Rice Convection Model simulation of the substorm‐associated injection of an observed plasma bubble into the inner magnetosphere: 2. Simulation results

Zhang, J.-C.; Wolf, R. A.; Spiro, R. W.; Erickson, G. M.; Sazykin, S.; Toffoletto, F.; Yang, Jian

doi:10.1029/2009ja014131

Cited by 38 publications

(54 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Fejer et al [1990] proposed that the magnetic field reconfiguration of the magnetosphere due to a northward turning and the associated shrinkage of the polar cap may effectively prolong the overshielding time period. This effect has been confirmed by the Rice Convection Model (RCM) with a time-dependent magnetic field model [Sazykin, 2000;De Zeeuw et al, 2004;Maruyama et al, 2007;Zhang et al, 2009] and has been discussed with observations [Wei et al, 2008b[Wei et al, , 2009. On the other hand, the IMF northward turning is preferable to trigger substorms [Lyons et al, 1997], but the effect of substorm on overshielding, reduction [e.g., Huang et al, 2004;Huang, 2009] or enhancement [Wei et al, 2009;Zhang et al, 2009] is still a controversial issue.…”

Section: Introductionmentioning

confidence: 84%

“…Moreover, the overshielding signatures are observed even under stable southward IMF [Fejer et al, 2007;Ebihara et al, 2008], implying that IMF northward turning is not a necessary condition for overshielding. What has become clear is that IMF northward turning is the most effective factor to cause overshielding, but some other factors, either outside or inside the magnetosphere-ionosphere system, can also contribute to the overshielding effect, such as a large drop of solar wind dynamic pressure [e.g., Wei et al, 2008b] and substorm processes [e.g., Ebihara et al, 2008;Wei et al, 2009;Zhang et al, 2009].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The transition to overshielding after sharp and gradual interplanetary magnetic field northward turning

Wei

Wan

et al. 2011

J. Geophys. Res.

View full text Add to dashboard Cite

[1] Overshielding is referred to a shielding status, during which the dawnward shielding electric field dominates over the duskward penetration electric field in the inner magnetosphere, typically appearing when the interplanetary magnetic field (IMF) suddenly turns northward after a prolonged southward orientation. It is expected that the transition to overshielding after IMF northward turning can be affected by the shape of northward turning (sharp or gradual). Moreover, the initial shielding status (undershielding or goodshielding) prior to the transition may also have influence on the transition. Here we analyze two groups of cases, in which the transitions appear after sharp (duration less than 5 min) and gradual (duration more than 30 min) northward turning. Each group includes two cases, in which the transition initiated from undershielding and goodshielding. These cases show that (1) the beginning of the transition to overshielding coincides with sharp IMF northward turning but appears in the midst of gradual IMF northward turning; (2) the transition from goodshielding to overshielding is always associated with convection electric field drop and/or polar cap shrinkage, regardless of the shape of IMF northward turning; and (3) the typical solar wind condition in which the IMF suddenly turns northward after a prolonged southward orientation is neither a necessary condition nor a sufficient condition for overshielding. Furthermore, we will discuss the effect of substorm processes on overshielding.

show abstract

Section: Introductionmentioning

confidence: 84%

Section: Introductionmentioning

confidence: 99%

The transition to overshielding after sharp and gradual interplanetary magnetic field northward turning

Wei

Wan

et al. 2011

J. Geophys. Res.

View full text Add to dashboard Cite

show abstract

“…Note that the model results indicate that the inductive electric fields dominate when Geotail observed fast earthward flow. This is partly due to the fact that the peak of the model's potential electric field occurs slightly west of Geotail, as illustrated in Figure 2 of Zhang et al [2009]. The series of spikes in the observed V x and E y probably represent the effects of waves bouncing back and forth between the middle plasma sheet and the high-magnetic field region near the Earth.…”

