Simulating Compressive Stream Interaction Regions during Parker Solar Probe’s First Perihelion Using Stream-aligned Magnetohydrodynamics
Simulating Compressive Stream Interaction Regions during Parker Solar Probe’s First Perihelion Using Stream-aligned Magnetohydrodynamics
复制标题
DOI：
10.3847/1538-4357/ad21fd
复制
发表时间：
2024-02
期刊：
影响因子：
--
通讯作者：
E. M. Wraback;A. P. Hoffmann;W. Manchester;I. V. Sokolov;B. van der Holst;D. Carpenter
中科院分区：
文献类型：
--
作者：
E. M. Wraback;A. P. Hoffmann;W. Manchester;I. V. Sokolov;B. van der Holst;D. Carpenter
我们使用流定向磁流体力学模型模拟了2018年11月6日36.5R⊙的卡林顿自转2210，其中包含了帕克太阳探测器的第一近日点，以提供现场和SWEAP的现场观测的背景。SA-MHD模型将磁场与每个点的速度向量对齐，从而允许航天器和太阳上的源区之间清晰地连接，而不存在非物理的磁场结构。在卡林顿自转期间，由于太阳深度极小，形成了两个流相互作用区(SIRS)。我们包括平行和垂直离子以及各向同性电子的能量分配，以研究通过压缩区域的温度各向异性，以更好地理解全球背景下的波能放大和质子热能分配。总体而言，我们发现SA-MHD结果与PSP、STEREO-A和地球上的观测结果之间的所有原位等离子体参数都很好地符合，包括在PSP近日点和通过SIRS的压缩区域。在典型的太阳风中，平行的质子温度优先被加热，但在SIR中，垂直质子温度有一个增强。这进一步体现在离子回旋弛豫时间上，它通过SIR压缩区域显示出明显的减少。这项工作证明了Alfvén波湍流理论在预测行星际磁场湍流水平方面的成功，同时自洽地再现了太阳风的速度、密度和总温度，包括在小的日心距离和通过SIR压缩区域。
We used the stream-aligned magnetohydrodynamics (SA-MHD) model to simulate Carrington rotation 2210, which contains Parker Solar Probe’s (PSP) first perihelion at 36.5 R ⊙ on 2018 November 6, to provide context to the in situ PSP observations by FIELDS and SWEAP. The SA-MHD model aligns the magnetic field with the velocity vector at each point, thereby allowing for clear connectivity between the spacecraft and the source regions on the Sun, without unphysical magnetic field structures. During this Carrington rotation, two stream interaction regions (SIRs) form, due to the deep solar minimum. We include the energy partitioning of the parallel and perpendicular ions and the isotropic electrons to investigate the temperature anisotropy through the compression regions to better understand the wave energy amplification and proton thermal energy partitioning in a global context. Overall, we found good agreement in all in situ plasma parameters between the SA-MHD results and the observations at PSP, STEREO-A, and Earth, including at PSP’s perihelion and through the compression region of the SIRs. In the typical solar wind, the parallel proton temperature is preferentially heated, except in the SIR, where there is an enhancement in the perpendicular proton temperature. This is further showcased in the ion cyclotron relaxation time, which shows a distinct decrease through the SIR compression regions. This work demonstrates the success of the Alfvén wave turbulence theory for predicting interplanetary magnetic turbulence levels, while self-consistently reproducing solar wind speeds, densities, and overall temperatures, including at small heliocentric distances and through SIR compression regions.