On the Origin of Alfven Waves Required for Heating in Solar Coronal Holes

地球位于太阳风中，其起源尚不清楚。这种现象的来源是“日冕洞”。这项研究是关于这种等离子体源的。阿尔芬波可能在日冕洞的能量平衡中发挥重要作用，这一事实多年来已为人所知。传统观点认为，这些波是在对流不稳定的亚光球层中产生的。就在最近，帕克(1991，占星术。J.，372,719)和摩尔等人。(1991年，占星术。J.，376，正在出版中)提出这些波可以由与网络相关的小尺度磁场产生，并提出了一些定性的论点来支持这一观点。由于在太阳大气中也有其他阿尔芬波产生机制，需要更详细的计算来估计哪种机制在这些波的激发中起主导作用。PI建议计算三种不同的Alfven波产生机制的波能谱和能量通量：(1)亚光球对流激发磁通量管上的横波；(2)光球颗粒化产生横向管波；(3)网络微耀斑激发Alfven波。为了找出哪一种机制在向日冕洞提供波能方面起主导作用，PI将把获得的所有三种波能通量与观测所需的总热输入进行比较。这项研究对于了解日冕洞的主要能源以及造成地球所在日光层的基本物理过程的持续努力具有重要意义。

The Earth is situated in a solar wind, whose origins are unclear. The source of this is "coronal holes". This study deals with this plasma source. The fact that Alfven waves may play a significant role in the energy balance in solar coronal holes has been known for many years. The traditional view has been that these waves are generated in the convectively unstable subphotospheric layers. Just very recently Parker (1991, Astrophys. J., 372, 719) and Moore et al. (1991, Astrophys. J., 376, in press) have suggested that these waves can be generated by small-scale magnetic fields assoicated with the network and presented some qualitative arguments to support this idea. Because there are also other mechanisms of Alfven wave generation operating in the solar atmosphere, more detailed calculations are needed to estimate which mechanism dominates in the excitation of these waves. The PI propose to calculate the wave energy spectra and energy fluxes for three different mechanisms of Alfven wave generation: (1) excitation of transverse waves on magnetic flux tubes by the subphotospheric convection, (2) generation of transverse tube waves by the photospheric granulation, and (3) excitation of Alfven waves by the network microflaring. To find out which mechanism is dominant in supplying the wave energy into solar coronal holes, the PI will compare all three obtained wave energy fluxes with total heat input required by observations. This study will be important in ongoing efforts to understand the principal energy sources for solar coronal holes and the basic physical processes responsible for creating the heliosphere, in which the Earth resides.