A multisource geomagnetic field model incorporating ocean circulation-induced magnetic field  

作　　者：HongBo Yao JuYuan Xu Cong Yang ZhengYong Ren Keke Zhang 

机构地区：[1]Macao Institute of Space Technology and Application,Macao University of Science and Technology,Macao 999078,China [2]School of Geosciences and Info-Physics,Central South University,Changsha 410083,China

出　　处：《Earth and Planetary Physics》2025年第3期550-563,共14页地球与行星物理(英文版)

基　　金：supported by the National Natural Science Foundation of China(42250101,42250102);the Macao Foundation.

摘　　要：The movement of global ocean circulation in the Earth’s main magnetic field generates a measurable induced magnetic field(about 2 nT at geomagnetic satellite altitudes).However,this ocean circulation-induced magnetic field has not been previously estimated or incorporated into geomagnetic field models,potentially causing leakage into the core field model.Here,we present a method to account for the circulation-induced magnetic field during geomagnetic field modeling.First,a forward model of the circulation-induced magnetic field is constructed by numerically solving electromagnetic induction equations based on a realistic ocean circulation model.Then,this forward model is subtracted from the observed data.Finally,the core and lithospheric fields,magnetospheric and Earth’s mantle-induced fields,and the ocean tide-induced magnetic field are co-estimated.Applying our method to over 20 years of MSS-1,Swarm,CryoSat-2,and CHAMP satellite magnetic data,we derive a new multisource geomagnetic field model(MGFM).We find that incorporating a forward model of the circulation-induced magnetic field marginally improves the fit to the data.Furthermore,we demonstrate that neglecting the circulation-induced magnetic field in geomagnetic field modeling results in leakage into the core field model.The highlights of the MGFM model include:(i)a good agreement with the widely used CHAOS model series;(ii)the incorporation of magnetic fields induced by both ocean tides and circulation;and(iii)the suppression of leakage of the circulation-induced magnetic field into the core field model.

关 键 词：Macao Science Satellite-1(MSS-1) geomagnetic field modeling ocean tides ocean circulation 

分 类 号：P318[天文地球—固体地球物理学]