Equatorial electrojet at African longitudes: first results from magnetic measurements
In the framework of the French participation in the International Equatorial Electrojet Year (IEEY), ten magnetotelluric stations were installed between November 1992 and November 1994 along a 1200-km-long meridian profile, between Lamto (latitude 6.2°N, Côte d'Ivoire) to the south and Tomb...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
1998-06-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/16/658/1998/angeo-16-658-1998.pdf |
| _version_ | 1818110816441860096 |
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| author | V. Doumouya J. Vassal Y. Cohen O. Fambitakoye M. Menvielle |
| author_facet | V. Doumouya J. Vassal Y. Cohen O. Fambitakoye M. Menvielle |
| author_sort | V. Doumouya |
| collection | DOAJ |
| description | In the framework of the French participation
in the International Equatorial Electrojet Year (IEEY), ten magnetotelluric
stations were installed between November 1992 and November 1994 along a
1200-km-long meridian profile, between Lamto (latitude 6.2°N, Côte d'Ivoire)
to the south and Tombouctou (latitude 16.7°N, Mali) to the north. These
stations measured digitally the three components of the magnetic field and the
two components of the telluric electric field, and operated over a period of 20
months. The magnetic data is used to study the features of the equatorial
electrojet (EEJ) in West African longitude. The measurement of the telluric
electric field variations will be presented elsewhere. Hourly mean values are
used to study the morphological structure of the regular diurnal variation S<sub>R</sub>
of the three components (<i>H</i>, <i>D</i>, and <i>Z</i>) of the earth magnetic
field and to characterize the EEJ during magnetically quiet days. The
occurrences of the counter-electrojet (CEJ) are set forth, emphasizing its
seasonal variability. Assumed to be a current ribbon, the EEJ main parameters
(the position of its center, its width, and the amplitude of its current density
at the center) are determined. A preliminary analysis of the time variations of
these parameters is presented over period of 20 months (from January 1993 to
August 1994). Results are compared with those obtained during previous
experiments of the same kind. |
| first_indexed | 2024-12-11T02:53:10Z |
| format | Article |
| id | doaj.art-edafaae18352439e966ac17376a0a09c |
| institution | Directory Open Access Journal |
| issn | 0992-7689 1432-0576 |
| language | English |
| last_indexed | 2024-12-11T02:53:10Z |
| publishDate | 1998-06-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Annales Geophysicae |
| spelling | doaj.art-edafaae18352439e966ac17376a0a09c2022-12-22T01:23:14ZengCopernicus PublicationsAnnales Geophysicae0992-76891432-05761998-06-011665866610.1007/s00585-998-0658-9Equatorial electrojet at African longitudes: first results from magnetic measurementsV. Doumouya0J. Vassal1Y. Cohen2O. Fambitakoye3M. Menvielle4Laboratoire de Physique de l'Atmosphère, Université d'Abidjan, Abidjan, Ivory CoastLaboratoire de Géophysique, ORSTOM, 32 av. Henri-Varagnat, F-93143 Bondy Cedex, FranceLaboratoire de Géomagnétisme, IPGP, B89, 4 Place Jussieu, F-75252 Paris Cedex 05, FranceLaboratoire de Géophysique, ORSTOM, 32 av. Henri-Varagnat, F-93143 Bondy Cedex, FranceCETP CNRS, 4 Avenue de Neptune, F-94107 Saint-Maur Des Fossés Cedex,FranceIn the framework of the French participation in the International Equatorial Electrojet Year (IEEY), ten magnetotelluric stations were installed between November 1992 and November 1994 along a 1200-km-long meridian profile, between Lamto (latitude 6.2°N, Côte d'Ivoire) to the south and Tombouctou (latitude 16.7°N, Mali) to the north. These stations measured digitally the three components of the magnetic field and the two components of the telluric electric field, and operated over a period of 20 months. The magnetic data is used to study the features of the equatorial electrojet (EEJ) in West African longitude. The measurement of the telluric electric field variations will be presented elsewhere. Hourly mean values are used to study the morphological structure of the regular diurnal variation S<sub>R</sub> of the three components (<i>H</i>, <i>D</i>, and <i>Z</i>) of the earth magnetic field and to characterize the EEJ during magnetically quiet days. The occurrences of the counter-electrojet (CEJ) are set forth, emphasizing its seasonal variability. Assumed to be a current ribbon, the EEJ main parameters (the position of its center, its width, and the amplitude of its current density at the center) are determined. A preliminary analysis of the time variations of these parameters is presented over period of 20 months (from January 1993 to August 1994). Results are compared with those obtained during previous experiments of the same kind.https://www.ann-geophys.net/16/658/1998/angeo-16-658-1998.pdf |
| spellingShingle | V. Doumouya J. Vassal Y. Cohen O. Fambitakoye M. Menvielle Equatorial electrojet at African longitudes: first results from magnetic measurements Annales Geophysicae |
| title | Equatorial electrojet at African longitudes: first results from magnetic measurements |
| title_full | Equatorial electrojet at African longitudes: first results from magnetic measurements |
| title_fullStr | Equatorial electrojet at African longitudes: first results from magnetic measurements |
| title_full_unstemmed | Equatorial electrojet at African longitudes: first results from magnetic measurements |
| title_short | Equatorial electrojet at African longitudes: first results from magnetic measurements |
| title_sort | equatorial electrojet at african longitudes first results from magnetic measurements |
| url | https://www.ann-geophys.net/16/658/1998/angeo-16-658-1998.pdf |
| work_keys_str_mv | AT vdoumouya equatorialelectrojetatafricanlongitudesfirstresultsfrommagneticmeasurements AT jvassal equatorialelectrojetatafricanlongitudesfirstresultsfrommagneticmeasurements AT ycohen equatorialelectrojetatafricanlongitudesfirstresultsfrommagneticmeasurements AT ofambitakoye equatorialelectrojetatafricanlongitudesfirstresultsfrommagneticmeasurements AT mmenvielle equatorialelectrojetatafricanlongitudesfirstresultsfrommagneticmeasurements |