Timescales of Dayside and Nightside Field-Aligned Current Response to Changes in Solar Wind-Magnetosphere Coupling

Milan, Stephen E., Carter, Jennifer Alyson, Sangha, Harneet, Laundal, Karl M., Østgaard, Nikolai, Tenfjord, Paul, Reistad, Jone Peter, Snekvik, Kristian, Coxon, John, Korth, Haje and Anderson, Brian J. (2018) Timescales of Dayside and Nightside Field-Aligned Current Response to Changes in Solar Wind-Magnetosphere Coupling. Journal of Geophysical Research: Space Physics, 123 (9). pp. 7307-7319. ISSN 2169-9380

JGR Space Physics - 2018 - Milan - Timescales of Dayside and Nightside Field‐Aligned Current Response to Changes in Solar.pdf - Published Version
Available under License Creative Commons Attribution 4.0.

Download (1MB) | Preview
Official URL: https://doi.org/10.1029/2018JA025645


Principal component analysis is performed on Birkeland or field-aligned current (FAC) measurements from the Active Magnetosphere and Planetary Electrodynamics Response Experiment, to determine the response of dayside and nightside FACs to reversals in the orientation of the interplanetary magnetic field (IMF) and the occurrence of substorms. Dayside FACs respond promptly to changes in IMF BY, but the nightside response is delayed by up to an hour and can take up to 4 hr to develop fully, especially during northward IMF. Nightside FAC asymmetries grow during substorm growth phase when the IMF has a significant BY component, and also promptly at substorm onset. Our findings suggest that magnetotail twisting and/or BY penetration into the magnetotail, due to subsolar reconnection with east-west orientated IMF, are the main cause of these nightside FAC asymmetries and that asymmetries also arise due to magnetotail reconnection of these twisted field lines.

Item Type: Article
Additional Information: Funding Information: S. E. M. and J. A. C. were supported by the Science and Technology Facilities Council (STFC), UK, grant ST/N000749/1; H. S. was supported by a STFC studentship. The work at the Birkeland Centre for Space Centre, University of Bergen, Norway, was supported by the Research Council of Norway/CoE under contract 223252/F50.
Uncontrolled Keywords: currents, ionosphere, magnetosphere
Subjects: F500 Astronomy
F600 Geology
F800 Physical and Terrestrial Geographical and Environmental Sciences
Department: Faculties > Engineering and Environment > Mathematics, Physics and Electrical Engineering
Depositing User: Rachel Branson
Date Deposited: 24 Feb 2022 15:05
Last Modified: 24 Feb 2022 15:15
URI: http://nrl.northumbria.ac.uk/id/eprint/48547

Actions (login required)

View Item View Item


Downloads per month over past year

View more statistics