文章基本信息
- 标题：Dipolar elementary current systems for ionospheric current reconstruction at low and middle latitudes
- 本地全文：下载
- 作者：Heikki Vanhamäki ; Astrid Maute ; Patrick Alken 等
- 期刊名称：Earth, Planets and Space
- 电子版ISSN：1880-5981
- 出版年度：2020
- 卷号：72
- 期号：1
- 页码：146-159
- DOI：10.1186/s40623-020-01284-1
- 出版社：Springer Verlag
- 摘要：The technique of spherical elementary current systems (SECS) is a powerful way to determine ionospheric and field-aligned currents (FAC) from magnetic field measurements made by low-Earth-orbiting satellites, possibly in combination with magnetometer arrays on the ground. The SECS method consists of two sets of basis functions for the ionospheric currents: divergence-free (DF) and curl-free (CF) components, which produce poloidal and toroidal magnetic fields, respectively. The original CF SECS are only applicable at high latitudes, as they build on the assumption that the FAC flow radially into or out of the ionosphere. The FAC at low and middle latitudes are far from radial, which renders the method inapplicable at these latitudes. In this study, we modify the original CF SECS by including FAC that flow along dipolar field lines. This allows the method to be applied at all latitudes. We name this method dipolar elementary current systems (DECS). Application of the DECS to synthetic data, as well as Swarm satellite measurements are carried out, demonstrating the good performance of this method, and its applicability to studies of ionospheric current systems at low and middle latitudes. © The Author(s) 2020.
- 关键词：Ionospheric current;Magnetic field;SECS method
