Article
Astronomy & Astrophysics
M. Lockwood
Summary: The study compares the IAGA-endorsed Polar Cap Indices (PCN and PCS) for the northern and southern hemispheres from 1998 to 2018. The effects of different magnetic coordinates of the two stations, Thule in Greenland and Vostok in Antarctica, are investigated. The results show that PCS consistently correlates slightly better with solar wind parameters than PCN, and the correlations are highest for the predicted magnetopause reconnection voltage.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Peter Stauning
Summary: Polar Cap (PC) indices are important for studying solar wind-magnetosphere interactions and space weather monitoring, but the South Polar Cap (PCS) indices have been found to be invalid, leading to potential inaccuracies in published research.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Peter Stauning
Summary: This study introduces different versions of the standard polar cap (PC) indices, as well as derivation procedures developed to generate alternative PCS index values based on Dome Concordia (Dome-C) data. The assessments of the new PCS index have shown its unprecedented high relevance. Some methods used in this study deviate from the corresponding features considered inadequate by the International Association for Geomagnetism and Aeronomy-endorsed PC index derivation methods.
SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS
(2022)
Article
Metallurgy & Metallurgical Engineering
Jiang Fei-fei, Zhou Hui, Sheng Jia, Li Xiang-dong, Kou Yong-yuan
Summary: Understanding the temperature effect on the shear behavior of the ore-backfill coupling structure is crucial for the safety and stability of backfill stopes in deep mining with high horizontal stress. Temperature can influence the shear performance of CRB and OCRB, with CRB performing relatively well at 40 degrees Celsius. The shear behavior of OCRB is affected by temperature and shear direction, with its performance along the axis direction significantly better than perpendicular to it.
JOURNAL OF CENTRAL SOUTH UNIVERSITY
(2021)
Article
Astronomy & Astrophysics
Peter Stauning
Summary: This study confirms the validity of using PC indices with ASY-H and Dst as well as SYM-H ring current indices in real-time applications. Equivalent values of ASY-H and Dst indices are derived from simulated real-time PC indices, showing close agreement with real values. The method can be used without modifications for real-time space weather applications.
SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS
(2021)
Article
Environmental Sciences
Yuxia Guo, Yonghui Zhao, Guorui Feng
Summary: Cemented gangue backfill (CGB) technology is beneficial for waste reuse and sustainable development. The impact of mine water on the strength and deformation of CGB was investigated in this study. The deformation, resistivity, and ultrasonic pulse velocity (UPV) of CGB under acid mine water were monitored. The results provide insights into the degradation mechanism of CGB and can guide the durability design of CGB.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Astronomy & Astrophysics
Katie Herlingshaw, Lisa Baddeley, Kjellmar Oksavik, Dag A. A. Lorentzen, Karl M. M. Laundal
Summary: This paper presents the first large-scale statistical study on ionospheric fast flow channels in the polar cap using the SuperDARN radar network. The study found that these flow channels are predominantly driven by IMF B-y dominant conditions and occur preferentially during disturbed IMF conditions. Additionally, large populations of flow channels were observed on the flanks of the polar cap region, suggesting significant momentum transfer from the magnetosphere in these areas.
JOURNAL OF SPACE WEATHER AND SPACE CLIMATE
(2022)
Article
Engineering, Marine
Jinghui Li, Wei Shi, Lixian Zhang, Constantine Michailides, Xin Li
Summary: This study introduces a combined floating energy system using different types of energy devices to maximize the utilization of offshore renewable energy resources. The research focuses on investigating the power performance, dynamic response, and survivability of the combined concept through numerical analysis and coupled models.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2021)
Article
Astronomy & Astrophysics
Peter Stauning
Summary: The Polar Cap PCC index correlates better with solar wind activity and geomagnetic disturbances than hemispheric indices, accurately representing the total energy input from the solar wind to the magnetosphere. The derived Dst values from PCC indices show a high degree of accuracy, with equivalent values correlating well with real Dst index values and allowing for correction of saturation effects. The timing relationship between PCC indices and ring current systems can help understand energy input from the solar wind and the formation of geomagnetic disturbances.
JOURNAL OF SPACE WEATHER AND SPACE CLIMATE
(2021)
Article
Physics, Nuclear
Wenchang Xiang, Mengliang Wang, Yanbing Cai, Daicui Zhou
Summary: This study analytically and numerically analyzes the solutions and predictive power of the Balitsky-Kovchegov equation in fixed and running coupling cases. The study finds that in the running coupling case, the analytic S-matrices in the two rapidity representations have similar rapidity dependence. The analytic and numerical results are consistent with experimental data, confirming the robustness and predictive power of the Balitsky-Kovchegov equation at the miming coupling level.
