English
 
Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Conference Paper

Recent Advances in the Research of Polar cap Auroras

Authors

Zhang,  Qing-He
IUGG 2023, General Assemblies, 1 General, International Union of Geodesy and Geophysics (IUGG), External Organizations;

Zhang,  Yong-Liang
IUGG 2023, General Assemblies, 1 General, International Union of Geodesy and Geophysics (IUGG), External Organizations;

Wang,  Chi
IUGG 2023, General Assemblies, 1 General, International Union of Geodesy and Geophysics (IUGG), External Organizations;

Oksavik,  Kjellmar
IUGG 2023, General Assemblies, 1 General, International Union of Geodesy and Geophysics (IUGG), External Organizations;

Lyons,  Larry
IUGG 2023, General Assemblies, 1 General, International Union of Geodesy and Geophysics (IUGG), External Organizations;

Lockwood,  Michael
IUGG 2023, General Assemblies, 1 General, International Union of Geodesy and Geophysics (IUGG), External Organizations;

Tang,  Bin-Bin
IUGG 2023, General Assemblies, 1 General, International Union of Geodesy and Geophysics (IUGG), External Organizations;

Xing,  Zan-Yang
IUGG 2023, General Assemblies, 1 General, International Union of Geodesy and Geophysics (IUGG), External Organizations;

Wang,  Xiang-Yu
IUGG 2023, General Assemblies, 1 General, International Union of Geodesy and Geophysics (IUGG), External Organizations;

External Ressource
No external resources are shared
Fulltext (public)
There are no public fulltexts stored in GFZpublic
Supplementary Material (public)
There is no public supplementary material available
Citation

Zhang, Q.-H., Zhang, Y.-L., Wang, C., Oksavik, K., Lyons, L., Lockwood, M., Tang, B.-B., Xing, Z.-Y., Wang, X.-Y. (2023): Recent Advances in the Research of Polar cap Auroras, XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) (Berlin 2023).
https://doi.org/10.57757/IUGG23-2172


Cite as: https://gfzpublic.gfz-potsdam.de/pubman/item/item_5018634
Abstract
During the periods of strong northward interplanetary magnetic field (IMF), the polar cap (normally no aurora) often appears clear auroral structures. Their appearance not only directly links to solar wind-magnetosphere-ionosphere coupling processes, but also often results in variable space weather disturbances. However, their formation and evolution are still poorly understood, and there is no forecasting tool to predict either their formation or evolution. Here we summarize the recent new progresses about the formation, evolution and space weather impact of polar cap auroras. 1) A general formation mechanism has been proposed for the formation of transpolar auroral arcs (TPA): strong flow shear sheets in the magnetosphere generate field aligned current (FAC) sheets which field-aligned accelerate electrons through the Knight’s current-voltage process to precipitate into the polar cap ionosphere. 2) A cyclone-shaped aurora has been identified and named as space hurricane above the Earth’s magnetic north pole with strong electron precipitations and a clockwise circulation of the plasma flow, and been. 3) A merging poleward edges of a conjugate horse-collar aurora (HCA) has been identified in both hemispheres’ polar ionosphere, indicating an almost complete disappearance of the open-flux polar cap and a shrunk and nearly closed magnetosphere due to the quasi-steady dual-lobe reconnection continuously eroding the magnetotail open and even closed magnetic field lines that reclosed at the dayside magnetopause under long-time strong northward IMF. These results indicate that there are still significant energy disposition and coupling in the solar wind-magnetosphere-ionosphere interactions under strong northward IMF conditions.