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Field-aligned current ordering in ground and space measurements

Research output: Contribution to conference - Without ISBN/ISSN Abstract

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Field-aligned current ordering in ground and space measurements. / Dunlop, Malcolm; Yang, Junying; Dong, Xiangcheng; Freeman, Mervyn; Rogers, Neil; Wild, Jim; Forsyth, Colin; Cao, Jinbin; Lühr, Hermann; Xiong, Chao.

2020. Abstract from European Geosciences Union General Assembly 2020.

Research output: Contribution to conference - Without ISBN/ISSN Abstract

Harvard

Dunlop, M, Yang, J, Dong, X, Freeman, M, Rogers, N, Wild, J, Forsyth, C, Cao, J, Lühr, H & Xiong, C 2020, 'Field-aligned current ordering in ground and space measurements', European Geosciences Union General Assembly 2020, 4/05/20 - 8/05/20. https://doi.org/10.5194/egusphere-egu2020-19203

APA

Dunlop, M., Yang, J., Dong, X., Freeman, M., Rogers, N., Wild, J., Forsyth, C., Cao, J., Lühr, H., & Xiong, C. (2020). Field-aligned current ordering in ground and space measurements. Abstract from European Geosciences Union General Assembly 2020. https://doi.org/10.5194/egusphere-egu2020-19203

Vancouver

Dunlop M, Yang J, Dong X, Freeman M, Rogers N, Wild J et al. Field-aligned current ordering in ground and space measurements. 2020. Abstract from European Geosciences Union General Assembly 2020. https://doi.org/10.5194/egusphere-egu2020-19203

Author

Dunlop, Malcolm ; Yang, Junying ; Dong, Xiangcheng ; Freeman, Mervyn ; Rogers, Neil ; Wild, Jim ; Forsyth, Colin ; Cao, Jinbin ; Lühr, Hermann ; Xiong, Chao. / Field-aligned current ordering in ground and space measurements. Abstract from European Geosciences Union General Assembly 2020.1 p.

Bibtex

@conference{ff70f429e29944bdbdd8f8c175c40697,
title = "Field-aligned current ordering in ground and space measurements",
abstract = "The orientation of field-aligned current sheets (FACs) can be inferred from dual-spacecraft correlations of the FAC signatures between two Swarm spacecraft (A and C), using the maximum correlations obtained from sliding data segments. Statistical analysis of both the correlations and the inferred orientations shows clear trends in magnetic local time (MLT) which reveal behaviour of both large and small scale currents. The maximum correlation coefficients show distinct behaviour in terms of either the time shift, or the shift in longitude between Swarm A and C for various filtering levels. The lower-latitude FACs show the strongest correlations for a broad range of MLT centred on dawn and dusk, with a higher correlation coefficient on the dusk-side and lower correlations near noon and midnight, and broadly follow the mean shape of the auroral boundary for the lower latitudes corresponding to Region 2 FACs (and are most well-ordered on the dusk side). Individual events sampled by higher altitude spacecraft (e.g. the 4 Cluster spacecraft), in conjunction with Swarm (mapping both to region 1 and 2), also show two different domains of FACs: time variable, small-scale (10s km), and more stationary large-scale (>100 km) FACs. We investigate further how these FAC regimes are dependent on geomagnetic activity, focusing on high activity events. Both the statistical trends, and individual conjugate events, show comparable effects seen in the ground magnetometer signals (dH/dt) during storm/substorm activity and show distributions that are similar.",
keywords = "field-aligned current, geomagnetic activity, Swarm spacecraft",
author = "Malcolm Dunlop and Junying Yang and Xiangcheng Dong and Mervyn Freeman and Neil Rogers and Jim Wild and Colin Forsyth and Jinbin Cao and Hermann L{\"u}hr and Chao Xiong",
year = "2020",
month = may,
day = "8",
doi = "10.5194/egusphere-egu2020-19203",
language = "English",
note = "European Geosciences Union General Assembly 2020 : Sharing Geosciences Online, EGU 2020 ; Conference date: 04-05-2020 Through 08-05-2020",
url = "https://www.egu2020.eu/",

}

RIS

TY - CONF

T1 - Field-aligned current ordering in ground and space measurements

AU - Dunlop, Malcolm

AU - Yang, Junying

AU - Dong, Xiangcheng

AU - Freeman, Mervyn

AU - Rogers, Neil

AU - Wild, Jim

AU - Forsyth, Colin

AU - Cao, Jinbin

AU - Lühr, Hermann

AU - Xiong, Chao

PY - 2020/5/8

Y1 - 2020/5/8

N2 - The orientation of field-aligned current sheets (FACs) can be inferred from dual-spacecraft correlations of the FAC signatures between two Swarm spacecraft (A and C), using the maximum correlations obtained from sliding data segments. Statistical analysis of both the correlations and the inferred orientations shows clear trends in magnetic local time (MLT) which reveal behaviour of both large and small scale currents. The maximum correlation coefficients show distinct behaviour in terms of either the time shift, or the shift in longitude between Swarm A and C for various filtering levels. The lower-latitude FACs show the strongest correlations for a broad range of MLT centred on dawn and dusk, with a higher correlation coefficient on the dusk-side and lower correlations near noon and midnight, and broadly follow the mean shape of the auroral boundary for the lower latitudes corresponding to Region 2 FACs (and are most well-ordered on the dusk side). Individual events sampled by higher altitude spacecraft (e.g. the 4 Cluster spacecraft), in conjunction with Swarm (mapping both to region 1 and 2), also show two different domains of FACs: time variable, small-scale (10s km), and more stationary large-scale (>100 km) FACs. We investigate further how these FAC regimes are dependent on geomagnetic activity, focusing on high activity events. Both the statistical trends, and individual conjugate events, show comparable effects seen in the ground magnetometer signals (dH/dt) during storm/substorm activity and show distributions that are similar.

AB - The orientation of field-aligned current sheets (FACs) can be inferred from dual-spacecraft correlations of the FAC signatures between two Swarm spacecraft (A and C), using the maximum correlations obtained from sliding data segments. Statistical analysis of both the correlations and the inferred orientations shows clear trends in magnetic local time (MLT) which reveal behaviour of both large and small scale currents. The maximum correlation coefficients show distinct behaviour in terms of either the time shift, or the shift in longitude between Swarm A and C for various filtering levels. The lower-latitude FACs show the strongest correlations for a broad range of MLT centred on dawn and dusk, with a higher correlation coefficient on the dusk-side and lower correlations near noon and midnight, and broadly follow the mean shape of the auroral boundary for the lower latitudes corresponding to Region 2 FACs (and are most well-ordered on the dusk side). Individual events sampled by higher altitude spacecraft (e.g. the 4 Cluster spacecraft), in conjunction with Swarm (mapping both to region 1 and 2), also show two different domains of FACs: time variable, small-scale (10s km), and more stationary large-scale (>100 km) FACs. We investigate further how these FAC regimes are dependent on geomagnetic activity, focusing on high activity events. Both the statistical trends, and individual conjugate events, show comparable effects seen in the ground magnetometer signals (dH/dt) during storm/substorm activity and show distributions that are similar.

KW - field-aligned current

KW - geomagnetic activity

KW - Swarm spacecraft

U2 - 10.5194/egusphere-egu2020-19203

DO - 10.5194/egusphere-egu2020-19203

M3 - Abstract

T2 - European Geosciences Union General Assembly 2020

Y2 - 4 May 2020 through 8 May 2020

ER -