Ion‐Scale Flux Rope Observed inside a Hot Flow Anomaly

Bai, Shaochun; Shi, Quanqi; Liu, Zixu; Zhang, Hui; Yue, Chao; Sun, W.; Tian, Anmin; Degeling, A. W.; Bortnik, J.; Rae, I. J.; Wang, Mengmeng

doi:10.1029/2019gl085933

Cited by 15 publications

(13 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A flux rope was also identified inside the compressional boundary of an HFA observed by MMS in the foreshock (Bai et al. 2020 ). Observations by Cluster, THEMIS, and MMS have revealed various types of reconnection induced in the magnetosheath and at the bow shock: reconnection due to compression of a non-reconnecting solar wind current sheet at the bow shock (Phan et al.…”

Section: Transient Processes In the Foreshock Bow Shock And Magnetosh...mentioning

confidence: 94%

Dayside Transient Phenomena and Their Impact on the Magnetosphere and Ionosphere

et al. 2022

Self Cite

View full text Add to dashboard Cite

Dayside transients, such as hot flow anomalies, foreshock bubbles, magnetosheath jets, flux transfer events, and surface waves, are frequently observed upstream from the bow shock, in the magnetosheath, and at the magnetopause. They play a significant role in the solar wind-magnetosphere-ionosphere coupling. Foreshock transient phenomena, associated with variations in the solar wind dynamic pressure, deform the magnetopause, and in turn generates field-aligned currents (FACs) connected to the auroral ionosphere. Solar wind dynamic pressure variations and transient phenomena at the dayside magnetopause drive magnetospheric ultra low frequency (ULF) waves, which can play an important role in the dynamics of Earth’s radiation belts. These transient phenomena and their geoeffects have been investigated using coordinated in-situ spacecraft observations, spacecraft-borne imagers, ground-based observations, and numerical simulations. Cluster, THEMIS, Geotail, and MMS multi-mission observations allow us to track the motion and time evolution of transient phenomena at different spatial and temporal scales in detail, whereas ground-based experiments can observe the ionospheric projections of transient magnetopause phenomena such as waves on the magnetopause driven by hot flow anomalies or flux transfer events produced by bursty reconnection across their full longitudinal and latitudinal extent. Magnetohydrodynamics (MHD), hybrid, and particle-in-cell (PIC) simulations are powerful tools to simulate the dayside transient phenomena. This paper provides a comprehensive review of the present understanding of dayside transient phenomena at Earth and other planets, their geoeffects, and outstanding questions.

show abstract

Section: Transient Processes In the Foreshock Bow Shock And Magnetosh...mentioning

confidence: 94%

Dayside Transient Phenomena and Their Impact on the Magnetosphere and Ionosphere

et al. 2022

Self Cite

View full text Add to dashboard Cite

show abstract

“…The magnetic field inside the core is typically very turbulent. A flux rope was observed inside an HFA (Bai et al, 2020;Hasegawa et al, 2012), which suggests the possibility that magnetic reconnection could occur inside foreshock transients just like in the magnetosheath, bow shock transition region, magnetopause, and plasma sheet and provide particle acceleration/heating (e.g., Burch & Phan, 2016;Eriksson et al, 2016;Phan et al, 2018;Torbert et al, 2018).…”

Section: Introductionmentioning

confidence: 97%

Magnetospheric Multiscale (MMS) Observations of Magnetic Reconnection in Foreshock Transients

Liu

Turner

et al. 2020

JGR Space Physics

Self Cite

View full text Add to dashboard Cite

Magnetic reconnection is a fundamental process of energy conversion in plasmas between electromagnetic fields and particles. Magnetic reconnection has been observed directly in a variety of plasmas in the solar wind and Earth's magnetosphere. Most recently, electron magnetic reconnection without ion coupling was observed for the first time in the turbulent magnetosheath and within the transition region of Earth's bow shock. In the ion foreshock upstream of Earth's bow shock, there may also be magnetic reconnection especially around foreshock transients that are very turbulent and dynamic. With observations from the National Aeronautics and Space Administration's Magnetospheric Multiscale mission inside foreshock transients, we report two events of magnetic reconnection with and without a strong guide field, respectively. In both events, a super-ion-Alfvénic electron jet was observed within a current sheet with thickness less than or comparable to one ion inertial length. In both events, energy was converted from the magnetic field to electrons, manifested as an increase in electron temperature. Weak or no ion coupling was observed in either event. Results from particle-in-cell simulations of magnetic reconnection with and without a strong guide field are qualitatively consistent with observations. Our results imply that magnetic reconnection is another electron acceleration/heating process inside foreshock transients and could play an important role in shock dynamics.

show abstract

“…In spacecraft observations, flux ropes are often identified from bipolar variations in one magnetic field component and enhancement of magnetic strength at the center. There are various observations of flux ropes in the magnetosphere (e.g., Khurana et al 1995;Slavin 2003;Yang et al 2014;Sun et al 2019;Poh et al 2019), boundary of magnetosphere (e.g., Rijnbeek et al 1984;Kawano & Russell 1997;Fear et al 2008Fear et al , 2009Akhavan-Tafti et al 2018;Hwang et al 2018;Yao et al 2020), and solar wind (e.g., Zheng & Hu 2018;BlancoCano et al 2019;Bai et al 2020). Flux ropes are also observed in magnetospheres of Mercury (Zhong et al 2020a), Mars (Briggs et al 2011), Jupiter (Sarkango et al 2021), and Saturn (Jasinski et al 2016).…”

Section: Introductionmentioning

confidence: 99%

“…Similar features are also found in various studies (Varsani et al 2014;Wang et al 2017;Yao et al 2020). On the other hand, there are also observations of non-force-free flux ropes, indicating that they are actively evolving (Zhao et al 2016;Teh et al 2017;Bai et al 2020). Sun et al (2019) carried out a statistical study to show that quasi-2D ion-scale flux ropes are more likely to be force-free structures.…”

Section: Introductionmentioning

confidence: 99%

Kinetic-scale flux ropes: Observations and applications of kinetic equilibrium models

Yang,

Zhou,

et al. 2022

Preprint

View full text Add to dashboard Cite

Magnetic flux ropes with helical field lines and strong core field are ubiquitous structures in space plasmas. Recently, kinetic-scale flux ropes have been identified by high-resolution observations from Magnetospheric Multiscale (MMS) spacecraft in the magnetosheath, which have drawn a lot of attention because of their non-ideal behavior and internal structures. Detailed investigation of flux rope structure and dynamics requires development of realistic kinetic models. In this paper, we generalize an equilibrium model to reconstruct a kinetic-scale flux rope previously reported via MMS observations. The key features in the magnetic field and electron pitch-angle distribution measurements of all four satellites are simultaneously reproduced in this reconstruction. Besides validating the model, our results also indicate that the anisotropic features previously attributed to asymmetric magnetic topologies in the magnetosheath can be alternatively explained by the spacecraft motion in the flux rope rest frame.

show abstract

Ion‐Scale Flux Rope Observed inside a Hot Flow Anomaly

Cited by 15 publications

References 54 publications

Dayside Transient Phenomena and Their Impact on the Magnetosphere and Ionosphere

Dayside Transient Phenomena and Their Impact on the Magnetosphere and Ionosphere

Magnetospheric Multiscale (MMS) Observations of Magnetic Reconnection in Foreshock Transients

Kinetic-scale flux ropes: Observations and applications of kinetic equilibrium models

Contact Info

Product

Resources

About