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Empirical evidence for latitude dependence and asymmetry of geomagnetic spatial variation in mainland China
Author(s) -
Lu Shikun,
Zhang Hao,
Li Xihai,
Liu Daizhi,
Wang Xiqin
Publication year - 2016
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2016gl068345
Subject(s) - earth's magnetic field , asymmetry , geophysics , geomagnetic secular variation , latitude , geology , mainland china , statistical physics , geodesy , magnetic field , physics , geography , china , archaeology , quantum mechanics , geomagnetic storm
Spatiotemporal geomagnetic variation is a significant research topic of geomagnetism and space physics. Generated by convection and flows within the fluid outer core, latitude dependence and asymmetry, as the inherent spatiotemporal properties of geomagnetic field, have been extensively studied. We apply and modify an extension of existing method, Hidden Markov Model (HMM), which is an efficient tool for modeling the statistical properties of time series. Based on ground magnetic measurement data set in mainland China, first, we find the parameters of HMM can be used as the geomagnetic statistical signature to represent the spatiotemporal geomagnetic variations for each site. The results also support the existence of the geomagnetic latitude dependence more apparently. Furthermore, we provide solid empirical evidence for geomagnetic asymmetry relying on such ground magnetic measurement data set.