Article
Engineering, Aerospace
E. Echer, W. D. Gonzalez
Summary: This study analyzed the relationship between Dst* and solar wind parameters in the main phase of single-step geomagnetic storms. The peak values of Bzp and E-yp had a higher correlation with Dst* than their difference values (DBz and DEy). The findings suggest that Eyp and Delta E-y values can serve as interplanetary criteria for assessing moderate and intense storms.
ADVANCES IN SPACE RESEARCH
(2022)
Article
Astronomy & Astrophysics
S. Blunier, B. Toledo, J. Rogan, J. A. Valdivia
Summary: The study uses Neural Networks to detect the driving relationship between solar wind variables and geomagnetic indices. Magnetic field component, electric field orientation, and particle speed are the most effective drivers, leading to significant model improvements.
SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS
(2021)
Article
Engineering, Aerospace
A. D. Danilov, A. V. Konstantinova
Summary: This study analyzes the deviations of foF2 from quiet conditions three days before a magnetic storm and identifies seasonal, solar activity, and magnetic storm intensity factors that affect the probability of event occurrence. The results suggest that these events could be considered as precursors of upcoming magnetic storms.
ADVANCES IN SPACE RESEARCH
(2021)
Article
Astronomy & Astrophysics
Rositsa Miteva, Mohamed Nedal, Susan W. Samwel, Manuela Temmer
Summary: In this study, correlations between the intensity of geomagnetic storms (GS) and solar and interplanetary (IP) phenomena parameters were examined. Three-dimensional geometry reconstructions of geo-effective coronal mass ejections (CMEs) were also performed using the PyThea framework, with a focus on the reliability of the de-projection capabilities. Different models for CME reconstruction and observer subjectivity led to large variations in the de-projections of CME speeds. The combination of fast speed and frontal orientation of the magnetic structure upon reaching the terrestrial magnetosphere proved to be the best indicator for GS strength. More accurate estimations of geometry and directivity, as well as de-projected speeds, are crucial for GS forecasting in operational space weather schemes.
Article
Engineering, Aerospace
A. D. Danilov
Summary: A detailed analysis was conducted on the dependence of the number and intensity of events on the intensity of magnetic storms and solar activity. The study found that an increase in magnetic storm intensity and solar activity leads to a decrease in the number of events, while an increase in magnetic storm intensity results in an increase in event intensity.
ADVANCES IN SPACE RESEARCH
(2022)
Article
Astronomy & Astrophysics
Slavisa Zivkovic, Giuliana Verbanac, Mario Bandic
Summary: The commonly used IMF component B-s at 1-hour resolution for studying solar wind-magnetosphere coupling neglects the fluctuations of B-z and IMF polarity within the hour. This study investigates whether the global patterns of B-s and sorted B-s fields change when considering these fluctuations using high 16-second resolution data. The results show that the initial IMF resolution does not affect the characteristic patterns of B-s fields and B-s sorted by IMF polarity, and both exist in all seasons.
Article
Environmental Sciences
Junchen Xue, Sreeja Vadakke Veettil, Marcio Aquino, Xiaogong Hu, Lin Quan, Dun Liu, Peng Guo, Mengjie Wu
Summary: This study investigated the performance of the BeiDou Navigation Satellite System (BDS) B1 frequency standard point positioning (SPP) during different classes of geomagnetic storms in China. The findings revealed that geomagnetic storms can degrade the accuracy of BDS positioning, with stronger storms having a greater impact. The positioning accuracy during storms of the same class varied as well.
Article
Geosciences, Multidisciplinary
Armando Collado-Villaverde, Pablo Munoz, Consuelo Cid
Summary: This study proposes a classification method for geomagnetic storms based on the cumulative distribution function of SYM-H and ASY-H indices, using industry-wide percentiles to determine storm classes. This approach enables objective classification of storms based on intensity and occurrence probability, with applications in storm forecasting and risk assessment.
Article
Astronomy & Astrophysics
S. Kumar, Y. Miyoshi, V. K. Jordanova, M. Engel, K. Asamura, S. Yokota, S. Kasahara, Y. Kazama, S-Y Wang, T. Mitani, K. Keika, T. Hori, C. Jun, I Shinohara
Summary: The study shows that during the main phase of a geomagnetic storm, the contribution of electrons to the ring current is significant and should not be neglected.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2021)
Article
Physics, Multidisciplinary
Anna Wawrzaszek, Renata Modzelewska, Agata Krasinska, Agnieszka Gil, Vasile Glavan
Summary: By analyzing the fractal nature of the horizontal components of the geomagnetic field, this study reveals temporal variations and differences in irregularity of the fractal dimension. The results show that the fractal dimension is sensitive to physical conditions such as interplanetary shocks, coronal mass ejections, and high-speed streams.
