Waves and irregularities in the solar wind
Waves and irregularities in the solar wind
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DOI：
10.1029/rg012i004p00671
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发表时间：
1974-11
影响因子：
25.2
通讯作者：
M. Lee;I. Lerche
中科院分区：
文献类型：
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作者：
M. Lee;I. Lerche
这篇评论并不是为那些已经了解该学科领域的专家准备的，而是为那些想要简单的物理图片的非专家准备的。因此，给出一些简单的计算，以显示为什么波和不规则的太阳风是重要的，在获得物理上的理解发生在行星际介质中的动力学过程。在日光层中观察到的潜水员现象的基本物理学，由于太阳风中存在波而产生，详细说明。在这篇评论中提出的最基本的一点是，太阳风中发生的相当多的现象要么是直接引起的，要么是由太阳风中始终存在的湍流波显著地改变的。航天器的数据表明，太阳风中基本上持续存在强磁不规则性，显然，这主要是阿尔芬波被太阳风从太阳向外对流。风携带的波浪和不规则性极大地改变了风的整体动力学特性，这种变化特别导致太阳风的速度比没有波浪时更高。此外，观测到的太阳风中“冻结”场线的传播可以追溯到来自太阳的光球场线的随机漫游。在探测器34上观察到的中子监测器强度和低能粒子波动的观测变化可以解释为一个包含不规则冻结磁场的“板”材料被对流通过观测者。这个场会引起探测器探测到的穿过平板的带电粒子数量的不规则波动。检测到的不规则性与“板”中的不规则性有关，其也是可测量的。协议出奇的好。太阳风中的磁不规则性和波的存在也会导致宇宙射线粒子从星际空间向内穿过太阳系时的散射。这导致了在地球上看到的宇宙射线强度的调制。相关的扩散系数，传统上用于描述这一过程，是在太阳风和带电粒子的参数，如速度，电荷和俯仰角的波的功率谱表示。虽然纳入这一过程的主要物理思想似乎已经得到了相当好的理解，但关于细节，仍然有大量的问题没有得到解答。
This review is not meant to be for the specialist who already knows the subject area but rather for the nonspecialist who wants a simple physical picture. Therefore some simple calculations are given to show why waves and irregularities in the solar wind are of importance in obtaining a physical understanding of the dynamical processes occurring in the interplanetary medium. The basic physics of divers phenomena observed in the heliosphere, resulting because of the presence of waves in the solar wind, is spelled out in some detail. The most fundamental point made in this review is that a considerable body of phenomena occurring in the solar wind are either caused directly or modified significantly by the turbulent waves that are always present in the solar wind. Spacecraft data indicate the essentially continuous presence of strong magnetic irregularities in the solar wind, which, apparently, are predominantly Alfven waves being convected outward from the sun by the solar wind. The bulk dynamical properties of the wind are changed substantively by the waves and irregularities that the wind carries, this change leading, in particular, to higher solar wind speeds than occur in the absence of the waves. Also the observed spread of the ‘frozen-in’ field lines in the solar wind can be traced back to the random wanderings of the photospheric ‘feet’ of field lines emanating from the sun. The observed variations in neutron monitor intensities and the low-energy particle fluctuations observed on Explorer 34 are accountable in terms of a ‘slab’ of material containing an irregular frozen-in magnetic field being convected past an observer. This field causes irregular fluctuations in the number of charged particles crossing the slab that are picked up by a detector. The detected irregularities are related to the irregularities in the ‘slab,’ which also are measurable. The agreement is surprisingly good. The presence of magnetic irregularities and waves in the solar wind also causes scattering of cosmic ray particles as they journey inward through the solar system from interstellar space. This leads to a modulation of the intensity of the cosmic rays seen at earth. The relevant diffusion coefficients, conventionally used to describe this process, are expressible in terms of both the power spectra of the waves present in the solar wind and the charged particle parameters, such as speed, charge, and pitch angle. Although the main physical ideas incorporated into this process seem to be reasonably well understood, there remain an embarrassingly large number of unanswered questions, concerning the details.