Article
Physics, Fluids & Plasmas
Thomas Speck
Summary: This study investigates microscopic engines that utilize a single active particle as the working medium, demonstrating the recovery of energy for work during the directed motion of the particle at constant temperature. By considering the chemical degrees of freedom, a wide range of synthetic active particles can be studied without the need to determine the exact microscopic mechanism. Analytical results reveal that the quasistatic thermodynamic efficiency increases beyond the linear-response regime and reaches a maximum at high propulsion speeds, indicating the nontrivial consequences of driving in the active engine's efficiency.
Article
Astronomy & Astrophysics
Rajkumar Hajra, Adrian Marques de Souza Franco, Ezequiel Echer, Mauricio Jose Alves Bolzan
Summary: The study reveals a dominant 10-11-year periodicity in geomagnetic activity, mainly influenced by the solar activity cycle, with solar wind speed inducing longer and shorter term variations. Solar cycles 20 and 24 are found to be weaker compared to cycles 19, 21, 22, and 23, and if the decreasing trend continues in cycle 25, it may have significant implications for space weather science and operations.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2021)
Article
Geosciences, Multidisciplinary
Fan Gong, Yiqun Yu, Jinbin Cao, Yong Wei, Jiawei Gao, Hui Li, Binzheng Zhang, Aaron Ridley
Summary: This study simulates the solar wind-magnetosphere interactions during a paleomagnetic reversal and finds that the magnetosphere shrinks, with the subsolar magnetopause approaching as close as 3 Re, and multiple magnetic reconnection sites emerge, allowing the solar wind to directly access the magnetosphere and increasing the power transmission efficiency to 18%.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Astronomy & Astrophysics
Francesco Carbone, Daniele Telloni, Emiliya Yordanova, Luca Sorriso-Valvo
Summary: Understanding extreme geomagnetic storms is crucial for space weather, particularly for forecasting strong storms. This study analyzes the relationship between the geomagnetic activity proxy Dst and the energy carried by solar wind streams. It finds a close correlation between solar wind energy and geomagnetic activity during different solar activity periods. Slow wind streams have minimal effects, while high-speed streams can induce severe geomagnetic storms depending on the energy carried.
Article
Materials Science, Multidisciplinary
S. Di Sabatino, J. Koskelo, J. A. Berger, P. Romaniello
Summary: By introducing electron screening, the band-gap opening in weakly as well as strongly correlated systems can be correctly described. This method has been applied to bulk LiH, Si, and paramagnetic as well as antiferromagnetic NiO, demonstrating its effectiveness. Although some incorrect features still exist in the full photoemission spectra, this result is significant for an ab-initio electronic structure method and paves the way for a unified description of photoemission spectra at weak and strong correlation.
Article
Astronomy & Astrophysics
S. E. Milan, J. A. Carter, G. E. Bower, A. L. Fleetham, B. J. Anderson
Summary: This study investigates the correlation between interplanetary magnetic field (IMF) measurements and associated ionospheric responses using solar wind data from the L1 Lagrangian point. The results show a decrease in correlation coefficient as the off-Sun-Earth line distance increases, along with a time-lag of approximately 17 minutes. These findings are important for understanding the coupling between solar wind and magnetosphere.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2022)
Article
Astronomy & Astrophysics
J. S. Halekas, S. Shaver, A. R. Azari, C. M. Fowler, Y. Ma, S. Xu, L. Andersson, C. Bertucci, S. M. Curry, C. Dong, Y. Dong, X. Fang, P. Garnier, K. G. Hanley, T. Hara, S. K. Howard, A. Hughes, R. J. Lillis, C. O. Lee, J. G. Luhmann, H. Madanian, M. Marquette, C. Mazelle, J. P. McFadden, K. Meziane, D. L. Mitchell, A. Rahmati, W. Reed, N. Romanelli, N. R. Schnepf
Summary: In December 2022, an extremely low-density solar wind stream caused significant changes in the Martian magnetosphere and its boundaries, revealing a unique state for the Mars-solar wind interaction.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Xin Cao, Jasper S. Halekas, Stein Haaland, Suranga Ruhunusiri, Karl-Heinz Glassmeier
Summary: This study analyzed data from ARTEMIS and Cluster spacecraft to investigate the mechanism of magnetospheric convection in the magnetotail lobes. Machine learning models were used to determine the solar wind parameters that drive the convection in these regions. The results show that IMF and magnetospheric activity play a significant role in influencing plasma convection in the magnetotail lobes.