Section: Electric Fields and Flowsmentioning

confidence: 95%

Rice Convection Model simulation of the substorm‐associated injection of an observed bubble into the inner magnetosphere: 1. Magnetic field and other inputs

et al. 2009

Self Cite

View full text Add to dashboard Cite

[1] The objective of this work is a realistic Rice Convection Model (RCM) simulation of a modest substorm that occurred on 22 July 1998 and was observed by the Geotail spacecraft in the inner plasma sheet. It represents the first time the RCM has been used for detailed modeling of an inner magnetospheric event using data from a spacecraft in the inner plasma sheet beyond geosynchronous orbit to drive the model's time-dependent boundary conditions. Since this represents a substantial departure from past practice, we present, in this paper, a detailed account of how model inputs are determined. An accompanying paper presents results and interpretations. Model inputs are adjusted to achieve approximate consistency between RCM-computed values and measurements by Geotail, which was within the RCM modeling region near X GSM = À9 R E , Y GSM = 0. To represent the magnetic field in the growth phase, we utilize a Tsyganenko (1989) statistical magnetic field model, adjusted to agree with Geotail-measured pressure and magnetic field in a new way using analytic solutions to the linear Grad-Shafranov equation. The magnetic field during the expansion phase is represented by adding a substorm current wedge using formulas developed by Tsyganenko. Induction electric fields play a central role in these simulations, because they are large in the vicinity of the substorm injection region. We provide a detailed description of how induction electric fields are included in the RCM as well as a prescription of the electromagnetic gauge condition used in the code.

show abstract

“…As shown by Birn et al [2004], flow vortices appear at the flanks of the bubble, twisting the magnetic field, and causing a downward (upward) field-aligned current at the dawnside (duskside) flank, and forming a local wedge like current system [e.g., Wolf, 1993, 1999;Sergeev et al, 1996a;Birn and Hesse, 1996;Birn et al, 1999Birn et al, , 2004Snekvik et al, 2007;Zhang et al, 2009]. A return plasma flow may occur at the flanks of the bubble, and the corresponding shear against the plasma flow in the bubble main channel may also be involved in the generation of the field-aligned currents [e.g., Chen and Wolf, 1999;Kauristie et al, 2000;Birn et al, 2004;Keiling et al, 2009;Ohtani et al, 2009;Walsh et al, 2009;Panov et al, 2010aPanov et al, , 2010bBirn et al, 2011;Ge et al, 2011;Pitkänen et al, 2011].…”

Section: Introductionmentioning

confidence: 99%

Energy conversion regions as observed by Cluster in the plasma sheet

et al. 2011

View full text Add to dashboard Cite

[1] In this article we present a review of recent studies of observations of localized energy conversion regions (ECRs) observed by Cluster in the plasma sheet at altitudes of 15-20R E . By examining variations in the power density, E · J, where E is the electric field and J is the current density, we show that the plasma sheet exhibits a high level of fine structure. Approximately three times as many concentrated load regions (CLRs) (E · J > 0) as concentrated generator regions (CGRs) (E · J < 0) are identified, confirming the average load character of the plasma sheet. Some ECRs are found to relate to auroral activity. While ECRs are relevant for the energy conversion between the electromagnetic field and the particles, bursty bulk flows (BBFs) play a central role for the energy transfer in the plasma sheet. We show that ECRs and BBFs are likely to be related, although details of this relationship are yet to be explored. The plasma sheet energy conversion increases rather simultaneously with increasing geomagnetic activity in both CLRs and CGRs. Consistent with large-scale magnetotail simulations, most of the observed ECRs appear to be rather stationary in space but varying in time. We estimate that the ECR lifetime and scale size are a few minutes and a few R E , respectively. It is conceivable that ECRs rise and vanish locally in significant regions of the plasma sheet, possibly oscillating between load and generator character, while some energy is transmitted as Poynting flux to the ionosphere.

show abstract

Rice Convection Model simulation of the substorm‐associated injection of an observed plasma bubble into the inner magnetosphere: 2. Simulation results

Cited by 38 publications

References 47 publications

The transition to overshielding after sharp and gradual interplanetary magnetic field northward turning

The transition to overshielding after sharp and gradual interplanetary magnetic field northward turning

Rice Convection Model simulation of the substorm‐associated injection of an observed bubble into the inner magnetosphere: 1. Magnetic field and other inputs

Energy conversion regions as observed by Cluster in the plasma sheet

Contact Info

Product

Resources

About