SUDDEN ENHANCEMENTS OF ATMOSPHERICS - SEA Month: MAY YEAR: 2021 Observing Station: OBSERVATORY U P I C E CZECH REPUBLIC Lat.: 50 30 26.6 N Sea level: 416 m Long.: 16 00 43.5 E Frequency: 27 kHz Band pass: 308 Hz a 3 dB Chart speed: 3.4 cm/H Recorder time constant: 27 sec Date Start End Max. Imp. Def. Dur. Type REMARKS UT UT UT SEA min. 08 1246 1340U 1253 1 2 54 6 22 0609 0700 0620 1 2 51 5 1708 1752 1715 1 3 44 5 23 1102 1134 1112 1 3 32 5 Evaluated by J.Klimes