A Quantitative Comparison of High Latitude Electric Field Models During a Large Geomagnetic Storm. Issue 1 (13th January 2023)

• Record Type: Journal Article
• Authors: Orr, L.; Grocott, A.; Walach, M.‐T.; Chisham, G.; Freeman, M. P.; Lam, M. M.; Shore, R. M.
• Is Part Of: Space weather. Volume 21:Issue 1(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2023-01-13
• Subjects: Space environment -- Periodicals; 551.509992
• DOI: 10.1029/2022SW003301
• Languages: English
• ISSNs: 1542-7390

Abstract

Abstract: Models of the high‐latitude ionospheric electric field (EF) are commonly used to specify the magnetospheric forcing in thermosphere or whole atmosphere models. The use of decades‐old models based on spacecraft data is still widespread. Currently the Heelis et al. (1982, https://doi.org/10.1029/ja087ia08p06339 ) and Weimer (2005b, https://doi.org/10.1029/2005ja011270 ) climatology models are most commonly used but it is possible a more recent EF model could improve forecasting functionality. Modern EF models, derived from radar data, have been developed to incorporate advances in data availability (Bristow et al., 2022, https://doi.org/10.1029/2021sw002920 ; Thomas & Shepherd, 2018, https://doi.org/10.1002/2018ja025280 ; Walach et al., 2022, https://doi.org/10.1029/2021ja029559 ). It is expected that climatologies based on this larger and up‐to‐date data set will better represent the high latitude ionosphere and improve forecasting abilities. An example of two such models, which have been developed using line‐of‐sight velocity measurements from the Super Dual Auroral Radar Network (SuperDARN) are the Thomas and Shepherd model (TS18) (Thomas & Shepherd, 2018, https://doi.org/10.1002/2018ja025280 ), and Walach and Grocott geomagnetic Storm model (WGS21) (Walach et al., 2021, https://doi.org/10.1029/2020ja028512 ). Here we compare the outputs of these EF models during the September 2017 storm, covering a range of solar wind and interplanetary magnetic field (IMF) conditions. We explore the relationships between the IMF conditions and the model output parameters such as transpolar voltage, the polar cap size and the lower latitude boundary of convection. We find that the electric potential and field parameters from the spacecraft‐based models have a significantly higher magnitude than the SuperDARN‐based models. We discuss the similarities and differences in topology and magnitude for each model. Plain Language Summary: To prevent collisions between satellites and space junk within the Earth's space environment we need to accurately predict their position. The Ionosphere is part of the upper atmosphere of the Earth a which is affected by space weather events such as geomagnetic storms. Accurate ionospheric electric field models are key to accurate orbit prediction. Currently the use of decades‐old models based on spacecraft data from the 80s is still widespread. We aim to compare the output from these commonly used spacecraft‐based models to more recent models which were developed using line‐of‐sight velocity measurements from the Super Dual Auroral Radar Network (SuperDARN). We find that the parameters output from the spacecraft‐based models often are significantly different to the SuperDARN‐based models. We discuss the similarities and differences in topology and magnitude for each model. Key Points: The Heelis model is strongly dependent on the transpolar voltage proxy as input. The Kp based proxy is poor in storm time compared to others Models similar during quiet conditions but the spacecraft‐based models are vastly different to the Super Dual Auroral Radar Network‐based models during storm times As storm times are important for Joule Heating and satellite drag these differences must be considered by model users