发表机构
Observatoire de Paris, Université PSL, Sorbonne Université, Université Paris Cité, CY Cergy Paris Université, CNRS; Dipartimento di Fisica, Università della Calabria; Astronomical Institute of the Czech Academy of Sciences; Institute of Atmospheric Physics of the Czech Academy of Sciences; The Blackett Laboratory, Department of Physics, Imperial College（巴黎天文台，巴黎文理研究大学，索邦大学，巴黎西岱大学，塞吉-蓬图瓦兹大学，法国国家科学研究中心; 卡拉布里亚大学物理系; 捷克科学院天文研究所; 捷克科学院大气物理研究所; 帝国理工学院物理学院布莱克特实验室）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
研究内日球层太阳风质子绝热不变量和温度各向异性径向演化，借助帕克太阳探测器及太阳轨道飞行器数据，发现垂直方向有显著加热，平行方向未偏离绝热性，垂直加热减少温度各向异性，部分太阳风各向异性受动力学软管不稳定性限制。
AI 中文摘要
本研究聚焦于内日球层中太阳风质子绝热不变量和温度各向异性的径向演化。具体而言，我们研究了帕克太阳探测器在距离太阳0.05天文单位至0.25天文单位之间以及太阳轨道飞行器在0.3天文单位至1天文单位之间的原位测量数据。在整个研究的径向距离范围内，我们观察到快速和慢速太阳风群体在垂直于局部磁场方向上均有显著的平均加热。另一方面，无论风速如何，平行方向上均未明显偏离绝热性。垂直加热足以显著减少双绝热演化预期的温度各向异性的产生。尽管有加热，太阳风的重要部分（特别是较慢的风束）仍会发展出具有较高平行温度的显著各向异性，最终受到动力学软管不稳定性的限制。
英文摘要
This study focuses on the radial evolution of the solar wind proton adiabatic invariants and temperature anisotropies in the inner heliosphere. More specifically, we study in-situ measurements provided by the Parker Solar Probe, between 0.05 au and 0.25 au from the Sun, and Solar Orbiter spacecraft between 0.3 au and 1 au. Throughout the studied range of radial distances, we observe a significant average heating in the direction perpendicular to the local magnetic field for both fast and slow solar wind populations. On the other hand, there is no clear deviation from adiabaticity in the parallel direction regardless of the wind speed. The perpendicular heating is enough to significantly reduce the generation of the temperature anisotropy expected from a double adiabatic evolution. Despite the heating, an important portion of the solar wind (especially the slower wind streams) develops substantial anisotropies with higher parallel temperatures, which eventually become constrained by kinetic firehose instabilities.
Comments14 pages, 7 figures
