Occurrence characteristics of electromagnetic ion cyclotron waves at sub-auroral Antarctic station Maitri during solar cycle 24
Abstract We present a statistical study of electromagnetic ion cyclotron (EMIC) waves observed at Antarctic station (geographic $$70.7{^\circ }\,\hbox {S}$$ 70.7 ∘ S , $$11.8{^\circ }\,\hbox {E}$$ 11.8 ∘ E , $$L=5$$ L = 5 ) on quiet and disturbed days during 2011–2017. The data span a fairly good pe...
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ftdoajarticles:oai:doaj.org/article:12ee52b4b18b483aba89e48bddeef52a 2023-05-15T13:52:04+02:00 Occurrence characteristics of electromagnetic ion cyclotron waves at sub-auroral Antarctic station Maitri during solar cycle 24 Aditi Upadhyay Bharati Kakad Amar Kakad Yoshiharu Omura Ashwini Kumar Sinha 2020-03-01T00:00:00Z https://doi.org/10.1186/s40623-020-01157-7 https://doaj.org/article/12ee52b4b18b483aba89e48bddeef52a EN eng SpringerOpen http://link.springer.com/article/10.1186/s40623-020-01157-7 https://doaj.org/toc/1880-5981 doi:10.1186/s40623-020-01157-7 1880-5981 https://doaj.org/article/12ee52b4b18b483aba89e48bddeef52a Earth, Planets and Space, Vol 72, Iss 1, Pp 1-16 (2020) ULF wave EMIC occurrence Solar cycle Induction coil magnetometer Geography. Anthropology. Recreation G Geodesy QB275-343 Geology QE1-996.5 article 2020 ftdoajarticles https://doi.org/10.1186/s40623-020-01157-7 2022-12-31T13:07:03Z Abstract We present a statistical study of electromagnetic ion cyclotron (EMIC) waves observed at Antarctic station (geographic $$70.7{^\circ }\,\hbox {S}$$ 70.7 ∘ S , $$11.8{^\circ }\,\hbox {E}$$ 11.8 ∘ E , $$L=5$$ L = 5 ) on quiet and disturbed days during 2011–2017. The data span a fairly good period of both ascending and descending phases of the solar cycle 24, which has witnessed extremely low activity. We noted EMIC wave occurrence by examining wave power in different frequency ranges in the spectrogram. EMIC wave occurrence during ascending and descending phases of solar cycle 24, its local time, seasonal dependence and durations have been examined. There are total 2367 days for which data are available. Overall, EMIC waves are observed for 3166.5 h ( $$\approx 5.57\%$$ ≈ 5.57 % of total duration) which has contributions from 1263 days. We find a significantly higher EMIC wave occurrence during the descending phase ( $$\approx$$ ≈ 6.83%) as compared to the ascending phase ( $$\approx$$ ≈ 4.08%) of the solar cycle, which implies nearly a twofold increase in EMIC wave occurrence. This feature is attributed to the higher solar wind dynamic pressure during descending phase of solar activity. There is no evident difference in the percentage occurrence of EMIC waves on magnetically disturbed and quiet days. On ground, EMIC waves show marginally higher occurrence during winter as compared to summer. This seasonal tendency is attributed to lower electron densities and conductivities in the ionosphere, which can affect the propagation of EMIC waves through ionospheric ducts. In local time, the probability distribution function of EMIC wave occurrence shows enhancement during 11.7–20.7 LT (i.e., afternoon–dusk sector). Daily durations of EMIC waves are in the range of 5–1015 min and it is noted that the longer duration (240–1015 min) events are prevalent on quiet days and are mostly seen during the descending phase of solar cycle. Article in Journal/Newspaper Antarc* Antarctic Directory of Open Access Journals: DOAJ Articles Antarctic Maitri ENVELOPE(11.733,11.733,-70.764,-70.764) Earth, Planets and Space 72 1 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
ULF wave EMIC occurrence Solar cycle Induction coil magnetometer Geography. Anthropology. Recreation G Geodesy QB275-343 Geology QE1-996.5 |
spellingShingle |
ULF wave EMIC occurrence Solar cycle Induction coil magnetometer Geography. Anthropology. Recreation G Geodesy QB275-343 Geology QE1-996.5 Aditi Upadhyay Bharati Kakad Amar Kakad Yoshiharu Omura Ashwini Kumar Sinha Occurrence characteristics of electromagnetic ion cyclotron waves at sub-auroral Antarctic station Maitri during solar cycle 24 |
