Ionosphere response to solar wind high‐speed streams

We present 9‐ and 7‐day periodic oscillations in the global mean Total Electron Content (TEC) from 1 January 2005 to 31 December 2006. Spectral analysis indicates that the pronounced periodicities of 9 and 7 days observed in TEC are associated with variations in solar wind high‐speed streams and geomagnetic activity. Neutral temperature and winds near 250 km, measured by a Fabry‐Perot Interferometer at Resolute Bay, also exhibit 9‐ and 7‐day periodicities. These pronounced periodicities support simultaneous observations of 9‐ and 7‐day periodicities in thermosphere neutral density (Lei et al., 2008a; Thayer et al., 2008). It is anticipated that the ionospheric response at 9 and 7 days represents some combination of effects due to chemical loss, neutral winds, and disturbance dynamo‐driven electric fields.