Solar wind and interplanetary magnetic field
Solar wind and interplanetary magnetic field
复制标题
太阳风和行星际磁场
DOI：
10.1029/rg005i001p00001
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发表时间：
1967
期刊：
影响因子：
--
通讯作者：
A. Dessler
中科院分区：
文献类型：
--
作者：
A. Dessler
简要介绍了我们关于太阳风的一些观点的历史。讨论了超音速膨胀的基本物理原理。这与理想气体通过火箭发动机喷嘴的流动有一个类比。恒星日冕的超音速膨胀要求恒星和日冕温度低于规定的最高温度。当温度超过这个最大值时，应该会发生亚音速膨胀。太阳的热结构是这样的，尽管原则上允许亚音速膨胀，但只发生超音速膨胀。
讨论了太阳风和行星际磁场的相关实验和理论的现状。特别要注意的是理论预测和实际测量之间的比较。结果表明，黄道面上投影场分量的测量值与理论值基本一致。然而，关于一个可能垂直于太阳赤道平面的分量，理论和实验之间存在着严重的差异。
简要讨论了太阳风中的波动问题。结果表明，在一定条件下，相对波幅应随日心距的增大而增大。
最后，对超音速太阳风的最终命运进行了评述。
A brief history is presented of some of our ideas regarding the solar wind. The basic physical principles of supersonic expansion are discussed. An analogy is drawn with the flow of an ideal gas through a rocket-engine nozzle. Supersonic expansion of a stellar corona requires a stellar and coronal temperature lower than a specified maximum. For temperatures above this maximum, subsonic expansion should result. The thermal structure of the sun is such that only supersonic expanion occurs although subsonic expansion is, in principal, allowed.
The present status of relevant experiments and theory regarding the solar wind and interplanetary magnetic field is discussed. In particular, attention is drawn to a comparison between theoretical predictions and actual measurements. It is concluded that measurements are consistent with theory for the component of field projected on the ecliptic plane. However, a serious discrepancy is noted between theory and experiment with regard to a possible component perpendicular to the sun's equatorial plane.
Wave motion in the solar wind is discussed briefly. It is shown that, under certain conditions, relative wave amplitudes should grow with increasing heliocentric distance.
Finally, ideas concerning the ultimate fate of the supersonic solar wind are reviewed.