Solar Wind Alfvén Waves: A Source of Pulsed Ionospheric Convection and Atmospheric Gravity Waves

摘要: Abstract. A case study of medium-scale travelling ionospheric disturbances (TIDs) that are correlated with solar wind Alfven waves is presented. The HF radar ground-scatter signatures TIDs caused by atmospheric gravity periods 20-40min traced to a source at high latitudes, namely pulsed flows (PIFs) due bursts in the convection electric field and/or associated current fluctuations inferred from ground magnetic perturbations. significance PIFs and context solar-terrestrial interaction Alfvenic interplanetary (IMF) observed plasma streaming coronal hole correlate TIDs. link between corroborated IMF-By oscillations negative-to-positive deflections X component interpreted as reconnection dayside magnetopause. Although clarity line-of-sight velocity data may have been affected anomalous propagation intervening TIDs, application pure state filtering technique analyze time series reveals one-to-one correspondence PIFs, waves. spectra perturbations similar those indicate TID wavelengths, phase velocities travel times consistent ray tracing, which shows subset possible wave group paths reach F region E after energy first downward upper mesosphere where reflected upward. modeling results for large-scale Millward et al. (1993a,b). correlation points very direct coupling into subauroral atmosphere.