Geomagnetically Induced Currents from Extreme Space Weather Events

Winter, L. M.

doi:10.1002/9781119434412.ch11

Cited by 3 publications

(2 citation statements)

References 48 publications

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“…At higher latitudes, the amplitudes may be larger since ULF wave amplitudes also generally increase with latitude. It thus seems reasonable that extreme storm time ULF wave E GEO amplitudes at middle and high latitudes could approach the 4‐ to 10‐V/km range, which has been linked to GIC of significant intensity during extreme storms (Winter, 2019). It should also be noted that 1 V/km is at the 1‐in‐100‐year event threshold in 70% of the contiguous United States (Lucas et al, 2020), although in the specific geographic region shown in Figure 4, the threshold for 1‐in‐100‐year events is much higher (10–20 V/km).…”

Section: Ulf Waves Drive Geoelectric Fields Of Significant Amplitude mentioning

confidence: 99%

Simultaneous Observations of Geoelectric and Geomagnetic Fields Produced by Magnetospheric ULF Waves

Hartinger

Shi

Lucas

et al. 2020

Geophysical Research Letters

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Geomagnetic perturbations (B GEO) related to magnetospheric ultralow frequency (ULF) waves induce electric fields within the conductive Earth-geoelectric fields (E GEO)-that in turn drive geomagnetically induced currents. Though numerous past studies have examined ULF wave B GEO from a space weather perspective, few studies have linked ULF waves with E GEO. Using recently available magnetotelluric impedance and E GEO measurements in the contiguous United States, we explore the relationship between ULF waves and E GEO. We use satellite, ground-based radar, B GEO , and E GEO measurements in a case study of a plasmaspheric virtual resonance (PVR), demonstrating that the PVR E GEO has significant spatial variation in contrast to a relatively uniform B GEO , consistent with spatially varying Earth conductivity. We further show ULF wave E GEO measurements during two moderate storms of ∼1 V/km. We use both results to highlight the need for more research characterizing ULF wave E GEO. Plain Language Summary A variety of phenomena in the near-Earth space environment produce disturbances in the magnetic field observed on the ground, including plasma waves in the ionized portion of the Earth's upper atmosphere. Though numerous studies have characterized magnetic disturbances related to waves with frequencies below a few hertz, few studies have addressed the electric fields they can induce in the Earth: geoelectric fields (E GEO). The latter are important because they drive potentially damaging electrical currents in power grids and other infrastructure. This study addresses the lack of constraints on wave E GEO fields by taking advantage of recently available models and measurements. The results show that extreme wave events can produce E GEO of significant amplitude, comparable to once-per-century values obtained in other studies. The results also indicate that more work is needed to characterize wave E GEO .

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Section: Ulf Waves Drive Geoelectric Fields Of Significant Amplitude mentioning

confidence: 99%

Simultaneous Observations of Geoelectric and Geomagnetic Fields Produced by Magnetospheric ULF Waves

Hartinger

Shi

Lucas

et al. 2020

Geophysical Research Letters

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“…The storm‐time compression of the magnetosphere is considered as one of the primary causes of electromagnetic disturbances and therefore is especially important for modern and technologically advanced societies (e.g., Baker, 1996; Winter, 2019). As shown in the previous section, the magnetospheric volume reduced significantly at SSC.…”

Section: Introductionmentioning

confidence: 99%

Cross‐Scale Quantification of Storm‐Time Dayside Magnetospheric Magnetic Flux Content

