On the response of quasi-adiabatic particles to magnetotail reconfigurations

Delcourt, Dominique; Malova, H. V.; Zelenyǐ, L. M.

doi:10.5194/angeo-35-11-2017

Cited by 5 publications

(6 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The proton motion in Mercury's magnetotail is adiabatic in the region outside the central plasma sheet as demonstrated in previous test‐particle simulations (Delcourt et al, 2017) during magnetic quiet period. In other words, the first adiabatic invariant (

μ = \frac{1}{2} m v_{⊥}^{2} false/ B

) conserves.…”

Section: Introductionsupporting

confidence: 63%

“…However, the radial variation of κ value indicates this energization process may not be adiabatic. The dawn‐dusk asymmetry of κ value also demonstrate the strong non‐adiabatic cross‐tail acceleration in Mercury's magnetotail (Delcourt et al, 2017; Ip, 1987; Sun et al, 2018). A previous study on the Earth's magnetotail also finds the dawn‐dusk asymmetry in κ for both ions and electrons (Espinoza et al, 2018).…”

Section: Discussion and Summarymentioning

confidence: 92%

See 1 more Smart Citation

Proton Properties in Mercury's Magnetotail: A Statistical Study

Zhao

Zong

Slavin

et al. 2020

Geophysical Research Letters

View full text Add to dashboard Cite

This study investigates the properties of protons in the magnetotail plasma sheet of Mercury. By superposing 5-year measurements from the MESSENGER spacecraft, we obtain the average energy spectrum of protons in the plasma sheet, which can be fitted nicely by the Gaussian-Kappa model. The proton density, pressure, and energy spectral index are found to be higher on the dawnside than on the duskside. The proton temperature shows a clearly outward radial gradient. The field-aligned density profile indicates that the protons in the outer plasma sheet move adiabatically. The pitch angle distribution reveals the reflected fluxes to be always less than the incident fluxes and indicates the loss of protons due to their impact on the planetary surface. Plain Language Summary Mercury has a miniature magnetosphere subject to intense solar wind forcing. This magnetosphere, among the smallest in the solar system, resembles the Earth's in many key respects. It is also an analog for other small and outside-driven magnetospheres, such as Ganymede's inside Jupiter's magnetosphere. Mercury does not have a significant atmosphere but a tenuous exosphere. Therefore, Mercury's magnetospheric ions are thought to come predominately from the solar wind, and only about 10% of the ions are of planetary origin. This study presents a statistical picture of the protons in Mercury's magnetotail plasma sheet measured by the Fast Imaging Plasma Spectrometer (FIPS) onboard MESSENGER spacecraft. Many parameters are obtained through a best fit procedure with a Gaussian-Kappa distribution. The proton number density, proton pressure, and spectral index show clear dawn-dusk asymmetric features. The results also suggest that the motion of the protons is adiabatic in the outer plasma sheet and non-adiabatic in the central plasma sheet. Furthermore, the loss feature of the protons is also revealed by their asymmetric pitch angle distributions.

show abstract

μ = \frac{1}{2} m v_{⊥}^{2} false/ B

) conserves.…”

Section: Introductionsupporting

confidence: 63%

Section: Discussion and Summarymentioning

confidence: 92%

Proton Properties in Mercury's Magnetotail: A Statistical Study

Zhao

Zong

Slavin

et al. 2020

Geophysical Research Letters

View full text Add to dashboard Cite

show abstract

“…Mercury's relatively small magnetosphere results in the temporal and spatial scale of the electric and magnetic field variations to be comparable to those of plasma motion at the planet. Under such circumstances, plasma motion and field variation strongly affect each other, resulting in a possible non-adiabatic energization of plasmas which leads to significant plasma heating (e.g., Delcourt et al, 2002Delcourt et al, , 2007Delcourt et al, , 2017Zelenyi et al, 2007). In the following subchapters, we focus on the different possible mechanisms of particle energization expected in Mercury's magnetosphere.…”

Section: Particle Energization In Mercury's Magnetospherementioning

confidence: 99%

Review of Mercury’s dynamic magnetosphere: Post-MESSENGER era and comparative magnetospheres

Sun

Dewey

Aizawa

et al. 2021

Sci. China Earth Sci.

