disturbances on the nightside and dayside middle latitude

Abstract. In this paper, we present further observational ev-idence for the transpolar propagation of large-scale travel-ing ionospheric disturbances (LSTIDs) from their nightside source region to the dayside reported by Cai et al. (2011). Slant total electron content (STEC) observed by longitudi-nally aligned GPS receiver chains in North American and European sectors was analyzed to demonstrate presences of LSTIDs at both nightside and dayside mid-latitude. Signa-tures of TID were inferred from phase difference in time se-ries of STEC perturbations (TECP) derived from measure-ments of ground-based GPS receivers, which are separated by hundreds of kilometers longitudinally. Periods of the day-time and nighttime ionospheric disturbances were estimated to be around 128 min, being in good agreement with that of the transpolar AGW (atmospheric gravity wave) recorde