A number of works have considered the role of turbulence in energy release and transport in solar flares, and in particular, on the transport of energy by thermal conduction. Here, we point out that for physical consistency, the effects of turbulence on the electrical conductivity, and hence on the ohmic heating by the return current that neutralizes the current in injected electron beams, must also be considered. Using radiative hydrodynamic simulations, in conjunction with thermal and electrical conductivities modified from their collisional values by turbulent processes, we model the heating rate along a flare loop. We derive the resulting temperature, pressure, velocity, and density profiles, and use them to calculate quantities such as the differential emission measure (DEM) and the emitted X-ray spectrum. For high levels of turbulence, the combination of high electrical resistivity and low thermal conductivity acts to create and sustain a region of very large temperature near the loop apex, creating a large overpressure that acts to suppress the upward evaporation of chromospheric material. Further, the associated large temperature gradients result in a reduction of the DEM at temperatures from 105 K to 107 K. The hard X-ray spectrum at high energies is reduced due to a lower electron flux reaching the chromosphere, but at low energies, it is enhanced due to thermal emission from the very hot coronal plasma. We assess the extent to which these results can be used to constrain the nature and role of turbulent motions in the flare volume.

中文翻译：

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湍流电阻率对太阳大气对耀斑能量输入响应的影响。I. 辐射流体动力学模拟的结果


许多工作已经考虑了湍流在太阳耀斑能量释放和传输中的作用，特别是对热传导能量传输的作用。在这里，我们指出，为了实现物理一致性，还必须考虑湍流对电导率的影响，从而考虑返回电流对欧姆加热的影响，该电流中和了注入电子束中的电流。使用辐射流体动力学仿真，结合由湍流过程的碰撞值修改的热导率和电导率，我们模拟了沿火炬回路的加热速率。我们推导出得到的温度、压力、速度和密度曲线，并使用它们来计算差分发射测量 （DEM） 和发射的 X 射线光谱等量。对于高水平的湍流，高电阻率和低热导率的组合作用在环顶点附近产生并维持一个非常大的温度区域，从而产生一个很大的超压，从而抑制色球层物质的向上蒸发。此外，相关的大温度梯度导致 DEM 在 105 K 到 107 K 的温度下降低。由于到达色球层的电子通量较低，高能量下的硬 X 射线光谱会减小，但在低能量下，由于非常热的日冕等离子体的热发射，硬 X 射线光谱会增强。我们评估了这些结果在多大程度上可用于限制耀斑体积中湍流运动的性质和作用。