Article
Astronomy & Astrophysics
Mark J. Engebretson, Laura E. Simms, Viacheslav A. Pilipenko, Lilia Bouayed, Mark B. Moldwin, James M. Weygand, Michael D. Hartinger, Zhonghua Xu, C. Robert Clauer, Shane Coyle, Anna N. Willer, Mervyn P. Freeman, Andy J. Gerrard
Summary: This study investigated impulsive geomagnetic disturbances (GMDs) at high latitude station pairs in both the northern and southern hemispheres. The analysis revealed that GMDs were larger in the winter hemisphere and were dependent on the sign of the interplanetary magnetic field (IMF) component By. Most events occurred simultaneously, regardless of the sign of By as long as |By| <= 2 |Bz|. Prior to most events, IMF Bz was negative. Supplementing the data with IMF data from other solar wind missions improved the consistency of IMF orientations.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Y. Y. Li, S. Y. Huang, S. B. Xu, Z. G. Yuan, K. Jiang, Y. Y. Wei, J. Zhang, Q. Y. Xiong, Z. Wang, R. T. Lin, L. Yu
Summary: Predicting the Dst index is crucial in space weather research, and neural networks have made significant progress in this field. The LRP method is used to select key parameters, predict the Dst index, and enhance the understanding of neural network interpretability.
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2022)
Article
Engineering, Aerospace
A. O. Akala, R. O. Afolabi, Y. Otsuka
Summary: This study investigates the ionospheric responses to CME-driven and CIR-driven geomagnetic storms over different latitude regions. The intensity and location of the Equatorial Ionization Anomaly (EIA) were significantly influenced by the storms, with asymmetries observed between the northern and southern hemispheres. The most intense and impactful storm was observed on 17 March 2015. The ionospheric responses to storms were dependent on the onset time, producing different plasma fountain effects.
ADVANCES IN SPACE RESEARCH
(2023)
Article
Astronomy & Astrophysics
Paula Reyes, Victor A. Pinto, Pablo S. Moya
Summary: The occurrence of intense geomagnetic storms is strongly correlated with the strength of the solar cycle measured by sunspot numbers. Different solar cycle phases show variations in storm activity and occurrence rates, with descending phases showing higher correlation with sigma values of the next cycle's maximum phase.
SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS
(2021)
Article
Astronomy & Astrophysics
Tommaso Alberti, Davide Faranda, Giuseppe Consolini, Paola De Michelis, Reik Donner, Vincenzo Carbone
Summary: An accurate understanding of the differences in geomagnetic variability between quiet and disturbed periods can improve space weather diagnosis. This study uses dynamical system theory to investigate the co-variation and recurrence statistics of two geomagnetic indices, SYM-H and AL, that measure the intensity of different current systems. The number of active degrees of freedom in the phase space dynamics of these indices depends on the geomagnetic activity level. The results suggest that the near-Earth electromagnetic environment is a complex system that is far from equilibrium.
Article
Astronomy & Astrophysics
Erika Palmerio, Nariaki V. Nitta, Tamitha Mulligan, Marilena Mierla, Jennifer O'Kane, Ian G. Richardson, Suvadip Sinha, Nandita Srivastava, Stephanie L. Yardley, Andrei N. Zhukov
Summary: Stealth CMEs are CME events that are difficult to observe clearly in coronagraph data, and their observation and prediction are of great importance in the context of space weather.
