Dynamics of TEC high density regions seen in JPL GIMs: variations with latitude, season and geomagnetic activity

Cafolla, M. A., Chapman, S. C., Watkins, N. W. ORCID: 0000-0003-4484-6588, Meng, X. and Verkhoglyadova, O. P. (2025) Dynamics of TEC high density regions seen in JPL GIMs: variations with latitude, season and geomagnetic activity. Space Weather, 23 (4). ISSN 1542-7390

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Abstract

Total Electron Content (TEC) is central to characterizing ionospheric response to solar and geomagnetic activity. Variations in TEC structures over time provide insight into underlying physical processes and inform monitoring of space weather events, which pose a risk to navigation and communication systems. JPL processed GNSS observations over 20 years provide a series of 15‐min Global Ionospheric Maps (GIMs) of spatial resolution 1° × 1° longitude/latitude. We translate these into geomagnetic coordinates centered about the sub‐solar point and we isolate the top 1% of TEC values in each map to define High Density Regions (HDRs) of TEC. Image processing tools are used to develop an algorithm that detects and tracks these to compile a set of contiguous, uniquely labeled space‐time TEC HDRs. We find that HDRs naturally divide into two populations by peak area, separated by a size of 8.0 × 106km2, which is around the continental scale. These populations are studied for different storm conditions—quiet (Kp < 4), moderate (4 ≤ Kp < 7) and extreme (Kp ≥ 7): small HDRs form primarily around four magnetic latitude bands and move roughly parallel to lines of constant magnetic latitude toward later MLT. Large HDRs form around the same latitude bands but follow more complex paths. The statistical nature of these results could be used in predictive ionospheric models and identify reproducible trends on these spatial/temporal scales.

Item Type:	Article
Additional Information:	© 2025 The Author(s)
Divisions:	Grantham Research Institute
Subjects:	Q Science > QC Physics
Date Deposited:	29 Apr 2025 11:00
Last Modified:	29 Apr 2025 11:00
URI:	http://eprints.lse.ac.uk/id/eprint/128021

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