Article
Astronomy & Astrophysics
Abd-ur Raheem, Huseyin Cavus, Gani Caglar Coban, Ahmet Cumhur Kinaci, Haimin Wang, Jason T. L. Wang
Summary: This study identified the source active regions for the majority of CMEs using a filtration process and machine learning to compare the physical parameters of sunspot groups with properties of CMEs to uncover the mechanisms behind CME initiation. The neural network successfully identified source HARPs for 4895 out of 14604 CMEs recorded from 2011 to 2020, showing the effectiveness of the method in source region identification.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
X. J. Zhang, L. H. Deng, Z. P. Qiang, Y. Fei, X. A. Tian, C. Li
Summary: This research investigates the hemispheric asymmetry of coronal mass ejections (CMEs) between 1996 and 2020, and finds that the hemispheric asymmetry of CMEs is mainly caused by specific CMEs rather than regular CMEs. The hemispheric asymmetry of high-latitude CMEs appears to have little connection to that of low-latitude CMEs. The dominant hemisphere, cumulative trend, and amplitude of CMEs vary between different solar cycles.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
S. W. Good, L. M. Hatakka, M. Ala-Lahti, J. E. Soljento, A. Osmane, E. K. J. Kilpua
Summary: Interplanetary coronal mass ejections (ICMEs) exhibit fluctuations in magnetic field and velocity at different scales, with the cross helicity serving as a measure of the balance between these fluctuations. Observations show that ICME flux ropes and sheaths at 1 au have varying levels of cross helicity, suggesting dynamic equilibrium influenced by solar activity.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
K. Martinic, M. Dumbovic, M. Temmer, A. Veronig, B. Vrsnak
Summary: This study investigates different methods for determining the orientation of coronal mass ejections (CMEs) in the near-Sun environment and explores the non-radial flow in the sheath region of interplanetary CMEs (ICMEs). The results show that current methods are limited in accurately determining the orientation of CMEs, but most CMEs have a low inclination. Consistent estimations of the tilt between remote and in situ data were obtained for the majority of CME-ICME pairs. The observed non-radial flows suggest that the CME orientation may impact its propagation.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Beili Ying, Li Feng, Bernd Inhester, Marilena Mierla, Weiqun Gan, Lei Lu, Shuting Li
Summary: This study investigates the formation mechanism of a shock driven by an aspherical CME and demonstrates the impact of the difference in CME's principal radius of curvature on the estimation of shock and coronal parameters. By using three-dimensional reconstructions, the researchers were able to derive corona parameters at high latitudes and analyze the bow-shock formation mechanism.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
L. Rodriguez-Garcia, T. Nieves-Chinchilla, R. Gomez-Herrero, I. Zouganelis, A. Vourlidas, L. A. Balmaceda, M. Dumbovic, L. K. Jian, L. Mays, F. Carcaboso, L. F. G. dos Santos, J. Rodriguez-Pacheco
Summary: The main objective of this study is to investigate the radial and longitudinal evolution of the interplanetary counterpart (ICME) in the inner heliosphere and to examine the different magnetic flux-rope configurations observed on the solar disk and in situ at various locations.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Q. M. Zhang
Summary: This paper aims to track the three-dimensional evolution of a full halo coronal mass ejection (CME) and uses a revised cone model to derive its morphological and kinematic properties. The results show that the revised cone model fits nicely with the observed CME and the CME exhibits changes in angle and distance over time.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Alexander W. James, David R. Williams, Jennifer O'Kane
Summary: This study aims to quantify the variation of critical height for torus instability-driven CMEs over time in solar active regions, and finds that the rate of CMEs is significantly higher when the critical height is increasing during phases of magnetic flux increase. Additionally, the critical height is generally proportional to the separation of magnetic polarities in the active regions.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Multidisciplinary Sciences
Alessandro Bemporad
Summary: Due to the lack of UV-EUV observations of CMEs far from the Sun, our understanding of the thermodynamic evolution of these solar phenomena is limited. This study analyzed a slow CME observed in visible and UV light and used the data to determine the distribution of plasma electron density, temperature, and thermal energy. The results showed that the CME core had higher temperatures compared to the surrounding void and front, and the core temperatures increased during the CME expansion, indicating plasma heating processes. The distribution of thermal energy also exhibited asymmetry, possibly due to interaction with nearby coronal structures. This work demonstrates the potential of combining UV and visible light data and future multi-slit spectroscopic observations of CMEs.
