Article
Astronomy & Astrophysics
Soumyaranjan Dash, Dibyendu Nandy, Ilya Usoskin
Summary: This study utilizes simulations and observational data to reveal the impact of magnetic fields generated by the Sun's internal dynamo mechanism on the variations of the solar corona and the state of the heliosphere, establishing causality between solar internal variations and the state of the heliosphere.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Allan R. Macneil, Mathew J. Owens, Adam J. Finley, Sean P. Matt
Summary: The study evaluates the heliospheric portion of two-step backmapping, finding that mapping using models can achieve good average agreement with observed data, but with significant standard deviation. It also suggests that previous assumptions about interplanetary acceleration and solar wind corotation height may have been overestimated, and that error cancellation may contribute to the performance of ballistic mapping.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
A. Zhukova, A. Khlystova, V Abramenko, D. Sokoloff
Summary: Long observational series for bipolar active regions (ARs) provide valuable information about the transformation of the global solar magnetic field. Most bipolar ARs follow the Hale's polarity law, but a small percentage of ARs have the opposite polarity. However, the lack of statistics hinders the study of these anti-Hale ARs.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Geosciences, Multidisciplinary
David Gubbins, Yi Jiang, Simon E. Williams, Keke Zhang
Summary: Mars has a magnetic field originating in its strongly magnetized crust. The decomposition of simple candidate magnetic structures helps separate the responsible parts for anomalies from those that are invisible. A uniform magnetic layer does not produce anomalies, while secondary magnetization may reflect the primordial dynamo field. A magnetized crust with variable thickness can produce large anomalies, but they are absent if the magnetic layer lies deeper than the crater floor.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Astronomy & Astrophysics
Valentina Abramenko, Regina A. Suleymanova, Anastasija Zhukova
Summary: Data from 3046 solar active regions observed over a period of 25 years were used to study the magnetic fluxes of regions with different complexity during the solar cycle. The study found that the fluxes from different classes of regions evolve synchronously and correlate strongly with each other. The deepest solar minimum occurs simultaneously for all classes, and only the simplest regions are observed during this period. The overall shape of the solar cycle is determined by regular regions, while the fine structures of the solar maximum are influenced by the most complex irregular regions. Approximately equal amounts of flux are contributed by A-class and B-class regions during the solar maximum.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Allan R. Macneil, Mathew J. Owens, Robert T. Wicks, Mike Lockwood
Summary: Research shows that HMF inversions observed by the Parker Solar Probe are typically characterized by anticorrelated field and velocity perturbations, exhibiting Alfvenic properties. As the distance from the Sun increases, these inversions depart further from the 'ideal' Alfvenic case.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Valentina I. Abramenko, Regina A. Suleymanova, Anastasija V. Zhukova
Summary: The study found that the magnetic fluxes of ARs of different complexity evolve synchronously with the solar cycle, with the simplest ARs observed during the deepest solar minimum. The overall shape of the cycle is controlled by regular ARs, while the fine structure of the solar maximum is determined by the most complex irregular ARs.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
J. Javaraiah
Summary: The study analyzed sunspot-group data and found a significant latitude-time dependence in both the residual rotation rate and meridional motion. There is a strong correlation between the slope and sunspot number, indicating a relationship between activity and angular momentum transport towards the equator. However, the cycle-to-cycle modulations in the slope show insignificant correlation with the strength of activity on a long-time scale.
