The May 1997 SOHO‐Ulysses quadrature
The May 1997 SOHO‐Ulysses quadrature
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1997 年 5 月 SOHO-尤利西斯求积
DOI：
10.1029/2000ja000044
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
G. Simnett
中科院分区：
文献类型：
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作者：
S. Suess;G. Poletto;M. Romoli;M. Neugebauer;B. Goldstein;G. Simnett
我们目前的结果从1997年5月SOHO-太阳正交（SOHO-太阳-太阳角=90°），接近太阳黑子最小。彗星位于5.1 Au，太阳赤道以北10°，并离开东翼。它也在流光带的北方边缘。然而，在太阳两极上空的太阳风观测仪器（SWOOPS）只探测到缓慢的、异常平稳的风，没有直接证据表明来自北方极冕洞的快风或与快风混合。大角度和光谱日冕仪（LASCO）图像显示，在两周的观测间隔开始和结束时，10°N的流光带狭窄而尖锐，但在中间变宽。密度的相关变化，但不是流速，发生在100 ℃。在这些条件下，有可能表明，在低日冕中的紫外线日冕光谱仪（UNOPS）导出的密度与太阳风中的密度密切相关，无论是在安静的间隔还是在临边的瞬态事件中。详细分析了LASCO和USCOM观测到的一个小瞬变过程中的密度和速度。
We present results from the May 1997 SOHO‐Ulysses quadrature (SOHO‐Sun‐Ulysses angle=90°), near sunspot minimum. Ulysses was at 5.1 AU, 10° north of the solar equator, and off the east limb. It was also at the very northern edge of the streamer belt. Nevertheless, the Solar Wind Observations Over the Poles of the Sun instrument (SWOOPS) detected only slow, unusually smooth wind and there was no direct evidence of fast wind from the northern polar coronal hole or of mixing with fast wind. The Large‐Angle and Spectrometric Coronagraph (LASCO) images show that the streamer belt at 10°N was narrow and sharp at the beginning and end of the 2 week observation interval, but broadened in the middle. A related change in density, but not flow speed, occurred at Ulysses. Under these conditions it was possible to show that densities derived from the Ultraviolet Coronagraph Spectrometer (UVCS) in the lower corona are closely related to those in the solar wind, both over quiet intervals and in transient events on the limb. Density and velocity in one small transient observed by both LASCO and UVCS are analyzed in detail.