topic_facet |
ULF wave EMIC occurrence Solar cycle Induction coil magnetometer Geography. Anthropology. Recreation G Geodesy QB275-343 Geology QE1-996.5 |
description |
Abstract We present a statistical study of electromagnetic ion cyclotron (EMIC) waves observed at Antarctic station (geographic $$70.7{^\circ }\,\hbox {S}$$ 70.7 ∘ S , $$11.8{^\circ }\,\hbox {E}$$ 11.8 ∘ E , $$L=5$$ L = 5 ) on quiet and disturbed days during 2011–2017. The data span a fairly good period of both ascending and descending phases of the solar cycle 24, which has witnessed extremely low activity. We noted EMIC wave occurrence by examining wave power in different frequency ranges in the spectrogram. EMIC wave occurrence during ascending and descending phases of solar cycle 24, its local time, seasonal dependence and durations have been examined. There are total 2367 days for which data are available. Overall, EMIC waves are observed for 3166.5 h ( $$\approx 5.57\%$$ ≈ 5.57 % of total duration) which has contributions from 1263 days. We find a significantly higher EMIC wave occurrence during the descending phase ( $$\approx$$ ≈ 6.83%) as compared to the ascending phase ( $$\approx$$ ≈ 4.08%) of the solar cycle, which implies nearly a twofold increase in EMIC wave occurrence. This feature is attributed to the higher solar wind dynamic pressure during descending phase of solar activity. There is no evident difference in the percentage occurrence of EMIC waves on magnetically disturbed and quiet days. On ground, EMIC waves show marginally higher occurrence during winter as compared to summer. This seasonal tendency is attributed to lower electron densities and conductivities in the ionosphere, which can affect the propagation of EMIC waves through ionospheric ducts. In local time, the probability distribution function of EMIC wave occurrence shows enhancement during 11.7–20.7 LT (i.e., afternoon–dusk sector). Daily durations of EMIC waves are in the range of 5–1015 min and it is noted that the longer duration (240–1015 min) events are prevalent on quiet days and are mostly seen during the descending phase of solar cycle. |
format |
Article in Journal/Newspaper |
author |
Aditi Upadhyay Bharati Kakad Amar Kakad Yoshiharu Omura Ashwini Kumar Sinha |
author_facet |
Aditi Upadhyay Bharati Kakad Amar Kakad Yoshiharu Omura Ashwini Kumar Sinha |
author_sort |
Aditi Upadhyay |
title |
Occurrence characteristics of electromagnetic ion cyclotron waves at sub-auroral Antarctic station Maitri during solar cycle 24 |
title_short |
Occurrence characteristics of electromagnetic ion cyclotron waves at sub-auroral Antarctic station Maitri during solar cycle 24 |
title_full |
Occurrence characteristics of electromagnetic ion cyclotron waves at sub-auroral Antarctic station Maitri during solar cycle 24 |
title_fullStr |
Occurrence characteristics of electromagnetic ion cyclotron waves at sub-auroral Antarctic station Maitri during solar cycle 24 |
title_full_unstemmed |
Occurrence characteristics of electromagnetic ion cyclotron waves at sub-auroral Antarctic station Maitri during solar cycle 24 |
title_sort |
occurrence characteristics of electromagnetic ion cyclotron waves at sub-auroral antarctic station maitri during solar cycle 24 |
publisher |
SpringerOpen |
publishDate |
2020 |
url |
https://doi.org/10.1186/s40623-020-01157-7 https://doaj.org/article/12ee52b4b18b483aba89e48bddeef52a |
long_lat |
ENVELOPE(11.733,11.733,-70.764,-70.764) |
geographic |
Antarctic Maitri |
geographic_facet |
Antarctic Maitri |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
Earth, Planets and Space, Vol 72, Iss 1, Pp 1-16 (2020) |
op_relation |
http://link.springer.com/article/10.1186/s40623-020-01157-7 https://doaj.org/toc/1880-5981 doi:10.1186/s40623-020-01157-7 1880-5981 https://doaj.org/article/12ee52b4b18b483aba89e48bddeef52a |
op_doi |
https://doi.org/10.1186/s40623-020-01157-7 |
container_title |
Earth, Planets and Space |
container_volume |
72 |
container_issue |
1 |
_version_ |
1766256305616453632 |