Article
Astronomy & Astrophysics
I. I. Baliukin, V. V. Izmodenov, D. B. Alexashov
Summary: This article discusses the distribution characteristics and property estimation of high-energy pickup protons in the heliosphere, and investigates the acceleration process of pickup protons from the Sun to the heliospheric termination shock under the action of the heliospheric magnetic field.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
R. Laker, T. S. Horbury, L. Matteini, S. D. Bale, J. E. Stawarz, L. D. Woodham, T. Woolley
Summary: Switchbacks are magnetic fluctuations in the solar wind that exhibit large rotations. This study re-examines the deflection direction of switchbacks and finds a systematic deflection direction consistent with interchange reconnection.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Shaoyu Lyu, Yuming Wang, Xiaolei Li, Quanhao Zhang
Summary: In this study, the CORAR technique was applied to reconstruct images from the COR-2 coronagraphs on board STEREO, and the impact of theta(Sun) on the reconstruction of coronal transients was explored. The optimal theta(Sun) for reconstruction was determined to be around 135 degrees. The findings provide valuable insights for future missions with multiple perspective coronagraphs.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
N. Kleeorin, I Rogachevskii
Summary: The combined action of plasma's helical motions and non-uniform rotation is a crucial mechanism in the generation of large-scale magnetic fields in the Sun and galaxies. The dynamics of magnetic helicity fluxes plays a significant role in the non-linear saturation of dynamos, preventing catastrophic quenching of the alpha effect. Turbulent magnetic helicity fluxes are produced in the convective zone of the Sun, solar-like stars, and galactic discs. These fluxes include non-gradient and gradient contributions, as well as source terms related to the kinetic alpha effect and large-scale shear.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
A. Fedorov, P. Louarn, C. J. Owen, T. S. Horbury, L. Prech, T. Durovcova, A. Barthe, A. P. Rouillard, J. C. Kasper, S. D. Bale, R. Bruno, H. O'Brien, V Evans, V Angelini, D. Larson, R. Livi, B. Lavraud, N. Andre, V Genot, E. Penou, G. Mele, V Fortunato
Summary: Researchers discovered that fluctuations in the solar wind and the phenomenon of rapid polarity reversals may have the same origin, possibly due to solar wind velocity shearing causing magnetic field lines to bend and produce flux ropes. These results provide further explanation for solar wind phenomena near the Sun.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
S. D. Korolkov, V. V. Izmodenov
Summary: The study aims to demonstrate that shock-wave heating is sufficient to explain the nonadiabatic radial profile of the solar wind proton temperature. By using a high-resolution data-driven solar wind model, the numerical simulations show good agreement with the observations obtained by Voyager-2.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
J. M. Schroeder, S. Boldyrev, P. Astfalk
Summary: This study presents a kinetic stability analysis of the solar wind electron distribution, revealing instabilities in the core-strahl electron distribution at specific heliospheric distances induced by various modes. These instabilities are primarily driven by the relative drift between electron and ion cores.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Zi-Fan Wang, Jie Jiang, Jing-Xiu Wang
Summary: A generalized algebraic method was proposed to describe the axial dipole contribution of active regions (ARs) with arbitrary configurations, showing equivalent precision to the Surface Flux Transport (SFT) model but with higher computational efficiency. In contrast, the Bipolar Magnetic Region (BMR)-based method is only accurate for symmetric ARs and tends to overestimate contributions of asymmetric ARs. The generalized method paves the way for more efficient and precise solar cycle predictions, compared to traditional methods.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Shao-Lan Bi, Tan-Da Li, Kang Liu, Jie Jiang, Ya-Guang Li, Jing-Hua Zhang, Xian-Fei Zhang, Ya-Qian Wu
Summary: The study showed that the change of sound speed at the base of the convection during solar cycles can be constrained by the solar internal magnetic field. The magnetic field generated by the solar dynamo can lead to cyclic variation of sound speed, which is in agreement with helioseismic observations.
