Flux transfer events at the dayside magnetopause: Transient reconnection or magnetosheath dynamic pressure pulses

Journal Article · Mon Apr 01 04:00:00 EST 1991 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/90JA02389· OSTI ID:5223461

Lockwood, M ^[1]

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1. Rutherford Appleton Lab., Chilton (England) Imperial Coll., London (England)

The suggestion is discussed that characteristic particle and field signatures at the dayside magnetopause, termed flux transfer events, are, in at least some cases, due to transient solar wind and/or magnetosheath dynamic pressure increases, rather than time-dependent magnetic reconnection. It is found that most individual cases of FTEs observed by a single spacecraft can, at least qualitatively, be explained by the pressure pulse model, provided a few rather unsatisfactory features of the predictions are explained in terms of measurement uncertainties. The most notable exceptions to this are some two-regime observations made by two satellites simultaneously, one on either side of the magnetopause. However, this configuration has not been frequently achieved for sufficient time, such observations are rare, and the relevant tests are still not conclusive. The strongest evidence that FTEs are produced by magnetic reconnection is the dependence of their occurence on the north-south component of the interplanetary magnetic field (IMF) or of the magnetosheath field. The pressure pulse model provides an explanation for this dependence in the case of magnetosheath FTEs, but does not apply to magnetosphere FTEs. The only surveys of magnetosphere FTEs have not employed the simultaneous IMF, but have shown that their occurence is strongly dependent on the north-south component of the magnetosheath field, as observed earlier/later on the same magnetopause crossing. This paper employs statistics on the variability of the IMF orientation to investigate the effects of IMF changes between the times of the magnetosheath and FTE observations. It is shown that the previously published results are consistent with magnetospheric FTEs being entirely absent when the magentosheath field is northward.

• OSTI ID: 5223461
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 96:A4; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AURORAL ZONES
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
INTERPLANETARY MAGNETIC FIELDS
IONOSPHERE
MAGNETIC FIELDS
MAGNETIC FLUX
MAGNETIC RECONNECTION
MAGNETOPAUSE
MAGNETOSHEATH
MATHEMATICAL MODELS
MATHEMATICS
ORIENTATION
PLANETARY IONOSPHERES
PRESSURE EFFECTS
SOLAR ACTIVITY
SOLAR WIND
STATISTICS
TIME DEPENDENCE
TRANSIENTS
VARIATIONS