{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,25]],"date-time":"2026-06-25T19:58:21Z","timestamp":1782417501290,"version":"3.54.5"},"reference-count":12,"publisher":"STEF92 Technology","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2022,11,15]]},"abstract":"<jats:p>The study of ultra-low frequency (ULF) waves and geomagnetic pulsations plays an important role in better understanding the mechanisms of their generation and spread in the magnetosphere and on the ground. The magnetospheric ULF waves, which provide useful information about the conditions in the solar wind and in the magnetosphere, can be detected on the ground by different types of magnetometers and recorded as geomagnetic pulsations \ufffd continuous and irregular. This paper aims to study the characteristics of Pc5 geomagnetic continuous pulsations recorded at mid latitudes during the strong geomagnetic storm (Kp =7) that occurred on May 12, 2021. The sets of time series of data at sampling period 1s, recorded along the three geomagnetic directions (X, Y and Z), are shown and analyzed. A spectral analysis, based on the Morlet Wavelet transform, is applied. It shows powerful geomagnetic disturbances in the Pc5 band (1.7-6.7 mHz) in two-time intervals: 00-02 UTC- before the beginning of the storm and 10-15 UTC- during the storm. Furthermore, the Fast Fourier Transform (FFT) band pass filter is applied to the data series, and Pc5 pulsations are shown. It was concluded that their emergence was correlated with the dynamics of changes in the interplanetary magnetic field (IMF) Bz component, solar wind plasma speed, and flow dynamic pressure.<\/jats:p>","DOI":"10.5593\/sgem2022\/1.1\/s05.063","type":"proceedings-article","created":{"date-parts":[[2023,2,13]],"date-time":"2023-02-13T05:06:21Z","timestamp":1676264781000},"page":"541-548","source":"Crossref","is-referenced-by-count":1,"title":["Pc5 PULSATIONS OBSERVED DURING THE GEOMAGNETIC STORM ON 12 MAY 2021"],"prefix":"10.5593","volume":"22","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8245-5604","authenticated-orcid":true,"given":"Maria","family":"Chamati","sequence":"first","affiliation":[{"name":"National Institute of Geophysics, Geodesy and Geography - Bulgarian Academy of Sciences","place":["Bulgaria"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Borislav","family":"Andonov","sequence":"additional","affiliation":[{"name":"National Institute of Geophysics, Geodesy and Geography - Bulgarian Academy of Sciences","place":["Bulgaria"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"3602","reference":[{"key":"ref=1","doi-asserted-by":"crossref","unstructured":"[1] McPherron RL. Magnetic Pulsations: Their Sources and Relationto Solar Wind and Geomagnetic Activity. Surv Geophys 2005;26:545\ufffd92. https:\/\/doi.org\/10.1007\/s10712- 005-1758-7.","DOI":"10.1007\/s10712-005-1758-7"},{"key":"ref=2","doi-asserted-by":"crossref","unstructured":"[2] Pilipenko V, Kozyreva O, Belakhovsky V, Engebretson MJ, Samsonov S. Generation of magnetic and particle Pc5 pulsations during the recovery phase of strong magnetic storms. