Laundal K M, Reistad J P, Hatch S M, Madelaire M, Walker S, Hovland A Ø, Ohma A, Merkin V G, Sorathia K A
Department of Physics and Technology Birkeland Centre for Space Science University in Bergen Bergen Norway.
Applied Physics Laboratory Johns Hopkins University Laurel MD USA.
J Geophys Res Space Phys. 2022 May;127(5):e2022JA030356. doi: 10.1029/2022JA030356. Epub 2022 May 7.
An accurate description of the state of the ionosphere is crucial for understanding the physics of Earth's coupling to space, including many potentially hazardous space weather phenomena. To support this effort, ground networks of magnetometer stations, optical instruments, and radars have been deployed. However, the spatial coverage of such networks is naturally restricted by the distribution of land mass and access to necessary infrastructure. We present a new technique for local mapping of polar ionospheric electrodynamics, for use in regions with high data density, such as Fennoscandia and North America. The technique is based on spherical elementary current systems (SECS), which were originally developed to map ionospheric currents. We expand their use by linking magnetic field perturbations in space and on ground, convection measurements from space and ground, and conductance measurements, via the ionospheric Ohm's law. The result is a technique that is similar to the Assimilative Mapping of Ionospheric Electrodynamics (AMIE) technique, but tailored for regional analyses of arbitrary spatial extent and resolution. We demonstrate our technique on synthetic data, and with real data from three different regions. We also discuss limitations of the technique and potential areas for improvement.
准确描述电离层状态对于理解地球与太空的耦合物理过程至关重要，这其中包括许多潜在危险的空间天气现象。为助力此项工作，已部署了由磁力仪站、光学仪器和雷达组成的地面网络。然而，此类网络的空间覆盖范围自然受到陆地分布以及获取必要基础设施的限制。我们提出了一种用于极地电离层电动力学局部绘图的新技术，适用于数据密度较高的地区，如芬兰斯堪的纳维亚半岛和北美洲。该技术基于球形基本电流系统（SECS），其最初是为绘制电离层电流而开发的。我们通过电离层欧姆定律，将空间和地面的磁场扰动、空间和地面的对流测量以及电导率测量联系起来，从而扩展了它们的用途。结果是一种类似于电离层电动力学同化绘图（AMIE）技术的方法，但专为任意空间范围和分辨率的区域分析而量身定制。我们在合成数据以及来自三个不同区域的真实数据上展示了我们的技术。我们还讨论了该技术的局限性以及潜在的改进领域。
