Oxygen energization by localized perpendicular electric fields at the cusp boundary

Lindstedt, T.; Khotyaintsev, Yuri V.; Vaivads, A.; André, Mats; Nilsson, Hans; Waara, Martin

doi:10.1029/2010gl043117

Cited by 18 publications

(24 citation statements)

References 33 publications

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“…Spatial gradients of E can energize particles if ∇E > qB 2 /m [Cole, 1976;Lindstedt et al, 2010], where q is the charge of the particle and m is its mass. Spatial gradients of E can energize particles if ∇E > qB 2 /m [Cole, 1976;Lindstedt et al, 2010], where q is the charge of the particle and m is its mass.…”

Section: Discussionmentioning

confidence: 99%

Cold ion heating at the dayside magnetopause during magnetic reconnection

Toledo‐Redondo

André

Vaivads

et al. 2016

Geophysical Research Letters

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Cold ions of ionospheric origin are known to be present in the magnetospheric side of the Earth's magnetopause. They can be very abundant, with densities up to 100 cm−3. These cold ions can mass load the magnetosphere, changing global parameters of magnetic reconnection, like the Alfvén speed or the reconnection rate. In addition they introduce a new length scale related to their gyroradius and kinetic effects which must be accounted for. We report in situ observations of cold ion heating in the separatrix owing to time and space fluctuations of the electric field. When this occurs, the cold ions are preheated before crossing the Hall electric field barrier. However, when this mechanism is not present cold ions can be observed well inside the reconnection exhaust. Our observations suggest that the perpendicular cold ion heating is stronger close to the X line owing to waves and electric field gradients linked to the reconnection process.

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Section: Discussionmentioning

confidence: 99%

Cold ion heating at the dayside magnetopause during magnetic reconnection

Toledo‐Redondo

André

Vaivads

et al. 2016

Geophysical Research Letters

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“…An example, in which O + was accelerated at the cusp/lobe boundary by an enhanced perpendicular electric field at the boundary, was shown by Lindstedt et al . []. Takada et al .…”

Section: Discussionmentioning

confidence: 99%

Acceleration of O⁺ from the cusp to the plasma sheet

et al. 2015

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Heavy ions from the ionosphere that are accelerated in the cusp/cleft have been identified as a direct source for the hot plasma in the plasma sheet. However, the details of the acceleration and transport that transforms the originally cold ions into the hot plasma sheet population are not fully understood. The polar orbit of the Cluster satellites covers the main transport path of the O + from the cusp to the plasma sheet, so Cluster is ideal for tracking its velocity changes. However, because the cusp outflow is dispersed according to its velocity as it is transported to the tail, due to the velocity filter effect, the observed changes in beam velocity over the Cluster orbit may simply be the result of the spacecraft accessing different spatial regions and not necessarily evidence of acceleration. Using the Cluster Ion Spectrometry/Composition Distribution Function instrument onboard Cluster, we compare the distribution function of streaming O + in the tail lobes with the initial distribution function observed over the cusp and reveal that the observations of energetic streaming O + in the lobes around À20 R E are predominantly due to the velocity filter effect during nonstorm times. During storm times, the cusp distribution is further accelerated. In the plasma sheet boundary layer, however, the average O + distribution function is above the upper range of the outflow distributions at the same velocity during both storm and nonstorm times, indicating that acceleration has taken place. Some of the velocity increase is in the direction perpendicular to the magnetic field, indicating that the E × B velocity is enhanced. However, there is also an increase in the parallel direction, which could be due to nonadiabatic acceleration at the boundary or wave heating.

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“…These simu- lations are of interest for reconnection in the magnetopause with O + ions [Pritchett, 2001;Lindstedt et al, 2010]. It has been found that the O + presence does not change the reconnected flux and therefore the pace magnetic reconnection occurs.…”

Section: Discussionmentioning

confidence: 99%

“…[15] To mimic the configuration of magnetic reconnection in the magnetopause, it is useful to add an uniform out-ofplane guide field in the initial Harris sheet equilibrium [Ricci et al, 2004;Swisdak et al, 2005;Lapenta et al, 2010;Lindstedt et al, 2010;Goldman et al, 2011]. A guide field, perpendicular to the X-Y plane, B g = B 0 is imposed in the initial magnetic configuration.…”

Section: The Effect Of a Guide Fieldmentioning

confidence: 99%

Kinetic simulations of magnetic reconnection in presence of a background O⁺population

et al. 2011

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[1] Particle-in-Cell simulations of magnetic reconnection with an H + current sheet and a mixed background plasma of H + and O + ions are completed using physical mass ratios. Four main results are shown. First, the O + presence slightly decreases the reconnection rate and the magnetic reconnection evolution depends mainly on the lighter H + ion species in the presented simulations. Second, the Hall magnetic field is characterized by a two-scale structure in presence of O + ions: it reaches sharp peak values in a small area in proximity of the neutral line, and then decreases slowly over a large region. Third, the two background species initially separate in the outflow region because H + and O + ions are accelerated by different mechanisms occurring on different timescales and with different strengths. Fourth, the effect of a guide field on the O + dynamics is studied: the O + presence does not change the reconnected flux and all the characteristic features of guide field magnetic reconnection are still present. Moreover, the guide field introduces an O + circulation pattern between separatrices that enhances high O + density areas and depletes low O + density regions in proximity of the reconnection fronts. The importance and the validity of these results are finally discussed.

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Oxygen energization by localized perpendicular electric fields at the cusp boundary

Cited by 18 publications

References 33 publications

Cold ion heating at the dayside magnetopause during magnetic reconnection

Cold ion heating at the dayside magnetopause during magnetic reconnection

Acceleration of O⁺ from the cusp to the plasma sheet

Kinetic simulations of magnetic reconnection in presence of a background O⁺population

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Oxygen energization by localized perpendicular electric fields at the cusp boundary

Cited by 18 publications

References 33 publications

Cold ion heating at the dayside magnetopause during magnetic reconnection

Cold ion heating at the dayside magnetopause during magnetic reconnection

Acceleration of O+ from the cusp to the plasma sheet

Kinetic simulations of magnetic reconnection in presence of a background O+population

Contact Info

Product

Resources

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Acceleration of O⁺ from the cusp to the plasma sheet

Kinetic simulations of magnetic reconnection in presence of a background O⁺population