An annual proxy for the geomagnetic signal of magnetospheric currents on Earth based on observatory data from 1900–2010
- We introduce the Annual Magnetospheric Currents index as long-term proxy for the geomagnetic signal of magnetospheric currents on Earth valid within the time span 1900–2010. Similar to the widely used disturbance storm time and ‘Ring Current’ indices, it is based on geomagnetic observatory data, but provides a realistic absolute level and uncertainty estimates. Crucial aspects to this end are the revision of observatory crustal biases as well as the implementation of a Bayesian inversion accounting for uncertainties in the main field estimate, both required for the index derivation. The observatory choice is based on a minimization of index variance during a reference period spanning 1960–2010. The new index is capable of correcting observatory time series from large-scale external signals in a user-friendly manner. At present the index is only available as annual mean values. An extension to hourly values for the same time span is in progress.
Author details: | Leonie PickORCiD, Monika KorteORCiDGND |
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DOI: | https://doi.org/10.1093/gji/ggx367 |
ISSN: | 1365-246X |
ISSN: | 0956-540X |
Title of parent work (English): | Geophysical Journal International |
Publisher: | Oxford Univ. Press |
Place of publishing: | Oxford |
Publication type: | Article |
Language: | English |
Date of first publication: | 2017/04/28 |
Publication year: | 2017 |
Release date: | 2020/08/28 |
Tag: | Inverse theory; Magnetic field variations through time; Satellite magnetics; Statistical methods; Time-series analysis |
Volume: | 211 |
Issue: | 2 |
Number of pages: | 14 |
First page: | 1223 |
Last Page: | 1236 |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Geowissenschaften |
DDC classification: | 5 Naturwissenschaften und Mathematik / 55 Geowissenschaften, Geologie / 550 Geowissenschaften |
Peer review: | Referiert |
License (German): | Keine öffentliche Lizenz: Unter Urheberrechtsschutz |
External remark: | This article is part of this cumulative dissertation |