric storms, which are direct consequences of geomagnetic storms, can simultaneously degrade GNSS positioning accuracy, induce loss of lock on satellite signals, corrupt ADS‑B messages, and black out HF communications within minutes. The International Civil Aviation Organization (ICAO) has recognized this threat by establishing a global space weather service (since November 2019). Yet, as recent extreme events demonstrate—most notably the geomagnetic storm of May 10–13, 2024—current forecasting models, threat definitions, and mitigation strategies remain incomplete. Despite growing empirical evidence of operational impacts, the aviation community has largely treated ionospheric storms as a statistical curiosity rather than a tangible hazard requiring systematic risk management. The gap is particularly acute for safety‑critical phases of flight, including Category II/III precision approaches that rely on Ground‑Based Augmentation Systems (GBAS), and for operations in equatorial and high‑latitude corridors where scintillation and polar cap absorption are most intense. This paper provides a comprehensive, physically grounded analysis of ionospheric storm effects on aviation navigation, communication, and surveillance systems. We synthesize mechanisms of propagation delay, extreme total electron content (TEC) gradients, ionospheric scintillation, and solar radio burst interference. Using empirical data from the May 2024 superstorm—including ADS‑B anomaly analyses from the OpenSky Network—we quantify operational risks. We further assess the differential vulnerability of GBAS, polar routes, and equatorial aviation, and propose a prioritized roadmap for monitoring, forecasting, and mitigation within the ICAO space weather framework. The objective is to move the discourse from post‑factum reporting toward prognostic, resilience‑based risk management. This paper explains how storms in Earth’s upper atmosphere, caused by solar activity, can disrupt airplane navigation and communication systems. Using data from a major space weathe","PeriodicalId":55597,"journal":{"name":"Geomagnetism and Aeronomy","volume":"66 4","pages":"123 - 132"},"PeriodicalIF":0.5,"publicationDate":"2026-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148928038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi Frequency Analysis of Solar Radio Burst on 28 August 2022 and Its Impact on GPS Signals and Positioning Accuracy","authors":"G. Venkata Ramana,&nbsp;M. Sridhar,&nbsp;R. Lakshmi Namratha,&nbsp;D. Venkata Ratnam","doi":"10.1134/S0016793226600219","DOIUrl":"10.1134/S0016793226600219","url":null,"abstract":"<p>At L-band frequencies, solar radio bursts (SRB) essentially function as a powerful and sudden radio interference source, causing the Global Navigation Satellite System (GNSS) receiver to experience an abruptly enhanced noise level and a simultaneous drop in C/N₀ or signal-to-noise ratio (SNR). This situation will become worse with strong intensity SRBs, where the tracking loops are unable to maintain lock, which causes cycle slips and even a momentary loss of some GNSS signals. In this paper, we present the details of the strong SRB event of 28 August 2022 and its effect on GNSS signals at L band frequencies over the American sector. A cubic spline based baseline fitting method was implemented to identify the affected satellites with the SNR deviations from the error-free reference level. The impact of the radio burst has been found at L1, L2 and L5 frequencies. The highest SNR deviations were recorded near 5° N latitude, with the BOGT station reporting peak values of 22.45 dB-Hz for the L2 signal and 19.62 dB-Hz for the L1 signal. From the results, SNR deviations are very significant at L2 frequencies than L1 and L5 frequencies. SRB threshold based classification procedure is implemented and GPS L1, L2 and L5 signals analysis is included. It is found that L2 signal is highly susceptible than L1 and L5 signals. Ionospheric Amplitude Index S4 is computed for the SRB affected GPS satellites. The GPS PPP error analysis is carried out to analyse the linkage between E, N, U positioning errors and SRB SNR fading levels.</p>","PeriodicalId":55597,"journal":{"name":"Geomagnetism and Aeronomy","volume":"66 4","pages":"133 - 145"},"PeriodicalIF":0.5,"publicationDate":"2026-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148928039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}