Energy Transport in Solar Flares

太阳耀斑中的能量传输

• 批准号: 8715195
• 负责人: Gordon Emslie
• 金额: $ 17.05万
• 依托单位: University of Alabama in Huntsville
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-12-01 至 1991-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8715195&HistoricalAwards=false
• 关键词: Energy; Transport; Solar; Flares

Over the past few years, in great part due to the acquisition of data from spacecraft observatories such as the NASA Solar Maximum Mission (SMM) and the Japanese Hinotori, a global picture of the impulsive phase of solar flares has started to emerge, in which the radiation signatures in different spectral regions are all seen to reflect the same underlying physical processes. The spacecraft data show that the hard X-ray source evolves temporally and spatially in a manner which is consistent with the predicted response of the atmosphere to flare energy input by collisional degradation of energetic electron beams. Spectral line profiles in soft X-rays reveal plasma emission measures and velocities which are broadly consistent with the predictions of these electron beam energy transport calculations of the group funded here. These and other results are encouraging, because observations over a wide range of wavelengths can indeed be used to address two of the most fundamental questions of solar flare physics - the nature and cause of the primary energy release, and the physics of the energy transport processes. The interplay between theory and observation has progressed well beyond a simple comparison of qualitative pictures. We are now at a stage where theoretical predictions can be used to refine theoretical models and so increase our understanding of the basic physics at work. This grant will support a program of work to continue this profitable line of analysis. It will address diagnostics of flare energy transport processes, notably those resulting from the acceleration and degradation of suprathermal electrons, in hard X-rays, soft X-rays, and EUV. In addition, it will critically examine the physics of the energy release and transport in such a picture of the impulsive phase of flares, refining existing models to include effects which have hitherto received only scant attention, such as reverse currents, plasma collective processes and non-uniform magnetic field geometry.

在过去的几年里，很大程度上由于从美国宇航局太阳最大任务（SMM）和日本Hinotori等航天器观测站获取的数据，太阳耀斑脉冲阶段的全球图景已经开始出现，其中不同光谱区域的辐射特征都反映了相同的潜在物理过程。 航天器数据显示，硬X射线源在时间和空间上的演化方式与大气对高能电子束碰撞退化产生的耀斑能量输入的预测响应一致。 软 X 射线的谱线轮廓揭示了等离子体发射测量和速度，这与此处资助的小组的电子束能量传输计算的预测大致一致。 这些结果和其他结果令人鼓舞，因为对广泛波长的观测确实可以用来解决太阳耀斑物理学的两个最基本的问题——初级能量释放的性质和原因，以及能量传输过程的物理学。 理论和观察之间的相互作用已经远远超出了定性图片的简单比较。 我们现在正处于一个阶段，理论预测可以用来完善理论模型，从而增加我们对基础物理的理解。 这笔赠款将支持一项工作计划，以继续进行这一有利可图的分析。 它将解决耀斑能量传输过程的诊断问题，特别是硬 X 射线、软 X 射线和 EUV 中超热电子加速和退化引起的能量传输过程。 此外，它将批判性地研究耀斑脉冲阶段图像中能量释放和传输的物理原理，完善现有模型，以包括迄今为止很少受到关注的效应，例如反向电流、等离子体集体过程和不均匀磁场几何形状。