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The Potential Impacts of the Erratic Motion of Dip Equator and Magnetic Poles
Author(s) -
Yizengaw Endawoke
Publication year - 2020
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
eISSN - 2169-9402
pISSN - 2169-9380
DOI - 10.1029/2020ja028129
Subject(s) - magnetic dip , earth's magnetic field , equator , declination , geodesy , magnetometer , geophysics , ionosphere , geomagnetic secular variation , geology , latitude , international reference ionosphere , secular variation , magnetic field , physics , geomagnetic storm , total electron content , astronomy , quantum mechanics , tec
This paper examined the secular displacement of the dip equator and the geomagnetic poles as well as the variations of the global magnetic inclination and declination angles using magnetometer measurements onboard different low‐Earth orbit (LEO) satellite. The secular variation of the dip equator and geomagnetic poles has different impacts on different applications—from affecting the long‐term characterization of the low‐latitude ionosphere to degrading the precision of geomagnetic navigation. The strong displacement of the dip equator can result in a systematic error in the determination of the long‐term equatorial electric field variations and hence in the characterization of ionospheric density structure, especially in the region, where the displacement of dip equator is large enough (more than 20 km or 0.2°/year) within the time scale of a solar cycle or less. Similarly, the slowly moving locations of magnetic poles, estimated from magnetometer observations onboard LEO satellite, exemplify noticeable discrepancy with that of world magnetic model (WMM) and International Geomagnetic Reference Field (IGRF) values, indicating inevitable possible impact on the precise geomagnetic navigation for commercial and military applications. Thus, accurately estimated locations of the dip equator and magnetic poles, as well as declination angles, are critically important.