Dynamics of magnetospheric ion Composition as observed by the GEOS mass spectrometer

Geiss, J.; Balsiger, H.; Eberhardt, P.; Walker, Hunter; Weber, Loris; Young, D. T.; Rosenbauer, H.

doi:10.1007/bf00223940

Cited by 174 publications

(73 citation statements)

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“…Several studies during the 1970s and the 1980s (Geiss et al, 1978;Peterson et al, 1981;Strangeway and Johnson, 1984) demonstrated that magnetospheric hot plasma contains a significant component of O + . However, the conclusive composition measurements covering the whole energy range important for the stormtime ring current, were performed by the AMPTE mission.…”

Section: Sources Of Ring Current Particlesmentioning

confidence: 98%

Ring Current Dynamics

Daglis

2006

Space Sci Rev

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This chapter reviews the current understanding of ring current dynamics. The terrestrial ring current is an electric current flowing toroidally around the Earth, centered at the equatorial plane and at altitudes of ∼10,000 to 60,000 km. Enhancements in this current are responsible for global decreases in the Earth's surface magnetic field, which have been used to define geomagnetic storms. Intense geospace magnetic storms have severe effects on technological systems, such as disturbances or even permanent damage of telecommunication and navigation satellites, telecommunication cables, and power grids. The main carriers of the ring current are positive ions, with energies from ∼1 keV to a few hundred keV, which are trapped by the geomagnetic field and undergo an azimuthal drift. The ring current is formed by the injection of ions originating in the solar wind and the terrestrial ionosphere into the inner magnetosphere. The injection process involves electric fields, associated with enhanced magnetospheric convection and/or magnetospheric substorms. The quiescent ring current is carried mainly by protons of predominantly solar wind origin, while active processes in geospace tend to increase the abundance (both absolute and relative) of O + ions, which are of ionospheric origin. During intense geospace magnetic storms, the O + abundance increases dramatically. This increase has been observed to occur concurrently with the rapid intensification of the ring current in the storm main phase and to result in O + dominance around storm maximum. This compositional change can affect several dynamic processes, such as species-and energy-dependent charge-exchange and wave-particle scattering loss.

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Section: Sources Of Ring Current Particlesmentioning

confidence: 98%

Ring Current Dynamics

Daglis

2006

Space Sci Rev

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“…What is surprising, however, is that upflowing ions contains substantial (and sometimes dominant) proportions of oxygen (see reviews in: Prange, 1978;Young etal., 1982), indicating the ionospheric origin of these upflowing ions found at satellite altitude. This is a key fact which forces us to revise our concept of the origins of plasmas in the near-Earth neighborhood because these upflowing ionospheric ions can reach the equatorial regions of auroral flux tubes (e.g., Horwitz, 1980;Geiss et al, 1978, Young, 1979Balsiger et al, 1980;Kaye et al, 1981) and be convected elsewhere subsequently (Lundin et al, 1981a, b).…”

Section: Ionospheric Plasma Sourcementioning

confidence: 99%

Auroral plasmas in the evening sector: Satellite observations and theoretical interpretations

et al. 1983

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Observations and theoretical interpretations of auroral plasma distributions have led to a spectacular advance, in the latter part of the 1970's, in understanding the formation of auroral arcs and the role that the aurora plays in the coupling between the magnetosphere and ionosphere in the evening sector.The key to this understanding is the verification of the existence of electric field components parallel to the magnetic field. The parallel electric field accelerates electrons downwards to form the aurora. At the same time, it accelerates ionospheric ions upwards to provide the magnetosphere with a new source of hot plasma. The auroral plasma observations indicate that the hot auroral plasmas behave according to laws of adiabatic motion coexisting with a measure of plasma turbulence. Theoretical considerations of auroral arc formation are in accord with this plasma characteristic.

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“…It flew aboard the European Space Agency satellite GEOS-1 in 1977 to altitudes of the geostationary orbit (6.6 RE where RE is the Earth's radius). Significant abundances of ionospheric ions in the outer magneto sphere were expected, but the discovery by the Bern group [3] that the ionosphere is a source for the magnetospheric plasma of comparable importance to the solar wind came as a big surprise. The ionospheric source sometimes dominates completely, as is shown Fig.…”

Section: An Historic Breakthroughmentioning

confidence: 99%