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meteorological influence from ionospheric disturbances P. Hoffmann, Ch. Jacobi Summary: The state and variability of the thermosphere/ionosphere system can be described by the to-tal electron content (TEC). The solar forcing through ionisation is dominant. But there are transport processes of the ionized plasma through thermospheric wind systems which cause anomalies in the behaviour of the electron density. An important question in this context is, whether signals of planetary waves (PW) from middle atmosphere may be detected in ionospheric disturbances of the total electron content. A direct penetration of PW into the thermosphere is not possible, but indirect mechanism of modulation of solar tides are not debarred. Thus, the analysis of hemispheric TEC-maps in combination to stratospheric reanalysis data and other atmospheric measurements may help to investigate the problem of vertical coupling. This study presents signatures of winter stratospheric planetary waves visible in the ionospheric TEC. The westward propagating component having zonal wavenumber 1 reveals a correspondence between the stratosphere and ionosphere for periods of quasi 16-, 7- and 4-days close to the atmospheric normal modes. Zusammenfassung: Der Zustand und die Variabilität des Systems der Thermosphäre/Ionosphäre lassen sich durch den totalen Elektronengehalt (TEC) beschrieben. Wenn gleich der solare Antrieb durch Ionisation überwiegt, gibt es Transportprozesse des ionisierten Plasma durch thermospherische Windsysteme, welche Anomalien in der Elektronendichte verursachen. Eine in diesem Zusammenhang wichtig