Article
Mathematics, Applied
Chonggang Du, Zheng H. Zhu, Gangqiang Li
Summary: This paper investigates the impact of rigid-flexible coupling on the attitude dynamics of an electric solar wind sail (E-sail) through the development of a dynamic model. It finds that deformation motion of flexible tethers causes disturbance torques on the central spacecraft. The analysis also shows that the E-sail is more stable when the spin plane passes through the center of mass of the spacecraft.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2021)
Article
Thermodynamics
Sun Ho Park, Jin Woo Son, Jeong Park, Min Suk Cha
Summary: This study investigates the effects of pressure on an ionic wind in methane premixed jet flames, finding significant changes in saturated current for rich premixed flames under pressure. A model was developed to predict voltage-current behavior and ion production rate, validated with experimental results. High pressure conditions were shown to enhance ionic wind-driven mass transport.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2021)
Article
Materials Science, Multidisciplinary
Te-Huan Liu, Jiawei Zhou, Qian Xu, Xin Qian, Bai Song, Ronggui Yang
Summary: The study shows that long-range electron-phonon interaction can significantly suppress thermal conductivity in certain polar semiconductors by scattering acoustic phonons. The breaking of centrosymmetry has different effects on phonon transport in different crystal structures.
MATERIALS TODAY PHYSICS
(2022)
Article
Automation & Control Systems
Qiujiang Liu, Yichen Ying, Mingli Wu
Summary: This article extends the frequency range of harmonic analysis to address high-frequency harmonic problems in high-power industrial applications. By addressing aliasing and sideband effects and using an artificial neural network regression method, the harmonic performance of grid-connected converters can be comprehensively analyzed.
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
(2022)
Article
Engineering, Chemical
Yang Chen, Ting Kang, Chao Wu
Summary: This study investigates the mechanical behavior and mechanism response of sandstone under the coupling effect of dynamic load disturbance and water content. The research findings suggest that water content and dynamic loading significantly affect the fracture characteristics and energy conversion mechanism of the rock. It is found that energy density and strength are positively correlated and the fractal dimension influences the energy density absorbed.
Article
Astronomy & Astrophysics
Donglai Ma, Xiangning Chu, Jacob Bortnik, Seth G. Claudepierre, W. Kent Tobiska, Alfredo Cruz, S. Dave Bouwer, Joseph F. Fennell, J. Bernard Blake
Summary: In this study, a set of neural network models are proposed to accurately reproduce the dynamics of electron fluxes in the outer radiation belt. These models have reliable prediction capability and can be applied to a wide range of space weather applications.
SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS
(2022)
Article
Geosciences, Multidisciplinary
E. Kallio, R. Jarvinen, S. Massetti, T. Alberti, A. Milillo, S. Orsini, E. De Angelis, G. Laky, J. Slavin, J. M. Raines, T. Pulkkinen
Summary: Ultra-low frequency (ULF) waves have been observed in Mercury's magnetosphere and are believed to be generated by dynamic processes. A global hybrid model showed the presence of 2-second circularly polarized right-handed waves in Mercury's magnetosphere, with the most intense wave power occurring on the dawn side closed magnetic field lines.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Astronomy & Astrophysics
Donglai Ma, Jacob Bortnik, Xiangning Chu, Seth G. G. Claudepierre, Qianli Ma, Adam Kellerman
Summary: In this study, the interpretability of a high-accuracy ML model for Earth's radiation belt electrons was investigated using the DeepSHAP method. The results demonstrate that the black box model can be successfully explained and that the identified features align with current physical understanding. This method can be applied to other similar models to better explain results and potentially discover new physical mechanisms.
SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS
(2023)
Article
Astronomy & Astrophysics
Jinxing Li, Jacob Bortnik, Xiangning Chu, Donglai Ma, Sheng Tian, Chih-Ping Wang, Jerry W. Manweiler, Louis J. Lanzerotti
Summary: This study uses geomagnetic indices and solar wind parameters to train an artificial neural network model, which can provide a global and time-varying distribution of the ring current proton. The model results show a high correlation and small error with satellite measurements, accurately capturing the energy-dependent proton dynamics during geomagnetic storms. The model results also capture spatiotemporal variations in proton fluxes, including latitudinal distribution and local time asymmetry, which are consistent with observations and can inform further theoretical development.
SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS
(2023)
Review
Physics, Multidisciplinary
Alexa J. Halford, Angeline G. Burrell, Michael W. Liemohn, McArthur Jones, Astrid Maute, Tuija I. Pulkkinen, Christopher M. Bard, Ryan M. McGranaghan, Lynn B. Wilson III, Robert C. Allen, Chuanfei Dong, Sarah K. Vines, Liang Wang, Niescja Turner, Katherine Garcia-Sage, Kathleen Mandt, Jeff Klenzing
Summary: A survey on heliophysics reveals that many heliophysicists suffer from bullying and harassment, leading to burnout and thoughts of leaving the field. This calls for collective efforts to establish policies and commitments towards a truly inclusive culture, ensuring the well-being of colleagues and the success of the field.
FRONTIERS IN PHYSICS
(2023)
Review
Astronomy & Astrophysics
Christine Gabrielse, Matina Gkioulidou, Slava Merkin, David Malaspina, Drew L. Turner, Margaret W. Chen, Shin-ichi Ohtani, Yukitoshi Nishimura, Jiang Liu, Joachim Birn, Yue Deng, Andrei Runov, Robert L. McPherron, Amy Keesee, Anthony Tat Yin Lui, Cheng Sheng, Mary Hudson, Bea Gallardo-Lacourt, Vassilis Angelopoulos, Larry Lyons, Chih-Ping Wang, Emma L. Spanswick, Eric Donovan, Stephen Roland Kaeppler, Kareem Sorathia, Larry Kepko, Shasha Zou
Summary: An important question in Heliophysics is how mesoscale phenomena contribute to the global response of the system. This review paper focuses on specific regions in Near-Earth space and the efforts to understand mesoscale transport and its impacts on various dynamics within the magnetosphere-ionosphere system. The paper also highlights the need to better characterize and quantify mesoscale messengers in order to understand the global system.
FRONTIERS IN ASTRONOMY AND SPACE SCIENCES
(2023)
Review
Astronomy & Astrophysics
J. -F. Ripoll, V. Pierrard, G. S. Cunningham, X. Chu, K. A. Sorathia, D. P. Hartley, S. A. Thaller, V. G. Merkin, G. L. Delzanno, S. De Pascuale, A. Y. Ukhorskiy
Summary: This review specifically focuses on the existing plasma density models, covering ionospheric source models, empirical density models, physics-based and machine-learning density models. The review is put into the context of radiation belt physics and space weather codes. It is limited to the most commonly used models or those recently developed and showing promise. A wide range of conditions are considered, such as magnetic local time variation, geomagnetic conditions, ionospheric source regions, radial and latitudinal dependence, and collisional vs. collisionless conditions. These models can be used to complement satellite observations of electron plasma density when data are lacking, they are commonly used in radiation belt physics simulations, and can enhance our understanding of plasmasphere dynamics.
FRONTIERS IN ASTRONOMY AND SPACE SCIENCES
(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
Geosciences, Multidisciplinary
Minna Palmroth, Tuija I. Pulkkinen, Urs Ganse, Yann Pfau-Kempf, Tuomas Koskela, Ivan Zaitsev, Markku Alho, Giulia Cozzani, Lucile Turc, Markus Battarbee, Maxime Dubart, Harriet George, Evgeniy Gordeev, Maxime Grandin, Konstantinos Horaites, Adnane Osmane, Konstantinos Papadakis, Jonas Suni, Vertti Tarvus, Hongyang Zhou, Rumi Nakamura
Summary: Rapid plasma eruptions release tremendous energy within Earth's magnetosphere, at the Sun and other planets. The exact mechanism leading to these eruptions, called plasmoids, has been a long-standing question in space physics. Two competing paradigms, magnetic reconnection and kinetic instabilities, have been proposed to explain the process.
