Observations of Pc5 micropulsation-related electric field oscillations in the equatorial ionosphere
A 54.95-MHz coherent backscatter radar, an ionosonde and the magnetometer located at Trivandrum in India (8.5°N, 77°E, 0.5°N dip angle) recorded large-amplitude ionospheric fluctuations and magnetic field fluctuations associated with a Pc5 micropulsation event, which occurred during an intense magne...
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ftdoajarticles:oai:doaj.org/article:d18f0d1c8a174b79bd1536b7709d5447 2023-05-15T16:29:47+02:00 Observations of Pc5 micropulsation-related electric field oscillations in the equatorial ionosphere C. A. Reddy Sudha Ravindran K. S. Viswanathan B. V. Krishna Murthy D. R. K. Rao T. Araki https://doaj.org/article/d18f0d1c8a174b79bd1536b7709d5447 EN eng Copernicus Publications http://www.ann-geophys.net/12/565/1994/angeo-12-565-1994.html https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 0992-7689 1432-0576 https://doaj.org/article/d18f0d1c8a174b79bd1536b7709d5447 Annales Geophysicae, Vol 12, Iss 6, Pp 565-573 (0000) Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 article ftdoajarticles 2022-12-31T13:57:16Z A 54.95-MHz coherent backscatter radar, an ionosonde and the magnetometer located at Trivandrum in India (8.5°N, 77°E, 0.5°N dip angle) recorded large-amplitude ionospheric fluctuations and magnetic field fluctuations associated with a Pc5 micropulsation event, which occurred during an intense magnetic storm on 24 March 1991 (A p =161). Simultaneous 100-nT-level fluctuations are also observed in the H-component at Brorfelde, Denmark (55.6°N gm) and at Narsarsuaq, Greenland (70.6°N gm). Our study of the above observations shows that the E-W electric field fluctuations in the E- and F-regions and the magnetic field fluctuations at Thumba are dominated by a near-sinusoidal oscillation of 10 min during 1730-1900 IST (1200-1330 UT), the amplitude of the electric field oscillation in the equatorial electrojet (EEJ) is 0.1-0.25 mV m -1 and it increases with height, while it is about 1.0 mV m -1 in the F-region, the ground-level H-component oscillation can be accounted for by the ionospheric current oscillation generated by the observed electric field oscillation in the EEJ and the H-component oscillations at Trivandrum and Brorfelde are in phase with each other. The observations are interpreted in terms of a compressional cavity mode resonance in the inner magnetosphere and the associated ionospheric electric field penetrating from high latitudes to the magnetic equator. Article in Journal/Newspaper Greenland Narsarsuaq Directory of Open Access Journals: DOAJ Articles Greenland |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
spellingShingle |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 C. A. Reddy Sudha Ravindran K. S. Viswanathan B. V. Krishna Murthy D. R. K. Rao T. Araki Observations of Pc5 micropulsation-related electric field oscillations in the equatorial ionosphere |
topic_facet |
Science Q Physics QC1-999 Geophysics. Cosmic physics QC801-809 |
description |
A 54.95-MHz coherent backscatter radar, an ionosonde and the magnetometer located at Trivandrum in India (8.5°N, 77°E, 0.5°N dip angle) recorded large-amplitude ionospheric fluctuations and magnetic field fluctuations associated with a Pc5 micropulsation event, which occurred during an intense magnetic storm on 24 March 1991 (A p =161). Simultaneous 100-nT-level fluctuations are also observed in the H-component at Brorfelde, Denmark (55.6°N gm) and at Narsarsuaq, Greenland (70.6°N gm). Our study of the above observations shows that the E-W electric field fluctuations in the E- and F-regions and the magnetic field fluctuations at Thumba are dominated by a near-sinusoidal oscillation of 10 min during 1730-1900 IST (1200-1330 UT), the amplitude of the electric field oscillation in the equatorial electrojet (EEJ) is 0.1-0.25 mV m -1 and it increases with height, while it is about 1.0 mV m -1 in the F-region, the ground-level H-component oscillation can be accounted for by the ionospheric current oscillation generated by the observed electric field oscillation in the EEJ and the H-component oscillations at Trivandrum and Brorfelde are in phase with each other. The observations are interpreted in terms of a compressional cavity mode resonance in the inner magnetosphere and the associated ionospheric electric field penetrating from high latitudes to the magnetic equator. |
format |
Article in Journal/Newspaper |
author |
C. A. Reddy Sudha Ravindran K. S. Viswanathan B. V. Krishna Murthy D. R. K. Rao T. Araki |
author_facet |
C. A. Reddy Sudha Ravindran K. S. Viswanathan B. V. Krishna Murthy D. R. K. Rao T. Araki |
author_sort |
C. A. Reddy |
title |
Observations of Pc5 micropulsation-related electric field oscillations in the equatorial ionosphere |
title_short |
Observations of Pc5 micropulsation-related electric field oscillations in the equatorial ionosphere |
title_full |
Observations of Pc5 micropulsation-related electric field oscillations in the equatorial ionosphere |
title_fullStr |
Observations of Pc5 micropulsation-related electric field oscillations in the equatorial ionosphere |
title_full_unstemmed |
Observations of Pc5 micropulsation-related electric field oscillations in the equatorial ionosphere |
title_sort |
observations of pc5 micropulsation-related electric field oscillations in the equatorial ionosphere |
publisher |
Copernicus Publications |
url |
https://doaj.org/article/d18f0d1c8a174b79bd1536b7709d5447 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Narsarsuaq |
genre_facet |
Greenland Narsarsuaq |
op_source |
Annales Geophysicae, Vol 12, Iss 6, Pp 565-573 (0000) |
op_relation |
http://www.ann-geophys.net/12/565/1994/angeo-12-565-1994.html https://doaj.org/toc/0992-7689 https://doaj.org/toc/1432-0576 0992-7689 1432-0576 https://doaj.org/article/d18f0d1c8a174b79bd1536b7709d5447 |
_version_ |
1766019488713539584 |