ANGEO Annales Geophysicae ANGEO Ann. Geophys. 1432-0576 Copernicus Publications Göttingen, Germany 10.5194/angeo-25-2185-2007 Observational evidence of coupling between quasi-periodic echoes and medium scale traveling ionospheric disturbances Saito S. 1 Yamamoto M. 2 Hashiguchi H. 2 Maegawa A. 2 Saito A. 3 National Institute of Information and Communications Technology, Nukui-kita 4-2-1, Koganei, Tokyo 184-8795, Japan Research Institute for Sustainable Humanosphere, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan Department of Geophysics, Faculty of Science, Kyoto University, Japan 06 11 2007 25 10 2185 2194 Copyright: © 2007 S. Saito et al. 2007 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://angeo.copernicus.org/articles/25/2185/2007/angeo-25-2185-2007.html The full text article is available as a PDF file from https://angeo.copernicus.org/articles/25/2185/2007/angeo-25-2185-2007.pdf

We have found that quasi-periodic (QP) echoes in the E region were well defined when medium scale traveling ionospheric disturbances (MSTIDs) in the F region were present. The appearance and disappearance of the MSTIDs observed with the dense GPS receiver network are well correlated with the development and decay of QP echoes observed with the Middle-and-Upper atmosphere (MU) radar. Interferometric imaging of the QP echoes obtained using the MU radar shows that bands of echoing regions aligned northwest to southeast drift southwestward, and their wavefront and propagation direction are the same as those of MSTIDs. This result confirms the expectation of Hysell et al. (2002) who observed band structures in QP echoes by using the MU radar and suggested their relation to MSTIDs. We found observational evidence that the midlatitude E- and F regions are coupled through the geomagnetic field line, although we could not clearly ascertain which of the two regions is the source.

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