The Radial Evolution of the Solar Wind as Organized by Electron Distribution Parameters
The Radial Evolution of the Solar Wind as Organized by Electron Distribution Parameters
复制标题
由电子分布参数组织的太阳风的径向演化
DOI：
10.3847/1538-4357/ac85b8
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
M. Pulupa
中科院分区：
文献类型：
--
作者：
J. Halekas;P. Whittlesey;D. Larson;M. Maksimović;R. Livi;M. Berthomier;J. Kasper;A. Case;M. Stevens;S. Bale;R. Macdowall;M. Pulupa
利用帕克太阳探测器（PSP）的观测资料，研究了日球层内太阳风的径向演化。我们分析了太阳风电子，阿尔法和质子套件观测到的电子速度分布函数，以估计太阳风中的日冕电子温度和局部电势。从后者的值和当地的流速，我们计算渐近太阳风的速度。我们分组的PSP观测的渐近速度，并表征径向演变的风速，电子温度，和每个组内的电势。与以前的工作一致，我们发现电子温度（包括本地和日冕）和电势与风速有很好的相关性。这意味着，电子热压力和相关的电场可以提供更多的净加速度在慢风比在快风。然后，我们利用推断的日冕温度和外推的电+引力势表明，电场驱动的外逸层模型和等效的热驱动的流体动力学模型可以解释整个观测到的速度最慢的太阳风流。另一方面，这两类模型都不能解释观测到的更快的太阳风流的速度，因此需要额外的加速机制。
We utilize observations from the Parker Solar Probe (PSP) to study the radial evolution of the solar wind in the inner heliosphere. We analyze electron velocity distribution functions observed by the Solar Wind Electrons, Alphas, and Protons suite to estimate the coronal electron temperature and the local electric potential in the solar wind. From the latter value and the local flow speed, we compute the asymptotic solar wind speed. We group the PSP observations by asymptotic speed, and characterize the radial evolution of the wind speed, electron temperature, and electric potential within each group. In agreement with previous work, we find that the electron temperature (both local and coronal) and the electric potential are anticorrelated with wind speed. This implies that the electron thermal pressure and the associated electric field can provide more net acceleration in the slow wind than in the fast wind. We then utilize the inferred coronal temperature and the extrapolated electric + gravitational potential to show that both electric field driven exospheric models and the equivalent thermally driven hydrodynamic models can explain the entire observed speed of the slowest solar wind streams. On the other hand, neither class of model can explain the observed speed of the faster solar wind streams, which thus require additional acceleration mechanisms.
DOI：
10.1073/pnas.1917905117
发表时间：
2020-04-28
影响因子：
11.1
作者：
Boldyrev, Stanislav;Forest, Cary;Egedal, Jan
通讯作者：
Egedal, Jan
0.13 至 0.5 天文单位的慢速太阳风中热电子和超热电子群的径向演化：帕克太阳探测器观测
DOI：
10.3847/1538-4357/ac6605
发表时间：
2022
期刊：
The Astrophysical Journal
影响因子：
--
作者：
Abraham J
通讯作者：
Abraham J
影响因子：
64.8
作者：
Kasper, J. C.;Bale, S. D.;Schwadron, N. A.
通讯作者：
Schwadron, N. A.