Fig. 5From: Solar activity dependence of medium-scale traveling ionospheric disturbances using GPS receivers in JapanLocal time and seasonal variations of a, b horizontal propagation direction and c, d velocity of MSTID in the area of 133.0°–137.0° E and 33.0°–37.0° N under high and low solar activity conditions. Black indicates missing data. The data are shown only when the MSTID occurrence rate in each cell exceeds 50%Back to article page