Scholarly record
ULTRA-LOW FREQUENCY GEOMAGNETIC PULSATIONS OBSERVED AT MID LATITUDES IN PANAGJURISTE, BULGARIA
Abstract
The spectral characteristics of the ULF waves (1mHz -1Hz) provide useful information about the conditions in the solar wind and in the magnetosphere. A series of geomagnetic field variations data are collected by the tri-axial search-coil instrument and acquisition system located at Panagjuriste, Geomagnetic Observatory (PAG), Bulgaria and other series of data are collected from two different instruments located at Conrad Observatory (WIC), Austria and Ebro Observatory (EBR), Spain, which operate within INTERMAGNET - the global network of geomagnetic observatories. We analyze the time series corresponding to the period 00 - 01 UT (02-03 LT) on 29 December 2020. To determine the spectral characteristics of observed geomagnetic pulsations, we apply the autocorrelation analysis to obtain the autocorrelation function and the power spectra, as well as Morlet wavelet analysis of the considered time series. Pulsations with an amplitude modulation period of about 15 min. (~900 s.) and main periods at 84, 75 and 68 seconds are determined. The specific spectral characteristics of these pulsations are obtained on the basis of the Morlet dynamic spectra. They show continuous ULF pulsations represented in four wave “packets” of sinusoidal oscillations with varying periods from 30 seconds till 115 seconds and main periods at 84 s., 75 s. and 68 seconds. We conclude that the recorded pulsations at Geomagnetic Observatory Panagjuriste, Bulgaria, located at mid latitudes, on 29 December 2020 during the time interval 00-01 UT are continuous ULF pulsations within the range Pc4 (45-150 seconds). Similar ULF continuous pulsations in the Pc4 range, with similar power spectra during the same time are observed both at Ebro and Conrad Observatories.
Publication Impact Profile
- Citations
- Scopus - Citation Indexes: 1
- Captures
- Mendeley - Readers: 2
Publication details
References13
McPherron RL. Magnetic Pulsations: Their Sources and Relationto Solar Wind and Geomagnetic Activity. Surv Geophys 2005;26:545–92. DOI: 10.1007/s10712-005-1758-7.
Liu W, Sarris TE, Li X, Ergun R, Angelopoulos V, Bonnell J, et al. Solar wind influence on Pc4 and Pc5 ULF wave activity in the inner magnetosphere. Journal of Geophysical Research: Space Physics 2010;115. DOI: 10.1029/2010JA015299.
Liu W, Sarris TE, Li X, Elkington SR, Ergun R, Angelopoulos V, et al. Electric and magnetic field observations of Pc4 and Pc5 pulsations in the inner magnetosphere: A statistical study. Journal of Geophysical Research: Space Physics 2009;114. DOI: 10.1029/2009JA014243.
Source of Pc4 pulsations observed on the nightside - Takahashi - 2005 - Journal of Geophysical Research: Space Physics - Wiley Online Library n.d. https://agupubs.onlinelibrary.wiley.com/doi/full/DOI: 10.1029/2005JA011093 (accessed February 9, 2021).
Menk FW. Spectral Structure of Mid-Latitude Pc3-4 Geomagnetic Pulsations. Journal of Geomagnetism and Geoelectricity 1988;40:33–61. DOI: 10.5636/jgg.40.33.
Korotova G, Sibeck D, Engebretson M, Wygant J, Thaller S, Spence H, et al. Multipoint spacecraft observations of long-lasting poloidal Pc4 pulsations in the dayside magnetosphere on 1–2 May 2014. Annales Geophysicae 2016;34:985–98. DOI: 10.5194/angeo-34-985-2016.
Chamati, M. Geomagnetic disturbances observed at Panagyuriste (PAG) station, Bulgaria on 7-8th of September 2017 during the geomagnetic storm. Proceedings of the IX National Geophysical Conference, Sofia, Bulgaria: 2018, p. 10–6.
Ghamry E, Lethy A, Arafa-Hamed T, Elaal EA. A comprehensive analysis of the geomagnetic storms occurred during 18 February and 2 March 2014. NRIAG Journal of Astronomy and Geophysics 2016;5:263–8. DOI: 10.1016/j.nrjag.2016.03.001.
Plyasova?Bakounina TA, Kangas J, Mursula K, Molchanov OA, Green AW. Pc 1–2 and Pc 4–5 pulsations observed at a network of high?latitude stations. Journal of Geophysical Research: Space Physics 1996;101:10965–73. DOI: 10.1029/95JA03770.
Cramm R, Glassmeier KH, Othmer C, Fornacon KH, Auster HU, Baumjohann W, et al. A case study of a radially polarized Pc4 event observed by the Equator-S satellite. Annales Geophysicae 2000;18:411–5. DOI: 10.1007/s00585-000-0411-5.
Villante U, Tiberi P. A comprehensive analysis of the occurrence and characteristics of midperiod ULF waves at low latitude. Journal of Geophysical Research: Space Physics 2015;120:1784–802. DOI: 10.1002/2014JA020558.
Andonov B, Muhtarov P, Kutiev I. Analogue model, relating Kp index to solar wind parameters. Journal of Atmospheric and Solar-Terrestrial Physics 2004;66:927–32. DOI: 10.1016/j.jastp.2004.03.006.
http://data.niggg.bas.bg/kp_for/kp_mod_bg.php). n.d.
View or Download full articleAccess options
SWS access login
Login as SWS Scientific CommitteeLogin as SWS Scientific PartnerLogin as SWS AuthorAuthors and approved SWS contributors will read and export their own linked papers after identity matching by SWS profile, email and SGEM GlobalID.
For librarian assistance: [email protected]
Purchase Instant Access
- Article can be downloaded after successful payment.
- Article may be used according to SWS library access terms.
- Article cannot be redistributed.