Article
Astronomy & Astrophysics
M. Akhavan-Tafti, T. Y. Atilaw, D. Fontaine, O. Le Contel, J. A. Slavin, T. Pulkkinen
Summary: Magnetospheric magnetic flux dynamics in 29 geomagnetic storms between 2015 and 2019 were quantified using near-equatorial Van Allen Probe, GOES, and Magnetospheric Multiscale satellites. Concurrent, multi-probe observations were utilized for the first time to preserve magnetospheric time history. It was revealed that during storm sudden commencement (SSC), magnetic flux uniformly increased by 15% throughout the magnetosphere, except for a 30% decrease in the nightside inner magnetosphere, and during the storm main and recovery phases, there was a decrease of 30% and 15% respectively in the nightside magnetosphere.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Bala Poduval, R. L. McPherron, R. Walker, M. D. Himes, K. M. Pitman, A. R. Azari, C. Shneider, A. K. Tiwari, S. Kapali, G. Bruno, M. K. Georgoulis, O. Verkhoglyadova, J. E. Borovsky, G. Lapenta, J. Liu, T. Alberti, P. Wintoft, S. Wing
Summary: In the field of space science, the accumulation of ground-based and space-borne data presents challenges in analysis and interpretation. However, the application of artificial intelligence (AI) has shown promise in extracting information from these extensive data sets. The preparation of AI-ready data, including collection, formatting, and processing, is a significant challenge in leveraging AI in space science. This article discusses the importance of AI-readiness for space science data and proposes strategies for its implementation.
FRONTIERS IN ASTRONOMY AND SPACE SCIENCES
(2023)
Article
Astronomy & Astrophysics
Sheng Huang, Wen Li, Qianli Ma, Xiao-Chen Shen, Luisa Capannolo, Miroslav Hanzelka, Xiangning Chu, Donglai Ma, Jacob Bortnik, Simon Wing
Summary: Hiss waves play a crucial role in removing energetic electrons from Earth's radiation belts. This study focuses on plasmaspheric and plume hiss and uses a neural network approach to model their global evolution. The study finds that plume hiss has a significant impact on electron dynamics, with the potential to decrease electron fluxes by up to 80% over several days. This research highlights the importance of considering dynamic hiss distribution in future simulations of radiation belt electron dynamics.
FRONTIERS IN ASTRONOMY AND SPACE SCIENCES
(2023)
Article
Astronomy & Astrophysics
Alexa J. Halford, Christopher M. Bard, Angeline G. Burrell, Ryan M. Mcgranaghan, Lynn B. Wilson Iii, Mcarthur Jones, Chuanfei Dong, Liang Wang, Tuija I. Pulkkinen, Niescja Turner, Michael W. Liemohn, Jeff Klenzing
Summary: A major obstacle to cultivating a strong Heliophysics (and broader scientific) community is the lack of diversity in STEM fields. The leaky pipeline analogy has been used to explain the phenomenon of minority students gradually leaving the field. However, there are also structural and policy issues that push even late career Ph.D.s out of a career in Heliophysics. The article identifies systemic problems and presents recommendations to create a culture of inclusion and innovative science.
FRONTIERS IN ASTRONOMY AND SPACE SCIENCES
(2023)
Article
Astronomy & Astrophysics
M. Akhavan-Tafti, L. Johnson, R. Sood, J. A. Slavin, T. Pulkkinen, S. Lepri, E. Kilpua, D. Fontaine, A. Szabo, L. Wilson, G. Le, T. Y. Atilaw, M. Ala-Lahti, S. L. Soni, D. Biesecker, L. K. Jian, D. Lario
Summary: The SWIFT mission aims to make significant discoveries on the structure and dynamics of heliospheric structures that drive space weather. It focuses on Interplanetary Coronal Mass Ejections (ICMEs) that cause geomagnetic storms and solar energetic particle events. The proposed groundbreaking mission concept will use solar sail technology for continuous, in-situ observations along the Sun-Earth line. This concept will provide insights into the spatial characteristics, temporal evolution, and particle energization mechanisms related to ICMEs, and also extend the forecasting lead-times for earthbound ICMEs.
FRONTIERS IN ASTRONOMY AND SPACE SCIENCES
(2023)
Article
Astronomy & Astrophysics
Homayon Aryan, Jacob Bortnik, Jinxing Li, James Michael Weygand, Xiangning Chu, Vassilis Angelopoulos
Summary: This study investigates the magnetospheric and ionospheric responses to fast flow bursts associated with substorms and pseudobreakups using multipoint analysis of observations. The results show that the responses to substorm fast flow bursts are stronger and more structured compared to pseudobreakups, and the magnetic flux and B-lobe are significantly different between the two events. The study highlights the importance of understanding the properties and activity of magnetospheric earthward flow vortices.
ANNALES GEOPHYSICAE
(2022)