RESEARCH IN ASTRONOMY AND ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Qirong Jiao, Jie Jiang, Zi-Fan Wang
Summary: This study investigates the tilt angles of sunspot groups in relation to the generation of the poloidal magnetic field in the Babcock-Leighton dynamo. The results show that the tilt coefficient is indeed anti-correlated with the cycle strength, with strong statistical significance. Different methods in handling uncertainties were found to be responsible for the controversial nature of previous results. Additionally, the study reveals a linear vs. square-root dependence of tilts on latitudes for weak vs. strong cycles.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Xianyong Bai, Hui Liu, Yuanyong Deng, Jie Jiang, Jingjing Guo, Yi Bi, Tao Feng, Zhenyu Jin, Wenda Cao, Jiangtao Su, Kaifan Ji
Summary: This study proposes a new method to estimate the magnetic field components from photospheric continuum images using deep convolutional neural networks. Experimental results show that the method can successfully estimate the magnetic field in different regions of the Sun, providing quick and accurate magnetic field information.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
K. L. Yeo, S. K. Solanki, N. A. Krivova, J. Jiang
Summary: The study established a relationship between the magnetic flux in newly emerged BMRs and the area of enclosed sunspots, and applied it to an established SFTM model. By deriving this relationship, a constraint on the BMR magnetic flux was determined and applied to the SFTM model, retaining its key features such as replicating various independent datasets and correlating the model output polar field with observed strength of the following cycle.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Zebin Zhang, Jie Jiang
Summary: In this study, we developed a new solar dynamo model which suggests that the magnetic field is mainly generated within the core of the convection zone and considers the role of the tachocline as negligible. The results show that our model reproduces the basic properties of the solar cycle.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Zi-Fan Wang, Jie Jiang, Jing-Xiu Wang
Summary: The poleward migration of magnetic flux in active regions on the solar surface is crucial for the development of large-scale fields, especially the polar-field reversal. In this study, a statistical method is proposed to analyze the nonuniformity of poleward flux transport during solar cycles 21-24. The results show that poleward surges are significant during these cycles, and the kurtosis, representing the tailedness of the distributions, varies with latitude and data source.
ASTROPHYSICAL JOURNAL
(2022)
Article
Engineering, Aerospace
Yuming Wang, Xianyong Bai, Changyong Chen, Linjie Chen, Xin Cheng, Lei Deng, Linhua Deng, Yuanyong Deng, Li Feng, Tingyu Gou, Jingnan Guo, Yang Guo, Xinjun Hao, Jiansen He, Junfeng Hou, Jiangjiang Huang, Zhenghua Huang, Haisheng Ji, Chaowei Jiang, Jie Jiang, Chunlan Jin, Xiaolei Li, Yiren Li, Jiajia Liu, Kai Liu, Liu Liu, Rui Liu, Rui Liu, Chengbo Qiu, Chenglong Shen, Fang Shen, Yuandeng Shen, Xiangjun Shi, Jiangtao Su, Yang Su, Yingna Su, Mingzhe Sun, Baolin Tan, Hui Tian, Yamin Wang, Lidong Xia, Jinglan Xie, Ming Xiong, Mengjiao Xu, Xiaoli Yan, Yihua Yan, Shangbin Yang, Shuhong Yang, Shenyi Zhang, Quanhao Zhang, Yonghe Zhang, Jinsong Zhao, Guiping Zhou, Hong Zou
Summary: Solar Ring (SOR) is a proposed space science mission that aims to monitor and study the Sun and inner heliosphere from a full 360 degrees perspective in the ecliptic plane. It will deploy three spacecraft separated by 120 degrees on the 1-AU orbit. With necessary science instruments, it will provide unprecedented capabilities to understand the deep interior of the Sun, the evolution of solar featured structures, and space weather in the inner heliosphere, addressing outstanding questions about solar cycle origin and extreme space weather events.
ADVANCES IN SPACE RESEARCH
(2023)
Article
Multidisciplinary Sciences
Yuanyong Deng, Guiping Zhou, Shuwu Dai, Ying Wang, Xueshang Feng, Jiansen He, Jie Jiang, Hui Tian, Shangbin Yang, Junfeng Hou, Yihua Yan, Weiqun Gan, Xianyong Bai, Leping Li, Lidong Xia, Hui Li, Yang Su, Ming Xiong, Yechi Zhang, Chenglin Zhu, Jiaben Lin, Haiying Zhang, Bo Chen, Lingping He, Li Feng, Hongxin Zhang, Mingzhe Sun, Aibing Zhang, Linjie Chen, Baolin Tan, Zhe Zhang, Jianfeng Yang, Mengfei Yang, Jingxiu Wang
Summary: Solar magnetic fields and activities play a dominant role in the heliospheric environments, from near-Earth space to the interstellar boundary. The polar magnetic fields and dynamic processes of the Sun are crucial for understanding its internal dynamo and shaping magnetic fields in the heliosphere. However, the polar regions of the Sun remain largely unexplored due to limitations in satellite observation. The Solar Polar-orbit Observatory (SPO) aims to directly image the polar regions with unprecedented high solar inclination angle and low ellipticity, providing crucial observations for understanding the solar magnetic activity cycle, the origin and effects of the solar wind, and for improving space weather predictions.