FRONTIERS IN ASTRONOMY AND SPACE SCIENCES
(2021)
Article
Astronomy & Astrophysics
D. -C. Talpeanu, S. Poedts, E. D'Huys, M. Mierla, I. G. Richardson
Summary: This study thoroughly analyzes the dynamics of solar eruptions and their ejecta using numerical simulations. The formation mechanism of stealth ejecta and plasma blobs is explained, and the effect of different background solar wind on their propagation is assessed.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
D. Lario, I. G. Richardson, L. B. Wilson III, L. Berger, L. K. Jian, D. Trotta
Summary: The properties of suprathermal particle distributions observed upstream of interplanetary shocks depend on both the properties of the shocks and the transport conditions encountered by the particles. This study presents observations of a rare extended anisotropic low-energy proton beam and a trapped high-energy proton population associated with the arrival of an oblique interplanetary shock. The findings suggest continuous injection of particles by the traveling shock into a smooth radial magnetic field region, resulting in an extended foreshock region of energetic particles.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Erika Palmerio, Christina O. Lee, M. Leila Mays, Janet G. Luhmann, David Lario, Beatriz Sanchez-Cano, Ian G. Richardson, Rami Vainio, Michael L. Stevens, Christina M. S. Cohen, Konrad Steinvall, Christian Mostl, Andreas J. Weiss, Teresa Nieves-Chinchilla, Yan Li, Davin E. Larson, Daniel Heyner, Stuart D. Bale, Antoinette B. Galvin, Mats Holmstrom, Yuri Khotyaintsev, Milan Maksimovic, Igor G. Mitrofanov
Summary: Predicting coronal mass ejections (CMEs) and solar energetic particles (SEPs) is crucial for space weather forecasting. This study analyzes the inner heliospheric context between two eruptive flares in late 2020 and tests the prediction capabilities using remote-sensing observations. The results show that CMEs and shock-accelerated SEPs can be reasonably studied and forecasted in real time using the prediction tools employed here.
SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS
(2022)
Article
Astronomy & Astrophysics
D. Lario, N. Wijsen, R. Y. Kwon, B. Sanchez-Cano, I. G. Richardson, D. Pacheco, E. Palmerio, M. L. Stevens, A. Szabo, D. Heyner, N. Dresing, R. Gomez-Herrero, F. Carcaboso, A. Aran, A. Afanasiev, R. Vainio, E. Riihonen, S. Poedts, M. Brueden, Z. G. Xu, A. Kollhoff
Summary: An intense solar energetic particle event was observed by multiple spacecraft near the Sun on October 9, 2021. The properties of the event were shaped by the influence of intervening large-scale interplanetary structures, such as the stream interaction region and the solar wind stream.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Erika Palmerio, Christina O. Lee, Ian G. Richardson, Teresa Nieves-Chinchilla, Luiz F. G. Dos Santos, Jacob R. Gruesbeck, Nariaki Nitta, M. Leila Mays, Jasper S. Halekas, Cary Zeitlin, Shaosui Xu, Mats Holmstrom, Yoshifumi Futaana, Tamitha Mulligan, Benjamin J. Lynch, Janet G. Luhmann
Summary: This paper reports on a series of solar transient events that occurred in August 2018, during the declining phase of Solar Cycle 24. The study focuses on the origin, evolution, and heliospheric impact of these events, particularly two successive coronal mass ejections (CMEs) and a high-speed stream (HSS) towards Earth and Mars. The analysis suggests that the interaction between the CME and HSS caused the second CME to rotate and deflect in interplanetary space, emphasizing the importance of accurately reproducing the ambient solar wind even during simpler solar minimum periods.
SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS
(2022)
Article
Astronomy & Astrophysics
E. M. Babu, H. Nesse Tyssoy, C. Smith-Johnsen, V Maliniemi, J. A. Salice, R. M. Millan, I. G. Richardson
Summary: This study uses measurements from six satellites from 2004 to 2014 to determine the latitudinal boundaries of energetic electron precipitation (EEP) and their variability. Regression analyses are applied to determine the best predictor variable based on solar wind parameters and geomagnetic indices. A model of the EEP boundary is developed separately for different energy channels and MLT sectors.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Nicolas Wijsen, David Lario, Beatriz Sanchez-Cano, Immanuel C. C. Jebaraj, Nina Dresing, Ian G. G. Richardson, Angels Aran, Athanasios Kouloumvakos, Zheyi Ding, Antonio Niemela, Erika Palmerio, Fernando Carcaboso, Rami Vainio, Alexandr Afanasiev, Marco Pinto, Daniel Pacheco, Stefaan Poedts, Daniel Heyner
Summary: This study presents simulation results and observations of a gradual solar energetic particle (SEP) event on October 9, 2021, showing that the event was influenced by a high-speed stream (HSS) despite the modest increase in solar wind speed. The EUHFORIA and PARADISE models were used to replicate the solar wind and CME-driven shock wave, and to analyze particle transport. The study reveals that the nonuniform solar wind affected the structure of the shock wave, resulting in variations in its properties, and demonstrates the influence of even modest solar wind structures on SEP events.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
