Local Mapping of Polar Ionospheric Electrodynamics. Issue 5 (7th May 2022)

• Record Type: Journal Article
• Authors: Laundal, K. M.; Reistad, J. P.; Hatch, S. M.; Madelaire, M.; Walker, S.; Hovland, A. Ø.; Ohma, A.; Merkin, V. G.; Sorathia, K. A.
• Is Part Of: Journal of geophysical research. Volume 127:Issue 5(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-05-07
• Subjects: polar ionosphere -- data assimilation -- ground magnetic field perturbation -- ionospheric convection -- auroral conductance -- ionospheric electrodynamics; Magnetospheric physics -- Periodicals; Space environment -- Periodicals; Cosmic physics -- Periodicals; Planets -- Atmospheres -- Periodicals; Heliosphere (Astrophysics) -- Periodicals; Geophysics -- Periodicals; 523.01
• DOI: 10.1029/2022JA030356
• Languages: English
• ISSNs: 2169-9380

Abstract

Abstract: 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. Plain Language Summary: The ionosphere, where a small but significant fraction of the atmosphere is ionized, forms the edge of space. At only 100‐km altitude, it is the region in space which is by far best monitored by human instruments. Space scientists routinely use measurements that inform about specific aspects of the dynamics in the ionosphere, but not the whole picture. For example, magnetometers on ground measure one part of the electric current system while magnetometers on satellites measure another part. Radars measure the flow of charged particles in the ionosphere, while optical images and particle measurements can be used to estimate electric conductivity. In this paper, we present a technique that combines all these different types of measurements to give a complete picture of what takes place in the ionosphere. The technique is tailored for use in regions where the data density is high, and the spatial resolution and extent of the analysis region are flexible. Key Points: We present a technique to use disparate data types to produce local maps of polar ionospheric electrodynamics ΔB and convection measurements are related via ionospheric Ohm's law and spherical elementary current systems We demonstrate the technique on real and synthetic data, and discuss limitations and future development