Rights statement: This is the peer reviewed version of the following article: Yang, J. ‐Y., Dunlop, M. W., Lühr, H., Xiong, C., Yang, Y.‐Y., Cao, J. ‐B., et al. (2018). Statistical correlation analysis of field‐aligned currents measured by Swarm. Journal of Geophysical Research: Space Physics, 123, 8170–8184. https://doi.org/10.1029/2018JA025205 which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1029/2018JA025205 This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.
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Available under license: CC BY-NC: Creative Commons Attribution-NonCommercial 4.0 International License
Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - Statistical correlation analysis of field-aligned currents measured by Swarm
AU - Yang, Junying
AU - Dunlop, Malcolm G
AU - Lühr, H.
AU - Xiong, Chao
AU - Yang, Yanyan
AU - Cao, Jin Bin
AU - Wild, James Anderson
AU - Li, L. Y.
AU - Ma, Yuduan
AU - Liu, Wenlong
AU - Fu, Huishan
AU - Lu, Haoyu
AU - Waters, Colin
AU - Ritter, Patricia
N1 - This is the peer reviewed version of the following article: Yang, J. ‐Y., Dunlop, M. W., Lühr, H., Xiong, C., Yang, Y.‐Y., Cao, J. ‐B., et al. (2018). Statistical correlation analysis of field‐aligned currents measured by Swarm. Journal of Geophysical Research: Space Physics, 123, 8170–8184. https://doi.org/10.1029/2018JA025205 which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1029/2018JA025205 This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.
PY - 2018/10
Y1 - 2018/10
N2 - We investigate the statistical, dual‐spacecraft correlations of field‐aligned current (FAC) signatures between two Swarm spacecraft. For the first time, we infer the orientations of the current sheets of FACs by directly using the maximum correlations obtained from sliding data segments. The current sheet orientations are shown to broadly follow the mean shape of the auroral boundary for the lower latitudes and that these are most well ordered on the dusk side. Orientations at higher latitudes are less well ordered. In addition, the maximum correlation coefficients are explored as a function of magnetic local time and in terms of either the time shift (δt) or the shift in longitude (δlon) between Swarms A and C for various filtering levels and choice of auroral region. We find that the low‐latitude FACs show the strongest correlations for a broad range of magnetic local time centered on dawn and dusk, with a higher correlation coefficient on the dusk side and lower correlations near noon and midnight. The positions of maximum correlation are sensitive to the level of low‐pass filter applied to the data, implying temporal influence in the data. This study clearly reflects the two different domains of FACs: small‐scale (some tens of kilometers), which are time variable, and large‐scale (>50 km), which are rather stationary. The methodology is deliberately chosen to highlight the locations of small‐scale influences that are generally variable in both time and space. We may fortuitously find a potential new way to recognize bursts of irregular pulsations (Pi1B) using low‐Earth orbit satellites.
AB - We investigate the statistical, dual‐spacecraft correlations of field‐aligned current (FAC) signatures between two Swarm spacecraft. For the first time, we infer the orientations of the current sheets of FACs by directly using the maximum correlations obtained from sliding data segments. The current sheet orientations are shown to broadly follow the mean shape of the auroral boundary for the lower latitudes and that these are most well ordered on the dusk side. Orientations at higher latitudes are less well ordered. In addition, the maximum correlation coefficients are explored as a function of magnetic local time and in terms of either the time shift (δt) or the shift in longitude (δlon) between Swarms A and C for various filtering levels and choice of auroral region. We find that the low‐latitude FACs show the strongest correlations for a broad range of magnetic local time centered on dawn and dusk, with a higher correlation coefficient on the dusk side and lower correlations near noon and midnight. The positions of maximum correlation are sensitive to the level of low‐pass filter applied to the data, implying temporal influence in the data. This study clearly reflects the two different domains of FACs: small‐scale (some tens of kilometers), which are time variable, and large‐scale (>50 km), which are rather stationary. The methodology is deliberately chosen to highlight the locations of small‐scale influences that are generally variable in both time and space. We may fortuitously find a potential new way to recognize bursts of irregular pulsations (Pi1B) using low‐Earth orbit satellites.
KW - field-aligned currents
KW - correlations
KW - Pi1B
U2 - 10.1029/2018JA025205
DO - 10.1029/2018JA025205
M3 - Journal article
VL - 123
SP - 8170
EP - 8184
JO - Journal of Geophysical Research: Space Physics
JF - Journal of Geophysical Research: Space Physics
SN - 2169-9402
IS - 10
ER -