Observations of whistler mode waves with nonlinear parallel electric fields near the dayside magnetic reconnection separatrix by the Magnetospheric Multiscale mission

Wilder, F. D.; Ergun, R. E.; Goodrich, K.; Goldman, M. V.; Newman, D. L.; Malaspina, D.; Jaynes, A. N.; Schwartz, Steven J.; Trattner, K. J.; Burch, J. L.; Argall, M. R.; Torbert, R. B.; Lindqvist, Per‐Arne; Marklund, Göran; Contel, O. Le; Mirioni, Laurent; Khotyaintsev, Yu. V.; Strangeway, R. J.; Russell, C. T.; Pollock, C. J.; Giles, B. L.; Plaschke, Ferdinand; Magnes, W.; Eriksson, S.; Stawarz, J. E.; Sturner, A. P.; Holmes, J. C.

doi:10.1002/2016gl069473

Cited by 68 publications

(102 citation statements)

References 49 publications

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“…There are instances of narrowband wave power between 1,000 and 2,000 Hz as MMS4 briefly passes out of the boundary layers and into the magnetosphere that tracks with f ce /2 (e.g., at 06:40:05–20 UT). This type of emission has been recently observed with MMS near reconnection sites by Le Contel et al () and Wilder et al () and indicates close proximity to the source region of this possible whistler mode‐type wave. There is also a clear band of wave power tracking with f lh at 06:39:15–25 UT.…”

Section: Encounters With the Llbl Separatrixmentioning

confidence: 97%

Magnetospheric Ion Evolution Across the Low‐Latitude Boundary Layer Separatrix

et al. 2017

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On 20 September 2015, the Magnetospheric Multiscale (MMS) spacecraft crossed the dusk magnetopause after a compression of the magnetosphere. Enhanced densities and fluxes of both colder (≤10 eV) and hotter (>1 keV) magnetospheric and magnetosheath heavy ion species were observed reaching the magnetopause. The evolution of the velocity distributions for H+, He+, and O+ measured by the Hot Plasma Composition Analyzer on MMS during this magnetopause crossing is presented. In particular, this study focuses on the changes in the species' distribution functions as MMS passes from the magnetosphere through the electron edge of the low‐latitude boundary layer (LLBL) separatrix and then into the LLBL. Two types of processes are suggested to play a role in the heating of colder magnetospheric ions across the LLBL separatrix in the region between the separatrix and the electron and ion edges of the LLBL. One mechanism leads to the formation and enhancement of ring distributions in this layer of the LLBL as the magnetospheric ions propagate across the separatrix. A second mechanism leading first to perpendicular heating and then to parallel heating of colder protons may arise from a possible two‐stream instability as the magnetospheric ions first encounter the warmer magnetosheath electrons in the electron layer and then the warmer magnetosheath ions between the electron and ion edges of the LLBL separatrix. Perpendicular heating of He+ and O+ is seen more so in the main reconnection exhaust, due to nonadiabatic behavior of these ions as they are accelerated up to the bulk flow speed.

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Section: Encounters With the Llbl Separatrixmentioning

confidence: 97%

Magnetospheric Ion Evolution Across the Low‐Latitude Boundary Layer Separatrix

et al. 2017

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“…For instance, Deng and Matsumoto [2001] reported a good mediation of reconnection rate by whistlers at the Earth's magnetopause, using the Geotail data; Wei et al [2007] observed whistlers prior to reconnection and enhancement of whistlers during reconnection in the Earth's magnetotail, using the Cluster data; Huang et al [2016] presented two types of whistlers during Hall magnetic reconnection, using the Cluster data; Graham et al [2016], Le Contel et al [2016a], and Wilder et al [2016] observed strong whistler emissions in the separatrix region, using the Magnetospheric Multiscale (MMS) data; Khotyaintsev et al [2016] reported whistlers in the outflow region, using MMS data. For instance, Deng and Matsumoto [2001] reported a good mediation of reconnection rate by whistlers at the Earth's magnetopause, using the Geotail data; Wei et al [2007] observed whistlers prior to reconnection and enhancement of whistlers during reconnection in the Earth's magnetotail, using the Cluster data; Huang et al [2016] presented two types of whistlers during Hall magnetic reconnection, using the Cluster data; Graham et al [2016], Le Contel et al [2016a], and Wilder et al [2016] observed strong whistler emissions in the separatrix region, using the Magnetospheric Multiscale (MMS) data; Khotyaintsev et al [2016] reported whistlers in the outflow region, using MMS data.…”