FRONTIERS IN ASTRONOMY AND SPACE SCIENCES
(2023)
Editorial Material
Astronomy & Astrophysics
Lauri Holappa, Jone Peter Reistad, Anders Ohma
Summary: The coupling of the interplanetary magnetic field with the Earth's magnetic field can lead to spectacular auroral displays. Recent research has shown that during periods of significant dipole tilt, the westward electrojet is strongly influenced by the dawn-dusk component of the IMF. However, there is controversy regarding the dependence of the AL index on the component along the Sun-Earth line.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Review
Geochemistry & Geophysics
Brian M. Walsh, Ying Zou
Summary: This study explores the impact of various magnetospheric plasma populations on solar wind-magnetosphere coupling, as well as their characteristics and possible coupling modes at the dayside magnetopause. It also discusses the mechanisms impacting wave formation and magnetic reconnection, as well as the broader categories of control over solar wind-magnetosphere coupling by local boundary physics or solar wind driving.
JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS
(2021)
Article
Astronomy & Astrophysics
A. Kouloumvakos, G. M. Mason, G. C. Ho, R. C. Allen, Robert F. Wimmer-Schweingruber, A. P. Rouillard, J. Rodriguez-Pacheco
Summary: Observations of Solar Energetic Particles using the Suprathermal Ion Spectrograph on the Solar Orbiter mission reveal extended time periods of high He-3 abundance, typically lasting seven days and coinciding with changes in the spacecraft's magnetic connection to active regions.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
S. E. Milan, M. K. Mooney, G. Bower, A. L. Fleetham, S. K. Vines, J. Gjerloev
Summary: High-Intensity Long-Duration Continuous AE Activity (HILDCAA) events, driven by High Speed solar wind Streams (HSSs), result in enhancements in the auroral electrojet (AE) index lasting for several days. Our study of 16 HILDCAA events shows that they exhibit characteristics of substorms and the activity mainly occurs in the pre-midnight sector.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Joseph E. Borovsky
Summary: This Brief Report highlights three dusk-dawn aberrations of the solar-wind plasma and magnetic structure near Earth, and estimates the magnitudes of these aberrations based on different solar-wind types monitored from L1. Solar-wind monitors closer to Earth than L1 are expected to have better performance.