CHINESE SCIENCE BULLETIN-CHINESE
(2023)
Review
Multidisciplinary Sciences
Mengfei Yang, Jingxiu Wang, Chi Wang, Qiugang Zon, Xiaoxin Zhang, Shuwu Dai, Yuanyong Deng, Xueshang Feng, Ying Wang, Chenglin Zhu, Yechi Zhang, Qingxiang Zhang, Fenggang Shen, Baiyi Tian, Wenyan Zhou, Linling Li, Yihua Yan, Guiping Zhou, Shangbin Yang, Ming Xiong, Aibing Zhang, Jiansen He, Hui Tian, Jiawei Li, Weigun Gan, Lidong Xia, Jilong Peng, Changning Huang, Jie Jiang, Lin Quan
Summary: Solar stereo exploration is crucial in studying solar physics and improving space weather forecasting. This paper introduces the scientific objectives, space layout, system composition, payload configuration, and major technical indicators of the mission. By providing high-quality data and promoting Chinese research in solar physics, solar stereo exploration will greatly enhance China's space weather forecast capabilities and contribute to the country's innovation-driven development strategy.
CHINESE SCIENCE BULLETIN-CHINESE
(2023)
Article
Astronomy & Astrophysics
Zebin Zhang, Jie Jiang, Haowei Zhang
Summary: The butterfly diagram is the equatorward migration of sunspots as the solar cycle evolves. Previous studies attributed the butterfly diagram to the equatorward meridional flow at the base of the convection zone. However, recent research suggests that the latitude-dependent radial flux transport plays a more important role. Numerical simulations show that faster radial transport at higher latitudes leads to earlier generation of toroidal fields for a new cycle.
ASTROPHYSICAL JOURNAL LETTERS
(2022)
Article
Geochemistry & Geophysics
Jie Jiang, Zebin Zhang, Kristof Petrovay
Summary: Physics-based solar cycle predictions are an effective way to verify our understanding of the solar cycle. This review compares 7 physics-based prediction models and emphasizes the importance of including uncertainties in initial magnetograms and sunspot emergence in such predictions. The review also demonstrates the significant impact of assimilated magnetograms on predictions through numerical tests.
JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS
(2023)
Review
Astronomy & Astrophysics
Anthony R. Yeates, Mark C. M. Cheung, Jie Jiang, Kristof Petrovay, Yi-Ming Wang
Summary: This paper reviews the surface flux transport model for the evolution of magnetic flux patterns on the Sun's surface. The focus is on the classical model, with recent advances in understanding transport parameters and the source term. The paper also discusses the physical justification for the model and efforts to incorporate radial diffusion, and summarizes the main directions where researchers have moved beyond the classical model.
SPACE SCIENCE REVIEWS
(2023)
Article
Astronomy & Astrophysics
Yukun Luo, Jie Jiang, Ruihui Wang
Summary: Magnetic spatial power spectral analysis provides a powerful tool for understanding the various scales of the Sun's magnetic field and its interactions with plasma motions. This paper focuses on the calibration and analysis of power spectra using the data from SOHO/MDI and SDO/HMI. For the first time, it is found that the calibration factor between the two instruments varies with the spatial scale of the magnetic field.
ASTROPHYSICAL JOURNAL
(2023)
Review
Astronomy & Astrophysics
Prantika Bhowmik, Jie Jiang, Lisa Upton, Alexandre Lemerle, Dibyendu Nandy
Summary: The dynamic activity of stars, such as the Sun, affects planetary space environments through various factors. Solar phenomena like flares and coronal mass ejections can cause hazardous space weather. The primary driver of solar activity is magnetic fields created by a mechanism called the magnetohydrodynamic dynamo. While the mechanism of solar cycles has been studied for a long time, predicting the strength of future sunspot cycles remains challenging. This review discusses observational constraints, recent physical insights, and advances in solar cycle predictions.
SPACE SCIENCE REVIEWS
(2023)
