Modeling the Geomagnetic Response to the September 2017 Space Weather Event Over Fennoscandia Using the Space Weather Modeling Framework: Studying the Impacts of Spatial Resolution. Issue 5 (26th May 2021)

• Record Type: Journal Article
• Authors: Dimmock, A. P.; Welling, D. T.; Rosenqvist, L.; Forsyth, C.; Freeman, M. P.; Rae, I. J.; Viljanen, A.; Vandegriff, E.; Boynton, R. J.; Balikhin, M. A.; Yordanova, E.
• Is Part Of: Space weather. Volume 19:Issue 5(2021)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-05-26
• Subjects: Geomagnetic storm -- GICs -- model validation -- space weather -- substorms -- SWMF; Space environment -- Periodicals; 551.509992
• DOI: 10.1029/2020SW002683
• Languages: English
• ISSNs: 1542-7390

Abstract

Abstract: We must be able to predict and mitigate against geomagnetically induced current (GIC) effects to minimize socio‐economic impacts. This study employs the space weather modeling framework (SWMF) to model the geomagnetic response over Fennoscandia to the September 7–8, 2017 event. Of key importance to this study is the effects of spatial resolution in terms of regional forecasts and improved GIC modeling results. Therefore, we ran the model at comparatively low, medium, and high spatial resolutions. The virtual magnetometers from each model run are compared with observations from the IMAGE magnetometer network across various latitudes and over regional‐scales. The virtual magnetometer data from the SWMF are coupled with a local ground conductivity model which is used to calculate the geoelectric field and estimate GICs in a Finnish natural gas pipeline. This investigation has lead to several important results in which higher resolution yielded: (1) more realistic amplitudes and timings of GICs, (2) higher amplitude geomagnetic disturbances across latitudes, and (3) increased regional variations in terms of differences between stations. Despite this, substorms remain a significant challenge to surface magnetic field prediction from global magnetohydrodynamic modeling. For example, in the presence of multiple large substorms, the associated large‐amplitude depressions were not captured, which caused the largest model‐data deviations. The results from this work are of key importance to both modelers and space weather operators. Particularly when the goal is to obtain improved regional forecasts of geomagnetic disturbances and/or more realistic estimates of the geoelectric field. Plain Language Summary: Geomagnetically induced currents (GICs) affect large ground‐based conducting infrastructure and are associated with the dynamic behavior of geospace electrical currents that drive rapid variations of the surface geomagnetic field. Through geomagnetic induction with the ground conductivity, a geoelectric field is set up which causes unwanted currents to flow in large‐scale technological systems. This can result in damage, which can eventually lead to failures and disruptions. To mitigate against GICs we need the capability to predict geomagnetic field variations at the surface with sufficient accuracy, knowledge of the ground conductivity, and a realistic description of the affected system. In this study, we use a global magnetohydrodynamic model (with additional integrated components) to model the surface geomagnetic field variations for the September 2017 event. We compare the simulated ground magnetic fields with those measured at equivalent locations. The spatial resolution of the model is modified to determine if this provides improved performance for capturing spatially structured geomagnetic disturbances. The modeled geomagnetic fields are employed with a ground conductivity model to compute GICs in a natural gas pipeline, which is compared with GIC recordings. We see that higher spatial resolution runs can improve GIC predictions when not driven by substorm activity. Key Points: Higher space weather modeling framework (SWMF) spatial resolution increased the variability of virtual ground magnetometer and inter‐station differences By increasing the SWMF spatial resolution, the ability to model geomagnetically induced currents (GICs) in terms of amplitudes and timing can be improved Regardless of the spatial resolution, substorms remain a problem and are a crucial process to driving GICs