Investigation of a secular variation impulse using satellite data: The 2003 geomagnetic jerk

Publication: Research - peer-reviewJournal article – Annual report year: 2007

Standard

Investigation of a secular variation impulse using satellite data: The 2003 geomagnetic jerk. / Olsen, Nils; Mandea, M.

In: Earth and Planetary Science Letters, Vol. 255, No. 1-2, 2007, p. 94-105.

Publication: Research - peer-reviewJournal article – Annual report year: 2007

Harvard

APA

CBE

MLA

Vancouver

Author

Olsen, Nils; Mandea, M. / Investigation of a secular variation impulse using satellite data: The 2003 geomagnetic jerk.

In: Earth and Planetary Science Letters, Vol. 255, No. 1-2, 2007, p. 94-105.

Publication: Research - peer-reviewJournal article – Annual report year: 2007

Bibtex

@article{8abfac3bbd874bc2a4cff6b4b38be644,
title = "Investigation of a secular variation impulse using satellite data: The 2003 geomagnetic jerk",
keywords = "magnetic satellite data, secular variation, geomagnetic jerk, geomagnetism",
publisher = "Elsevier BV",
author = "Nils Olsen and M. Mandea",
year = "2007",
doi = "10.1016/j.epsl.2006.12.008",
volume = "255",
number = "1-2",
pages = "94--105",
journal = "Earth and Planetary Science Letters",
issn = "0012-821X",

}

RIS

TY - JOUR

T1 - Investigation of a secular variation impulse using satellite data: The 2003 geomagnetic jerk

A1 - Olsen,Nils

A1 - Mandea,M.

AU - Olsen,Nils

AU - Mandea,M.

PB - Elsevier BV

PY - 2007

Y1 - 2007

N2 - Observatory monthly means provide an excellent opportunity to study the temporal changes of the magnetic field at a given location. Unfortunately, the uneven distribution of the present observatory network makes it difficult to determine the global field change pattern. Recently, we have developed an approach to extract satellite monthly means at a regular network of "virtual observatories" at 400 km altitude, based on CHAMP magnetic measurements. Using monthly means for 2001-2005 from those "virtual observatories" we investigate the space-time structure of the short-period variation of the Earth's magnetic field by means of a Spherical Harmonic Expansion, followed by a separation into external (magnetospheric) and internal part. This allows, for the first time, to study the secular variation globally and directly from satellite magnetic data. Analyzing the time series of the magnetic field at the "virtual observatories" as well as those of the spherical harmonic expansion coefficients, we detect a secular variation impulse (an abrupt jump in the second time derivative of the magnetic field) in the CHAMP satellite data during the first months of the year 2003. The jerk occurred simultaneously in the northern and southern hemispheres in a rather limited area near 90 degrees E, with maximumjerk strength at about 301 latitude, a region also characterized by a strong secular acceleration (second time derivative of the magnetic field). We show that the 2003 geomagnetic jerk is not worldwide in occurrence and that there is an evidence for this event in the length-of-day variation.

AB - Observatory monthly means provide an excellent opportunity to study the temporal changes of the magnetic field at a given location. Unfortunately, the uneven distribution of the present observatory network makes it difficult to determine the global field change pattern. Recently, we have developed an approach to extract satellite monthly means at a regular network of "virtual observatories" at 400 km altitude, based on CHAMP magnetic measurements. Using monthly means for 2001-2005 from those "virtual observatories" we investigate the space-time structure of the short-period variation of the Earth's magnetic field by means of a Spherical Harmonic Expansion, followed by a separation into external (magnetospheric) and internal part. This allows, for the first time, to study the secular variation globally and directly from satellite magnetic data. Analyzing the time series of the magnetic field at the "virtual observatories" as well as those of the spherical harmonic expansion coefficients, we detect a secular variation impulse (an abrupt jump in the second time derivative of the magnetic field) in the CHAMP satellite data during the first months of the year 2003. The jerk occurred simultaneously in the northern and southern hemispheres in a rather limited area near 90 degrees E, with maximumjerk strength at about 301 latitude, a region also characterized by a strong secular acceleration (second time derivative of the magnetic field). We show that the 2003 geomagnetic jerk is not worldwide in occurrence and that there is an evidence for this event in the length-of-day variation.

KW - magnetic satellite data

KW - secular variation

KW - geomagnetic jerk

KW - geomagnetism

U2 - 10.1016/j.epsl.2006.12.008

DO - 10.1016/j.epsl.2006.12.008

JO - Earth and Planetary Science Letters

JF - Earth and Planetary Science Letters

SN - 0012-821X

IS - 1-2

VL - 255

SP - 94

EP - 105

ER -