Article
Astronomy & Astrophysics
D. E. Morosan, A. Kumari, E. K. J. Kilpua, A. Hamini
Summary: The study conducted a statistical analysis of 64 moving bursts to determine how often CMEs are accompanied by moving radio bursts. The majority of moving radio sources are found to be associated with CMEs and wide CMEs, suggesting strong lateral expansion during the early stages of the eruption plays a key role in radio emission occurrence.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Carlos R. Braga, Angelos Vourlidas
Summary: This study examines two coronal mass ejections observed from different viewpoints and distances relative to the Sun, finding that both CMEs propagate slowly and eastward of the Sun-Earth line. The second CME appears to accelerate and deflect westward within a certain range, in line with solar rotation speed.asyarakjsdrflksajdfkljsalkdfjlsadkdiruqweoruirqwpeiorqweiroqwieurqiweuriqwreiouqrewiuqwreiouroqiwreiuqwriouqweiurqiweuirqweiouroqwieuqwoieurqwieurqiweuroiqweuroiqrweuirqweiuoroqwieruqweoiruqwierqweoiruqwreiqrweiuqwroiuewqrweioruqweioruqwrioqwreiqwreuqwioreuqwiroiqwreoirueirese we look at the effect of PSP observations on CME kinematics due to its proximity to the Sun.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
D. Sudar, B. Vrsnak, M. Dumbovic, M. Temmer, J. Calogovic
Summary: The study reveals that under isotropic solar wind conditions, the distance between the apex and the flank of a CME increases monotonically with time, but never becomes fully circular. The velocity of the leading edge segments converges towards the solar wind speed, while the flank speed does not exceed that of the apex.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Manon Jarry, Alexis P. Rouillard, Illya Plotnikov, Athanasios Kouloumvakos, Alexander Warmuth
Summary: This study analyzes the geometrical and kinematic properties of coronal and interplanetary shock waves produced by CMEs. The results show the evolution of the shock wave's shape, expansion speeds, and their correlation with the underlying flare activity. These findings contribute to improving space weather forecasting and understanding the eruption process of CMEs.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
O. Chang, R. F. Gonzalez, M. M. Bisi, R. A. Fallows
Summary: IPS observations provide valuable information about solar wind conditions and density irregularities, but interpreting complex structures can be challenging due to the changing physical properties of plasma with distance from the Sun. Numerical simulations can help compare CME structure and physical changes, shedding light on the complexity of IPS observations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
D. E. Morosan, J. Pomoell, A. Kumari, R. Vainio, E. K. J. Kilpua
Summary: This study investigates the early acceleration location, escape, and propagation directions of electron beams associated with herrinbgone bursts during the early evolution of a strongly expanding CME-driven shock wave. By combining ground-based radio observations and space-based extreme-ultraviolet and white-light observations, the researchers were able to produce a three-dimensional representation of the electron acceleration locations and investigate the origin of the observed bursts.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Debesh Bhattacharjee, Prasad Subramanian, Angelos Vourlidas, Teresa Nieves-Chinchilla, Niranjana Thejaswi, Nishtha Sachdeva
Summary: The pressure and energy density of gas and magnetic field inside solar coronal mass ejections are believed to be important in determining their dynamics. The study compared the specific energy inside magnetic clouds (MCs) and the solar wind background and examined their correlation with the propagation and internal expansion speeds. The results showed that the excess thermal+magnetic specific energy in MCs is greater or equivalent to the specific kinetic energy of the solar wind, which may explain their structural integrity.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Debesh Bhattacharjee, Prasad Subramanian, Teresa Nieves-Chinchilla, Angelos Vourlidas
Summary: We use data from the Wind spacecraft to study turbulent fluctuations in proton density and total magnetic field inside near-Earth magnetic clouds associated with coronal mass ejections from the Sun. The modulation index for proton density fluctuations inside magnetic clouds ranges from 0.13 to 0.16, while the modulation index for total magnetic field fluctuations ranges from 0.04 to 0.05. The Mach number fluctuations inside magnetic clouds have a most probable value of approximately 0.1. The anomalous resistivity caused by turbulent magnetic field fluctuations in near-Earth magnetic clouds exceeds the commonly used Spitzer resistivity by a factor of approximately 500-1000. The enhanced Joule heating resulting from this anomalous resistivity could impact our understanding of CME propagation energetics.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Review
Astronomy & Astrophysics
N. E. Raouafi, L. Matteini, J. Squire, S. T. Badman, M. Velli, K. G. Klein, C. H. K. Chen, W. H. Matthaeus, A. Szabo, M. Linton, R. C. Allen, J. R. Szalay, R. Bruno, R. B. Decker, M. Akhavan-Tafti, O. V. Agapitov, S. D. Bale, R. Bandyopadhyay, K. Battams, L. Bercic, S. Bourouaine, T. A. Bowen, C. Cattell, B. D. G. Chandran, R. Chhiber, C. M. S. Cohen, R. D'Amicis, J. Giacalone, P. Hess, R. A. Howard, T. S. Horbury, V. K. Jagarlamudi, C. J. Joyce, J. C. Kasper, J. Kinnison, R. Laker, P. Liewer, D. M. Malaspina, I. Mann, D. J. McComas, T. Niembro-Hernandez, T. Nieves-Chinchilla, O. Panasenco, P. Pokorny, A. Pusack, M. Pulupa, J. C. Perez, P. Riley, A. P. Rouillard, C. Shi, G. Stenborg, A. Tenerani, J. L. Verniero, N. Viall, A. Vourlidas, B. E. Wood, L. D. Woodham, T. Woolley
Summary: Launched in 2018, NASA's Parker Solar Probe has completed 13 orbits around the Sun by November 2022, exceeding expectations in terms of data quantity and quality. The mission aims to study the Sun's coronal magnetic field, solar corona and wind heating and acceleration, and energetic particle acceleration processes. The probe has contributed to numerous discoveries, resulting in nearly 700 peer-reviewed publications.
