Magnetohydrodynamic Phenomena in the Sun and Solar Wind

太阳和太阳风中的磁流体动力学现象

• 批准号: 8713042
• 负责人: Ellen Zweibel
• 金额: $ 26.08万
• 依托单位: University of Colorado at Boulder
• 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: 1987-10-01 至 1991-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8713042&HistoricalAwards=false
• 关键词: Magnetohydrodynamic; Phenomena; Sun; Solar; Wind

This grant will support theoretical research in 3 areas, - The solar magnetic field is continuously regenerated and reconfigured by a hydromagnetic dynamo in the solar interior. The field emerges at the surface in the form of thin flux ropes and active regions. The strength and topology of the interior field are not directly observable; neither is the depth at which it fragments into flux tubes. However, by computing the effect of the field on the acoustic oscillation frequencies it is possible to use helioseismology to constrain the properties of the interior field. The magnetic field emerges from the photosphere and plays a dominant role in the structure and energetics of the solar corona. Energy is stored in the field by photospheric motions; these motions may cause current sheets to develop. Dissipation of these current sheets can heat the corona in a patchy or episodic fashion which is masked by low resolution observations. Energy stored in the field can also be released by magnetohydrodynamic instabilities. The magnetic field also plays a role in the origin and propagation of shock waves in the corona and heliosphere. Shocks can accelerate particles; the resulting nonthermal particle distribution can be unstable to the growth of waves, which modify the upstream medium so that the shock evolves. These ideas may explain observed evolution of shocks in the solar wind. All of the above is very relevant to solar terrestrial relations; the origin of the magnetic field, the heating of the corona and the propagation of the shocks all have impact on the terrestrial environment.

该赠款将支持3个领域的理论研究， - 太阳能磁场是通过太阳能内部的水力磁发电机连续再生和重新配置的。 该场以细磁带绳和活动区域的形式出现在表面。 内部场的强度和拓扑不是直接观察到。它的深度也不是碎片变成通量管的深度。 但是，通过计算场对声学振荡频率的影响，可以使用HelioseSology来限制内部场的性质。 磁场从光球出现，在太阳电晕的结构和能量中起主要作用。 能量通过光电运动存储在现场。 这些动作可能导致当前的床单发展。 这些当前床单的耗散可以以斑点或情节的方式加热电晕，并通过低分辨率观察掩盖。 磁水动力学不稳定性也可以释放存储在现场中的能量。 磁场在电晕和地球球中的冲击波的起源和传播中也起着作用。 冲击可以加速颗粒；所得的非热粒子分布可能不稳定波的生长，这会改变上游培养基，从而使冲击发生。 这些想法可以解释观察到的太阳风中冲击的演变。 以上所有与太阳陆地关系非常相关。磁场的起源，电晕的加热和冲击的传播都对陆地环境产生了影响。