Average field‐aligned current configuration parameterized by solar wind conditions

Carter, Jennifer; Milan, S. E.; Coxon, J. C.; Walach, Maria-Theresia; Anderson, B. J.

doi:10.1002/2015ja021567

Cited by 53 publications

(98 citation statements)

References 26 publications

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“…The average strength of these currents has been shown to be dependent on both IMF clock angle and magnitude (Anderson et al, 2008;Carter et al, 2016;Ganushkina et al, 2015;Weimer, 2001). The average strength of these currents has been shown to be dependent on both IMF clock angle and magnitude (Anderson et al, 2008;Carter et al, 2016;Ganushkina et al, 2015;Weimer, 2001).…”

Section: 1029/2019ja027249mentioning

confidence: 91%

“…The average strength of these currents has been shown to be dependent on both IMF clock angle and magnitude (Anderson et al, 2008;Carter et al, 2016;Ganushkina et al, 2015;Weimer, 2001). This model is derived using magnetometer data from the CHAallenging Minisatellite Payload, Ø rsted, and Swarm satellite missions, which has created a database that spans more than 15 years.…”

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confidence: 99%

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A Third Generation Field‐Aligned Current Model

et al. 2020

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A new empirical model of field-aligned currents in the Earth's ionosphere has been developed. This model is derived using magnetometer data from the CHAallenging Minisatellite Payload, Ø rsted, and Swarm satellite missions, which has created a database that spans more than 15 years. These data have been associated with solar wind conditions using the Advanced Composition Explorer satellite, as well as the F 10.7 , S 10.7 , M 10.7 , and Y 10.7 solar indices. With the wealth of data and associated driving conditions, this model has been developed to reproduce field-aligned current maps of the ionosphere based on solar wind electric field, interplanetary magnetic field clock angle, dipole tilt angle, solar index, and geographic hemisphere. This model was constructed using a series of spherical cap harmonic analysis fits based on small selections of the overall database. The coefficients of these fits were then used to develop a model that would reproduce these coefficients based on the previously described driving conditions. One of the most notable improvements demonstrated by this model is the ability to show distinct current regions in the ionosphere, particularly with respect to Region 0 currents during northward B z and highly positive or negative B . 10.1029/2019JA027249Key Points: • A new field-aligned current model based on satellite magnetometer data from the CHAMP, Ørsted, and Swarm missions has been developed • Driving response has been updated from previous models and reflects recent findings by Edwards et al. (2017) and Weimer et al. (2017) • Comparisons to AMPERE and AMPStotal current for a selection of events has been made, and this model has shown comparable results ). The average strength of these currents has been shown to be dependent on both IMF clock angle and magnitude (Anderson et al., 2008;Carter et al., 2016;Ganushkina et al., 2015;Weimer, 2001). It is not certain, however, how these currents scale with increasingly strong driving conditions. While it was thought that the FACs had a nonlinear response to increasing driving conditions, recent work by Weimer et al. (2017) using the same data set as this work has suggested that the response is much more linear than expected. The FAC response to solar indices, such as the F 10.7 solar index, has been shown to be nonlinear and levels off for high solar index conditions Ohtani et al., 2014). These recent publications have informed the construction of this model, including the selection of fitting functions.

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Section: 1029/2019ja027249mentioning

confidence: 91%

“…The average strength of these currents has been shown to be dependent on both IMF clock angle and magnitude (Anderson et al, 2008;Carter et al, 2016;Ganushkina et al, 2015;Weimer, 2001). This model is derived using magnetometer data from the CHAallenging Minisatellite Payload, Ø rsted, and Swarm satellite missions, which has created a database that spans more than 15 years.…”

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confidence: 99%

A Third Generation Field‐Aligned Current Model

et al. 2020

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“…The global layout of the northern hemispheric magnetospheric current systems of the Earth, including the Region 1 and 2 currents (blue and red and downward and upward, respectively), magnetopause current (black), partial ring current (black dashed), and ionospheric Pedersen currents flowing across the polar cap (green). Figure reproduced with permission from Carter et al ().…”

Section: Introductionmentioning

confidence: 99%

A Comprehensive Analysis of Multiscale Field‐Aligned Currents: Characteristics, Controlling Parameters, and Relationships

2017

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We explore the characteristics, controlling parameters, and relationships of multiscale field‐aligned currents (FACs) using a rigorous, comprehensive, and cross‐platform analysis. Our unique approach combines FAC data from the Swarm satellites and the Advanced Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) to create a database of small‐scale (∼10–150 km, <1° latitudinal width), mesoscale (∼150–250 km, 1–2° latitudinal width), and large‐scale (>250 km) FACs. We examine these data for the repeatable behavior of FACs across scales (i.e., the characteristics), the dependence on the interplanetary magnetic field orientation, and the degree to which each scale “departs” from nominal large‐scale specification. We retrieve new information by utilizing magnetic latitude and local time dependence, correlation analyses, and quantification of the departure of smaller from larger scales. We find that (1) FACs characteristics and dependence on controlling parameters do not map between scales in a straight forward manner, (2) relationships between FAC scales exhibit local time dependence, and (3) the dayside high‐latitude region is characterized by remarkably distinct FAC behavior when analyzed at different scales, and the locations of distinction correspond to “anomalous” ionosphere‐thermosphere behavior. Comparing with nominal large‐scale FACs, we find that differences are characterized by a horseshoe shape, maximizing across dayside local times, and that difference magnitudes increase when smaller‐scale observed FACs are considered. We suggest that both new physics and increased resolution of models are required to address the multiscale complexities. We include a summary table of our findings to provide a quick reference for differences between multiscale FACs.

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“…The recent study of Carter et al [] performed an indirect comparison of FACs position, given by AMPERE, with auroral UV emissions, observed by IMAGE. This study (unexpectedly) revealed a discrepancy between the region 1 current location and auroral oval in the dusk sector.…”

Section: Introductionmentioning

confidence: 99%

Magnetotail magnetic flux monitoring based on simultaneous solar wind and magnetotail observations

et al. 2016

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The magnetotail magnetic flux (MTF) is an important global variable to describe the magnetospheric state and dynamics. Existing methods of MTF estimation on the basis of the polar cap area, inferred from observations of global auroras and field‐aligned currents, do not allow benchmarking due to the absence of a gauge for comparison; besides, they rarely allow a systematic nearly real time MTF monitoring. We describe three modifications (F0, F1, and F2) of the method to calculate the MTF, based on simultaneous spacecraft observations in the magnetotail and in the solar wind, suitable for real‐time MTF monitoring. The MTF dependence on the solar wind parameters and the observed tail lobe magnetic field is derived from the pressure balance conditions. An essential part of this study is the calibration of our approximate method against global 3‐D MHD simulations and the empirical T14 magnetospheric field model. The calibration procedure provides all variables required to evaluate F0, F1, and F2 quantities and, at the same time, computes the reference MTF value through any tail cross section. It allowed us to extend the method to be used in the near tail, investigate its errors, and define the applicability domain. The method was applied to Cluster and THEMIS measurements and compared with methods of polar cap area calculation based on IMAGE and AMPERE observations. We also discuss possible applications and some recent results based on the proposed method.

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Average field‐aligned current configuration parameterized by solar wind conditions

Cited by 53 publications

References 26 publications

A Third Generation Field‐Aligned Current Model

A Third Generation Field‐Aligned Current Model

A Comprehensive Analysis of Multiscale Field‐Aligned Currents: Characteristics, Controlling Parameters, and Relationships

Magnetotail magnetic flux monitoring based on simultaneous solar wind and magnetotail observations

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