Ulysses at 50° south: constant immersion in the high‐speed solar wind
Ulysses at 50° south: constant immersion in the high‐speed solar wind
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DOI：
10.1029/94gl01065
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发表时间：
1994-06
影响因子：
5.2
通讯作者：
J. Phillips;A. Balogh;S. Bame;B. Goldstein;J. Gosling;J. Hoeksema;D. McComas;M. Neugebauer;N. Sheeley;Y.-M. Wang
中科院分区：
文献类型：
--
作者：
J. Phillips;A. Balogh;S. Bame;B. Goldstein;J. Gosling;J. Hoeksema;D. McComas;M. Neugebauer;N. Sheeley;Y.-M. Wang
本文介绍了通过南纬50°太阳风等离子体实验的速度观测结果。由太阳自转和日磁电流片倾斜引起的明显的速度调制几乎消失了。现在，地球观测卫星正在观测700至800公里/秒的风速，其磁极表明起源于南极的大日冕洞。先前看到的强压缩、稀薄和冲击波已经减弱或消失。偶尔日冕物质抛射的特点是低等离子体密度所造成的径向膨胀已被观察到。1993年的日冕结构简单而稳定，表明观测到的太阳风变化是由航天器纬度增加引起的。随着纬度的增加，普遍速度的趋势支持以前的调查结果。纬度40°以南的峰值速度下降可能表明最快的太阳风来自极冕洞的赤道延伸部分。
We present speed observations from the Ulysses solar wind plasma experiment through 50° 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−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 spacecraft latitude. Trends in prevailing speed with increasing latitude support previous findings. A decrease in peak speed southward of 40° latitude may indicate that the fastest solar wind comes from the equatorial extensions of the polar coronal holes.