Seasonal evolution of Sq current system at sub-auroral latitude
The quiet-time (ΣKp ≤ 3) daily variations of the geomagnetic field at the Indian Antarctic station, Maitri (Geographic Coord.: 70.75°S, 11.73°E; Geomagnetic Coord.: 66.84°S, 56.29°E) during two consecutive years of a solar minimum are considered in order to investigate the characteristics of the sol...
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2012
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ftindinstgeomagn:oai:localhost:123456789/945 2023-05-15T14:04:08+02:00 Seasonal evolution of Sq current system at sub-auroral latitude Vichare, Geeta Rawat, Rahul Hanchinal, A.N. Sinha, Ashwini K. Dhar, Ajay Pathan, B.M. 2012 http://14.139.123.141:8080/jspui/handle/123456789/945 en eng Sq current system Seasonal variation Sub-auroral latitude Solar quiet (Sq) Article 2012 ftindinstgeomagn 2019-11-26T08:39:32Z The quiet-time (ΣKp ≤ 3) daily variations of the geomagnetic field at the Indian Antarctic station, Maitri (Geographic Coord.: 70.75°S, 11.73°E; Geomagnetic Coord.: 66.84°S, 56.29°E) during two consecutive years of a solar minimum are considered in order to investigate the characteristics of the solar quiet (Sq) current system. The present work reports the signatures of the south limb of the Sq current loop of the southern hemisphere over a sub-auroral station. It is observed that the seasonal variation of the Sq current strength over Maitri is strongest during the summer months and weakest during the winter months. In spite of the total darkness during the winter months, an Sq pattern is identified at Maitri. The range of the horizontal field variation in the daily Sq pattern during summer is one order higher than that during winter. An interesting feature regarding the phase of the local time variation in the seasonal pattern is found here. A sharp shift in the time of the peak Sq current to later local times (> 1 hour per month) is observed during January–February and July–August, which may correspond to the transition from the complete presence, or absence, of sunlight to partial sunlight. The differences in the incoming solar UV radiation during such transitions can cause a sudden change in the local ionospheric conductivity pattern, and can also trigger some unusual thermo-tidal activity, that might be responsible for modifying the global Sq pattern. Article in Journal/Newspaper Antarc* Antarctic Indian Institute of Geomagnetism (IIG): Repository Antarctic Indian Maitri ENVELOPE(11.733,11.733,-70.764,-70.764) |
institution |
Open Polar |
collection |
Indian Institute of Geomagnetism (IIG): Repository |
op_collection_id |
ftindinstgeomagn |
language |
English |
topic |
Sq current system Seasonal variation Sub-auroral latitude Solar quiet (Sq) |
spellingShingle |
Sq current system Seasonal variation Sub-auroral latitude Solar quiet (Sq) Vichare, Geeta Rawat, Rahul Hanchinal, A.N. Sinha, Ashwini K. Dhar, Ajay Pathan, B.M. Seasonal evolution of Sq current system at sub-auroral latitude |
topic_facet |
Sq current system Seasonal variation Sub-auroral latitude Solar quiet (Sq) |
description |
The quiet-time (ΣKp ≤ 3) daily variations of the geomagnetic field at the Indian Antarctic station, Maitri (Geographic Coord.: 70.75°S, 11.73°E; Geomagnetic Coord.: 66.84°S, 56.29°E) during two consecutive years of a solar minimum are considered in order to investigate the characteristics of the solar quiet (Sq) current system. The present work reports the signatures of the south limb of the Sq current loop of the southern hemisphere over a sub-auroral station. It is observed that the seasonal variation of the Sq current strength over Maitri is strongest during the summer months and weakest during the winter months. In spite of the total darkness during the winter months, an Sq pattern is identified at Maitri. The range of the horizontal field variation in the daily Sq pattern during summer is one order higher than that during winter. An interesting feature regarding the phase of the local time variation in the seasonal pattern is found here. A sharp shift in the time of the peak Sq current to later local times (> 1 hour per month) is observed during January–February and July–August, which may correspond to the transition from the complete presence, or absence, of sunlight to partial sunlight. The differences in the incoming solar UV radiation during such transitions can cause a sudden change in the local ionospheric conductivity pattern, and can also trigger some unusual thermo-tidal activity, that might be responsible for modifying the global Sq pattern. |
format |
Article in Journal/Newspaper |
author |
Vichare, Geeta Rawat, Rahul Hanchinal, A.N. Sinha, Ashwini K. Dhar, Ajay Pathan, B.M. |
author_facet |
Vichare, Geeta Rawat, Rahul Hanchinal, A.N. Sinha, Ashwini K. Dhar, Ajay Pathan, B.M. |
author_sort |
Vichare, Geeta |
title |
Seasonal evolution of Sq current system at sub-auroral latitude |
title_short |
Seasonal evolution of Sq current system at sub-auroral latitude |
title_full |
Seasonal evolution of Sq current system at sub-auroral latitude |
title_fullStr |
Seasonal evolution of Sq current system at sub-auroral latitude |
title_full_unstemmed |
Seasonal evolution of Sq current system at sub-auroral latitude |
title_sort |
seasonal evolution of sq current system at sub-auroral latitude |
publishDate |
2012 |
url |
http://14.139.123.141:8080/jspui/handle/123456789/945 |
long_lat |
ENVELOPE(11.733,11.733,-70.764,-70.764) |
geographic |
Antarctic Indian Maitri |
geographic_facet |
Antarctic Indian Maitri |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
_version_ |
1766275145656172544 |