Magnetosheath filamentary structures formed by ion acceleration at the quasi‐parallel bow shock

Omidi, N.; Sibeck, D. G.; Gutynska, O.; Trattner, K. J.

doi:10.1002/2013ja019587

Cited by 48 publications

(80 citation statements)

References 78 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For small IMF cone angles, these structures can be observed in the quasi-perpendicular magnetosheath. Our spatial analysis of plasma structures occurrence in the magnetosheath confirms the concept of their formation and evolution proposed in hybrid simulations by Omidi et al [2014]. Associated Universities through a contract with NASA.…”

Section: Discussionsupporting

confidence: 83%

“…Global electromagnetic hybrid simulations [Omidi et al, 2014] suggest that magnetosheath filamentary structures are the field-aligned density and temperature structures that form at the quasi-parallel bow shock and extend into the quasi-parallel magnetosheath. For small IMF cone angles, these structures can be observed in the quasi-perpendicular magnetosheath.…”

Section: Discussionmentioning

confidence: 99%

“…We compare these observations with the results from 2.5-D global hybrid simulations [Omidi et al, 2014] which show the formation of field-aligned filamentary plasma structures in the magnetosheath and describe their properties.…”

Section: Introductionmentioning

confidence: 90%

“…In order to understand the nature of the enhanced density structures, we compare the observations with results from the global electromagnetic hybrid simulation presented by Omidi et al [2014]. According to these authors, field-aligned density and temperature structures in the magnetosheath form behind the quasi-parallel bow shock and convect into the quasi-parallel magnetosheath toward the magnetopause (Figure 7).…”

Section: Comparison With Simulationsmentioning

confidence: 99%

See 3 more Smart Citations

Magnetosheath plasma structures and their relation to foreshock processes

2015

Self Cite

View full text Add to dashboard Cite

We present simultaneous Time History of Events and Macroscale Interactions during Substormsobservations of plasma parameters upstream in the solar wind and downstream in the magnetosheath (MSH) from 2007 to 2008. We discuss the connection of foreshock (FSH) processes and magnetospheric disturbances to transmission mechanisms in the MSH. In 60% of the analyzed cases, the MSH was strongly influenced by the FSH. We analyze the results as a function of location, time scale, spatial orientation of the observed structures, and the prevailing interplanetary magnetic field (IMF) and solar wind plasma parameters. We find that plasma structures with density enhancement are mostly observed during radial IMF orientations and for small BN , the angle between the upstream magnetic field and the local bow shock normal; the observed structures are pressure balanced with strong anticorrelation between density and temperature; the scale size of the density fluctuations is about 0.4R E . We compare the observations with results from a 2.5-dimensional hybrid simulation to investigate the mechanisms by which the foreshock plasma structures are generated, propagate through the bow shock, and evolve.

show abstract

Section: Discussionsupporting

confidence: 83%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 90%

Section: Comparison With Simulationsmentioning

confidence: 99%

See 2 more Smart Citations

Magnetosheath plasma structures and their relation to foreshock processes

2015

Self Cite

View full text Add to dashboard Cite

show abstract

“…Therefore, it is plausible that during Alfvénic solar wind, the IMF directions change Figure 6. In addition to HFAs and FBs, there are other types of density or dynamic pressure perturbations created in association with the quasi-parallel bow shock, such as spontaneous HFAs [Zhang et al, 2013], magnetosheath filamentary structures [Omidi et al, 2014], transient flux enhancements or jets [e.g., Němeček et al, 1998;Hietala et al, 2012], or large-scale low-frequency electromagnetic wavefronts [Karimabadi et al, 2014]. But these perturbations can occur without IMF discontinuities.…”

Section: The Bow Shock Perturbationsmentioning

confidence: 99%

Dawn‐dusk asymmetry in bursty hot electron enhancements in the midtail magnetosheath

et al. 2015

View full text Add to dashboard Cite

Bursty (a few minutes) enhancements of hot electrons (1–10 keV) in the tail magnetosheath, which we name hot electron enhancements (HEEs), are sometimes observed. To understand the processes leading to HEEs, we have used 4 years of measurements from Acceleration Reconnection Turbulence and Electrodynamics of Moon's Interaction with the Sun mission to statistically investigate the dawn‐dusk asymmetry of HEEs in the midtail (x from −30 to −70 RE) magnetosheath and their correlations with the solar wind/interplanetary magnetic field (IMF) conditions. We find two strong dawn‐dusk asymmetries associated with HEEs: (1) they occur about 3 to 4 times more frequently on the dawnside. (2) Their fluxes on the dawnside are about twice as large as those on the duskside. The magnitudes of HEE fluxes are similar to those of the magnetosphere fluxes near the magnetopause, which are also a factor of 2 higher on the dawnside, indicating that the magnetosphere electrons are likely the source for HEEs and the cause for the HEE flux asymmetry. HEEs occur preferentially during higher solar wind speed, and the majority of HEEs are associated with sharp IMF direction changes and are accompanied by large and transient magnetosheath density changes. These correlations are stronger on the dawnside, suggesting that perturbations created near the quasi‐parallel bow shock, which is most of the time on the dawnside, associated with IMF discontinuities is a possible process leading to HEEs and could account for the higher HEE occurrence on the dawnside.

show abstract

Parametric dependencies of spontaneous hot flow anomalies

et al. 2014

Self Cite

View full text Add to dashboard Cite

Parametric dependencies of spontaneous hot flow anomalies at the quasi-parallel bow shock are investigated using global hybrid (kinetic ions and fluid electron) simulations with a variety of solar wind Mach numbers and directions of the interplanetary magnetic field (IMF). Simulations with solar wind Alfvénic Mach number of 3 and small IMF cone angles (with the flow velocity) show sporadic formation of spontaneous hot flow anomalies (SHFAs). Increasing the Mach number shows the formation of copious number of SHFAs whose properties are examined in this study. It is shown that the duration of SHFAs does not show much variation with Mach number indicating that their size generally increases with Mach number. Additionally, the level of solar wind deceleration associated with SHFAs increases with Mach number as does the core ion temperature. It is also found that the edges of SHFAs are associated with jumps in magnetic field that increase with shock Mach number. The results also show that the rate of SHFA formation increases with increasing Mach number. Simulations with IMF cone angle of 90°show that SHFAs form at the quasi-parallel bow shock provided the shock Alfvén Mach number is~>3. This shows that SHFAs may form at all cone angles.

show abstract

Magnetosheath filamentary structures formed by ion acceleration at the quasi‐parallel bow shock

Cited by 48 publications

References 78 publications

Magnetosheath plasma structures and their relation to foreshock processes

Magnetosheath plasma structures and their relation to foreshock processes

Dawn‐dusk asymmetry in bursty hot electron enhancements in the midtail magnetosheath

Parametric dependencies of spontaneous hot flow anomalies

Contact Info

Product

Resources

About