et al. 2020

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A clear understanding of storm-time magnetospheric dynamics is essential for a reliable storm forecasting capability. The dayside magnetospheric response to an interplanetary coronal mass ejection (ICME; dynamic pressure P dyn > 20 nPa and storm-time index SYM-H < −150 nT) is investigated using in situ OMNI, Geotail, Cluster, MMS, GOES, Van Allen Probes, and THEMIS measurements. The dayside magnetic flux content is directly quantified from in situ magnetic field measurements at different radial distances. The arrival of the ICME, consisting of shock and sheath regions preceding a magnetic cloud, initiated a storm sudden commencement (SSC) phase (SYM-H~+50 nT). At SSC, the magnetopause standoff distance was compressed earthward at ICME shock encounter at an average rate~−10.8 Earth radii per hour for~10 min, resulting in a rapid 40% reduction in the magnetospheric volume. The "closed" magnetic flux content remained constant at 170 ± 30 kWb inside the compressed dayside magnetosphere, even in the presence of dayside reconnection, as evident by an outsized flux transfer event containing 160 MWb. During the storm main and recovery phases, the magnetosphere expanded. The dayside magnetic flux did not remain constant within the expanding magnetosphere (110 ± 30 kWb), resulting in a 35% reduction in pre-storm flux content during the magnetic cloud encounter. At that stage, the magnetospheric magnetic flux was eroded resulting in a weakened dayside magnetospheric field strength at radial distances R ≥ 5 R E. It is concluded that the inadequate replenishment of the eroded dayside magnetospheric flux during the magnetosphere expansion phase is due to a time lag in storm-time Dungey cycle. Plain Language Summary A clear understanding of Earth's magnetospheric dynamics is essential for a reliable space weather forecasting capability. To achieve this, we take advantage of the Heliophysics System Observatory's (HSO) multitude of in situ observations in order to, for the first time, quantify the amount of magnetic flux stored in the dayside magnetosphere. The stored magnetic flux shields our ground-based and space-borne assets from adverse space weather events. We examine the dayside magnetic flux content during an encounter with an interplanetary coronal mass ejection (ICME). ICME is a large-scale bundle of magnetic flux and charged particles originating from the Sun. Upon arrival, the ICME which occupied nearly one third of the space between the Sun and Earth forced the dayside magnetosphere to rapidly shrink down to geosynchronous orbit where most communications and weather satellites are located. Though the dayside magnetosphere significantly shrunk, its magnetic flux content remained constant. It was only when the dayside magnetosphere started to expand that the dayside magnetospheric flux content gradually reduced by 35%. It is concluded that, during large ICME encounters, the rate at which dayside magnetic flux is transported to the magnetotail is faster than the rate at which magnetic flux is recycled, via a process kno...

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Geomagnetically Induced Current Analysis in Malaysian Power Transmission System

et al. 2022

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For many decades, Geomagnetically Induced Current (GIC) has posed a significant risk over the electrical power grid infrastructures worldwide. The phenomenon occurs due to geomagnetic disturbance (GMD) and related space weather events arising from solar activity. It represents a potential hazard to the secure and safe operation of electrical power grids by causing half-cycle saturation of grounded High Voltage (HV) power transformers, relay misoperation, and increased reactive power demand in the power systems. Previous studies have shown that the occurrence of intense GIC is not limited to high and mid-latitude regions, but powerful space weather events can also result in intense GIC in power systems located in lower geographic latitudes. This study aims to estimate GIC and its impacts on a Malaysian power grid. A network model of the grid was constructed by using the Power System Simulator for Engineering (PSS/E). This represents the first attempt to study GICs in south-eastern Asian power grids since a region is considered to have low GIC risk up to now. During the analysis, firstly, we exposed the entire power network which includes 500 kV, 275 kV, and 132 kV system voltages to different geoelectric field strengths in the 0-180 • directions. The applied geoelectric fields were calculated based on benchmark value for 1 in 100 years of GMD events. Then we disconnected the 132 kV low voltage systems from the network model to investigate their influence on the calculated GICs. The results demonstrated that the most vulnerable substations to GMD events and experienced large GICs were those located in the middle of the Malaysian power network. The maximum GIC was recorded at substation 22 with the value of 44.58 A due to the peak electric field of 1.2 V/km at 100 • field direction. Also, the results showed that the calculated GICs slightly increased when 132 kV systems were removed from the power network, especially at the substations directly connected to these systems.INDEX TERMS Geomagnetically induced current, geomagnetic disturbances, space weather, energy, high voltage transformers, Malaysian power system.

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Geomagnetically Induced Currents from Extreme Space Weather Events

Cited by 3 publications

References 48 publications

Simultaneous Observations of Geoelectric and Geomagnetic Fields Produced by Magnetospheric ULF Waves

Simultaneous Observations of Geoelectric and Geomagnetic Fields Produced by Magnetospheric ULF Waves

Cross‐Scale Quantification of Storm‐Time Dayside Magnetospheric Magnetic Flux Content

Geomagnetically Induced Current Analysis in Malaysian Power Transmission System

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