| B. Andonov 1, Pl. Mukhtarov 1 , D. Pancheva 1 ,C. Borries 2, and N. Jakowski 2
1 - Geophysical Institute, Bulgarian Academy of Sciences, Sofia, Bulgaria
2 - DLR, Institute of Communications and Navigation, Kalkhorstweg 53, 17235 Neustrelitz,
Germany
This presentation focuses on planetary wave type responses of the thermosphere/ionosphere system to forcing from above and below during the Arctic winter of 2005/2006. The forcing from above is described by the sunspot numbers, the solar wind speed, the Bz component of the IMF and the geomagnetic Kp-index, while the forcing from below, i.e. by upward propagating atmospheric waves, is represented by the SABER/TIMED temperatures. The observed global ionospheric zonally symmetric oscillations with periods of ~9, ~14 and ~24-27 days were approved to be of solar origin. The most persistent ~9-day oscillation is linked to a triad of solar coronal holes distributed roughly 120o apart in solar longitude. The ~18-day westward propagating wave with zonal wavenumber 1, observed in the ionospheric currents (detected by magnetometer data), and in the F-region plasma (foF2 and TEC) is allocated to a simultaneous 18-day westward propagating planetary wave observed in the stratosphere/mesosphere/lower thermosphere region with large (~70 km) vertical wavelength. |