Storm-time longitudinally propagating asymmetric modes at low latitudes
The westward flowing toroidal ring current at about 2–7 <I>R</I><sub>E</sub> in the Earth's equatorial plane consists of symmetric and asymmetric parts. Zonal mean of <I>H</I> disturbances from longitudinally distributed low latitude stations represents th...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2012-01-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/30/131/2012/angeo-30-131-2012.pdf |
| _version_ | 1811337234638438400 |
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| author | A. K. Singh A. K. Sinha R. Rajaram R. Rajaram B. M. Pathan |
| author_facet | A. K. Singh A. K. Sinha R. Rajaram R. Rajaram B. M. Pathan |
| author_sort | A. K. Singh |
| collection | DOAJ |
| description | The westward flowing toroidal ring current at about 2–7 <I>R</I><sub>E</sub> in the Earth's
equatorial plane consists of symmetric and asymmetric parts. Zonal mean of
<I>H</I> disturbances from longitudinally distributed low latitude stations
represents the symmetric contribution, whereas departure from the zonal mean
gives local time dependent asymmetric component at each of the stations.
Through a standard analysis of closely spaced low latitude geomagnetic data
we demonstrate 24 h periodicity in the asymmetric component of the
storm-time ring current, which is related to the changing local time due to
rotation of the Earth. Detailed examination of shorter period oscillations,
when observed globally, often show westward propagating modes. Eastward
propagating mode was also observed in one case. Based on satellite and radar
observations covering a narrow longitude region, westward and eastward
propagating modes had been reported in earlier studies. In this study, we
report that similar propagating modes which are available on global scale,
can be identified using ground-based magnetometer data. These globally
propagating modes, observed from ground-based studies, find obvious practical
application in diagnostics of the magnetosphere, especially the ring current
region. Simultaneous use of satellite and ground-based data should establish
the morphology of such modes. |
| first_indexed | 2024-04-13T17:51:57Z |
| format | Article |
| id | doaj.art-e817f83a60874321bfcfccb521c998d5 |
| institution | Directory Open Access Journal |
| issn | 0992-7689 1432-0576 |
| language | English |
| last_indexed | 2024-04-13T17:51:57Z |
| publishDate | 2012-01-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Annales Geophysicae |
| spelling | doaj.art-e817f83a60874321bfcfccb521c998d52022-12-22T02:36:40ZengCopernicus PublicationsAnnales Geophysicae0992-76891432-05762012-01-013013114110.5194/angeo-30-131-2012Storm-time longitudinally propagating asymmetric modes at low latitudesA. K. Singh0A. K. Sinha1R. Rajaram2R. Rajaram3B. M. Pathan4Indian Institute of Geomagnetism, Kalamboli Highway, New Panvel (W), Navi Mumbai – 410218, Maharashtra, IndiaIndian Institute of Geomagnetism, Kalamboli Highway, New Panvel (W), Navi Mumbai – 410218, Maharashtra, IndiaIndian Institute of Geomagnetism, Kalamboli Highway, New Panvel (W), Navi Mumbai – 410218, Maharashtra, IndiaMicro Technologies (India) Ltd., MIDC, Mahape, Navi Mumbai – 400709, Maharashtra, IndiaIndian Institute of Geomagnetism, Kalamboli Highway, New Panvel (W), Navi Mumbai – 410218, Maharashtra, IndiaThe westward flowing toroidal ring current at about 2–7 <I>R</I><sub>E</sub> in the Earth's equatorial plane consists of symmetric and asymmetric parts. Zonal mean of <I>H</I> disturbances from longitudinally distributed low latitude stations represents the symmetric contribution, whereas departure from the zonal mean gives local time dependent asymmetric component at each of the stations. Through a standard analysis of closely spaced low latitude geomagnetic data we demonstrate 24 h periodicity in the asymmetric component of the storm-time ring current, which is related to the changing local time due to rotation of the Earth. Detailed examination of shorter period oscillations, when observed globally, often show westward propagating modes. Eastward propagating mode was also observed in one case. Based on satellite and radar observations covering a narrow longitude region, westward and eastward propagating modes had been reported in earlier studies. In this study, we report that similar propagating modes which are available on global scale, can be identified using ground-based magnetometer data. These globally propagating modes, observed from ground-based studies, find obvious practical application in diagnostics of the magnetosphere, especially the ring current region. Simultaneous use of satellite and ground-based data should establish the morphology of such modes.https://www.ann-geophys.net/30/131/2012/angeo-30-131-2012.pdf |
| spellingShingle | A. K. Singh A. K. Sinha R. Rajaram R. Rajaram B. M. Pathan Storm-time longitudinally propagating asymmetric modes at low latitudes Annales Geophysicae |
| title | Storm-time longitudinally propagating asymmetric modes at low latitudes |
| title_full | Storm-time longitudinally propagating asymmetric modes at low latitudes |
| title_fullStr | Storm-time longitudinally propagating asymmetric modes at low latitudes |
| title_full_unstemmed | Storm-time longitudinally propagating asymmetric modes at low latitudes |
| title_short | Storm-time longitudinally propagating asymmetric modes at low latitudes |
| title_sort | storm time longitudinally propagating asymmetric modes at low latitudes |
| url | https://www.ann-geophys.net/30/131/2012/angeo-30-131-2012.pdf |
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