SPACE SCIENCE REVIEWS
(2023)
Article
Astronomy & Astrophysics
Paulett C. Liewer, Angelos Vourlidas, Guillermo Stenborg, Russell A. Howard, Jiong Qiu, Paulo Penteado, Olga Panasenco, Carlos R. Braga
Summary: Parker Solar Probe (PSP) crossed the heliospheric current sheet (HCS) near the perihelion on encounters E8 and E11, enabling the Wide-field Imager for Solar Probe (WISPR) to image the streamer belt plasma in high resolution while flying through it. As PSP flies closer to the Sun, fine-scale structures are resolved within the coronal rays of the streamer belt. Near the HCS, WISPR observes a fan of rays of various sizes and brightnesses, indicating large density variations in the HCS plasma sheet transverse to the radial direction.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Juliana T. Vievering, Angelos Vourlidas, Chunming Zhu, Jiong Qiu, Lindsay Glesener
Summary: We investigate the temporal relationships among magnetic reconnection, flare energy release, and the acceleration of coronal mass ejections (CMEs) to study the evolution of solar eruptive events. By analyzing data from STEREO, SDO, and RHESSI, we identify 12 events for detailed examination and expand upon previous timing studies by examining fast-varying features in the HXR and reconnection rate profiles. Through time lag correlation analysis, we find that HXR bursts occur throughout the main CME acceleration phase and lag the acceleration by 2 +/- 9 minutes. There is also a nearly one-to-one correspondence between HXR bursts and reconnection rate profiles, with the HXRs lagging the reconnection rate by 1.4 +/- 2.8 minutes. Events with multiple HXR bursts correspond with faster CMEs.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Nour E. Raouafi, G. Stenborg, D. B. Seaton, H. Wang, J. Wang, C. E. DeForest, S. D. Bale, J. F. Drake, V. M. Uritsky, J. T. Karpen, C. R. DeVore, A. C. Sterling, T. S. Horbury, L. K. Harra, S. Bourouaine, J. C. Kasper, P. Kumar, T. D. Phan, M. Velli
Summary: We present EUV solar observations providing evidence for omnipresent jetting activity driven by small-scale magnetic reconnection at the base of the solar corona. This discovery highlights the importance of small-scale magnetic reconnection in solar and stellar atmospheres in understanding phenomena such as coronal heating and solar wind acceleration. The observed switchback solar wind phenomenon might be linked to the magnetic activity at the base of the corona.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Marilena Mierla, Hebe Cremades, Vincenzo Andretta, Iulia Chifu, Andrei N. Zhukov, Roberto Susino, Frederic Auchere, Angelos Vourlidas, Dana-Camelia Talpeanu, Luciano Rodriguez, Jan Janssens, Bogdan Nicula, Regina Aznar Cuadrado, David Berghmans, Alessandro Bemporad, Elke D'Huys, Laurent Dolla, Samuel Gissot, Giovanna Jerse, Emil Kraaikamp, David M. Long, Benjamin Mampaey, Christian Moestl, Paolo Pagano, Susanna Parenti, Matthew J. West, Olena Podladchikova, Marco Romoli, Clementina Sasso, Koen Stegen, Luca Teriaca, William Thompson, Cis Verbeeck, Emma Davies
Summary: In this study, three prominence eruptions associated with coronal mass ejections were analyzed using multiple instruments. The morphology, direction of propagation, and 3D properties were investigated, and two 3D reconstruction methods were successfully applied. The study highlights the importance of multi-perspective observations in studying the morphology, source regions, and associated coronal mass ejections of prominence eruptions.
