Fig. 3From: Solar and geomagnetic activity dependence of 150-km echoes observed by the Equatorial Atmosphere Radar in IndonesiaMatrix of the occurrence rate of 150-km echoes against the EUV flux on the same day and \(\Sigma\)Kp index on a the same day, b 1 day before, and c 2 days before. The number in each cell denotes the occurrence rate in percentage within the range of the two indicesBack to article page