Article
Astronomy & Astrophysics
Rajkumar Hajra
Summary: We present a statistical study of intense geomagnetically induced currents (GICs) in the subauroral region. From the analysis of natural gas pipeline recordings near Mantsala, Finland, we found a total of 605 GIC events with peak intensity > 10 A from 1999 to 2019. The occurrence of events was higher during solar maximum, lower during the descending phase, and absent during solar minimum. The overall occurrence rate was lower during Solar Cycle 24.
Article
Astronomy & Astrophysics
Samuel J. Schonfeld, Carl J. Henney, Shaela Jones, Charles N. Arge
Summary: This study explores the use of observed polar coronal holes to constrain the flux distribution within the polar regions of global solar magnetic field maps. The findings show that modifications to the polar flux can improve predictions for coronal holes and solar wind, and that low-latitude magnetic fields have a significant impact on setting the boundaries of polar coronal holes.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
B. Badruddin, O. P. M. Aslam, M. Derouich
Summary: This study examines the development of strong geomagnetic storms caused by coronal mass ejections in near-Earth space. The time evolution of geomagnetic disturbances is compared with the variation of solar wind plasma and field parameters, focusing on the development of the main phase of the storms. By analyzing geomagnetic indices and solar wind parameters with different time resolutions, the time lag between them during the development of the storms is determined.
ASTROPHYSICS AND SPACE SCIENCE
(2022)
Article
Astronomy & Astrophysics
Yulia Shugay, Vladimir Kalegaev, Ksenia Kaportseva, Vladimir Slemzin, Denis Rodkin, Valeriy Eremeev
Summary: Solar wind disturbances associated with coronal mass ejections cause geomagnetic storms, which can lead to infrastructure damage. CMEs, formed in the solar corona, propagate to Earth as Interplanetary CME structures. The Space Monitoring Data Center (SMDC) of Moscow State University forecasts ICME arrival using data from space telescopes and coronagraphs.
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
Chemistry, Physical
N. M. Wateed, H. A. Motaweh, M. Y. Hanfi, M. Sayyed, M. U. Khandaker, A. A. Darwish, A. Sh. M. Elshoukrofy
Summary: The study of solar wind is important due to its key role in space weather. Solar wind is composed of plasma streams with varying hydrodynamic and magnetic properties, and it can be categorized into slow, rapid, and disturbed streams. By analyzing data on solar wind speed and cosmic ray intensity, it was found that low-speed solar wind events occur more frequently.
RADIATION PHYSICS AND CHEMISTRY
(2022)
Article
Engineering, Aerospace
O. E. Abe, M. O. Fakomiti, W. N. Igboama, O. O. Akinola, O. Ogunmodimu, Y. O. Migoya-Orue
Summary: This study examines the occurrence rate of geomagnetic storms during solar cycles 20-24 and investigates the solar sources during cycles 23 and 24. The study shows that the rate of geomagnetic storm occurrences is higher during the descending phases and lower during the minimum phases of the solar cycle. Severe and extreme geomagnetic storms rarely occur during low solar activity but are mostly associated with coronal mass ejections (CMEs) during high solar activity. The study also reveals that CME + CH-HSSW is more prominent in causing storms during the descending phase.
ADVANCES IN SPACE RESEARCH
(2023)
Article
Astronomy & Astrophysics
Jihyeon Son, Suk-Kyung Sung, Yong-Jae Moon, Harim Lee, Hyun-Jin Jeong
Summary: In this study, a deep-learning model is used to forecast solar wind speed for the next 3 days using SDO/AIA 211 and 193 images and solar wind speed data. The model consists of two networks: a convolutional layer-based network for images and a dense layer-based network for solar wind speeds. The results show that the model successfully predicts the solar wind speed for the next 3 days and outperforms previous studies.
