Statistical survey of day-side magnetospheric current flow using Cluster observations: magnetopause

Liebert, Evelyn; Nabert, Christian; Perschke, Christopher; Fornaçon, K.‐H.; Glaßmeier, Karl‐Heinz

doi:10.5194/angeo-35-645-2017

Cited by 4 publications

(4 citation statements)

References 23 publications

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“…A thorough introduction to the Curlometer technique and an error analysis focussing on our application can be found in our previous publication (Liebert et al, 2017) where we conducted a similar study on magnetopause 15 currents. The reliability of Curlometer results depends on the Cluster tetrahedron geometry which is constantly changing along its trajectory.…”

Section: Data Selection and Preparationmentioning

confidence: 99%

Statistical survey of day-side magnetospheric current flow using Cluster observations: Bow shock

Liebert¹,

Nabert²,

Glaßmeier³

2018

Preprint

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Abstract. We present the first comprehensive statistical survey of the day-side terrestrial bow shock current system based on a large number of Cluster spacecraft bow shock crossings. Calculating the 3-D current densities using Fluxgate Magnetometer data and the Curlometer technique enables the investigation of current locations, directions and magnitudes in dependence on arbitrary IMF orientation. In case of quasi-perpendicular shock geometries we find that the current properties are in good accordance to theory and existing simulation results. However, currents at quasi-parallel shock geometries next to the foreshock 5 region underlie distinct variations regarding their directions.

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Section: Data Selection and Preparationmentioning

confidence: 99%

Statistical survey of day-side magnetospheric current flow using Cluster observations: Bow shock

Liebert¹,

Nabert²,

Glaßmeier³

2018

Preprint

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“…On 24 May 2011 15:17 UTC the probes TH‐A, TH‐D, and TH‐E were located in a plane approximately parallel to the X Z plane, roughly enclosing the TS6 neutral plane (Figure , left). Using a two‐dimensional form of the curlometer technique (Dunlop et al, ; Dunlop & Eastwood, ; Liebert et al, ), estimates on the current density through the enclosed area can be formulated. Similar constellations were analyzed by Lu et al () using THEMIS data, resulting in the detection of the reduction of the total current density ahead of the dipolarization front.…”

Section: Case Study 2: Observation Of the Current Layer In The Central Part Of The Structurementioning

confidence: 99%

The Plasma Sheet as Natural Symmetry Plane for Dipolarization Fronts in the Earth's Magnetotail

Frühauff

Glassmeier

2017

JGR Space Physics

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In this work, observations of multispacecraft mission Time History of Events and Macroscale Interactions during Substorms are used for statistical investigation of dipolarization fronts in the near‐Earth plasma sheet of the magnetotail. Using very stringent criteria, 460 events are detected in almost 10 years of mission data. Minimum variance analysis is used to determine the normal directions of the phase fronts, providing evidence for the existence of a natural symmetry of these phenomena, given by the neutral sheet of the magnetotail. This finding enables the definition of a local coordinate system based on the Tsyganenko model, reflecting the intrinsic orientation of the neutral sheet and, therefore, the dipolarization fronts. In this way, the comparison of events with very different background conditions is improved. Through this study, the statistical results of Liu, Angelopoulos, Runov, et al. (2013) are both confirmed and extended. In a case study, the knowledge of this plane of symmetry helps to explain the concave curvature of dipolarization fronts in the XZ plane through phase propagation speeds of magnetoacoustic waves. A second case study is presented to determine the central current system of a passing dipolarization front through a constellation of three spacecraft. With this information, a statistical analysis of spacecraft observations above and below the neutral sheet is used to provide further evidence for the neutral sheet as the symmetry plane and the central current system. Furthermore, it is shown that the signatures of dipolarization fronts are under certain conditions closely related to that of flux ropes, indicating a possible relationship between these two transient phenomena.

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“…A thorough introduction to the curlometer technique and an error analysis focussing on our application can be found in our previous publication (Liebert et al, 2017), where we conducted a similar study on magnetopause currents. The reliability of curlometer results depends on the Cluster tetrahedron geometry which is constantly changing along its trajectory.…”

Section: Introductionmentioning

confidence: 99%

“…In this study we limit our investigation to bow shock crossings, where the quality factor takes values of 2.5 or more, leaving us 111 orbit segments. The usage of this quality factor for our investigation is discussed in detail by Liebert et al (2017). Q G ≥ 2.5 allows us to expect accuracies of at least 2 • to 10 • in direction and 3 % to 15 % for the relative error in magnitude.…”

Section: Introductionmentioning

confidence: 99%

Statistical survey of day-side magnetospheric current flow using Cluster observations: bow shock

2018

Self Cite

View full text Add to dashboard Cite

Abstract. We present the first comprehensive statistical survey of the day-side terrestrial bow shock current system based on a large number of Cluster spacecraft bow shock crossings. Calculating the 3-D current densities using fluxgate magnetometer data and the curlometer technique enables the investigation of current locations, directions, and magnitudes in dependence on arbitrary IMF orientation. In case of quasi-perpendicular shock geometries we find that the current properties are in good accordance with theory and existing simulation results. However, currents at quasi-parallel shock geometries next to the foreshock region underlie distinct variations regarding their directions.

show abstract

Statistical survey of day-side magnetospheric current flow using Cluster observations: magnetopause

Cited by 4 publications

References 23 publications

Statistical survey of day-side magnetospheric current flow using Cluster observations: Bow shock

Statistical survey of day-side magnetospheric current flow using Cluster observations: Bow shock

The Plasma Sheet as Natural Symmetry Plane for Dipolarization Fronts in the Earth's Magnetotail

Statistical survey of day-side magnetospheric current flow using Cluster observations: bow shock

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