The University of Southampton
University of Southampton Institutional Repository

The magnitudes of the regions 1 and 2 Birkeland currents observed by AMPERE and their role in solar wind-magnetosphere-ionosphere coupling

The magnitudes of the regions 1 and 2 Birkeland currents observed by AMPERE and their role in solar wind-magnetosphere-ionosphere coupling
The magnitudes of the regions 1 and 2 Birkeland currents observed by AMPERE and their role in solar wind-magnetosphere-ionosphere coupling

In this paper we present the first large-scale statistical study of the influence of magnetic reconnection on the magnitude of the regions 1 and 2 Birkeland field-aligned currents (FACs). While previous studies have employed single spacecraft measurements to construct a statistical picture of the location and density of the Birkeland currents, it has hitherto been difficult to compare in situ measurements of the solar wind with instantaneous global field-aligned current measurements. To that end, we utilize the Active Magnetosphere Planetary Electrodynamics Response Experiment (AMPERE), which yields field-aligned current density in both hemispheres at a cadence of 10 min. We quantify the amount of current flowing in the regions 1 (R1) and 2 (R2) FACs, and we compare these with the dayside reconnection rate ΦD deduced from interplanetary parameters from the OMNI data set and with the AL index to examine whether magnetic reconnection is responsible for driving currents in the coupled magnetosphere-ionosphere system. We find that current magnitudes are strongly correlated with both ΦD and AL index. We also find that R1 currents tend to be higher than R2 currents during periods of magnetic reconnection, suggesting leakage of current across the polar cap or an association with the substorm current wedge.

AMPERE, field-aligned currents, magnetic reconnection, magnetosphere-ionosphere coupling, solar wind-magnetosphere coupling, substorms
2169-9380
9804-9815
Coxon, J. C.
566baea5-6a30-4855-bde3-a09c115efde4
Milan, S. E.
b6dd5367-b0c4-4f30-953a-f2d13078d656
Clausen, L. B.N.
7ab01029-f55b-431b-911e-8e0f599ef534
Anderson, B. J.
c194e807-9400-41db-ac79-05140b759d4a
Korth, H.
47ef62e1-890c-46c6-8d1f-b715ba2b1cca
Coxon, J. C.
566baea5-6a30-4855-bde3-a09c115efde4
Milan, S. E.
b6dd5367-b0c4-4f30-953a-f2d13078d656
Clausen, L. B.N.
7ab01029-f55b-431b-911e-8e0f599ef534
Anderson, B. J.
c194e807-9400-41db-ac79-05140b759d4a
Korth, H.
47ef62e1-890c-46c6-8d1f-b715ba2b1cca

Coxon, J. C., Milan, S. E., Clausen, L. B.N., Anderson, B. J. and Korth, H. (2014) The magnitudes of the regions 1 and 2 Birkeland currents observed by AMPERE and their role in solar wind-magnetosphere-ionosphere coupling. Journal of Geophysical Research: Space Physics, 119 (12), 9804-9815. (doi:10.1002/2014JA020138).

Record type: Article

Abstract

In this paper we present the first large-scale statistical study of the influence of magnetic reconnection on the magnitude of the regions 1 and 2 Birkeland field-aligned currents (FACs). While previous studies have employed single spacecraft measurements to construct a statistical picture of the location and density of the Birkeland currents, it has hitherto been difficult to compare in situ measurements of the solar wind with instantaneous global field-aligned current measurements. To that end, we utilize the Active Magnetosphere Planetary Electrodynamics Response Experiment (AMPERE), which yields field-aligned current density in both hemispheres at a cadence of 10 min. We quantify the amount of current flowing in the regions 1 (R1) and 2 (R2) FACs, and we compare these with the dayside reconnection rate ΦD deduced from interplanetary parameters from the OMNI data set and with the AL index to examine whether magnetic reconnection is responsible for driving currents in the coupled magnetosphere-ionosphere system. We find that current magnitudes are strongly correlated with both ΦD and AL index. We also find that R1 currents tend to be higher than R2 currents during periods of magnetic reconnection, suggesting leakage of current across the polar cap or an association with the substorm current wedge.

Text
Coxon_et_al-2014-Journal_of_Geophysical_Research__Space_Physics - Version of Record
Available under License Creative Commons Attribution.
Download (1MB)

More information

Accepted/In Press date: 7 November 2014
e-pub ahead of print date: 11 November 2014
Published date: December 2014
Keywords: AMPERE, field-aligned currents, magnetic reconnection, magnetosphere-ionosphere coupling, solar wind-magnetosphere coupling, substorms

Identifiers

Local EPrints ID: 430692
URI: https://eprints.soton.ac.uk/id/eprint/430692
ISSN: 2169-9380
PURE UUID: c9d082de-6017-4070-a374-e528677b71f8
ORCID for J. C. Coxon: ORCID iD orcid.org/0000-0002-0166-6854

Catalogue record

Date deposited: 08 May 2019 16:30
Last modified: 08 Nov 2019 01:31

Export record

Altmetrics

Contributors

Author: J. C. Coxon ORCID iD
Author: S. E. Milan
Author: L. B.N. Clausen
Author: B. J. Anderson
Author: H. Korth

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of https://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×