Vis enkel innførsel

dc.contributor.authorReistad, Jone Peter
dc.contributor.authorØstgaard, Nikolai
dc.contributor.authorLaundal, Karl Magnus
dc.contributor.authorOhma, Anders
dc.contributor.authorSnekvik, Kristian
dc.contributor.authorTenfjord, Paul
dc.contributor.authorGrocott, Adrian
dc.contributor.authorOksavik, Kjellmar
dc.contributor.authorMilan, Steve
dc.contributor.authorHaaland, Stein
dc.PublishedReistad JP, Østgaard N, Laundal KM, Ohma A, Snekvik K, Tenfjord PAR, Grocott A, Oksavik K, Milan S, Haaland SE. Observations of asymmetries in ionospheric return flow during different levels of geomagnetic activity. Journal of Geophysical Research - Space Physics. 2018;123(6):4638-4651eng
dc.description.abstractIt is known that the magnetic field of the Earth's closed magnetosphere can be highly displaced from the quiet‐day configuration when interacting with the interplanetary magnetic field (IMF), an asymmetry largely controlled by the dawn‐dusk component of the IMF. The corresponding ionospheric convection has revealed that footprints in one hemisphere tend to move faster to reduce the displacement, a process we refer to as the restoring of symmetry. Although the influence on the return flow convection from the process of restoring symmetry has been shown to be strongly controlled by the IMF, the influence from internal magnetospheric processes has been less investigated. We use 14 years of line‐of‐sight measurements of the ionospheric plasma convection from the Super Dual Auroral Radar Network to produce high‐latitude convection maps sorted by season, IMF, and geomagnetic activity. We find that the restoring symmetry flows dominate the average convection pattern in the nightside ionosphere during low levels of magnetotail activity. For increasing magnetotail activity, signatures of the restoring symmetry process become less and less pronounced in the global average convection maps. We suggest that tail reconnection acts to reduce the asymmetric state of the closed magnetosphere by removing the asymmetric pressure distribution in the tail set up by the IMF By interaction. During active periods the nightside magnetosphere will therefore reach a more symmetric configuration on a global scale. These results are relevant for better understanding the dynamics of flux tubes in the asymmetric geospace, which is the most common state of the system.en_US
dc.rightsAttribution CC BYeng
dc.titleObservations of asymmetries in ionospheric return flow during different levels of geomagnetic activityen_US
dc.typePeer reviewed
dc.typeJournal article
dc.rights.holderCopyright 2018 The Author(s)en_US
dc.source.journalJournal of Geophysical Research - Space Physics
dc.relation.projectFulbright: -
dc.relation.projectAndre: NERC NE/P001556/1
dc.relation.projectNorges forskningsråd: 223252
dc.relation.projectAndre: STFC ST/M001059/1

Tilhørende fil(er)


Denne innførselen finnes i følgende samling(er)

Vis enkel innførsel

Attribution CC BY
Med mindre annet er angitt, så er denne innførselen lisensiert som Attribution CC BY