Reconstruction of Magnetospheric Storm‐Time Dynamics Using Cylindrical Basis Functions and Multi‐Mission Data Mining
Reconstruction of Magnetospheric Storm‐Time Dynamics Using Cylindrical Basis Functions and Multi‐Mission Data Mining
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DOI：
10.1029/2020ja028390
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发表时间：
2021-01
期刊：
影响因子：
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通讯作者：
N. Tsyganenko;V. Andreeva;M. Sitnov
中科院分区：
文献类型：
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作者：
N. Tsyganenko;V. Andreeva;M. Sitnov
首先给出了磁层风暴事件的模拟结果，其基础是：(I)一种用所谓的柱面基函数来表示磁场的新方法；(Ii)Sitnov等人的数据挖掘方法。(2008年)；https://doi.org/10.1029/2007ja013003，和(3)1995年至2019年多任务数据库的升级和扩展。研究的重点是以足点纬度为±70°的场线壳为边界的3-18RE距离范围内的低纬磁层区域。利用行星际数据和地面扰动指数，利用最近邻方法从大数据库中选择的数据子集重建磁力构形。研究了2017年5月27-29日的一次强风暴对低纬磁层重构的影响。模式再现了地磁场压低/压缩和极可变场线伸展的磁层动力学的主要特征。在风暴突然开始期间，磁层的初始收缩导致了内部尾流的局部瞬变激增和磁通量的显著反太阳放电。随着风暴的发展，环电流的积聚导致内部磁层强烈抑制磁场，从而将磁通量驱逐到更远的距离，并增加了跨越更远的尾部等离子体片的场线连接。同时，由于黄昏部分环电流的形成，形成了一个强烈的黎明-黄昏不对称性，这与以前的独立结果一致。
First results are presented of the modeling of magnetospheric storm events, based on: (i) a new method to represent the magnetic field by means of the so‐called cylindrical basis functions, (ii) the data mining approach by Sitnov et al. (2008); https://doi.org/10.1029/2007ja013003, and (iii) upgraded and extended pool of multi‐mission data taken in 1995–2019. The study is focused on the low‐latitude magnetospheric domain in the distance range 3–18RE bounded by field line shells with footpoint latitudes ±70°. The magnetic configurations are reconstructed from data subsets, selected from the grand database by the nearest‐neighbor method, using both interplanetary data and the ground disturbance indices. A strong storm of May 27–29, 2017, has been studied in relation to its effect on the reconfiguration of the low‐latitude magnetosphere. The modeling reproduces the main features of the magnetosphere dynamics in terms of the geomagnetic field depression/compression and extremely variable field line stretching. The initial contraction of the magnetosphere during the storm sudden commencement results in a local transient surge of the inner tail current and a dramatic antisunward discharge of the magnetic flux. As the storm progresses, the ring current buildup results in a strongly depressed magnetic field in the inner magnetosphere, which expels the magnetic flux to larger distances and increases the field line connection across the more distant tail plasma sheet. At the same time, a strong dawn‐dusk asymmetry is developed due to the formation of the duskside partial ring current, in agreement with previous independent results.