GIC drivers - the Characteristics of Storm-time Rapid Geomagnetic Variations

2020 ◽  
Author(s):  
Hermann J. Opgenoorth ◽  
Audrey Schilling ◽  
Maria Hamrin
Keyword(s):  
Space Weather ◽  
Critical Power ◽  
Three Dimensional ◽  
Physical Characteristics ◽  
Local Times ◽  
Temporal Behavior ◽  
Geomagnetic Disturbances ◽  
Geomagnetic Variations ◽  
Statistical Studies ◽  
Spatio Temporal

<p>Rapid storm-time geomagnetic disturbances, typically at sub-auroral latitudes, have been recognized as one of the most detrimental space weather phenomena, potentially leading to damage to and outage of critical power infrastructure. We can show that sub-auroral magnetic spikes in storms (of the order of 1000 nT/min) do resemble in their appearance and spatio-temporal behavior small but intense and very short-lived substorms, including three-dimensional current wedge and electrojet-enhancement formation. Statistically these spikes do occur at all local times, but preferably pre-midnight and around 0600 MLT in the morning sector, which is only partially in agreement with the substorm analogy, and indicate that there may indeed be several mechanisms at work. We will present results from event and statistical studies to clarify the physical characteristics and potential drivers for these potentially most damaging geomagnetic disturbances in the SWx realm.</p><p> </p>

scholarly journals Space weather impact on ground-based technological systems

2021 ◽  
Vol 7 (3) ◽  
pp. 73-110
Author(s):  
Vyacheslav Pilipenko
Keyword(s):  
Space Weather ◽  
Geomagnetic Field ◽  
Extreme Values ◽  
Economic Effects ◽  
Geoelectric Field ◽  
Technological Systems ◽  
Geomagnetic Disturbances ◽  
Geomagnetic Variations ◽  
Weather Impact ◽  
Field Variability

This review, offered for the first time in the Russian scientific literature, is devoted to various aspects of the problem of the space weather impact on ground-based technological systems. Particular attention is paid to hazards to operation of power transmission lines, railway automation, and pipelines caused by geomagnetically induced currents (GIC) during geomagnetic disturbances. The review provides information on the main characteristics of geomagnetic field variability, on rapid field variations during various space weather mani-festations. The fundamentals of modeling geoelectric field disturbances based on magnetotelluric sounding algorithms are presented. The approaches to the assessment of possible extreme values of GIC are considered. Information about economic effects of space weather and GIC is collected. The current state and prospects of space weather forecasting, risk assessment for technological systems from GIC impact are discussed. While in space geophysics various models for predicting the intensity of magnetic storms and their related geomagnetic disturbances from observations of the interplanetary medium are being actively developed, these models cannot be directly used to predict the intensity and position of GIC since the description of the geomagnetic field variability requires the development of additional models. Revealing the fine structure of fast geomagnetic variations during storms and substorms and their induced GIC bursts appeared to be important not only from a practical point of view, but also for the development of fundamentals of near-Earth space dynamics. Unlike highly specialized papers on geophysical aspects of geomagnetic variations and engineering aspects of the GIC impact on operation of industrial transformers, the review is designed for a wider scientific and technical audience without sacrificing the scientific level of presentation. In other words, the geophysical part of the review is written for engineers, and the engineering part is written for geophysicists. Despite the evident applied orientation of the studies under consideration, they are not limited to purely engineering application of space geophysics results to the calculation of possible risks for technological systems, but also pose a number of fundamental scientific problems

scholarly journals Space weather impact on ground-based technological systems

2021 ◽  
Vol 7 (3) ◽  
pp. 68-104
Author(s):  
Vyacheslav Pilipenko
Keyword(s):  
Space Weather ◽  
Geomagnetic Field ◽  
Extreme Values ◽  
Economic Effects ◽  
Geoelectric Field ◽  
Technological Systems ◽  
Geomagnetic Disturbances ◽  
Geomagnetic Variations ◽  
Weather Impact ◽  
Field Variability

This review, offered for the first time in the Russian scientific literature, is devoted to various aspects of the problem of the space weather impact on ground-based technological systems. Particular attention is paid to hazards to operation of power transmission lines, railway automation, and pipelines caused by geomagnetically induced currents (GIC) during geomagnetic disturbances. The review provides information on the main characteristics of geomagnetic field variability, on rapid field variations during various space weather mani-festations. The fundamentals of modeling geoelectric field disturbances based on magnetotelluric sounding algorithms are presented. The approaches to the assessment of possible extreme values of GIC are considered. Information about economic effects of space weather and GIC is collected. The current state and prospects of space weather forecasting, risk assessment for technological systems from GIC impact are discussed. While in space geophysics various models for predicting the intensity of magnetic storms and their related geomagnetic disturbances from observations of the interplanetary medium are being actively developed, these models cannot be directly used to predict the intensity and position of GIC since the description of the geomagnetic field variability requires the development of additional models. Revealing the fine structure of fast geomagnetic variations during storms and substorms and their induced GIC bursts appeared to be important not only from a practical point of view, but also for the development of fundamentals of near-Earth space dynamics. Unlike highly specialized papers on geophysical aspects of geomagnetic variations and engineering aspects of the GIC impact on operation of industrial transformers, the review is designed for a wider scientific and technical audience without sacrificing the scientific level of presentation. In other words, the geophysical part of the review is written for engineers, and the engineering part is written for geophysicists. Despite the evident applied orientation of the studies under consideration, they are not limited to purely engineering application of space geophysics results to the calculation of possible risks for technological systems, but also pose a number of fundamental scientific problems

scholarly journals Do 3D Face Images Capture Cues of Strength, Weight, and Height Better than 2D Face Images do?

