Oulujärvi MAXIMUM TIME DERIVATIVE (0.01 nT/sec) OF HORIZONTAL COMPONENT (X,Y) Time (UT) 01...03 04...06 07...09 10...12 13...15 16...18 19...21 22...24 2023 12 1 29 29 34 17 11 10 10 13 9 60 30 129 138 135 100 55 32 190 120 50 331 135 91 53 2023 12 2 65 66 33 52 29 18 17 7 3 4 4 11 10 4 5 17 23 9 3 5 6 20 7 11