DOI: 10.1002/2015GL066636
论文题名: Mapping geoelectric fields during magnetic storms: Synthetic analysis of empirical United States impedances
作者: Bedrosian P.A. ; Love J.J.
刊名: Geophysical Research Letters
ISSN: 0094-8373
EISSN: 1944-8104
出版年: 2015
卷: 42, 期: 23 起始页码: 10160
结束页码: 10170
语种: 英语
英文关键词: Earth conductivity
; extreme event
; induction hazard
; magnetic storm
; magnetotellurics
; space weather
Scopus关键词: Earth (planet)
; Geomagnetism
; Hazards
; Magnetism
; Magnetotellurics
; Mapping
; Tensors
; Earth conductivity
; Extreme events
; Geomagnetic oscillations
; Geophysical measurements
; Magnetic storms
; Oscillation frequency
; Space weather
; Three-dimensional conductivity
; Magnetic field effects
; continental interior
; Earth structure
; electric field
; electrical conductivity
; extreme event
; geomagnetic field
; geomagnetic storm
; hazard assessment
; magnetotelluric method
; United States
英文摘要: Empirical impedance tensors obtained from EarthScope magnetotelluric data at sites distributed across the midwestern United States are used to examine the feasibility of mapping magnetic storm induction of geoelectric fields. With these tensors, in order to isolate the effects of Earth conductivity structure, we perform a synthetic analysis - calculating geoelectric field variations induced by a geomagnetic field that is geographically uniform but varying sinusoidally with a chosen set of oscillation frequencies that are characteristic of magnetic storm variations. For north-south oriented geomagnetic oscillations at a period of T0=100 s, induced geoelectric field vectors show substantial geographically distributed differences in amplitude (approximately a factor of 100), direction (up to 130), and phase (over a quarter wavelength). These differences are the result of three-dimensional Earth conductivity structure, and they highlight a shortcoming of one-dimensional conductivity models (and other synthetic models not derived from direct geophysical measurement) that are used in the evaluation of storm time geoelectric hazards for the electric power grid industry. A hypothetical extremely intense magnetic storm having 500 nT amplitude at T0=100 s would induce geoelectric fields with an average amplitude across the midwestern United States of about 2.71 V/km, but with a representative site-to-site range of 0.15 V/km to 16.77 V/km. Significant improvement in the evaluation of such hazards will require detailed knowledge of the Earth's interior three-dimensional conductivity structure. © 2015. American Geophysical Union. All Rights Reserved. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84953637524&doi=10.1002%2f2015GL066636&partnerID=40&md5=ff914dfa8d9704c79683a464054b3455
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/7989
Appears in Collections: 科学计划与规划 气候变化与战略
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作者单位: Crustal Geophysics and Geochemistry Science Center, U.S. Geological Survey, Denver, CO, United States
Recommended Citation:
Bedrosian P.A.,Love J.J.. Mapping geoelectric fields during magnetic storms: Synthetic analysis of empirical United States impedances[J]. Geophysical Research Letters,2015-01-01,42(23).