Review
Astronomy & Astrophysics
Matthew J. West, Daniel B. Seaton, David B. Wexler, John C. Raymond, Giulio Del Zanna, Yeimy J. Rivera, Adam R. Kobelski, Bin Chen, Craig DeForest, Leon Golub, Amir Caspi, Chris R. Gilly, Jason E. Kooi, Karen A. Meyer, Benjamin L. Alterman, Nathalia Alzate, Vincenzo Andretta, Frederic Auchere, Dipankar Banerjee, David Berghmans, Phillip Chamberlin, Lakshmi Pradeep Chitta, Cooper Downs, Silvio Giordano, Louise Harra, Aleida Higginson, Russell A. Howard, Pankaj Kumar, Emily Mason, James P. Mason, Richard J. Morton, Katariina Nykyri, Ritesh Patel, Laurel Rachmeler, Kevin P. Reardon, Katharine K. Reeves, Sabrina Savage, Barbara J. Thompson, Samuel J. Van Kooten, Nicholeen M. Viall, Angelos Vourlidas, Andrei N. Zhukov
Summary: The middle corona, spanning heliocentric distances from 1.5 to 6 solar radii, plays a crucial role in governing the behavior of coronal outflow and connecting the corona to the heliosphere. Despite being poorly studied in the past, recent advances in instrumentation and increased recognition of its importance have led to growing interest in the middle corona. This article aims to define its location, extension, physical characteristics, and the processes that occur there.
Article
Astronomy & Astrophysics
Evangelos Paouris, Angelos Vourlidas, Athanasios Kouloumvakos, Athanasios Papaioannou, Vamsee Krishna Jagarlamudi, Timothy Horbury
Summary: The coronal mass ejection on September 5, 2022 was the fastest and one of the largest CMEs observed so far. It is of great significance for space weather studies, as it may result in a high-energy particle event that requires careful attention.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Abril Sahade, Angelos Vourlidas, Laura A. A. Balmaceda, Mariana Cecere
Summary: We study the low corona evolution of the Cartwheel coronal mass ejection (CME; 2008 April 9) using reconstruction and magnetohydrodynamic simulations. We find a pseudostreamer structure with a null point that may be responsible for the complex evolution of the magnetic flux rope (MFR) at the initial phase. By setting up a similar magnetic configuration in a numerical simulation, we reproduce the observed behavior and validate the importance of the pseudostreamer null point.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Guillermo Stenborg, Evangelos Paouris, Russell A. Howard, Angelos Vourlidas, Phillip Hess
Summary: The Parker Solar Probe mission studies the solar corona at distances closer than 20 solar radii. Using images from the PSP's Wide-field Imager, this work examines the causes of brightness reductions in the corona during the probe's rapid transit through perihelia. The study finds that the presence of coronal holes and energetic coronal mass ejection events directly correlate with the observed brightness depletions, attributed to the loss of free electrons and interplanetary dust.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Sotiris Stamkos, Spiros Patsourakos, Angelos Vourlidas, Ioannis A. Daglis
Summary: To understand the interaction between coronal mass ejections (CMEs) and the magnetized solar wind, this study investigates the effects of magnetic erosion on the aerodynamic drag force acting on fast-traveling CMEs. Empirical relationships are generated to describe the physical parameters of CMEs, and the impact of virtual mass on their motion equation is examined. It is found that magnetic erosion can significantly delay the arrival of the leading edge of CMEs at near-Earth space and may cause a significant mass decrease.
Article
Astronomy & Astrophysics
Steven R. Cranmer, Rohit Chhiber, Chris R. Gilly, Iver H. Cairns, Robin C. Colaninno, David J. Mccomas, Nour E. Raouafi, Arcadi V. Usmanov, Sarah E. Gibson, Craig E. Deforest
Summary: This article reviews the properties of the Alfvén surface and its importance in models of solar-wind acceleration, MHD waves and turbulence, and the geometry of coronal loops. Studies suggest that the Alfvén surface spends most of its time at heliocentric distances between about 10 and 20 solar radii. The region of the heliosphere where the Alfvén surface is located is sufficiently turbulent, leading to multiple crossings along any radial ray.
