Original Article

Econ. Environ. Geol. 2015; 48(1): 51-63

Published online February 28, 2015

© THE KOREAN SOCIETY OF ECONOMIC AND ENVIRONMENTAL GEOLOGY

A Localized Secular Variation Model of the Geomagnetic Field Over Northeast Asia Region between 1997 to 2011

Hyung Rae Kim*

Dept. of Geoenvironmental Sciences, Kongju National Univ., Gongju 314-701, Korea

Correspondence to : kimhr@kongju.ac.kr

Received: December 27, 2014; Revised: January 13, 2015; Accepted: January 20, 2015

Abstract

I produced a secular variation model of geomagnetic field by using the magnetic component data from four geomagnetic observatories located in Northeast Asia during the years between 1997 and 2011. The Earth’s magnetic field varies with time and location due to the dynamics of fluid outer core and the magnetic observatories on the surface measure in time series. To adequately represent the magnetic field or secular variations of the Earth, a spatio- temporal model is required. In making a global model, satellite observations as well as limited observatory data are necessary to cover the regions and time intervals. However, you need a considerable work and time to process a huge amount of the dataset with complicated signal separation procedures. When you update the model, the same amount of chores is demanded. Besides, the global model might be affected by the measurement errors of each observatory that are biased and the processing errors in satellite data so that the accuracy of the model would be degraded. In this study, as considered these problems, I introduced a localized method in modeling secular variation of the Earth’s magnetic field over Northeast Asia region. Secular variation data from three Japanese observatories and one Chinese observatory that are all in the INTERMAGNET are implemented in the model valid between 1997 to 2011 with the interval of 6 months. With the resulting model, I compared with the global model called CHAOS-4, which includes the main, secular variation and secular acceleration models between 1997 to 2013 by using the three satellites’ databases and INTERMAGNET observatory data. Also, the geomagnetic ‘jerk’ which is known as a sudden change in the time derivatives of the main field of the Earth, was discussed from the localized secular acceleration coefficients derived from spline models.

Keywords Geomagnetic field, localized modeling, secular variation, magnetic observatory, geomagnetic jerk

Article

Original Article

Econ. Environ. Geol. 2015; 48(1): 51-63

Published online February 28, 2015

Copyright © THE KOREAN SOCIETY OF ECONOMIC AND ENVIRONMENTAL GEOLOGY.

A Localized Secular Variation Model of the Geomagnetic Field Over Northeast Asia Region between 1997 to 2011

Hyung Rae Kim*

Dept. of Geoenvironmental Sciences, Kongju National Univ., Gongju 314-701, Korea

Correspondence to:kimhr@kongju.ac.kr

Received: December 27, 2014; Revised: January 13, 2015; Accepted: January 20, 2015

Abstract

I produced a secular variation model of geomagnetic field by using the magnetic component data from four geomagnetic observatories located in Northeast Asia during the years between 1997 and 2011. The Earth’s magnetic field varies with time and location due to the dynamics of fluid outer core and the magnetic observatories on the surface measure in time series. To adequately represent the magnetic field or secular variations of the Earth, a spatio- temporal model is required. In making a global model, satellite observations as well as limited observatory data are necessary to cover the regions and time intervals. However, you need a considerable work and time to process a huge amount of the dataset with complicated signal separation procedures. When you update the model, the same amount of chores is demanded. Besides, the global model might be affected by the measurement errors of each observatory that are biased and the processing errors in satellite data so that the accuracy of the model would be degraded. In this study, as considered these problems, I introduced a localized method in modeling secular variation of the Earth’s magnetic field over Northeast Asia region. Secular variation data from three Japanese observatories and one Chinese observatory that are all in the INTERMAGNET are implemented in the model valid between 1997 to 2011 with the interval of 6 months. With the resulting model, I compared with the global model called CHAOS-4, which includes the main, secular variation and secular acceleration models between 1997 to 2013 by using the three satellites’ databases and INTERMAGNET observatory data. Also, the geomagnetic ‘jerk’ which is known as a sudden change in the time derivatives of the main field of the Earth, was discussed from the localized secular acceleration coefficients derived from spline models.

Keywords Geomagnetic field, localized modeling, secular variation, magnetic observatory, geomagnetic jerk

    KSEEG
    Apr 30, 2024 Vol.57 No.2, pp. 107~280

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