论文标题
遥远的太阳风的冲击波加热机制：Voyager-2数据的解释
Shock-wave heating mechanism of the distant solar wind: explanation of Voyager-2 data
论文作者
论文摘要
Voyager-2的重要发现之一是太阳风质子温度的非绝热径向轮廓。这种现象已经研究了几十年。湍流能量的耗散已被提出为负责温度剖面的主要物理过程。湍流都被太阳风吸引了，并由流动中的压缩和剪切物和拾取离子造成了太阳风。外气球中太阳能加热的压缩源出现，这是由于冲击波引起的，该冲击波起源于太阳能电晕或太阳风本身。这项工作的目的是证明冲击波加热本身足以解释Voyager-2获得的温度曲线。冲击波加热的效果在非常简单的球形对称高分辨率（在时空和时间上）气体数据驱动的太阳风模型的框架中得到了证明。该数据驱动的模型以分辨率分辨率采用1 AU的太阳能参数。数据取自NASA OmniWeb数据库。重要的是要强调（1）模型捕获了在太阳风中捕获的冲击和/或起源于太阳风，并且（2）在模型中未考虑其他加热来源。我们将这个简单模型扩展到磁流失动力学（MHD）和两个组件模型，并发现了非常相似的结果。用一分钟的OMNI数据作为边界条件的数值建模的结果与Voyager-2获得的太阳风温度曲线非常吻合。还值得注意的是，每天平均OMNI数据的数值结果显示出非常相似的温度曲线，而数值则以27天平均的OMNI数据运行，显示了温度的绝热行为。
One of the important discoveries made by Voyager-2 is the nonadiabatic radial profile of the solar wind proton temperature. This phenomenon has been studied for several decades. The dissipation of turbulence energy has been proposed as the main physical process responsible for the temperature profile. The turbulence is both convected with the solar wind and originated in the solar wind by the compressions and shears in the flows and by pick-up ions. The compression source of the solar wind heating in the outer heliosphere appears due to shock waves, which originated either in the solar corona or in the solar wind itself. The goal of this work is to demonstrate that the shock-wave heating itself is enough to explain the temperature profile obtained by Voyager-2. The effect of shock-wave heating is demonstrated in the frame of a very simple spherically symmetric high-resolution (in both space and time) gas-dynamical data-driven solar wind model. This data-driven model employs the solar-wind parameters at 1 AU with minute resolution. The data are taken from the NASA OMNIWeb database. It is important to underline that (1) the model captures the shocks traveling and/or originating in the solar wind, and (2) other sources of heating are not taken into account in the model. We extended this simple model to the magnetohydrodynamic (MHD) and two-component models and found very similar results. The results of the numerical modeling with the one-minute OMNI data as the boundary condition show very good agreement with the solar-wind temperature profiles obtained by Voyager-2. It is also noteworthy that the numerical results with daily averaged OMNI data show a very similar temperature profile, while the numerical runs with 27-day-averaged OMNI data demonstrate the adiabatic behavior of the temperature.
