The Interplanetary and Magnetospheric causes of Geomagnetically Induced Currents (GICs) > 10 A in the Mäntsälä Finland Pipeline: 1999 through 2019

Abstract

The interplanetary and magnetospheric causes of 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. 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. The PPs are possibly the loop and filament portions of coronal mass ejections (CMEs). From a study of > 30 A GIC events, it is found that supersubstorm (SSS: SML < -2500 nT) and intense substorm (-2500 nT < SML < -2000 nT) auroral electrojet intensifications are the most frequent (76%) cause of all of these GIC events. These events occur most often (76%) in superstorm (SYM-H ≤ -250 nT) main phases, but they can occur in other storm phases and lesser intensity storms as well. After substorms, PPs were the most frequent causes of Mäntsälä GIC > 30 A events. Forward shocks were the third most frequent cause of the > 30 A events. Shock-related GICs were observed to occur at all local times. 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). In the first Halloween superstorm, a shock-triggered SSS (SML < -3548 nT) caused 33, 57, 51 and 52 A GICs. The 57 A GIC was the most intense event of the superstorm and of this study. Equally intense magnetic storms were also studied but their related GICs were far less numerous and less intense.

September 2017 Space-Weather Events: A Study on Magnetic Reconnection and Geoeffectiveness

“…The location of the day-side magnetopause, which depends on the pressure balance between the solar-wind ram pressure and the magnetospheric magnetic pressure, exhibited large variability during the geomagnetic activity. These results are consistent with present understanding of geomagnetic activity (Tsurutani and Gonzalez, 1987;Tsurutani et al, 1988Tsurutani et al, , 1995Tsurutani et al, , 2006Gonzalez et al, 1994;Zhang et al, 2007;Echer, Gonzalez, and Tsurutani, 2008;Hajra et al, 2014;Meng, Tsurutani, and Mannucci, 2019;Hajra, Tsurutani, and Lakhina, 2020;Tsurutani and Hajra, 2021). On the average, the intensity of the ring-current index and the auroral-activity indices exhibited linear relationships with the reconnection parameters.…”

Impact Angle Control of Local Intense dB/dt Variations During Shock‐Induced Substorms

“…Considering that these dB/dt thresholds can cause damage to power grid equipment operating in different timescales (Molinski et al, 2000;Pulkkinen et al, 2013), power plant operators can take advantage of these results to plan ahead and avoid long-term damage associated with space weather effects particularly caused by IP shocks that are observed at L1 and bound to impact Earth nearly head-on (Kruparova et al, 2013;Paulson et al, 2012;Vorotnikov et al, 2011). Tsurutani and Hajra (2021) used over 2 years of GIC data collected in southern Finland to show that 76% of the events with GIC 𝐴𝐴 𝐴 30 A were caused by supersubstorms, whereas all events with GIC 𝐴𝐴 𝐴 10 A were caused by intense substorms. Tsurutani and Hajra (2021) noted that all events showed shock-related GIC effects.…”

Magnetospheric chaos and dynamical complexity response during storm time disturbance

“…A prolonged southward turning of interplanetary magnetic field (IMF, B z ), which indicates that solar-wind-magnetosphere coupling is in progress, was confirmed on many occasions for which such a geomagnetic storm was driven by co-rotating interaction regions (CIRs), by the sheath preceding an interplanetary coronal mass ejection (ICME), or by a combination of the sheath and an ICME magnetic cloud (Gonzalez and Tsurutani, 1987;Tsurutani and Gonzalez, 1987;Tsurutani et al, 1988;Cowley, 1995;Tsutomu, 2002;Yurchyshyn et al, 2004;Kozyra et al, 2006;Echer et al, 2008;Meng et al, 2019;Tsurutani et al, 2020;Echer et al, 2006). The sporadic magnetic reconnection between the southward component of the Alfvén waves and the earth's magnetopause leads to isolated substorms or convection events such as the high-intensity long-duration continuous AE activity (HILDCAA, where AE represents auroral electrojet) which are shown to last from days to weeks (Akasofu, 1964;Tsurutani and Meng, 1972;Meng et al, 1973;Tsurutani and Gonzalez, 1987;Hajra et al, 2013;Liou et al, 2013;Mendes et al, 2017;Hajra and Tsurutani, 2018;Tsurutani and Hajra, 2021;Russell, 2001). Notably, the introduction of the disturbance storm time (D st ) index (Sugiura, 1964;Sugiura and Kamei, 1991) unveiled a quantitative mea-Published by Copernicus Publications on behalf of the European Geosciences Union & the American Geophysical Union.…”