2021 ◽  
Vol 7 (3) ◽  
pp. 209-219
Author(s):  
Iris J Holzleitner ◽  
Alex L Jones ◽  
Kieran J O’Shea ◽  
Rachel Cassar ◽  
Vanessa Fasolt ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Physical Characteristics ◽  
Two Dimensional ◽  
3D Images ◽  
3D Face ◽  
Face Images ◽  
Similar Accuracy ◽  
2D And 3D ◽  
2D Images ◽  
Better Than

Abstract Objectives A large literature exists investigating the extent to which physical characteristics (e.g., strength, weight, and height) can be accurately assessed from face images. While most of these studies have employed two-dimensional (2D) face images as stimuli, some recent studies have used three-dimensional (3D) face images because they may contain cues not visible in 2D face images. As equipment required for 3D face images is considerably more expensive than that required for 2D face images, we here investigated how perceptual ratings of physical characteristics from 2D and 3D face images compare. Methods We tested whether 3D face images capture cues of strength, weight, and height better than 2D face images do by directly comparing the accuracy of strength, weight, and height ratings of 182 2D and 3D face images taken simultaneously. Strength, height and weight were rated by 66, 59 and 52 raters respectively, who viewed both 2D and 3D images. Results In line with previous studies, we found that weight and height can be judged somewhat accurately from faces; contrary to previous research, we found that people were relatively inaccurate at assessing strength. We found no evidence that physical characteristics could be judged more accurately from 3D than 2D images. Conclusion Our results suggest physical characteristics are perceived with similar accuracy from 2D and 3D face images. They also suggest that the substantial costs associated with collecting 3D face scans may not be justified for research on the accuracy of facial judgments of physical characteristics.

scholarly journals Modelling natural electromagnetic interference in man-made conductors for space weather applications

2016 ◽  
Vol 34 (4) ◽  
pp. 427-436 ◽  
Author(s):  
Larisa Trichtchenko
Keyword(s):  
Exact Solution ◽  
Space Weather ◽  
Electromagnetic Interference ◽  
Geomagnetic Storms ◽  
Electromagnetic Properties ◽  
Electromagnetic Response ◽  
Frequency Range ◽  
Geomagnetically Induced Currents ◽  
Geomagnetic Variations ◽  
Wide Range

Abstract. Power transmission lines above the ground, cables and pipelines in the ground and under the sea, and in general all man-made long grounded conductors are exposed to the variations of the natural electromagnetic field. The resulting currents in the networks (commonly named geomagnetically induced currents, GIC), are produced by the conductive and/or inductive coupling and can compromise or even disrupt system operations and, in extreme cases, cause power blackouts, railway signalling mis-operation, or interfere with pipeline corrosion protection systems. To properly model the GIC in order to mitigate their impacts it is necessary to know the frequency dependence of the response of these systems to the geomagnetic variations which naturally span a wide frequency range. For that, the general equations of the electromagnetic induction in a multi-layered infinitely long cylinder (representing cable, power line wire, rail or pipeline) embedded in uniform media have been solved utilising methods widely used in geophysics. The derived electromagnetic fields and currents include the effects of the electromagnetic properties of each layer and of the different types of the surrounding media. This exact solution then has been used to examine the electromagnetic response of particular samples of long conducting structures to the external electromagnetic wave for a wide range of frequencies. Because the exact solution has a rather complicated structure, simple approximate analytical formulas have been proposed, analysed and compared with the results from the exact model. These approximate formulas show good coincidence in the frequency range spanning from geomagnetic storms (less than mHz) to pulsations (mHz to Hz) to atmospherics (kHz) and above, and can be recommended for use in space weather applications.

Insights into Attacks’ Progression: Prediction of Spatio-Temporal Behavior of DDoS Attacks

2020 ◽  
pp. 362-374
Author(s):  
Ahmed Abusnaina ◽  
Mohammed Abuhamad ◽  
DaeHun Nyang ◽  
Songqing Chen ◽  
An Wang ◽  
...  
Keyword(s):  
Temporal Behavior ◽  
Ddos Attacks ◽  
Spatio Temporal ◽  
Progression Prediction

scholarly journals Product reputation mining: bring informative review summaries to producers and consumers

2019 ◽  
Vol 16 (2) ◽  
pp. 359-380
Author(s):  
Zhehua Piao ◽  
Sang-Min Park ◽  
Byung-Won On ◽  
Gyu Choi ◽  
Myong-Soon Park
Keyword(s):  
Low Cost ◽  
Three Dimensional ◽  
Word Level ◽  
Sentence Level ◽  
Survey Results ◽  
Statistical Studies ◽  
Sentiment Orientation ◽  
Level Method ◽  
Points Of View ◽  
Graph Based Model

Product reputation mining systems can help customers make their buying decision about a product of interest. In addition, it will be helpful to investigate the preferences of recently released products made by enterprises. Unlike the conventional manual survey, it will give us quick survey results on a low cost budget. In this article, we propose a novel product reputation mining approach based on three dimensional points of view that are word, sentence, and aspect?levels. Given a target product, the aspect?level method assigns the sentences of a review document to the desired aspects. The sentence?level method is a graph-based model for quantifying the importance of sentences. The word?level method computes both importance and sentiment orientation of words. Aggregating these scores, the proposed approach measures the reputation tendency and preferred intensity and selects top-k informative review documents about the product. To validate the proposed method, we experimented with review documents relevant with K5 in Kia motors. Our experimental results show that our method is more helpful than the existing lexicon?based approach in the empirical and statistical studies.

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