View full text Add to dashboard Cite

This review paper summarizes the research of Mercury’s magnetosphere in the Post-MESSENGER era and compares its dynamics to those in other planetary magnetospheres, especially to those in Earth’s magnetosphere. This review starts by introducing the planet Mercury, including its interplanetary environment, magnetosphere, exosphere, and conducting core. The frequent and intense magnetic reconnection on the dayside magnetopause, which is represented by the flux transfer event “shower”, is reviewed on how they depend on magnetosheath plasma β and magnetic shear angle across the magnetopause, following by how it contributes to the flux circulation and magnetosphere-surface-exosphere coupling. In the next, Mercury’s magnetosphere under extreme solar events, including the core induction and the reconnection erosion on the dayside magnetosphere, the responses of the nightside magnetosphere, are reviewed. Then, the dawn-dusk properties of the plasma sheet, including the features of the ions, the structure of the current sheet, and the dynamics of magnetic reconnection, are summarized. The last topic is devoted to the particle energization in Mercury’s magnetosphere, which includes the energization of the Kelvin-Helmholtz waves on the magnetopause boundaries, reconnection-generated magnetic structures, and the cross-tail electric field. In each chapter, the last section discusses the open questions related to each topic, which can be considered by the simulations and the future spacecraft mission. We end this paper by summarizing the future BepiColombo opportunities, which is a joint mission of ESA and JAXA and is en route to Mercury.

show abstract

“…Second, characteristics of electron PADs may implicate the electron acceleration/cooling mechanisms. For example, the pancake‐type PAD is believed to be a consequence of betatron acceleration, which is driven by the enhancement of magnetic field strength on both large and small scales (e.g., Fu et al, 2011; Fu, Khotyaintsev, et al, 2013; Fu, Xu, et al, 2019; Liu, Fu, Xu, Wang, et al, 2017; Liu, Fu, Cao, Xu, et al, 2017; Liu, Fu, Xu, Cao, et al, 2017); the cigar‐type PAD is suggested as a result of Fermi acceleration due to the shrinking of magnetic field lines (e.g., Fu et al, 2011; Lu et al, 2016; Liu, Fu, Xu, Wang, et al, 2017) or betatron cooling driven by the weakening of the local magnetic field (e.g., Fu, Khotyaintsev, et al, 2013; Liu, Liu, Xu, & Zhao, 2018); the isotropy type of PAD is thought as a result of the wave‐particle interactions (e.g., Fu, Khotyaintsev, Vaivads, André, Sergeev, et al, 2012) or the nonadiabatic electron motion along the strongly curved magnetic field lines (e.g., Delcourt et al, 2017); the butterfly type of PAD is suggested to be a combinational consequence of betatron cooling and magnetic mirror effect (e.g., Liu, Fu, Cao, Xu, et al, 2017); and the rolling‐pin distribution is thought as a result of the global‐scale Fermi acceleration together with local‐scale betatron acceleration (Liu, Fu, Xu, Cao, & Liu, 2017). Therefore, investigating the characteristics of PAD of suprathermal electrons can improve our understanding of electron dynamics in the Earth's magnetotail.…”

Section: Introductionmentioning

confidence: 99%

Electron Pitch‐Angle Distribution in Earth's Magnetotail: Pancake, Cigar, Isotropy, Butterfly, and Rolling‐Pin

Liu

et al. 2020

JGR Space Physics

View full text Add to dashboard Cite

Electron pitch-angle distributions, including isotropy, pancake, cigar, butterfly, and recently discovered rolling-pin distributions, are crucial to understanding electron dynamics in the magnetotail. However, occurrence rates of these distributions remain unclear. Here, for the first time, we reveal the occurrence rates of these distributions in the magnetotail by using Cluster data during 2001-2009, with special focus on the newly reported rolling-pin distribution. We find that percentages of these distributions are 44.7% (isotropy), 31.3% (pancake), 17.5% (cigar), 4.9% (rolling-pin), and 1.6% (butterfly), respectively. We find that in the XY GSM plane, occurrence rates of these PADs peak near:butterfly), respectively; and along the r direction, where r is the distance to the center of the Earth in the XY GSM plane, their occurrence rates peak near: −18 R E < r < −12 R E (isotropy), −20 R E < r < −12 R E (pancake), −16 R E < r < −10 R E (cigar), r ≈ −13 R E (rolling-pin), and −14 R E < r < −10 R E (butterfly), respectively. Such rates indicate that the rolling-pin and cigar distributions have similar occurrence rates, supporting previous studies suggesting that rolling-pin distributions arise from cigar distributions. All distributions have maximum occurrences near the equator but at different subregions. We cannot find any statistical correlation between magnetic structures and the rolling-pin distributions, different from previous studies suggesting a close connection between them.

show abstract

On the response of quasi-adiabatic particles to magnetotail reconfigurations

Cited by 5 publications

References 29 publications

Proton Properties in Mercury's Magnetotail: A Statistical Study

Proton Properties in Mercury's Magnetotail: A Statistical Study

Review of Mercury’s dynamic magnetosphere: Post-MESSENGER era and comparative magnetospheres

Electron Pitch‐Angle Distribution in Earth's Magnetotail: Pancake, Cigar, Isotropy, Butterfly, and Rolling‐Pin

Contact Info

Product

Resources

About