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 2010;466:3363\ufffd90. https:\/\/doi.org\/10.1098\/rspa.2010.0079.","DOI":"10.1098\/rspa.2010.0079"},{"key":"ref=3","doi-asserted-by":"crossref","unstructured":"[3] Yumoto K, Saito T. Hydromagnetic waves driven by velocity shear instability in the magnetospheric boundary layer. Planetary and Space Science 1980;28:789\ufffd98. https:\/\/doi.org\/10.1016\/0032-0633(80)90076-8.","DOI":"10.1016\/0032-0633(80)90076-8"},{"key":"ref=4","doi-asserted-by":"crossref","unstructured":"[4] Kim K-H, Cattell CA, Lee D-H, Takahashi K, Yumoto K, Shiokawa K, et al. Magnetospheric responses to sudden and quasiperiodic solar wind variations. Journal of Geophysical Research: Space Physics 2002;107:SMP 36-1-SMP 36-12. https:\/\/doi.org\/10.1029\/2002JA009342.","DOI":"10.1029\/2002JA009342"},{"key":"ref=5","doi-asserted-by":"crossref","unstructured":"[5] Takahashi K, Ukhorskiy AY. Solar wind control of Pc5 pulsation power at geosynchronous orbit. Journal of Geophysical Research: Space Physics 2007;112. https:\/\/doi.org\/10.1029\/2007JA012483.","DOI":"10.1029\/2007JA012483"},{"key":"ref=6","unstructured":"[6] Heilig B, Beggan C, Lichtenberger J. Natural sources of geomagnetic field variations. 2018."},{"key":"ref=7","doi-asserted-by":"crossref","unstructured":"[7] Kepko L, Spence HE, Singer HJ. ULF waves in the solar wind as direct drivers of magnetospheric pulsations. Geophysical Research Letters 2002;29:39-1-39\ufffd4. https:\/\/doi.org\/10.1029\/2001GL014405.","DOI":"10.1029\/2001GL014405"},{"key":"ref=8","doi-asserted-by":"crossref","unstructured":"[8] Rostoker G, Skone S, Baker DN. On the origin of relativistic electrons in the magnetosphere associated with some geomagnetic storms. Geophysical Research Letters 1998;25:3701\ufffd4. https:\/\/doi.org\/10.1029\/98GL02801.","DOI":"10.1029\/98GL02801"},{"key":"ref=9","doi-asserted-by":"crossref","unstructured":"[9] Friedel RHW, Reeves GD, Obara T. Relativistic electron dynamics in the inner magnetosphere \ufffd a review. Journal of Atmospheric and Solar-Terrestrial Physics 2002;64:265\ufffd82. https:\/\/doi.org\/10.1016\/S1364-6826(01)00088-8.","DOI":"10.1016\/S1364-6826(01)00088-8"},{"key":"ref=10","doi-asserted-by":"crossref","unstructured":"[10] Potapov A, Guglielmi A, Tsegmed B, Kultima J. Global Pc5 event during 29\ufffd31 October 2003 magnetic storm. Advances in Space Research 2006;38:1582\ufffd6. https:\/\/doi.org\/10.1016\/j.asr.2006.05.010.","DOI":"10.1016\/j.asr.2006.05.010"},{"key":"ref=11","doi-asserted-by":"crossref","unstructured":"[11] Kleimenova NG, Kozyreva OV. Penetration of Pc5 geomagnetic pulsations to unusually low latitudes during the recovery phase of a superstrong magnetic storm of October 31, 2003. Geomagnetism and Aeronomy 2009;49:1199\ufffd203. https:\/\/doi.org\/10.1134\/S0016793209080325.","DOI":"10.1134\/S0016793209080325"},{"key":"ref=12","unstructured":"[12] 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\ufffd6."}],"event":{"name":"22nd SGEM International Multidisciplinary Scientific GeoConference 2022","theme":"Earth and Planetary Sciences","location":"Albena, BG","acronym":"SGEM2022","number":"22","sponsor":["SGEM WORLD SCIENCE (SWS) Scholarly Society, Austria"],"start":{"date-parts":[[2022,7,4]]},"end":{"date-parts":[[2022,7,10]]}},"container-title":["SGEM International Multidisciplinary Scientific GeoConference\ufffd EXPO Proceedings","22nd SGEM International Multidisciplinary Scientific GeoConference Proceedings 2022, Science and Technologies in Geology, Exploration And Mining"],"original-title":[],"deposited":{"date-parts":[[2026,6,25]],"date-time":"2026-06-25T19:25:21Z","timestamp":1782415521000},"score":1,"resource":{"primary":{"URL":"https:\/\/epslibrary.at\/items\/0b15f1fb-694c-4acd-89b6-3f4487c2190c\/pc5-pulsations-observed-during-the-geomagnetic-storm-on-12-may-2021"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,11,15]]},"references-count":12,"URL":"https:\/\/doi.org\/10.5593\/sgem2022\/1.1\/s05.063","relation":{},"ISSN":["1314-2704"],"issn-type":[{"value":"1314-2704","type":"print"}],"subject":[],"published":{"date-parts":[[2022,11,15]]}}}