Electric Fields and Magnetic Fields in the Plasmasphere: A Perspective From CLUSTER and IMAGE

Matsui, H.; Foster, J. C.; Carpenter, D. L.; Dandouras, I.; Darrouzet, F.; Keyser, Johan De; Gallagher, D. L.; Goldstein, J.; Puhl-Quinn, P.; Vallat, C.

doi:10.1007/s11214-008-9471-8

Cited by 6 publications

(5 citation statements)

References 109 publications

(139 reference statements)

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“…In addition, there is an eastward drift channel in the midnight-morning sector, which is also consistent with the statistical patterns of SAPS [Foster and Vo, 2002]. Same SAPS fields are applied in both the northern and southern hemispheres as observations have shown that there is almost perfect mapping of SAPS electric field between the conjugate hemispheres [Anderson et al, 2001;Puhl-Quinn et al, 2007;Mishin and Puhl-Quinn, 2007;Matsui et al, 2009].…”

Section: The Saps-tiegcmsupporting

confidence: 76%

“…They are found to be confined in a latitudinally very narrow (∼1°–2°) region and coincide with the ionospheric footprint of the plasmapause [ Smidy et al , 1977; Anderson et al , 2001] and the location of the middle latitude ionospheric F region plasma density trough [ Anderson et al , 1991]. Later, Yeh et al [1991] and Foster and Vo [2002] used observations by the Millstone incoherent scattering radar to show that subauroral sunward plasma drifts can occur over a wider latitude region and often contain narrower and more intense PJ/SAIDs during geomagnetically active periods [ Matsui et al , 2009, and references therein]. Foster and Burke [2002] then proposed to use the term Subauroral Polarization Stream (SAPS) to include all observations of subauroral plasma flows and electric fields equatorward of the regular high latitude evening convection cell and diffuse aurora [ Oksavik et al , 2006; Baker et al , 2007].…”

Section: Introductionmentioning

confidence: 99%

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Thermosphere and ionosphere response to subauroral polarization streams (SAPS): Model simulations

Wang¹,

Talaat²,

Burns³

et al. 2012

J. Geophys. Res.

148

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[1] An empirical model of subauroral polarization streams (SAPS) has been incorporated into the Thermosphere Ionosphere Electrodynamics General Circulation Model (TIEGCM). This SAPS driven TIEGCM is used to simulate the effect of SAPS on the global thermosphere and ionosphere during a moderate geomagnetically active period between day of year (DOY) 329 and 333 in 2008. Model results show: (1) SAPS caused an increase in global thermospheric temperature which became stronger with time. This neutral temperature increase was more significant in subauroral and auroral regions. Joule heating by the SAPS and the redistribution of this heat by dynamic processes were the primary mechanisms for the simulated global neutral temperature changes. (2) In the SAPS driven TIEGCM, the strong ion drag effect in the subauroral SAPS channel drove large changes in thermospheric winds. Zonal neutral winds had either an extra, separate channel of westward flow in the subauroral region in the afternoon-midnight sector or a broad westward wind jet that merged with the regular duskside auroral westward zonal neutral wind driven by the high latitude convection pattern. The exact latitudinal profile of the zonal winds depended on local time. (3) The response of neutral temperature and wind to SAPS was more significant at higher altitudes and exhibited seasonal/hemispheric asymmetry. (4) The heating to the thermosphere by SAPS also resulted in changes in thermospheric composition with upwelling of molecular rich air in subauroral and auroral regions and downwelling of atomic oxygen rich air at other latitudes. These changes in thermospheric composition contributed to the deeper and more extended ionospheric electron density depletions in subauroral middle latitude regions, as well as electron density increases along the equatorward edge of the SAPS channel in the afternoon sector.

