Global geomagnetic field modeling based on Swarm Alpha magnetic field measurement
Global multi-sources geomagnetic field models have been applied to many fields because of their superiority in simultaneously describing many sources and convenience of use.In this work,nine year's high-resolution magnetic field data from Swarm Alpha satellite are used to develop a global geomagnetic field models including the main field and its variation,lithospheric field and magnetospheric field.During the modeling,the internal field is solved up to spherical harmonic degree and order 70,corresponding to wavelength of 571 km at the Earth's surface;the main field variation is described by 6 0rder B-spline,which can be used to the estimation of the main field secular variation,secular acceleration and so on;the external field is solved up to spherical harmonic degree and order 2.The final modeling rms is 3.63 nT.To evaluate the model,the power spectrum and global features is comprehensively compared with CM6 and CHAOS-7 geomagnetic field model.It indicates that these models are comparable in trend and magnitude.Specially,the typical residual field between our model and CHAOS-7 is respectively within 5 nT,1 nT and 3 nT for main field,lithospheric field and external field.Based on our model,the global changing of the main field since 2014 has been analyzed and the main characteristics of the lithospheric field and magnetospheric field are also shown.
Satellite magnetometryGeomagnetic field modelMian fieldLithospheric fieldExternal field
NETL
NSTL
万方数据