FRONTIERS IN ASTRONOMY AND SPACE SCIENCES
(2022)
Article
Astronomy & Astrophysics
M. V. Kubyshkina, V. S. Semenov, N. A. Tsyganenko, X. G. Wang, I. V. Kubyshkin
Summary: In this work, we challenge the existing view that the interplanetary magnetic field (IMF) Sun-Earth (Bx) component is not important for geomagnetic activity. We demonstrate that both Bx and By, as the two principal components of the Parker's spiral, are equally significant. We also find that the asymmetric behavior of activity indices around solstices can be explained by the combined effect of symmetrical IMF By and asymmetrical IMF Bx, which is interpreted as a result of the geodipole tilt influence on magnetotail stability and nightside reconnection. Furthermore, we show that the geoeffective IMF Bz component may increase or decrease depending on the IMF sector polarity and season due to the 7.5 degrees inclination of the Earth orbital plane to the solar equatorial plane.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Rohit Chhiber, William H. Matthaeus, Arcadi Usmanov, Riddhi Bandyopadhyay, Melvyn L. Goldstein
Summary: Motivated by theoretical, numerical, and observational evidence, this study explores the possibility that the critical transition between sub-Alfvenic flow and super-Alfvenic flow in the solar atmosphere takes place within fragmented subvolumes. The initial observations could not provide enough evidence to distinguish between this possibility and a folded surface separating simply connected regions. However, future observations may help differentiate between the two possibilities. A global magnetohydrodynamic model coupled with a turbulence transport model is used to generate possible realizations of this critical zone.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
M. H. Denton, M. F. Thomsen, V. K. Jordanova, M. G. Henderson, J. E. Borovsky, J. S. Denton, D. Pitchford, D. P. Hartley
SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS
(2015)
Article
Astronomy & Astrophysics
Lauren Blum, Xinlin Li, Mick Denton
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2015)
Article
Geosciences, Multidisciplinary
J. -F. Ripoll, G. D. Reeves, G. S. Cunningham, V. Loridan, M. Denton, O. Santolik, W. S. Kurth, C. A. Kletzing, D. L. Turner, M. G. Henderson, A. Y. Ukhorskiy
GEOPHYSICAL RESEARCH LETTERS
(2016)
Article
Geosciences, Multidisciplinary
M. H. Denton, G. E. Reeves, M. F. Thomsen, M. G. Henderson, R. H. W. Friedel, B. Larsen, R. M. Skoug, H. O. Funsten, H. E. Spence, C. A. Kletzing
GEOPHYSICAL RESEARCH LETTERS
(2016)
Article
Astronomy & Astrophysics
M. H. Denton, M. G. Henderson, V. K. Jordanova, M. F. Thomsen, J. E. Borovsky, J. Woodroffe, D. P. Hartley, D. Pitchford
SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS
(2016)
Article
Astronomy & Astrophysics
Joseph E. Borovsky, Michael H. Denton
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2016)
Review
Astronomy & Astrophysics
Joseph E. Borovsky, Michael H. Denton
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2016)
Article
Astronomy & Astrophysics
Geoffrey D. Reeves, Reiner H. W. Friedel, Brian A. Larsen, Ruth M. Skoug, Herbert O. Funsten, Seth G. Claudepierre, Joseph F. Fennell, Drew L. Turner, Mick H. Denton, Harlan E. Spence, J. Bernard Blake, Daniel N. Baker
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2016)
Editorial Material
Astronomy & Astrophysics
M. H. Denton, J. E. Borovsky, M. Stepanova, J. A. Valdivia
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2016)
Article
Astronomy & Astrophysics
Joseph E. Borovsky, Thomas E. Cayton, Michael H. Denton, Richard D. Belian, Roderick A. Christensen, J. Charles Ingraham
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2016)
Article
Geochemistry & Geophysics
M. H. Denton, R. Kivi, T. Ulich, C. J. Rodger, M. A. Clilverd, R. B. Horne, A. J. Kavanagh
JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS
(2018)
Article
Astronomy & Astrophysics
Philip A. Fernandes, Brian A. Larsen, Michelle F. Thomsen, Ruth M. Skoug, Geoffrey D. Reeves, Michael H. Denton, Reinhard H. W. Friedel, Herbert O. Funsten, Jerry Goldstein, Michael G. Henderson, Jorg-Micha Jahn, Elizabeth A. MacDonald, David K. Olson
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2017)
Article
Astronomy & Astrophysics
J. -F. Ripoll, O. Santolik, G. D. Reeves, W. S. Kurth, M. H. Denton, V. Loridan, S. A. Thaller, C. A. Kletzing, D. L. Turner
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2017)
Article
Astronomy & Astrophysics
M. H. Denton, J. E. Borovsky
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2017)
Article
Astronomy & Astrophysics
M. H. Denton, G. D. Reeves, B. A. Larsen, R. F. W. Friedel, M. F. Thomsen, P. A. Fernandes, R. M. Skoug, H. O. Funsten, L. K. Sarno-Smith
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2017)