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Section: The Saps-tiegcmsupporting

confidence: 76%

Section: Introductionmentioning

confidence: 99%

Thermosphere and ionosphere response to subauroral polarization streams (SAPS): Model simulations

Wang¹,

Talaat²,

Burns³

et al. 2012

J. Geophys. Res.

148

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“…Figure exemplifies meridional electric fields in the dipole meridian system (DMS) from (Figure a) C1 and DMSP F16 on 8 April 2004 and (Figure b) C1, DMSP F14, and Polar on 18 March 2002 [cf. PQ07, Figure and Matsui et al , , Figure ]. Here + Y dms points eastward, + Z dms is along magnetic north, and X dms − Z dms is the meridional plane at ≈21:50 MLT (8 April 2004) and at 23:00 MLT (18 March 2002).…”

Section: Near‒equatorial Substorm Said Eventsmentioning

confidence: 93%

Interaction of substorm injections with the subauroral geospace: 1. Multispacecraft observations of SAID

Mishin

2013

JGR Space Physics

201

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[1] Subauroral ion drifts (SAID) are the prominent feature of the active subauroral geospace, just earthward of the electron plasma sheet (PS) boundary in the premidnight sector. We explore magnetically conjugate satellite observations of substorm SAID near the magnetic equator and in the topside ionosphere confirming and expanding on our previous results. The SAID channels reside between the hot electron (PS/auroral) boundary at the plasmapause and the drop in the hot ion flux inside the plasmasphere. The overall features are inconsistent with the paradigm of voltage and current generators. Rather, they are explained in terms of a short circuiting of substorm-injected hot plasma jets over the plasmapause and formation of a turbulent plasmaspheric boundary layer. The short circuiting occurs when the cold plasma density exceeds a critical value of 5-10 cm -3 . As the polarization field at the front of the hot plasma jet is shorted out, the hot electrons are arrested, while the hot ions yet move inward. This provides a natural explanation of the long-known dispersionless auroral precipitation boundary. Enhanced plasma turbulence within the SAID channel provides anomalous circuit resistivity and magnetic diffusion, as with the well-documented plasmoid-magnetic barrier problem.

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“…The related electric field causes an erosion of the plasmasphere in the dusk sector driving sunward flowing plumes, and contributes to the dynamics of the PP (Goldstein et al, 2005;Brandt et al, 2005). These events are accompanied by Sub-Auroral Polarisation Streams (SAPS) (Goldstein et al, 2005;Matsui et al, 2009) at ionospheric altitudes.…”

Section: Published By Copernicus Publications On Behalf Of the Europementioning

confidence: 99%

New plasmapause model derived from CHAMP field-aligned current signatures

Heilig

Lühr

2013

Ann. Geophys.

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We introduce a new model for the plasmapause location in the equatorial plane. The determination of the L-shell bounding the plasmasphere is based on magnetic field observations made by the CHAMP satellite in the topside ionosphere. Related signals are medium-scale field-aligned currents (MSFAC) (some 10 km scale size). The mid-latitude boundary of these MSFACs is used for determining the plasmapause. We are presenting a procedure for detecting the MSFAC boundary. Reliable L-values are obtained on the night side, whenever the solar zenith angle is below 90°. This means, the boundary is not determined well in the 08:00 to 16:00 magnetic local time (MLT) sector. The radial distance of the boundary is closely controlled by the magnetic activity index Kp. Over the Kp range 0 to 9, the L-value varies from 6 to 2 R_E. Conversely, the dependence on solar flux is insignificant. For a fixed Kp level, the obtained L-values of the boundary form a ring on an MLT dial plot with a centre somewhat offset from the geomagnetic pole. This Kp and local time dependent feature is used for predicting the location of the MSFAC boundary at all MLTs based on a single L-value determination by CHAMP. We compared the location of the MSFAC boundary during the years 2001–2002 with the L-value of the plasmapause, determined from in situ observations by the IMAGE spacecraft. The mean difference in radial distance is within a 1 R_E range for all local times and Kp values. The plasmapause is generally found earthward of the FAC boundary, except for the duskside. By considering this systematic displacement and by taking into account the diurnal variation and Kp-dependence of the residuals, we are able to construct an empirical model of the plasmapause location that is based on MSFAC measurements from CHAMP. Our new model PPCH-2012 agrees with IMAGE in situ observations within a standard deviation of 0.79 R_E

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Electric Fields and Magnetic Fields in the Plasmasphere: A Perspective From CLUSTER and IMAGE

Cited by 6 publications

References 109 publications

Thermosphere and ionosphere response to subauroral polarization streams (SAPS): Model simulations

Thermosphere and ionosphere response to subauroral polarization streams (SAPS): Model simulations

Interaction of substorm injections with the subauroral geospace: 1. Multispacecraft observations of SAID

New plasmapause model derived from CHAMP field-aligned current signatures

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