A . Saito 1,2 , M.C. Kelley 1 , T. Tsugawa 2 , J.J. Makela 1 , Y. Otsuka 3 , and S. Miyazaki 4
description
Transcript of A . Saito 1,2 , M.C. Kelley 1 , T. Tsugawa 2 , J.J. Makela 1 , Y. Otsuka 3 , and S. Miyazaki 4
Seasonal dependence of the nighttime traveling ionospheric disturbances
in the mid-latitude ionosphereA . Saito1,2, M.C. Kelley1, T. Tsugawa2, J.J. Makela1,
Y. Otsuka3, and S. Miyazaki4
1. School of Electrical and Computer Engineering, Cornell University 2. Department of Geophysics, Graduate School of Science, Kyoto University3. Solar-Terrestrial Environment Laboratory, Nagoya University4. 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 MSTIDs
May 16-24, 1998 Geomagnetic Activity: Kp
Kp:19 17+ 17
11- 18 22
14- 20- 21
Summer
Equinox
Winter
Standard deviation of TEC Ratio to the background TEC
Standard deviation of TECTsukuba
January 1994 – August 2000
Ratio to the background TECTsukuba
January 1994 – August 2000
CGM-Lat: 38.6 (Receiver 0001) CGM-Lat: 33.3 (Receiver 0183)
CGM-Lat: 21.5 (Receiver 0494)CGM-Lat: 27.4 (Receiver 0428)
European Sector: NotoLong: 15.0, Lat: 36.9, CGM-Lat: 29.1
West Pacific Sector (South): Alice SpringsLong: 133.9, Lat: -23.7, CGM-Lat: -34.2
American Sector (South): La PlataLong: 302.1, Lat: -34.9, CGM-Lat: -23.1
American Sector (South): IsabellaLong: 292.9, Lat: 18.5, CGM-Lat: 28.9
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]