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Holocene geocentric dipole tilt model constrained by sedimentary paleomagnetic data

Nilsson, Andreas LU ; Snowball, Ian LU ; Muscheler, Raimund LU and Bertacchi Uvo, Cintia LU (2010) In Geochemistry Geophysics Geosystems 11. p.08018-08018
Abstract
Paleomagnetic data, although undeniably limited, have been used to constrain complex time-varying geomagnetic field models. Here we present four different versions of a time varying geocentric dipole model for the past approximately 9000 years based on a limited selection of sedimentary paleomagnetic data with good spatial coverage. The robustness of the modeling approach is evaluated using modern magnetic observation station data provided by the World Data Centre for Geomagnetism in Edinburgh and we discuss the magnitude of the error introduced by insufficient data coverage. The prediction in terms of directional variations is tested against paleomagnetic data from 63 different sedimentary sites and compared to results from recently... (More)
Paleomagnetic data, although undeniably limited, have been used to constrain complex time-varying geomagnetic field models. Here we present four different versions of a time varying geocentric dipole model for the past approximately 9000 years based on a limited selection of sedimentary paleomagnetic data with good spatial coverage. The robustness of the modeling approach is evaluated using modern magnetic observation station data provided by the World Data Centre for Geomagnetism in Edinburgh and we discuss the magnitude of the error introduced by insufficient data coverage. The prediction in terms of directional variations is tested against paleomagnetic data from 63 different sedimentary sites and compared to results from recently published spherical harmonic geomagnetic field models. We find that the dipole estimate can explain the paleomagnetic data almost as well as the more complicated spherical harmonic models. Specific areas and records are identified where there are significant differences between the performance of the dipole estimate and the spherical harmonic models. Our results suggest that many of the differences between the dipole model predictions and the paleomagnetic data can be related to poor paleomagnetic quality and/or the lack of accurate and precise time control inherent to some of the records. These results agree with Valet et al. ( 2008) who suggested that the CALS7K. 2 model probably underestimates the dipole contribution in order to reduce the misfit between the inversion and the data. We conclude that better paleomagnetic data and associated time control are needed to improve global geomagnetic field models. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
nondipole field, dipole field, secular variation, paleomagnetism, Holocene
in
Geochemistry Geophysics Geosystems
volume
11
pages
08018 - 08018
publisher
American Geophysical Union
external identifiers
  • wos:000281137500002
  • scopus:77956068722
ISSN
1525-2027
DOI
10.1029/2010GC003118
language
English
LU publication?
yes
id
df1b735c-e2b8-42f5-8783-238312af0873 (old id 1673752)
date added to LUP
2010-09-23 07:57:19
date last changed
2018-05-29 09:45:39
@article{df1b735c-e2b8-42f5-8783-238312af0873,
  abstract     = {Paleomagnetic data, although undeniably limited, have been used to constrain complex time-varying geomagnetic field models. Here we present four different versions of a time varying geocentric dipole model for the past approximately 9000 years based on a limited selection of sedimentary paleomagnetic data with good spatial coverage. The robustness of the modeling approach is evaluated using modern magnetic observation station data provided by the World Data Centre for Geomagnetism in Edinburgh and we discuss the magnitude of the error introduced by insufficient data coverage. The prediction in terms of directional variations is tested against paleomagnetic data from 63 different sedimentary sites and compared to results from recently published spherical harmonic geomagnetic field models. We find that the dipole estimate can explain the paleomagnetic data almost as well as the more complicated spherical harmonic models. Specific areas and records are identified where there are significant differences between the performance of the dipole estimate and the spherical harmonic models. Our results suggest that many of the differences between the dipole model predictions and the paleomagnetic data can be related to poor paleomagnetic quality and/or the lack of accurate and precise time control inherent to some of the records. These results agree with Valet et al. ( 2008) who suggested that the CALS7K. 2 model probably underestimates the dipole contribution in order to reduce the misfit between the inversion and the data. We conclude that better paleomagnetic data and associated time control are needed to improve global geomagnetic field models.},
  author       = {Nilsson, Andreas and Snowball, Ian and Muscheler, Raimund and Bertacchi Uvo, Cintia},
  issn         = {1525-2027},
  keyword      = {nondipole field,dipole field,secular variation,paleomagnetism,Holocene},
  language     = {eng},
  pages        = {08018--08018},
  publisher    = {American Geophysical Union},
  series       = {Geochemistry Geophysics Geosystems},
  title        = {Holocene geocentric dipole tilt model constrained by sedimentary paleomagnetic data},
  url          = {http://dx.doi.org/10.1029/2010GC003118},
  volume       = {11},
  year         = {2010},
}