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Titel |
Measuring the dayside reconnection rate during an interval of due northward interplanetary magnetic field |
VerfasserIn |
G. Chisham, M. P. Freeman, I. J. Coleman, M. Pinnock, M. R. Hairston, Mark Lester, G. Sofko |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
0992-7689
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Digitales Dokument |
URL |
Erschienen |
In: Annales Geophysicae ; 22, no. 12 ; Nr. 22, no. 12 (2004-12-22), S.4243-4258 |
Datensatznummer |
250015088
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Publikation (Nr.) |
copernicus.org/angeo-22-4243-2004.pdf |
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Zusammenfassung |
This study presents, for the first time, detailed spatiotemporal measurements of the reconnection electric field
in the Northern Hemisphere ionosphere during an extended interval of northward interplanetary magnetic field.
Global convection mapping using the SuperDARN HF radar network provides global estimates of the convection electric
field in the northern polar ionosphere.
These are combined with measurements of the ionospheric footprint of the reconnection X-line to
determine the spatiotemporal variation of the reconnection electric field along the whole X-line.
The shape of the spatial variation is stable throughout the interval, although
its magnitude does change with time.
Consequently, the total reconnection potential along the X-line is temporally variable but its typical magnitude
is consistent with the cross-polar cap potential measured by low-altitude satellite overpasses.
The reconnection measurements are mapped out from the ionosphere along Tsyganenko model magnetic field lines to determine
the most likely reconnection location on the lobe magnetopause.
The X-line length on the lobe magnetopause is estimated to be ~6–11 RE in extent, depending on the
assumptions made when determining the length of the ionospheric X-line.
The reconnection electric field on the lobe magnetopause is estimated to be ~0.2mV/m
in the peak reconnection region.
Key words. Space plasma physics (Magnetic reconnection)
– Magnetospheric physics (Magnetopause, cusp and boundary
layers) – Ionosphere (Plasma convection) |
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