Geoelectric hazard maps for the continental United States. Issue 18 (19th September 2016)

• Record Type: Journal Article
• Authors: Love, Jeffrey J.; Pulkkinen, Antti; Bedrosian, Paul A.; Jonas, Seth; Kelbert, Anna; Rigler, E. Joshua; Finn, Carol A.; Balch, Christopher C.; Rutledge, Robert; Waggel, Richard M.; Sabata, Andrew T.; Kozyra, Janet U.; Black, Carrie E.
• Is Part Of: Geophysical research letters. Volume 43:Issue 18(2016)
• Page Start: 9415
• Page End: 9424
• Publication Date: 2016-09-19
• Subjects: induction hazards -- geoelectric fields -- space weather -- geomagnetically induced currents -- solid‐earth impedance; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2016GL070469
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: In support of a multiagency project for assessing induction hazards, we present maps of extreme‐value geoelectric amplitudes over about half of the continental United States. These maps are constructed using a parameterization of induction: estimates of Earth surface impedance, obtained at discrete geographic sites from magnetotelluric survey data, are convolved with latitude‐dependent statistical maps of extreme‐value geomagnetic activity, obtained from decades of magnetic observatory data. Geoelectric amplitudes are estimated for geomagnetic waveforms having 240 s sinusoidal period and amplitudes over 10 min that exceed a once‐per‐century threshold. As a result of the combination of geographic differences in geomagnetic activity and Earth surface impedance, once‐per‐century geoelectric amplitudes span more than 2 orders of magnitude and are an intricate function of location. For north‐south induction, once‐per‐century geoelectric amplitudes across large parts of the United States have a median value of 0.26 V/km; for east‐west geomagnetic variation the median value is 0.23 V/km. At some locations, once‐per‐century geoelectric amplitudes exceed 3 V/km. Key Points: We construct geoelectric hazard maps using solid‐earth impedances and magnetic observatory data Results summarize extreme‐event 100 year amplitude of storm‐time geoelectric fields This work is motivated by power‐grid industry needs and United States space weather strategic plans