D. Lario, I. G. Richardson, A. Aran, N. Wijsen
Summary: We analyzed periods of high-energy proton intensity (>40 MeV) near Earth over a 43-year span (1973-2016) that were associated with interplanetary (IP) shocks. These shocks coincided with solar energetic particle (SEP) events, but not all of them were directly related. By focusing on cases where the shocks were confidently linked to the solar eruptions generating the SEP events, we examined the components of SEP events localized near the shocks (energetic storm particles, ESPs). We found that the origin of the shocks producing >40 MeV proton ESP intensity enhancements was usually within +/- 50 degrees longitude of the central meridian and associated with fast coronal mass ejections.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Anatoly Belov, Nataly Shlyk, Maria Abunina, Artem Abunin, Athanasios Papaioannou, Ian G. Richardson, David Lario
Summary: We studied cosmic ray Forbush decreases (FDs) observed by the Helios 1 and 2 spacecraft from 1974 to 1985, covering heliocentric distances of 0.28-1 au. A catalogue of Helios FDs was compiled, including the characteristics of cosmic ray variations and the solar wind (SW) and interplanetary magnetic field (IMF) of associated disturbances. A statistical study found that the size of Helios FDs at different distances from the Sun is determined by the parameters of the interplanetary disturbances. The FD magnitudes observed at Helios and near Earth correlate well with VB, the product of maximum SW velocity and IMF intensity normalized by their average values at the radial distance of observations. However, on average, the size of Helios FDs is statistically independent of the radial distance in the range of 0.28-1 au.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
J. A. Salice, H. Nesse, E. M. Babu, C. Smith-Johnsen, I. G. Richardson
Summary: Medium Energy Electron (MEE) precipitation ionizes the mesosphere and can reduce ozone in the atmosphere. Existing parameterizations show considerable differences in the representation of MEE precipitation, especially its high-energy tail. This study compares the nature of different electron fluxes to better understand MEE precipitation. The results provide insights into the correlation and timing of electron fluxes, as well as their response to solar wind drivers.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Astronomy & Astrophysics
R. D. Strauss, N. Dresing, I. G. Richardson, J. P. van den Berg, P. J. Steyn
Summary: This study investigates the acceleration processes of solar energetic particles (SEPs) and finds that electrons and protons may be accelerated by a common mechanism. Additionally, the research suggests that diffusive shock acceleration at large shock structures plays a significant role in the acceleration of these SEPs, as a relatively broad particle source is required to accurately describe the observations.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
A. Bruno, G. A. de Nolfo, J. M. Ryan, I. G. Richardson, S. Dalla
Summary: Large solar eruptions with high-energy ions interacting with the solar atmosphere can cause long-duration gamma-ray emissions, but the dominant acceleration process is still uncertain.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
C. J. Farrugia, B. J. Vasquez, N. Lugaz, N. A. Al-Haddad, I. G. Richardson, E. E. Davies, R. M. Winslow, B. Zhuang, C. Scolini, R. B. Torbert, L. B. Wilson, F. Regnault, A. Rogers, A. B. Galvin, W. Yu
Summary: On April 19-20, 2020, a solar ejection was observed by Solar Orbiter and Wind spacecraft, showing a correlation in magnetic field and plasma parameters between the two spacecraft. The structure, called an unperturbed magnetic flux rope (UMFR), exhibited weaker coherence in the upstream (US) region. Analysis of data collected by Solar Orbiter and Wind suggests that the lack of coherence in the US can be attributed to front erosion and internal reconnection. The presence of erosion is supported by magnetic field data, showing a significant shrinkage of the front portion of the US, and internal reconnection is occurring at thin current sheets inside the US, causing reconfiguration of the structure.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Anatoly Belov, Athanasios Papaioannou, Maria Abunina, Mateja Dumbovic, Ian G. Richardson, Bernd Heber, Patrick Kuhl, Konstantin Herbst, Anastasios Anastasiadis, Angelos Vourlidas, Eugenia Eroshenko, Artem Abunin
Summary: The rigidity dependence of all Forbush decreases events recorded from 1995 to 2015 were analyzed, showing that the majority of events have spectral indices within 0.3-0.7, with significant variations observed within each event. The spectrum becomes gradually harder during the initial decay phase of the events, contrasting with the softening spectrum during the recovery phase. Low energies are better suited for studying fine structures of interplanetary disturbances.
ASTROPHYSICAL JOURNAL
(2021)
