The ISEE-C Vector Helium Magnetometer

Frandsen, A. M. A.; Connor, B.; Amersfoort, J. Van; Smith, E. J.

doi:10.1109/tge.1978.294545

Cited by 166 publications

(53 citation statements)

References 5 publications

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“…We use data from 2 instruments on the spacecraft. The magnetic field data are taken from the JPL magnetometer [Frandsen et al, 1978] In this study the start and stop times are found to the nearest minute, and then divided into an integer number of 5-min periods. The average spacecraft position, plasma density, temperature, bulk flow speed and direction, and magnetic field strength and direction, were calculated for each of the 5-min plasma sheet intervals.…”

Section: Discussionmentioning

confidence: 99%

Observations of slow flows in the distant plasma sheet

Mist¹,

Owen²

1999

J. Geophys. Res.

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Abstract.A statistical analysis of the properties of the plasma sheet in the geomagnetic tail using the ISEE 3 deep-tail data set is undertaken. The observed plasma sheet properties are compared to predictions of two models of reconnection.The first model [Cowley, 1980;Cowley and Southwood, 1980] is based on the balance of stress between a cold plasma inflow and the magnetic tension of reconnected field lines at the current sheet. The second [Owen et al., 1991] makes an attempt to incorporate heating of the plasma sheet population into this class of model. We find that only 60% of all plasma sheet events show densities greater than that in the adjacent lobe, as would be expected on the basis of mass conservation in the reconnection models. In addition, comparison of the distribution of the predicted velocities with the observed velocities shows that for a significant proportion of events, neither reconnection model accurately predicts the observed flows. In fact, the plasma sheet is most often seen to be in a quasi-stagnant state. During periods of tailward convection, the heated model appears the more appropriate for describing plasma sheet flow due to reconnection. However, in the case of the heated (simple) model, at least 50% (60%) of tailward flows are observed at velocities well below the predictions. These events also have positive B z on average and may therefore be associated with the tailward transport of closed flux tubes. They are also associated with geomagnetically quiet times. Such events are seen at all distance between-60 and-240 R• in the plasma sheet. These results strongly support previous suggestions that even at large downtail distances, the observed plasma sheet flows are often driven by processes other than reconnection. While the models correctly predict a significant proportion of the flow speeds for tailward flows, the earthward flow events are not well described by either model. In summary, 40% of the data set cannot be described by the reconnection models due to mass conservation requirements, and at most only 50% of the tailward flow speeds are in agreement with the predictions of these models. As such, only 30% of tailward flow events are well described by the models presented here.

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Section: Discussionmentioning

confidence: 99%

Observations of slow flows in the distant plasma sheet

Mist¹,

Owen²

1999

J. Geophys. Res.

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“…In Figure 7 we have plotted the y component of B measured by the ISEE 3 magnetometer [Frandsen et al, 1978] during days 7 --99 of 1979. The interval spans more than three solar rotations, and a regular sector structure is present.…”

Section: Shorter Data Intervalsmentioning

confidence: 99%

Stationarity of magnetohydrodynamic fluctuations in the solar wind

Matthaeus¹,

Goldstein²

1982

J. Geophys. Res.

138

101

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“…To examine simultaneous wave and solar energetic particle events, we use the ISEE-3 1 AU data from the magnetometer instrument (Frandsen et al, 1978) and the Ultra Low Energy Wide Angle Telescope (ULEWAT) instrument . For the 3 He-rich events, we examine 8 of the examples previously published in Kahler et al (1985).…”

Section: Methods Of Analysesmentioning

confidence: 99%

Particle transport in <sup>3</Sup>He-rich events: wave-particle interactions and particle anisotropy measurements

et al. 2002

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Abstract. Energetic particles and MHD waves are studied using simultaneous ISEE-3 data to investigate particle propagation and scattering between the source near the Sun and 1 AU. 3 He-rich events are of particular interest because they are typically low intensity "scatter-free" events. The largest solar proton events are of interest because they have been postulated to generate their own waves through beam instabilities. For 3 He-rich events, simultaneous interplanetary magnetic spectra are measured. The intensity of the interplanetary "fossil" turbulence through which the particles have traversed is found to be at the "quiet" to "intermediate" level of IMF activity. Pitch angle scattering rates and the corresponding particle mean free paths λ W −P are calculated using the measured wave intensities, polarizations, and k directions. The values of λ W −P are found to be ∼ 5 times less than the value of λ H e , the latter derived from He intensity and anisotropy time profiles. It is demonstrated by computer simulation that scattering rates through a 90 • pitch angle are lower than that of other pitch angles, and that this is a possible explanation for the discrepancy between the λ W −P and λ H e values. At this time the scattering mechanism(s) is unknown. We suggest a means where a direct comparison between the two λ values could be made. Computer simulations indicate that although scattering through 90 • is lower, it still occurs. Possibilities are either large pitch angle scattering through resonant interactions, or particle mirroring off of field compression regions.The largest solar proton events are analyzed to investigate the possibilities of local wave generation at 1 AU. In accordance with the results of a previous calculation (Gary et al., 1985) of beam stability, proton beams at 1 AU are found to be marginally stable. No evidence for substantial wave amplitude was found. Locally generated waves, if present, wereCorrespondence to: B. T. Tsurutani (bruce.tsurutani@jpl.nasa.gov) less than 10 −3 nT 2 Hz −1 at the leading proton event edge, where dispersion effects (beaming) are the greatest, and at the point of peak proton flux, where the particle energy flux is the greatest.

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The ISEE-C Vector Helium Magnetometer

Cited by 166 publications

References 5 publications

Observations of slow flows in the distant plasma sheet

Observations of slow flows in the distant plasma sheet

Stationarity of magnetohydrodynamic fluctuations in the solar wind

Particle transport in <sup>3</Sup>He-rich events: wave-particle interactions and particle anisotropy measurements

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The ISEE-C Vector Helium Magnetometer

Cited by 166 publications

References 5 publications

Observations of slow flows in the distant plasma sheet

Observations of slow flows in the distant plasma sheet

Stationarity of magnetohydrodynamic fluctuations in the solar wind

Particle transport in &lt;sup&gt;3&lt;/Sup&gt;He-rich events: wave-particle interactions and particle anisotropy measurements

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Product

Resources

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Particle transport in <sup>3</Sup>He-rich events: wave-particle interactions and particle anisotropy measurements