Abstract
Observational data of scintillation monitoring with typical time about 1 s at the frequency 111 MHz
are presented for the period between December 18 and December 23 when ICME of flare origin resulted
in the geomagnetic storm on December 20-21.2015 with Dst ~- 200 nT. Our estimates show that the mean
ICME speed between the solar corona and the start of IPS enhancement is close to the mean speed between
the corona and the Earth. The strong increase of the night time scintillation level is observed after
ICME coming to the Earth. Scintillation analysis of the individual radio sources shows that the 1 s
night scintillation are of ionospheric origin and can be explained by an order increase of irregularities
drift speed in the disturbed ionosphere.