The heliosphere and the Ulysses mission
The heliosphere and the Ulysses mission
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日光层和尤利西斯任务
DOI：
10.1098/rsta.1994.0127
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
A. Balogh
中科院分区：
文献类型：
--
作者：
A. Balogh
行星际介质主要由超音速太阳风组成，携带着从日冕延伸出来的冻结磁场。这种介质的性质是由电晕状态和介质本身发生的动态过程控制的。因此，这些性质随太阳经度的变化而有显著的变化。过去三十年的现场观测主要局限于太阳赤道平面附近。虽然许多重要的过程已经被确定和广泛研究，但需要观测作为日经角的函数来定义大尺度结构及其对日冕过程的依赖。1990年10月发射的尤利西斯号任务是第一个致力于探索黄道面以外的日球层的太空探测器。到1994年1月，飞船到达了南纬50度。这里总结了这次任务的初步结果，包括行星际磁区结构的演变和消失；高速太阳风流的主导地位开始于膨胀的南日冕洞；复杂日冕物质抛射特征的观测日球层磁场的高纬度结构，以及旋转相互作用区域随日纬的演化。特别是1992年中期扇区结构自转速率的突变，以及随后南极日冕洞向赤道方向的延伸，代表了与大尺度日冕结构和太阳磁场的演化以及控制太阳活动周期的过程有关的新观测结果。
The interplanetary medium consists primarily of the supersonic solar wind, carrying the frozen-in magnetic field extending from the solar corona. The properties of this medium are controlled by the state of the corona and by dynamic processes occurring in the medium itself. As a result, there are significant variations in those properties as a function of heliolatitude. In situ observations over the past three decades have been largely confined to the neighbourhood of the solar equatorial plane. While many of the important processes have been identified and studied extensively, observations are required as a function of heliolatitude to define large-scale structures and their dependence on processes in the solar corona. The Ulysses mission, launched in October 1990, is the first space probe dedicated to the exploration of the heliosphere out of the ecliptic plane. By January 1994, the spacecraft had reached a heliolatitude of 50° south. The first results of the mission are summarized here, including the evolution and disappearance of the interplanetary magnetic sector structure; the onset of the dominance of the high-speed solar wind stream originating in the expanding southern coronal hole; observations of the signatures of complex coronal mass ejections; the high-latitude structure of the heliospheric magnetic field, and the evolution of corotating interaction regions as a function of heliolatitude. In particular, the abrupt change in the rotation rate of the sector structure in mid-1992, followed by the equatorward extension of the southern polar coronal hole, represent new observations related to the evolution of large-scale coronal structures and solar magnetic fields and to processes controlling the solar activity cycle.