利用聚类算法区分小尺度电离层行扰事件与赤道等离子体泡事件

汪领; 尹凡

doi:10.11728/cjss2020.06.1014

利用聚类算法区分小尺度电离层行扰事件与赤道等离子体泡事件

doi: 10.11728/cjss2020.06.1014

汪领,
尹凡^,

武汉大学电子信息学院武汉 430072

基金项目:

国家重点研发计划项目（2018YFC1503501，2018YFC1503501-01），国家自然科学基金重点项目（41431073）和国家自然科学基金面上项目（41474157）共同资助

详细信息

作者简介:
汪领,E-mail:wlydjqcg@whu.edu.cn

通讯作者:
尹凡,E-mail:yinfan@whu.edu.cn

中图分类号: P352
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- PDF下载量: 88
- 被引次数: 0
出版历程
- 收稿日期: 2020-01-13
- 修回日期: 2020-04-17
- 刊出日期: 2020-11-15

Distinguish Small-scale Traveling Ionospheric Disturbances and Equatorial Plasma Bubbles by Clustering Algorithm

WANG Ling,
YIN Fan^,

School of Electronic Information, Wuhan University, Wuhan 430072

摘要

摘要: 利用Swarm卫星2015年1月1日至2019年12月31日的50Hz高频磁场数据，根据阈值判断垂直于主磁场方向的扰动，对磁纬45°N-45°S之间的小尺度电离层行扰事件进行探测.为避免混淆而产生的干扰，可以根据阈值判断平行于主磁场方向是否发生扰动，从而排除典型的赤道等离子体泡事件.但对于较弱的赤道等离子体泡事件，扰动阈值判断无效.为避免弱赤道等离子体泡事件的污染，根据小尺度电离层行扰事件和赤道等离子体泡事件在不同参数空间中的密度分布差异，利用基于密度的聚类算法将赤道等离子体泡事件进一步甄别提取.结果表明，聚类算法能够有效地将赤道等离子体泡事件从小尺度电离层行扰事件中甄选出来，并使小尺度电离层行扰事件聚类与赤道等离子体泡事件聚类形成清晰的边界.由聚类算法导出的弱赤道等离子体泡事件主要分布在磁纬15°N-15°S，地理经度20°-60°W，月份10至3月之间，并且在20:00MLT-24:00MLT存在高发生率，同时依赖于太阳活动，这也验证了前人的相关研究结果.
- 聚类算法 /
- 电离层 /
- 小尺度电离层行扰 /
- 赤道等离子体泡
Abstract: By analyzing the 50Hz high-frequency magnetic field data by Swarm from January 2015 to December 2019, according to the magnetic disturbances above the threshold in the perpendicular direction to the main field, Small-Scale Traveling Ionospheric Disturbances (SSTID) within ±45°N magnetic latitude have been detected. When detecting SSTID, Equatorial Plasma Bubbles (EPB) can be excluded by determining whether there is magnetic disturbance above the threshold in the direction which is parallel to the mean ambient field. However, when the disturbance is weak, the algorithm cannot completely exclude it. According to the different density distribution of SSTID and EPB in parameter space, the EPB can be distinguished by a density-based clustering algorithm. The results demonstrate that the clustering algorithm is very effective on separating EPB and SSTID in different two-dimensional parameter spaces and brings out a clear boundary between the high density region and low density region. The EPB identified by the clustering algorithm shows the strong dependence on solar activity and their statistical features are consistent with the previous study.
- Clustering algorithm /
- Ionosphere /
- Small-Scale Traveling Ionospheric Disturbance (SSTID) /
- Equatorial Plasma Bubble (EPB)

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参考文献(21)

