Multi‐Scale Density Structures in the Plasmaspheric Plume During a Geomagnetic Storm
Multi‐Scale Density Structures in the Plasmaspheric Plume During a Geomagnetic Storm
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地磁暴期间等离子体层羽流的多尺度密度结构
DOI：
10.1029/2021ja030230
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Nishitani, N.
中科院分区：
文献类型：
--
作者：
Nishimura, Y.;Goldstein, J.;Martinis, C.;Ma, Q.;Li, W.;Zhang, S. R.;Coster, A. J.;Mrak, S.;Semeter, J. L.;Nishitani, N.
在2015年9月7日至8日的风暴期间，使用空间-地面协调观测的羽流研究了大尺度和细尺度等离子体层羽流密度结构的演变。货车艾伦探测器A的大尺度等离子体层羽流密度与沿着卫星足迹的总电子含量（TEC）大致成正比，表明TEC分布代表了磁层中大尺度羽流密度的分布。等离子体层羽流包含细尺度密度结构和亚极光偏振流（SAPS）速度波动。高分辨率TEC数据支持这样的解释，即细尺度羽流结构是在电离层中大小为300 km、速度为500-800 m/s的斑点（在磁层中大小为3,000 km、速度为500 -8 km/s），出现在羽流底部并漂移到羽流。短基线全球导航卫星系统接收器探测到较小尺度（电离层10公里，磁层100公里）的TEC梯度及其向日漂移。精细尺度密度结构与增强相闪烁指数相关。速度波动被发现是细尺度SAPS流的空间结构，其向日漂移，密度不规则性下降到10米尺度。精细尺度的密度结构遵循幂律，斜率为1/2 - 5/3，较小尺度的密度结构比较大尺度的结构发展得更慢。我们认为，湍流SAPS流创建细尺度密度结构和它们的级联到更小的尺度。我们还发现，羽流细尺度密度结构与哨声模式强度调制和羽流中的局部电子沉淀有关。羽流中的结构性降水可能有助于电离层加热、SAPS速度降低和电导增强。
Evolution of large‐scale and fine‐scale plasmaspheric plume density structures was examined using space‐ground coordinated observations of a plume during the 7–8 September 2015 storm. The large‐scale plasmaspheric plume density at Van Allen Probes A was roughly proportional to the total electron content (TEC) along the satellite footprint, indicating that TEC distribution represents the large‐scale plume density distribution in the magnetosphere. The plasmaspheric plume contained fine‐scale density structures and subauroral polarization streams (SAPS) velocity fluctuations. High‐resolution TEC data support the interpretation that the fine‐scale plume structures were blobs with ∼300 km size and ∼500–800 m/s in the ionosphere (∼3,000 km size and ∼5–8 km/s speed in the magnetosphere), emerging at the plume base and drifting to the plume. The short‐baseline Global Navigation Satellite System receivers detected smaller‐scale (∼10 km in the ionosphere, ∼100 km in the magnetosphere) TEC gradients and their sunward drift. Fine‐scale density structures were associated with enhanced phase scintillation index. Velocity fluctuations were found to be spatial structures of fine‐scale SAPS flows that drifted sunward with density irregularities down to ∼10 s of meter‐scale. Fine‐scale density structures followed a power law with a slope of ∼−5/3, and smaller‐scale density structures developed slower than the larger‐scale structures. We suggest that turbulent SAPS flows created fine‐scale density structures and their cascading to smaller scales. We also found that the plume fine‐scale density structures were associated with whistler‐mode intensity modulation, and localized electron precipitation in the plume. Structured precipitation in the plume may contribute to ionospheric heating, SAPS velocity reduction, and conductance enhancements.
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影响因子：
5.2
作者：
W. Li;X. Shen;Q. Ma;L. Capannolo;R. Shi;R. Redmon;J. Rodriguez;G. Reeves;C. Kletzing;W. Kurth;G. Hospodarsky
通讯作者：
W. Li;X. Shen;Q. Ma;L. Capannolo;R. Shi;R. Redmon;J. Rodriguez;G. Reeves;C. Kletzing;W. Kurth;G. Hospodarsky
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.
根据 Millstone Hill E 区域相干散射观测推断偏振射流的电场变化
影响因子：
1.6
作者：
P. J. Erickson;John C. Foster;John M. Holt
通讯作者：
John M. Holt
影响因子：
1.6
作者：
Mrak, Sebastijan;Semeter, Joshua;Groves, Keith
通讯作者：
Groves, Keith
多航天器观测等离子体层羽流密度和场的小尺度波动
影响因子：
1.9
作者：
H. Matsui;F. Darrouzet;J. Goldstein;P. Puhl;Y. Khotyaintsev;P. Lindqvist;E. Georgescu;C. Mouikis;R. Torbert
通讯作者：
R. Torbert