SPECTRAL CHARACTERISTICS IN ULF RANGE OF GEOMAGNETIC STORM OBSERVED AT PANAGJURISTE, BULGARIA ON 27-28 SEPTEMBER 2017
On 27-28 September 2017 at Geomagnetic Observatory Panagjuriste (PAG), Bulgaria the geomagnetic storm – class G2 increasing to G3 was observed. It caused disturbances over the ultra-low frequency (ULF) geomagnetic field variations. The time series of the collected data along the X (north-south), the Y (east-west) and Z (vertical) directions are analyzed. Trough Morlet wavelet analysis the dynamic spectra for the X and the Y components are obtained. They show disturbances strongly corresponding with geomagnetic activity and covers all investigated time scales (1-600s). The two most powerful interferences are recorded on 28 September- 09UTC and 21UTC- along the Y component which strongly correspond with Kp index, but not with local K index. They don’t appear along the other two components. It is found that during the time interval 00-03UTC on 28 September the pulsations are recorded along the X component with periodicity that covers time scales 40-110s and main period about 85s, and they are most likely related to injections of energetic plasma.
ULF variations, spectral properties, geomagnetic storm, Panagjuriste
Bulgarian Geophysical Journal, 2021, Vol. 44, DOI: 10.34975/bgj-2021.44.9
Author: Maria Chamati
Affiliation: National Institute of Geophysics, Geodesy and Geography – BAS, str. Acad. G. Bonchev, bl. 3, Sofia 1113, Bulgaria
This work is supported by Contract No D01-404/18.12.2020 (Project “National Geoinformation Center (NGIC)” financed by the National Roadmap for Scientific Infrastructure 2017-2023.
How to cite:
Chamati, M. (2022). Spectral characteristics in ULF range of geomagnetic storm observed at Panagjuriste, Bulgaria on 27-28 september 2017. Bulgarian Geophysical Journal, Vol. 44, p. 109-116. https://doi.org/10.34975/BGJ-2021.44.9