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2023)
Article
Astronomy & Astrophysics
A. Santa Fe Duenas, R. W. Ebert, M. A. Dayeh, M. I. Desai, L. K. Jian, G. Li
Summary: We examined variations in energetic storm particle (ESP) heavy-ion average intensities and energy spectra between 0.1 and 75 MeV nucleon(-1) for coronal mass ejection (CME)-driven interplanetary shocks. Comparing observations from solar cycles 23 and 24, we found that the number of heavy-ion ESP events was higher during cycle 23 and there were more events at higher energies (>10 MeV nucleon(-1)). This suggests more efficient ESP acceleration during cycle 23.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
C. Kay, T. Nieves-Chinchilla
Summary: This study presents a comprehensive description of the interplanetary evolution of CMEs using the ANTEATR-PARADE model, highlighting the importance of thermal and magnetic model parameterization over initial temperature or magnetic field strength for fast CMEs. Different parameters impact the predictions differently, with thermal forces playing a more crucial role for weaker CMEs and magnetic forces being more significant for stronger CMEs. Critical parameters for space weather predictions include CME mass, initial magnetic field strength, adiabatic index, and axial magnetic field strength profile.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Roque Marquez Rodriguez, Luca Sorriso-Valvo, Emiliya Yordanova
Summary: Solar wind measurements carried out by NASA's Wind spacecraft before, during, and after the passing of an interplanetary coronal mass ejection (ICME) in September 2014 were used to analyze the properties of magnetohydrodynamic (MHD) turbulence. The measurements provided a standard description of turbulence characteristics within different sub-regions of the ICME and its surroundings. The analysis confirmed the fully developed nature of turbulence in the ICME plasma and estimated the energy transfer rate in each sub-region and the surrounding solar wind.
Article
Astronomy & Astrophysics
Rajkumar Hajra
Summary: A comparative study on the plasma and IMF properties of near-Earth slow solar wind (SSW) and high-speed solar wind (HSW) is conducted using solar wind measurements from 1963 to 2022. HSW is characterized by higher alpha-to-proton density ratio, ram pressure, proton temperature, reconnection electric field, Alfven speed, magnetosonic speed, and lower proton density and plasma-beta than SSW. It is found that geomagnetic activity is enhanced during HSW compared to SSW.
Article
Astronomy & Astrophysics
Megan L. Maunder, Claire Foullon, Robert Forsyth, David Barnes, Jackie Davies
Summary: This study presents a combined analysis of a coronal mass ejection (CME) observed on 27 June 2007 by STEREO spacecraft and its subsequent impact on the interplanetary medium observed by Ulysses on 4 July 2007. Various methods, such as triangulation and self-similar expansion fitting, were used to analyze the CME features and interactions with the solar wind. The relatively small size of the ICME at Ulysses was attributed to its interaction with a high-speed stream and its unique magnetic cloud configuration.
Article
Astronomy & Astrophysics
Jinhye Park, Hyun-Jin Jeong, Yong-Jae Moon
Summary: By comparing different magnetic field data, we find interesting differences in the source regions and magnetic field configurations of solar energetic particle (SEP) events. AI-generated magnetograms provide more accurate information about the source regions, which is crucial for understanding SEP events.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Anatoly Belov, Nataly Shlyk, Maria Abunina, Artem Abunin, Athanasios Papaioannou
Summary: This study investigates the dependence of Interplanetary Coronal Mass Ejections' (ICMEs) transit speed on the corresponding Coronal Mass Ejections' (CMEs) initial speed. It is found that the transit speed and transit time are not only determined by the CME's initial speed, but also by the longitude of the solar source. By analyzing 288 CMEs associated with solar flares observed from 1995 to 2020, the longitudinal dependence of the expected transit speeds and times is obtained. A model is developed to estimate the transit and maximum speeds, as well as the time of arrival of an ICME to Earth, based on the initial CME speed and the longitude of the associated solar flare. It is demonstrated that including the longitude of the solar source significantly improves the quality of the model, especially for events in the central part of the solar disk (E10 degrees-W10 degrees).
Article
Astronomy & Astrophysics
Yu Chen, Qiang Hu, Robert C. Allen, Lan K. Jian
Summary: Using in situ measurements from the Parker Solar Probe and Wind spacecraft, this study investigates the properties of small-scale magnetic flux ropes (SFRs) within stream interaction regions (SIRs). The SFRs are found to exist across a wide range of solar wind speeds and their Alfvenicity decreases with increasing heliocentric distances. Suprathermal electron enhancements within the SIRs persist at 1 au and SFRs appear to occur repeatedly with recurring SIRs.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Juska E. Soljento, Simon W. Good, Adnane Osmane, Emilia K. J. Kilpua
Summary: We investigated the impact of large-scale velocity shears on the degree of imbalance in solar wind turbulence. The quantification of the balance between counterpropagating Alfvenic fluctuations was done using cross helicity and Elsasser ratio. We identified velocity shears at a 30-minute timescale and analyzed their effect on interplanetary coronal mass ejection (ICME) sheaths. Our findings suggest that velocity shears act as local sources of sunward fluctuations, reducing net imbalances in the antisunward direction, and the Kelvin-Helmholtz instability plays a role in this process.
