1/4/2024 0 Comments Omniweb virus2 Databases, methods of analyses, and related background space plasma observations 2.1 GIC data It will be shown that new, important potential causes of GICs at Mäntsälä will be discovered. A survey of this type has never been performed before. Of course, the GIC intensities for the other subauroral systems will be different (owing to different physical layouts, ground conductances, etc.), but statistically the physical interplanetary causes may be the same. The d B/d t events that cause Mäntsälä GICs could also cause GICs in other subauroral systems. Why are we performing this study? All GIC events on Earth are believed to be ultimately related to interplanetary drivers. Similar studies on other data sets will be needed to determine the causes of GICs at these other regions of the Earth. We caution the reader that Mäntsälä is located at subauroral (57.9° magnetic) latitudes, so the interplanetary and magnetospheric causes of GICs at auroral latitudes, mid-latitudes, and equatorial latitudes might be different. We will also identify the Mäntsälä GIC relationships with magnetic storms and substorms (which are causes by interplanetary magnetic field (IMF) southward component Bs) to obtain information about the relationship between the intensity of the GICs and the intensities of the magnetospheric and ionospheric activity. This paper is intended to be a top-level survey, to identify the possible relationship between Mäntsälä intense GIC events and interplanetary time-coincident features. The purpose of this present paper is to identify for the first time the interplanetary, magnetospheric and ionospheric phenomena time-coincident with intense > 10 A and > 30 A Mäntsälä GIC events over a 21-year interval, from 1 January 1999 to 31 December 2019. (2010) performed a nice 11-year study on this data set for GIC > 5 A events during magnetic storm intervals. This paper was motivated by the extensive GIC data set existing for the natural gas pipeline near Mäntsälä, Finland (57.9°N geomagnetic latitude 60.6°N geographic latitude, 25.2☎ geographic longitude: Pirjola & Lehtinen, 1985 Pulkkinen et al., 2001 Viljanen et al., 2006). More recently Campbell (1980) observed electric currents flowing in the Alaska oil pipeline and deduced that the source was the auroral electrojet current (a midnight sector current flowing in the ionosphere at ~100 km altitude with intensities of up to and possibly greater than 10 6 A). Currents were noted to flow even when the batteries were not connected. Such a phenomenon was noted a century and a half ago when the deflection of telegraph magnetic needles of the Midland Railroad (England) was observed to be coincident with auroral sightings ( Barlow, 1849). Geomagnetically induced currents (GICs) are currents induced in the solid Earth or in conductors on the Earth’s surface by sudden, intense currents flowing in space plasmas. Special Issue - 10 years of JSWSC 1 Introduction This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( ), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Equally intense magnetic storms were also studied but their related GICs were far less numerous and less intense. It is possible that this SSS is a new form of substorm. The 57 A GIC was the most intense event of the superstorm and of this study. In the first Halloween superstorm, a shock-triggered SSS ( SML < −3548 nT) caused 33, 57, 51 and 52 A GICs. The two “Halloween” superstorms of 29–30 and 30–31 October 2003 produced by far the greatest number of GICs in the interval of study (9 > 30 A GICs and 168 > 10 A GICs). Shock-related GICs were observed to occur at all local times. Forward shocks were the third most frequent cause of the > 30 A events. The PPs are possibly the loop and filament portions of coronal mass ejections (CMEs).įrom a study of > 30 A GIC events, it is found that supersubstorm ( SSS: SML 30 A events. Although forward shocks and substorms are predominant causes of intense GICs, some newly discovered geoeffective interplanetary features are: solar wind plasma parcel (PP) impingements, possible interplanetary magnetic field (IMF) northward (Bn) and southward (Bs) turnings, and reverse shocks. * Corresponding author: interplanetary and magnetospheric phenomena time-coincident with intense geomagnetically induced current (GIC) > 10 A and > 30 A events during 21 years (1999 through 2019) at the Mäntsälä, Finland (57.9° magnetic latitude) gas pipeline have been studied. Indian Institute of Technology Indore, Simrol, Indore 453552, India Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA
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