Global Characteristics of Cold Protons Around Midnight in the Magnetotail: Implication for Efficient Heating and Origin
Global Characteristics of Cold Protons Around Midnight in the Magnetotail: Implication for Efficient Heating and Origin
复制标题
磁尾午夜左右冷质子的整体特征：对高效加热和起源的影响
DOI：
10.1029/2021ja029576
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Fuselier S. A.
中科院分区：
文献类型：
--
作者：
Keika K.;Asami R.;Hoshino M.;Fuselier S. A.
我们研究等离子体传输和等离子体加热的等离子体片在中午-午夜子午线，表征质子的温度低于核心等离子体片质子（<700 eV）。我们从磁层多尺度航天器上的热等离子体成分分析仪仪器测量的速度分布函数中提取冷质子的密度和温度，径向距离（r）为6-25 Re，执行双分量麦克斯韦拟合。我们选择的时间间隔，没有观察到快速流动，检查磁尾等离子体的特性不直接影响磁重联和相关的现象。在r> 0.10 Re的区域内，在等离子体片边界附近比在中心等离子体片附近更容易识别出双组分粒子群。冷组分密度在边界附近达到峰值，而热组分在中心等离子体片附近显示高密度。这些特征表明，冷质子通过开放场线从波瓣对流，然后被加热并与波瓣-等离子体片边界附近的等离子体片热等离子体混合。提取的冷分量的统计特征表明，在尾区（r> 1020 Re），温度随距等离子体片（用等离子体β表示）垂直距离的减小而增加，其趋势与热分量相似。在近地等离子体片（r<15 Re）中，冷质子温度在高β区域较低;密度随着r的增加而降低。这些特征表明，近地等离子体片中的冷质子是电离层起源的，在闭合磁场配置中被传输到等离子体片。
We investigate plasma transport to and plasma heating in the plasma sheet in the noon‐midnight meridian, characterizing protons with temperature colder than the core plasma sheet protons (<700 eV). We extract the density and temperature of the cold protons from velocity distribution functions measured by the Hot Plasma Composition Analyzer instrument on board the Magnetospheric Multiscale spacecraft in the radial distance (r) of 6–25 Re, performing two‐component Maxwellian fits. We selected time intervals with no fast flow observed, to examine the characteristics of magnetotail plasma not directly affected by magnetic reconnection and associated phenomena. In the region ofr> ∼10 Re, the two‐component populations are identified more frequently near the plasma sheet boundary than the central plasma sheet. The cold component density peaks near the boundary, in contrast to the hot components which display high density near the central plasma sheet. These characteristics suggest that cold protons are convected from the lobe by the open field lines and then heated and mixed with the plasma sheet hot plasma near the lobe‐plasma sheet boundary. The statistical features of the extracted cold components indicate that, in the tailward regions (r> ∼20 Re), temperature increases with decreasing vertical distance from the plasma sheet (represented by plasmaβ) in a similar trend to the hot components. In the near‐Earth plasma sheet (r< ∼15 Re), cold proton temperature is lower at higher‐β regions; the density decreases as increasingr. These features suggest that cold protons in the near‐Earth plasma sheet are of ionospheric origin, transported to the plasma sheet in the closed magnetic field configuration.
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对地磁尾粒子群的来源、传输、加速/加热和损失过程的考虑
影响因子：
10.3
作者：
Donald J. Williams
通讯作者：
Donald J. Williams
影响因子：
64.8
作者：
Hasegawa, H;Fujimoto, M;TanDokoro, R
通讯作者：
TanDokoro, R
梅村、环境
DOI：
--
发表时间：
2005
期刊：
Cyclopedia of Central Eurasia. (H., Komatsu et al. (eds)) 625
影响因子：
--
作者：
H.;Sohma;T.
通讯作者：
T.
影响因子：
10.3
作者：
R. Torbert;C. Russell;W. Magnes;R. Ergun;P. Lindqvist;O. Lecontel;H. Vaith;J. Macri;S. Myers-S.
通讯作者：
R. Torbert;C. Russell;W. Magnes;R. Ergun;P. Lindqvist;O. Lecontel;H. Vaith;J. Macri;S. Myers-S.
影响因子：
5.2
作者：
Kistler, L. M.
通讯作者：
Kistler, L. M.