Ulysses at 50{degrees} south: Constant immersion in the high-speed solar wind

Journal Article · Wed Jun 15 04:00:00 EDT 1994 · Geophysical Research Letters

DOI:https://doi.org/10.1029/94GL01065· OSTI ID:35582

Phillips, J L; Bame, S J; Gosling, J T; McComas, D J ^[1]; Balogh, A ^[2]; Goldstein, B E; Neugebauer, M ^[3]; Hoeksema, J T ^[4]; Sheeley, Jr, N R; Wang, Y M ^[5]

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1. Los Alamos National Lab., NM (United States)
2. Imperial College, London (United Kingdom)
3. Jet Propulsion Lab., Pasadena, CA (United States)
4. Stanford Univ., CA (United States)
5. Naval Research Lab., Washington, DC (United States)

The authors present speed observations from the Ulysses solar wind plasma experiment through 50{degrees} south latitude. The pronounced speed modulation arising from solar rotation and the tilt of the heliomagnetic current sheet has nearly disappeared. Ulysses is now observing wind speeds in the 700 to 800 km s{sup {minus}1} range, with a magnetic polarity indicating an origin in the large south polar coronal hole. The strong compressions, rarefactions, and shock waves previously seen have weakened or disappeared. Occasional coronal mass ejections characterized by low plasma density caused by radial expansion have been observed. The coronal configuration was simple and stable in 1993, indicating that the observed solar wind changes were caused by increasing latitude support previous findings. A decrease in peak speed southward of 40{degrees} latitude may indicate that the fastest solar wind comes from the equatorial extensions of the polar coronal holes. 16 refs., 4 figs.

• OSTI ID: 35582
• Journal Information: Geophysical Research Letters, Journal Name: Geophysical Research Letters Journal Issue: 12 Vol. 21; ISSN GPRLAJ; ISSN 0094-8276
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
SOLAR CORONA
SOLAR WIND
VELOCITY