Magnetic Field Perturbations from Currents in the Dark Polar Regions During Quiet Geomagnetic Conditions

Eigil Friis-Christensen, Chris Finlay, M. Hesse , K.M. Laundal

Research output: Contribution to journalJournal articleResearchpeer-review

1 Downloads (Pure)

Abstract

In the day-side sunlit polar ionosphere the varying and IMF dependent convection creates strong ionospheric currents even during quiet geomagnetic conditions. Observations during such times are often excluded when using satellite data to model the internal geomagneticmain field. Observations from the night-side or local winter during quiet conditions are, however, also influenced by variations in the IMF. In this paper we briefly review the large scale features of the ionospheric currents in the polar regions with emphasis on the current distribution during undisturbed conditions. We examine the distribution of scalar measurements of the magnetic field intensity minus predictions from a geomagnetic field model. These ‘residuals’ fall into two main categories. One category is consistently distributed according to the well-known ionospheric plasma convection and its associated Birkeland currents. The other category represent contributions caused by geomagnetic activity related to the substorm current wedge around local magnetic midnight. A new observation is a strong IMF By control of the residuals in the midnight sector indicating larger ionospheric currentsin the substorm current wedge in the northern polar region for By > 0 and correspondingly in the southern hemisphere for By < 0.
Original languageEnglish
JournalSpace Science Reviews
Volume206
Pages (from-to)281–297
ISSN0038-6308
DOIs
Publication statusPublished - 2017

Cite this

Friis-Christensen, Eigil ; Finlay, Chris ; Hesse , M. ; Laundal, K.M. / Magnetic Field Perturbations from Currents in the Dark Polar Regions During Quiet Geomagnetic Conditions. In: Space Science Reviews. 2017 ; Vol. 206. pp. 281–297.
@article{907a4bcd24de43c18c562f8daf4b1c1c,
title = "Magnetic Field Perturbations from Currents in the Dark Polar Regions During Quiet Geomagnetic Conditions",
abstract = "In the day-side sunlit polar ionosphere the varying and IMF dependent convection creates strong ionospheric currents even during quiet geomagnetic conditions. Observations during such times are often excluded when using satellite data to model the internal geomagneticmain field. Observations from the night-side or local winter during quiet conditions are, however, also influenced by variations in the IMF. In this paper we briefly review the large scale features of the ionospheric currents in the polar regions with emphasis on the current distribution during undisturbed conditions. We examine the distribution of scalar measurements of the magnetic field intensity minus predictions from a geomagnetic field model. These ‘residuals’ fall into two main categories. One category is consistently distributed according to the well-known ionospheric plasma convection and its associated Birkeland currents. The other category represent contributions caused by geomagnetic activity related to the substorm current wedge around local magnetic midnight. A new observation is a strong IMF By control of the residuals in the midnight sector indicating larger ionospheric currentsin the substorm current wedge in the northern polar region for By > 0 and correspondingly in the southern hemisphere for By < 0.",
author = "Eigil Friis-Christensen and Chris Finlay and M. Hesse and K.M. Laundal",
year = "2017",
doi = "10.1007/s11214-017-0332-1",
language = "English",
volume = "206",
pages = "281–297",
journal = "Space Science Reviews",
issn = "0038-6308",
publisher = "Springer Netherlands",

}

Magnetic Field Perturbations from Currents in the Dark Polar Regions During Quiet Geomagnetic Conditions. / Friis-Christensen, Eigil; Finlay, Chris; Hesse , M.; Laundal, K.M.

In: Space Science Reviews, Vol. 206, 2017, p. 281–297.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Magnetic Field Perturbations from Currents in the Dark Polar Regions During Quiet Geomagnetic Conditions

AU - Friis-Christensen, Eigil

AU - Finlay, Chris

AU - Hesse , M.

AU - Laundal, K.M.

PY - 2017

Y1 - 2017

N2 - In the day-side sunlit polar ionosphere the varying and IMF dependent convection creates strong ionospheric currents even during quiet geomagnetic conditions. Observations during such times are often excluded when using satellite data to model the internal geomagneticmain field. Observations from the night-side or local winter during quiet conditions are, however, also influenced by variations in the IMF. In this paper we briefly review the large scale features of the ionospheric currents in the polar regions with emphasis on the current distribution during undisturbed conditions. We examine the distribution of scalar measurements of the magnetic field intensity minus predictions from a geomagnetic field model. These ‘residuals’ fall into two main categories. One category is consistently distributed according to the well-known ionospheric plasma convection and its associated Birkeland currents. The other category represent contributions caused by geomagnetic activity related to the substorm current wedge around local magnetic midnight. A new observation is a strong IMF By control of the residuals in the midnight sector indicating larger ionospheric currentsin the substorm current wedge in the northern polar region for By > 0 and correspondingly in the southern hemisphere for By < 0.

AB - In the day-side sunlit polar ionosphere the varying and IMF dependent convection creates strong ionospheric currents even during quiet geomagnetic conditions. Observations during such times are often excluded when using satellite data to model the internal geomagneticmain field. Observations from the night-side or local winter during quiet conditions are, however, also influenced by variations in the IMF. In this paper we briefly review the large scale features of the ionospheric currents in the polar regions with emphasis on the current distribution during undisturbed conditions. We examine the distribution of scalar measurements of the magnetic field intensity minus predictions from a geomagnetic field model. These ‘residuals’ fall into two main categories. One category is consistently distributed according to the well-known ionospheric plasma convection and its associated Birkeland currents. The other category represent contributions caused by geomagnetic activity related to the substorm current wedge around local magnetic midnight. A new observation is a strong IMF By control of the residuals in the midnight sector indicating larger ionospheric currentsin the substorm current wedge in the northern polar region for By > 0 and correspondingly in the southern hemisphere for By < 0.

U2 - 10.1007/s11214-017-0332-1

DO - 10.1007/s11214-017-0332-1

M3 - Journal article

VL - 206

SP - 281

EP - 297

JO - Space Science Reviews

JF - Space Science Reviews

SN - 0038-6308

ER -