ASTROPHYSICAL JOURNAL LETTERS
(2023)
Article
Geosciences, Multidisciplinary
Yuri Y. Y. Shprits, Ingo Michaelis, Dedong Wang, Hayley Allison, Ruggero Vasile, Andrei Runov, Alexander Drozdov, Christopher T. Russell, Vladimir Kalegaev, Artem Smirnov
Summary: This study used measurements from the ELFIN-L suit of instruments on the Lomonosov spacecraft to distinguish between stably trapped and drift loss cone electrons. The results show that the loss at MeV energies mainly occurs on the dawn-side, consistent with loss induced by chorus waves.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Physics, Fluids & Plasmas
Michael Gedalin, Andrew P. Dimmock, Christopher T. Russell, Nikolai V. Pogorelov, Vadim Roytershteyn
Summary: A collisionless shock is a self-organized structure that adjusts fields and particle distributions to ensure stable mass, momentum, and energy transfer from the upstream to the downstream region. The motion of charged particles generates fields inside the shock front, which in turn governs the particle motion. The overshoot compensates for the deceleration of ion flow by increasing the magnetic field, adjusting downstream ion temperature and pressure, speeding up collisionless relaxation, and reducing anisotropy.
JOURNAL OF PLASMA PHYSICS
(2023)
Review
Astronomy & Astrophysics
Benjamin P. P. Weiss, Jose M. G. Merayo, Jodie B. B. Ream, Rona Oran, Peter Brauer, Corey J. J. Cochrane, Kyle Cloutier, Linda T. T. Elkins-Tanton, John L. L. Jorgensen, Clara Maurel, Ryan S. S. Park, Carol A. A. Polanskey, Maria de Soria Santacruz-Pich, Carol A. A. Raymond, Christopher T. T. Russell, Daniel Wenkert, Mark A. A. Wieczorek, Maria T. T. Zuber
Summary: The Psyche Magnetometry Investigation aims to test the hypothesis that asteroid (16) Psyche formed from a differentiated planetesimal. The instrument will measure the magnetic field around the asteroid to search for evidence of remanent magnetization. It consists of two three-axis fluxgate Sensor Units (SUs) mounted along a 2.15-m long boom, connected to Electronics Units (EUs) within the spacecraft bus. The Magnetometer will acquire data for the full duration of the mission to estimate Psyche's dipole moment.
SPACE SCIENCE REVIEWS
(2023)
Article
Astronomy & Astrophysics
N. Omidi, X. -Y. Zhou, C. T. Russell, V. Angelopoulos
Summary: In this study, the interaction between interplanetary shocks and the Moon is investigated using 3-D electromagnetic hybrid simulations and observations. The results show the formation and recovery of a density hole in the shock front on the Moon's dayside, as well as the broadening of the magnetic field shock front in the lunar tail. The interplanetary shock also accelerates energetic ions in the lunar tail. Comparisons between the measurements in the solar wind and lunar tail confirm the absence of a shock front in density and the expected broadening of the magnetic field profile.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Wenyi Sun, Yingjuan Ma, Christopher T. Russell, Janet Luhmann, Andrew Nagy, David Brain
Summary: Although photochemistry-enabled escape of oxygen is dominant at Mars today, ion outflow, including planetary proton loss, plays an important role in the atmosphere's long-term evolution. Improving the MHD model of Mars to differentiate between planetary and solar wind protons, we find that planetary proton escape rates exceed heavy ion loss rates and solar wind proton inflows. However, the contribution of planetary protons to hydrogen loss is limited. By considering different reactions, we conclude that H-O charge exchange affects low altitude densities while impact ionizations impact escape rates at higher altitudes. This research highlights the need to include specific treatment of proton origins in future studies on the fate of water on Mars.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Astronomy & Astrophysics
A. Wagner, E. K. J. Kilpua, R. Sarkar, D. J. Price, A. Kumari, F. Daei, J. Pomoell, S. Poedts
Summary: Investigating the early-stage evolution of erupting solar flux ropes is crucial for understanding their stability loss and space-weather impact. By developing an efficient tracking scheme and analyzing the early-stage properties, we successfully extracted a flux rope and studied its footpoint movement and magnetic flux evolution. The results generally agree well with observational data.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Chaitanya Prasad Sishtla, Jens Pomoell, Rami Vainio, Emilia Kilpua, Simon Good
