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Geomagnetic jerks in the polar regions
Language
English
Obiettivo Specifico
3.4. Geomagnetismo
Status
Published
JCR Journal
JCR Journal
Peer review journal
Yes
Title of the book
Issue/vol(year)
/36 (2009)
Publisher
AGU
Pages (printed)
L15304
Issued date
August 8, 2009
Abstract
The occurrence of geomagnetic jerks over the Arctic and Antarctic regions is here investigated. Maps of geomagnetic secular acceleration over the polar regions are produced from the CM4 and CHAOS models and the occurrence of geomagnetic jerks is associated with jumps in secular acceleration. The obtained results confirm that in Antarctica geomagnetic jerks systematically follow geomagnetic jerks in the Arctic region with a time delay
from one to three years. Evidence is found of an abrupt change in secular acceleration in both polar regions around 1985, suggesting that the 1985 local jerk could actually be a worldwide event. Combining our results with the results previously obtained on the occurrence of a geomagnetic jerk
at low-mid latitudes around 2003, we support the hypothesis of a global extension of an event occurred at the beginning of the 21st century.
from one to three years. Evidence is found of an abrupt change in secular acceleration in both polar regions around 1985, suggesting that the 1985 local jerk could actually be a worldwide event. Combining our results with the results previously obtained on the occurrence of a geomagnetic jerk
at low-mid latitudes around 2003, we support the hypothesis of a global extension of an event occurred at the beginning of the 21st century.
References
Alexandrescu, M., D. Gibert, G. Hulot, J. L. Moue¨l, and G. Saracco (1995),
Detection of geomagnetic jerks using wavelet analysis, J. Geophys. Res.,
100, 12,557– 12,572.
Alexandrescu, M., D. Gibert, G. Hulot, J. L. Moue¨l, and G. Saracco (1996),
Worldwide wavelet analysis of geomagnetic jerks, J. Geophys. Res., 101,
21,975– 21,994.
Chambodut, A., and M. Mandea (2005), Evidence for geomagnetic jerks in
comprehensive models, Earth Planets Space, 57, 139– 149.
Chambodut, A., C. Eymin, and M. Mandea (2007), Geomagnetic jerks from
the Earth’s surface to the top of the core, Earth Planets Space, 59, 675–
684.
De Michelis, P., and R. Tozzi (2005), A local intermittency measure (LIM)
approach to the detection of geomagnetic jerks, Earth Planet. Sci. Lett.,
235, 261– 272, doi:10.1016/j.espl.2005.04.001.
De Michelis, P., L. Cafarella, and A. Meloni (1998),Worldwide character of
the 1991 geomagnetic jerk, Geophys. Res. Lett., 25, 377–380.
Kotze´, P. (2003), The time-varying geomagnetic field of southern africa,
Earth Planets Space, 55, 111–116.
Malin, S., and B. Hodder (1982),Was the 1970 geomagnetic jerk of internal
or external origin?, Nature, 296, 726–728.
Mandea, M., E. Bellanger, and J. L. Moue¨l (2000), A geomagnetic jerk for
the end of the 20th century?, Earth Planet. Sci. Lett., 183, 369– 373.
Olsen, N., and M. Mandea (2007), Investigation of a secular variation
impulse using satellite data: The 2003 geomagnetic jerk, Earth Planet.
Sci. Lett., 255, 94– 105, doi:10.1016/j.epsl.2006.12.008.
Olsen, N., and M. Mandea (2008), Rapidly changing flows in the Earth’s
core, Nat. Geosci., 1, 390–394, doi:10.1038/ngeo203.
Olsen, N., H. Lu¨hr, T. Sabaka, M. Mandea, M. Rother, L. Tofner-Clausen,
and S. Choi (2006), CHAOS-a model of the earth’s magnetic field
derived from CHAMP, Ørsted, and SAC-C magnetic satellite data,
Geophys. J. Int., 166, 67–75, doi:10.1111/j.1365-246X.2006.02959.x.
