On the role of pressure and flow perturbations around dipolarizing flux bundles

Liu, Jiang; Angelopoulos, V.; Zhou, X.‐Z.; Yao, Zhonghua

doi:10.1002/2013ja019256

Cited by 73 publications

(142 citation statements)

References 69 publications

Supporting

Mentioning

129

Contrasting

Order By: Relevance

“…Our results show that the occurrence rate of the DFs is larger on the dusk side of the plasma sheet than on the dawn side and the maximum occurrence rate occurs in the central plasma sheet, which is in agreement with the findings of Fu et al (2012a) and Liu et al (2013b). The maximum occurrence rate is 15.3 events per day in the XY plane, much higher than that of Fu et al (2012a), who reported values of 6.2 per day.…”

Section: Discussionsupporting

confidence: 91%

“…The dawn-dusk scale of DFs is ∼ 3 R E (Liu et al, 2013b), therefore, the spatial bin size in the XY plane is chosen to be 3 R E . We use all data with B XY /B Lobe < 0.8 and DF events observed by C1-4 satellites to determine the occurrence rate of the DFs.…”

Section: Statistical Resultsmentioning

confidence: 99%

“…Observations show that the typical scale of DFs in the dawn-dusk direction is ∼ 3 R E (Liu et al, 2013b;Huang et al, 2015). We assume that the DF propagates only in the X direction and the scale of the DF in the dawn-dusk direction is 3 R E ; thus, a satellite located at Y = 0 could observe the DF with the central line located between Y = −1.5 and 1.5 R E .…”

Section: Discussionmentioning

confidence: 99%

“…The typical length scales of fast flows are 2-3 R E in the dawn-dusk direction and 1.5-2 R E in the north-south direction (Nakamura et al, 2004). Liu et al (2013b) statistically found that the length scale of DFs in the dawn-dusk direction is about 3 R E .…”

Section: Introductionmentioning

confidence: 90%

See 3 more Smart Citations

Occurrence rate of dipolarization fronts in the plasma sheet: Cluster observations

et al. 2017

View full text Add to dashboard Cite

Abstract. We investigate the occurrence rate of dipolarization fronts (DFs) in the plasma sheet by taking full advantage of all four Cluster satellites (C1-4) from years 2001 to 2009. In total, we select 466 joint-observation DF events, in which 318, 282, 254, and 236 DFs are observed by C1, C2, C3, and C4, respectively. Our findings are as follows: (1) the maximum occurrence rate is ∼ 15.3 events per day at X ∼ 15 R E in the XY plane, and the average occurrence rate is ∼ 5.4 events per day over the whole observation period; (2) the occurrence rate on the dusk side of the plasma sheet is larger and decreases with increasing B XY /B Lobe ; (3) the occurrence rate within |Y | < 6 R E increases gradually from X ≈ −19 to −15 R E and then decreases from X ≈ −15 to −10 R E ; (4) the occurrence rate when AE > 200 nT is much larger than that when AE < 200 nT, indicating that DFs preferentially occur during high geomagnetic activity. The magnetic pileup and earthward and duskward ion flows could contribute to the increases in the occurrence rate from X ≈ −19 to −15 R E . We suggest that both geomagnetic activity and multiple DFs contribute to the high occurrence rate of the DFs. In addition, the finite length of the DF in the dawn-dusk direction can affect the chance that a satellite observes the DF.

show abstract

Section: Discussionsupporting

confidence: 91%

Section: Statistical Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 90%

See 2 more Smart Citations

Occurrence rate of dipolarization fronts in the plasma sheet: Cluster observations

et al. 2017

View full text Add to dashboard Cite

show abstract

“…The current disruption started at the leading edge of the flow, as a sharp dipolarization front (DF) with a magnetic dip ahead of the front layer. The magnetic dip current, which is of Region 2 sense, has been studied recently [Liu et al, 2013a[Liu et al, , 2013bYao et al, 2013b;Sun et al, 2013]. Those studies presented the FAC features ahead of the DF, while this paper has studied the cross-tail current density evolution ahead of earthward flow.…”

Section: Discussionmentioning

confidence: 99%

Current reduction in a pseudo‐breakup event: THEMIS observations

Yao

Owen³

et al. 2014

JGR Space Physics

Self Cite

View full text Add to dashboard Cite

Pseudo-breakup events are thought to be generated by the same physical processes as substorms. This paper reports on the cross-tail current reduction in an isolated pseudo-breakup observed by three of the THEMIS probes (THEMIS A (THA), THEMIS D (THD), and THEMIS E (THE)) on 22 March 2010. During this pseudo-breakup, several localized auroral intensifications were seen by ground-based observatories. Using the unique spatial configuration of the three THEMIS probes, we have estimated the inertial and diamagnetic currents in the near-Earth plasma sheet associated with flow braking and diversion. We found the diamagnetic current to be the major contributor to the current reduction in this pseudo-breakup event. During flow braking, the plasma pressure was reinforced, and a weak electrojet and an auroral intensification appeared. After flow braking/diversion, the electrojet was enhanced, and a new auroral intensification was seen. The peak current intensity of the electrojet estimated from ground-based magnetometers,~0.7 × 10 5 A, was about 1 order of magnitude lower than that in a typical substorm. We suggest that this pseudo-breakup event involved two dynamical processes: a current-reduction associated with plasma compression ahead of the earthward flow and a current-disruption related to the flow braking/diversion. Both processes are closely connected to the fundamental interaction between fast flows, the near-Earth ambient plasma, and the magnetic field.

show abstract

Current structures associated with dipolarization fronts

Yao

Sun

et al. 2013

JGR Space Physics

Self Cite

View full text Add to dashboard Cite

[1] Recently, observational results on currents around the dipolarization fronts (DFs) of earthward flow bursts have attracted much research attention. These currents are found to have close association with substorm intensifications. This paper devotes to further study of the current system ahead and within the DFs with high-resolution magnetic field measurements from Cluster constellation in 2003. The separation of four spacecraft is much smaller than the scales of spatial structures ahead and within the DF layer so that the currents can be reliably obtained. Based on features of the magnetic field variations prior to the fronts, we categorized the DFs into two types: DFs with magnetic dips immediate ahead of the fronts (type I) and DFs without magnetic dips (type II). For type I DFs, it is found that dawnward currents along the DFs exist in the dip region; duskward currents exist within the fronts. Furthermore, the dawnward currents in the dip region are found to be mainly parallel to the local magnetic field with a spatial scale of~1000 km, whereas the duskward currents within the fronts have both significant parallel and perpendicular components. On the other hand, for type II DFs, only significant duskward and mainly perpendicular currents show up within the fronts; no dawnward currents exist ahead of DFs. The dawnward and mainly parallel current in the type I DFs is important in the current coupling process between magnetosphere and ionosphere and may lead to local current disruptions for substorm initiations.

show abstract

On the role of pressure and flow perturbations around dipolarizing flux bundles

Cited by 73 publications

References 69 publications

Occurrence rate of dipolarization fronts in the plasma sheet: Cluster observations

Occurrence rate of dipolarization fronts in the plasma sheet: Cluster observations

Current reduction in a pseudo‐breakup event: THEMIS observations

Current structures associated with dipolarization fronts

Contact Info

Product

Resources

About