Summary: Alfvenic fluctuations and CMEs have interactions, including the transmission of solar wind fluctuations to CME sheath and the influence of fluctuation frequencies on the extent of CME sheath.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Z. C. Tian, M. Zhou, H. Y. Man, Z. H. Zhong, X. H. Deng, D. J. Gershman, Y. V. Khotyaintsev, C. T. Russell
Summary: This paper presents the simultaneous observation of the inner and outer electron diffusion region (EDR) in magnetic reconnection with a large guide field at the dayside magnetopause by the magnetospheric multiscale (MMS) spacecraft. The inner EDR is characterized by positive J·E', while the outer EDR is manifested by negative J·E' and opposite out-of-plane electric field. The observation of bidirectional accelerated electron jets on the opposite side of the X-line is significant, and the fortuitous formation of MMS provides estimates for the length of the inner EDR and the reconnection rate.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Matti Ala-Lahti, Tuija I. Pulkkinen, Julia Ruohotie, Mojtaba Akhavan-Tafti, Simon W. Good, Emilia K. J. Kilpua
Summary: This study investigates the front boundary of interplanetary coronal mass ejections (ICMEs) and their interaction with the ambient medium using multipoint observations. The observations reveal a two-sided jet and multiple reconnection sites associated with ICME erosion. The study also highlights the incoherence of the mixed plasma and emphasizes the importance of continuous plasma and field measurements in the solar wind.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
David B. Wexler, Ward B. Manchester, Lan K. Jian, Lynn B. Wilson III, Natchimuthuk Gopalswamy, Paul Song, Jason E. Kooi, Bart van der Holst, Elizabeth A. Jensen
Summary: This study investigates stream interaction regions (SIRs) using a new instrument called FETCH, and identifies density and magnetic field enhancements, as well as magnetic polarity reversal, in the simulated observations. FETCH provides 4.5-5.7 days lead time for predicting the arrival of SIR features at Earth, with an estimated SIR radial speed of 350-390 km/s.
ASTROPHYSICAL JOURNAL
(2023)
Article
Geosciences, Multidisciplinary
Tongkuai Li, Wenya Li, Binbin Tang, Yuri. V. Khotyaintsev, Daniel Bruce Graham, Akhtar Ardakani, J. L. Burch, D. J. Gershman, B. Lavraud, C. T. Russell, Quanming Lu, Xiaocheng Guo, Chi Wang
Summary: This study presents Magnetospheric Multiscale (MMS) observations of a K-H wave event accompanied by ongoing magnetic reconnection under southward IMF conditions. The nonlinear K-H waves exhibit quasi-periodic fluctuations, presence of low-density and high-speed ions, and variations in the boundary normal vectors. Through the identification of Alfvenic ion jets and the escape of energetic magnetospheric electrons, clear evidence of on-going magnetic reconnection is revealed. Notably, out of the 36 magnetopause current-sheet crossings in this event, 19 exhibit unambiguous signatures of reconnection at both the leading and trailing edges, indicating the compression effect resulting from the large-scale evolution of the K-H waves.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Physics, Fluids & Plasmas
Harry C. Lewis, Julia E. Stawarz, Luca Franci, Lorenzo Matteini, Kristopher Klein, Chadi S. Salem, James L. Burch, Robert E. Ergun, Barbara L. Giles, Christopher T. Russell, Per-Arne Lindqvist
Summary: Turbulence in space plasmas is analyzed using Magnetospheric Multiscale (MMS) measurements. Different linear and nonlinear processes are decomposed using the electric field dynamics measured by MMS. Spectral characteristics of the terms in generalized Ohm's law are identified, including the dominance of the Hall effect over MHD, constant amplitude ratio of electron pressure to Hall effect, and independent scaling of nonlinear and linear components. The findings provide insights into the relationship between fluctuation amplitudes and plasma conditions.
PHYSICS OF PLASMAS
(2023)
Article
Andrology
Lorena Rodriguez-Paez, Charmina Aguirre-Alvarado, German Chamorro-Cevallos, Alcantara-Farfan Veronica, Calderon-Espinosa Sandra Irel, Castillo-Perez Hugo, Carlos Armando Garcia-Perez, Guadalupe Elizabeth Jimenez-Gutierrez, Joaquin Cordero-Martinez
Summary: This study evaluated the effects of spermine, spermidine, and putrescine on sperm motility, capacitation, and acrosome reaction. The results showed that polyamines significantly decreased these parameters and may act by inhibiting the activity of sAC. Furthermore, polyamines also caused a decrease in cAMP concentration.
SYSTEMS BIOLOGY IN REPRODUCTIVE MEDICINE
(2023)