[1]	YIN F, LUHR H, PARK J, et al. Comprehensive analysis of the magnetic signatures of small-scale traveling ionospheric disturbances, as observed by Swarm[J]. J. Geophys. Res: Space Phys., 2019, 124(12):10794-10815.DOI: 10.1029/2019JA027523
[2]	MARTINIS C, BAUMGARDNER J, WROTEN J, et al. Seasonal dependence of MSTIDs obtained from 630.0nm airglow imaging at Arecibo[J]. Geophys. Res. Lett., 2010, 37(11):1-5.DOI: 10.1029/2010GL043569
[3]	YOKOYAMA T, HYSELL D L, OTSUKA Y, et al. Three-Dimensional simulation of the coupled Perkins and Es-Layer instabilities in the nighttime midlatitude ionosphere[J]. J. Geophys. Res.: Space Phys., 2009, 114(A3): 1-16.DOI: 10.1029/2008JA013789
[4]	BEHNKE R. F layer height bands in the nocturnal ionosphere over Arecibo[J]. J. Geophys. Res.: Space Phys., 1979, 84(A3):974-978
[5]	COSGROVE R B, TSUNODA R T. Instability of the E-F coupled nighttime midlatitude ionosphere[J]. J. Geophys. Res.: Space Phys., 2004, 109(A4):1-7.DOI: 10.1029/2003JA010243
[6]	TSUNODA, ROLAND T. On the coupling of layer instabilities in the nighttime midlatitude ionosphere[J]. J. Geophys. Res.: Space Phys., 2006, 111(A11):1-14.DOI: 10.1029/2006JA011630
[7]	PARK J, LUHR H, STOLLE C, et al. Statistical survey of nighttime midlatitude magnetic fluctuations: their source location and Poynting flux as derived from the Swarm constellation[J]. J. Geophys. Res.: Space Phys., 2016, 121(11):11235-11248. DOI: 10.1002/2016JA023408
[8]	PARK J, LUHR H, STOLLE C, et al. Magnetic signatures of medium-scale traveling ionospheric disturbances as observed by CHAMP[J]. J. Geophys. Res.: Space Phys., 2009, 114(A3):1-13. DOI: 10.1029/2008JA013792
[9]	PARK J, LUHR H, KERVALISHVILI G, et al. Nighttime magnetic field fluctuations in the topside ionosphere at midlatitudes and their relation to medium-scale traveling ionospheric disturbances: the spatial structure and scale sizes[J]. J. Geophys. Res.: Space Phys., 2015, 120 (8):6818-6830.DOI: 10.1002/2015JA021315
[10]	KELLY M. The Earth's Ionosphere: Plasma Physics And Electrodynamics[M]. 2nd. Boston: Academic Press, 2009
[11]	WOODMAN R F. Spread F-an old equatorial aeronomy problem finally resolved[J]. Ann. Geophys., 2009, 27(5):1915-1934
[12]	KELLEY M C, MAKELA J J, LA BEAUJARDIERE O D, et al. Convective ionospheric storms: a review[J]. Rev. Geophys., 2011, 49(2):1-26. DOI: 10.1029/2010RG000340
[13]	LUHR H, ROTHER M, MAUS S, et al. The diamagnetic effect of the equatorial Appleton anomaly: its characteristics and impact on geomagnetic field modeling[J]. Geophys. Res. Lett., 2003, 30(17):1-4.DOI: 10.1029/2003GL017407
[14]	PARK J, LUHR H, STOLLE C, et al. The characteristics of field-aligned currents associated with equatorial plasma bubbles as observed by the CHAMP satellite[J]. Ann. Geophys., 2009, 27:2685-2697
[15]	XIONG C, LUHR H, MA S Y, et al. Features of highly structured equatorial plasma irregularities deduced from CHAMP observations[J]. Ann. Geophys., 2012, 30(8): 1259-1269
[16]	STOLLE C, LUHR H, ROTHER M, et al. Magnetic signatures of equatorial spread F as observed by the CHAMP satellite[J]. J. Geophys. Res.: Space Phys., 2006, 111(A2):1-13. DOI: 10.1029/2005JA011184
[17]	LUHR H, XIONG C, PARK J, et al. Systematic study of intermediate-scale structures of equatorial plasma irregularities in the ionosphere based on CHAMP observations[J]. Front. Phys., 2014, 2:15
[18]	YOKOYAMA T, STOLLE C. Low and midlatitude ionospheric plasma density irregularities and their effects on geomagnetic field[J]. Space Sci. Rev., 2017, 206(1):495-519
[19]	ESTER M, KRIEGEL H, SANDER J, et al. A density-based algorithm for discovering clusters in large spatial Databases with Noise[C]//Proceeding of 2nd International Conference on Knowledge Discovery and Data Mining. Portland: AIAA Press, 1996:226-231
[20]	PARK J, STOLLE C, LUHR H, et al. Magnetic signatures and conjugate features of low-latitude plasma blobs as observed by the CHAMP satellite[J]. J. Geophys. Res.: Space Phys., 2008, 113(A9):1-10.DOI: 10.1029/2008JA013211
[21]	WANG Cheng, LIU Yafeng, WANG Xincheng, et al. Appraisal identification of classifier's performance[J]. Electron. Design Eng., 2011, 19(8):13-15, 21(王成, 刘亚峰, 王新成, 等. 分类器的分类性能评价指标[J]. 电子设计工程, 2011, 19(8):13-15, 21)