Section: Introductionmentioning

confidence: 99%

MMS observations of whistler waves in electron diffusion region

Cao

et al. 2017

Geophysical Research Letters

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Whistler waves that can produce anomalous resistivity by affecting electrons' motion have been suggested as one of the mechanisms responsible for magnetic reconnection in the electron diffusion region (EDR). Such type of waves, however, has rarely been observed inside the EDR so far. In this study, we report such an observation by Magnetospheric Multiscale (MMS) mission. We find large‐amplitude whistler waves propagating away from the X line with a very small wave‐normal angle. These waves are probably generated by the perpendicular temperature anisotropy of the ~300 eV electrons inside the EDR, according to our analysis of dispersion relation and cyclotron resonance condition; they significantly affect the electron‐scale dynamics of magnetic reconnection and thus support previous simulations.

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“…Thus, we exclude unstructured whistler mode hiss [Thorne et al, 1973;Bortnik et al, 2009;Li et al, 2012] and other types of whistler mode emission known to be generated at different locations in the magnetosphere, like at high latitudes on the dayside on compressed auroral field lines [Stenberg et al, 2005;Vaivads et al, 2007], or in the magnetotail in connection with dipolarization fronts Deng et al, 2010;Breuillard et al, 2016], or in the separatrix regions of magnetic reconnection sites at the dayside magnetopause [Øieroset et al, 2014;Graham et al, 2016;Le Contel et al, 2016;Wilder et al, 2016]. Thus, we exclude unstructured whistler mode hiss [Thorne et al, 1973;Bortnik et al, 2009;Li et al, 2012] and other types of whistler mode emission known to be generated at different locations in the magnetosphere, like at high latitudes on the dayside on compressed auroral field lines [Stenberg et al, 2005;Vaivads et al, 2007], or in the magnetotail in connection with dipolarization fronts Deng et al, 2010;Breuillard et al, 2016], or in the separatrix regions of magnetic reconnection sites at the dayside magnetopause [Øieroset et al, 2014;Graham et al, 2016;Le Contel et al, 2016;Wilder et al, 2016].…”

Section: Introductionmentioning

confidence: 99%

Poynting vector and wave vector directions of equatorial chorus

et al. 2016

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We present new results on wave vectors and Poynting vectors of chorus rising and falling tones on the basis of 6 years of THEMIS (Time History of Events and Macroscale Interactions during Substorms) observations. The majority of wave vectors is closely aligned with the direction of the ambient magnetic field (B0). Oblique wave vectors are confined to the magnetic meridional plane, pointing away from Earth. Poynting vectors are found to be almost parallel to B0. We show, for the first time, that slightly oblique Poynting vectors are directed away from Earth for rising tones and toward Earth for falling tones. For the majority of lower band chorus elements, the mutual orientation between Poynting vectors and wave vectors can be explained by whistler mode dispersion in a homogeneous collisionless cold plasma. Upper band chorus seems to require inclusion of collisional processes or taking into account azimuthal anisotropies in the propagation medium. The latitudinal extension of the equatorial source region can be limited to ±6∘ around the B0 minimum or approximately ±5000 km along magnetic field lines. We find increasing Poynting flux and focusing of Poynting vectors on the B0 direction with increasing latitude. Also, wave vectors become most often more field aligned. A smaller group of chorus generated with very oblique wave normals tends to stay close to the whistler mode resonance cone. This suggests that close to the equatorial source region (within ∼20∘ latitude), a wave guidance mechanism is relevant, for example, in ducts of depleted or enhanced plasma density.

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Observations of whistler mode waves with nonlinear parallel electric fields near the dayside magnetic reconnection separatrix by the Magnetospheric Multiscale mission

Cited by 68 publications

References 49 publications

Magnetospheric Ion Evolution Across the Low‐Latitude Boundary Layer Separatrix

Magnetospheric Ion Evolution Across the Low‐Latitude Boundary Layer Separatrix

MMS observations of whistler waves in electron diffusion region

Poynting vector and wave vector directions of equatorial chorus

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