Ulysses observations of a recurrent high speed solar wind stream and the heliomagnetic streamer belt

Journal Article · Fri Nov 05 04:00:00 EST 1993 · Geophysical Research Letters (American Geophysical Union); (United States)

DOI:https://doi.org/10.1029/93GL02630· OSTI ID:5409180

Bame, S J; Gosling, J T; McComas, D J; Phillips, J L ^[1]; Goldstein, B E; Neugebauer, M ^[2]; Harvey, J W

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1. Los Alamos National Lab., NM (United States)
2. Jet Propulsion Lab, Pasadena, CA (United States)

Near-ecliptic solar wind observations by Ulysses on its way to the polar regions of the Sun, compared with those from IMP 8 at 1 AU, showed that high-speed streams decay and broaden with heliocentric distance from IMP 8 to Ulysses, as expected. In July 1992 while travelling south at [approximately]13[degrees]S and 5.3 AU, Ulysses encountered a recurrent high-speed stream, that may also have been observed at IMP 8. The stream has been observed a total of 14 times, once in each solar rotation through June 1993 at [approximately]34[degrees]S. The source of the high-speed stream is an equatorward extension of the south polar coronal hole. From July 1992 through June 1993, averages of solar wind peak speed increased while density decreased with heliographic latitude. Both the stream and a low-speed, high-density flow, presumably associated with the heliomagnetic (coronal) streamer belt encircling the heliomagnetic equator, crossed Ulysses with the solar rotation period until April 1993 when the spacecraft was at [approximately]29[degrees]S heliographic latitude. After this time, as the spacecraft climbed to higher latitudes, the central portion of the streamer belt with lowest speed and highest density disappeared. Therefore, at its maximum inclination, the belt was tilted at [approximately]29[degrees] to the heliographic equator at this point in the solar cycle. 11 refs., 5 figs.

• OSTI ID: 5409180
• Journal Information: Geophysical Research Letters (American Geophysical Union); (United States), Journal Name: Geophysical Research Letters (American Geophysical Union); (United States) Vol. 20:21; ISSN GPRLAJ; ISSN 0094-8276
• Country of Publication: United States
• Language: English

Related Subjects

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Ionospheric
& Magnetospheric Phenomena-- (1992-)
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SOLAR WIND
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VELOCITY