Pinheiro, K., and A. Jackson (2008), Can a 1-D mantle electrical conductivity
model generate magnetic jerk differential time delays?, Geophys.
J. Int., 173, 781–792, doi:10.1111/j.1365-246X.2008.03762.x.
Sabaka, T., N. Olsen, and R. Langel (2002), A comprehensive model of the
quiet-time, near-Earth magnetic field: Phase 3, Geophys. J. Int., 151, 32–68.
Sabaka, T., N. Olsen, and M. Purucker (2004), Extending comprehensive
models of the Earth’s magnetic field with Ørsted and CHAMP data,
Geophys. J. Int., 159, 521– 547.
Wessel, P., and W. H. F. Smith (1991), Free software helps map and display
data, Eos Trans. AGU, 72(41), 441.
Detection of geomagnetic jerks using wavelet analysis, J. Geophys. Res.,
100, 12,557– 12,572.
Alexandrescu, M., D. Gibert, G. Hulot, J. L. Moue¨l, and G. Saracco (1996),
Worldwide wavelet analysis of geomagnetic jerks, J. Geophys. Res., 101,
21,975– 21,994.
Chambodut, A., and M. Mandea (2005), Evidence for geomagnetic jerks in
comprehensive models, Earth Planets Space, 57, 139– 149.
Chambodut, A., C. Eymin, and M. Mandea (2007), Geomagnetic jerks from
the Earth’s surface to the top of the core, Earth Planets Space, 59, 675–
684.
De Michelis, P., and R. Tozzi (2005), A local intermittency measure (LIM)
approach to the detection of geomagnetic jerks, Earth Planet. Sci. Lett.,
235, 261– 272, doi:10.1016/j.espl.2005.04.001.
De Michelis, P., L. Cafarella, and A. Meloni (1998),Worldwide character of
the 1991 geomagnetic jerk, Geophys. Res. Lett., 25, 377–380.
Kotze´, P. (2003), The time-varying geomagnetic field of southern africa,
Earth Planets Space, 55, 111–116.
Malin, S., and B. Hodder (1982),Was the 1970 geomagnetic jerk of internal
or external origin?, Nature, 296, 726–728.
Mandea, M., E. Bellanger, and J. L. Moue¨l (2000), A geomagnetic jerk for
the end of the 20th century?, Earth Planet. Sci. Lett., 183, 369– 373.
Olsen, N., and M. Mandea (2007), Investigation of a secular variation
impulse using satellite data: The 2003 geomagnetic jerk, Earth Planet.
Sci. Lett., 255, 94– 105, doi:10.1016/j.epsl.2006.12.008.
Olsen, N., and M. Mandea (2008), Rapidly changing flows in the Earth’s
core, Nat. Geosci., 1, 390–394, doi:10.1038/ngeo203.
Olsen, N., H. Lu¨hr, T. Sabaka, M. Mandea, M. Rother, L. Tofner-Clausen,
and S. Choi (2006), CHAOS-a model of the earth’s magnetic field
derived from CHAMP, Ørsted, and SAC-C magnetic satellite data,
Geophys. J. Int., 166, 67–75, doi:10.1111/j.1365-246X.2006.02959.x.
Pinheiro, K., and A. Jackson (2008), Can a 1-D mantle electrical conductivity
model generate magnetic jerk differential time delays?, Geophys.
J. Int., 173, 781–792, doi:10.1111/j.1365-246X.2008.03762.x.
Sabaka, T., N. Olsen, and R. Langel (2002), A comprehensive model of the
quiet-time, near-Earth magnetic field: Phase 3, Geophys. J. Int., 151, 32–68.
Sabaka, T., N. Olsen, and M. Purucker (2004), Extending comprehensive
models of the Earth’s magnetic field with Ørsted and CHAMP data,
Geophys. J. Int., 159, 521– 547.
Wessel, P., and W. H. F. Smith (1991), Free software helps map and display
data, Eos Trans. AGU, 72(41), 441.
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