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Seasonal dependence of the nighttime traveling ionospheric disturbances in the mid-latitude ionosphere. A . Saito 1,2 , M.C. Kelley 1 , T. Tsugawa 2 , J.J. Makela 1 , Y. Otsuka 3 , and S. Miyazaki 4 School of Electrical and Computer Engineering, Cornell University
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Seasonal dependence of the nighttime traveling ionospheric disturbances in the mid-latitude ionosphere A.Saito1,2,M.C. Kelley1, T. Tsugawa2, J.J. Makela1, Y. Otsuka3, and S. Miyazaki4 • School of Electrical and Computer Engineering, Cornell University • Department of Geophysics, Graduate School of Science, Kyoto University • Solar-Terrestrial Environment Laboratory, Nagoya University • Geographical Survey Institute • A GPS network in Japan has detected TEC wave fronts that travel to the southwest in the nighttime. Medium-scale traveling ionosphere disturbances (MSTIDs) • Local time, seasonal, latitudinal and solar cycle dependencies of these MSTIDs
Standard deviation of TEC over the MU radar: amplitude of MSTIDsMay 16-24, 1998 Geomagnetic Activity:SKp SKp:19 17+ 17 11- 18 22 14- 20- 21
Standard deviation of TEC Ratio to the background TEC
Ratio to the background TEC TsukubaJanuary 1994 – August 2000 Standard deviation of TECTsukubaJanuary 1994 – August 2000
CGM-Lat: 38.6 (Receiver 0001) CGM-Lat: 33.3 (Receiver 0183) CGM-Lat: 27.4 (Receiver 0428) CGM-Lat: 21.5 (Receiver 0494)
European Sector: Noto Long: 15.0, Lat: 36.9, CGM-Lat: 29.1 West Pacific Sector (South): Alice Springs Long: 133.9, Lat: -23.7, CGM-Lat: -34.2 American Sector (South): Isabella Long: 292.9, Lat: 18.5, CGM-Lat: 28.9 American Sector (South): La Plata Long: 302.1, Lat: -34.9, CGM-Lat: -23.1
SummaryMedium-scale traveling ionospheric disturbances in the midlatitude ionosphere detected with total electron content observation by GPS receivers. • Propagation velocity:100m/s, wavelength: 300km • Nighttime: Southwestward propagation, Summer and Winter • Daytime: Southward (south-southeastward) propagation, Winter • Daytime peak is common at any longitudes. Nighttime peaks show longitudinal differences. • Day-to-day variation: No geomagnetic activity dependency • Low amplitude in the high solar activity period • Amplitude of nighttime TID is large at lower latitudes. [CGM-Lat: 20-40 degrees]