English
 
Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
Add to Basket
  Local TagsRelease HistoryDetailsSummary

Released
Conference Paper

The origin of semidiurnal neutral wind oscillations in the high-latitude ionospheric dynamo region

Authors

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

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

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

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

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

Mitchell,  Nicholas J.
IUGG 2023, General Assemblies, 1 General, International Union of Geodesy and Geophysics (IUGG), External Organizations;

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

Borries,  Claudia
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

Günzkofer, F., Pokhotelov, D., Stober, G., Liu, H., Liu, H., Mitchell, N. J., Tjulin, A., Borries, C. (2023): The origin of semidiurnal neutral wind oscillations in the high-latitude ionospheric dynamo region, XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) (Berlin 2023).
https://doi.org/10.57757/IUGG23-2920


Cite as: https://gfzpublic.gfz-potsdam.de/pubman/item/item_5018962
Abstract
Tidal wind oscillations in the high-latitude ionospheric dynamo/transition region can be in situ forced or propagate there from lower atmospheric layers. Investigating the complex mixing of tidal modes allows determining the solar, geomagnetic, and atmospheric impact on the transition region dynamics. In classical tidal theory at high latitudes, semidiurnal tides forced by UV and IR absorption in lower atmospheric regions propagate upwards and are the dominant tidal mode up to about 120 km. Above, diurnal modes forced in situ by EUV absorption and ion drag due to the polar plasma convection are assumed dominant. We analyze a 22-day-long measurement campaign with the EISCAT UHF incoherent scatter radar during September 2005. The beam-swinging experiment allows for obtaining neutral winds from 96 - 142 km altitude which are combined with simultaneous Kiruna meteor radar measurements. An Adaptive Spectral Filtering technique is applied to determine tidal amplitudes and phases. The zonal wind showed the expected transition from semidiurnal to diurnal oscillations at about 120 km. The meridional wind showed a more complex structure with dominant 12h oscillations below 110 km and above 130 km. General Circulation Model runs with different forcing settings are analyzed to determine the origin of these high-altitude semidiurnal oscillations. The measured asymmetry of tidal amplitudes in zonal and meridional winds is found in all investigated model runs. It is shown that at high latitudes, atmospheric tides do not influence semidiurnal oscillations above 120 km. The polar ion convection and EUV absorption both contribute to the observed high-altitude semidiurnal oscillations.