Sudden Impulses in the Magnetosphere and at Ground

Villante, U.; Piersanti, Mirko

doi:10.5772/36770

Cited by 4 publications

(5 citation statements)

References 38 publications

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“…Of these four parameters, the lack of temporal correlation with Psw may seem to be the most surprising, for two reasons. First, there is a well-documented association between interplanetary shocks and sudden impulses (large transient changes in geomagnetic fields on the dayside) and consequent large changes in geomagnetic fields (Araki, 1994;Oliveira & Raeder, 2015;Villante & Piersanti, 2012). However, dayside MPEs, which are often associated with sudden impulses stimulated by large solar wind-induced magnetospheric compressions, were not included in our database.…”

Section: Discussionmentioning

confidence: 99%

Superposed Epoch Analysis of Nighttime Magnetic Perturbation Events Observed in Arctic Canada

et al. 2021

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Rapid changes of magnetic fields associated with nighttime magnetic perturbation events (MPEs) with amplitudes |ΔB| of hundreds of nT and 5–10 min duration can induce geomagnetically induced currents (GICs) that can harm technological systems. Here we present superposed epoch analyses of large nighttime MPEs (|dB/dt| ≥ 6 nT/s) observed during 2015 and 2017 at five stations in Arctic Canada ranging from 64.7° to 75.2° in corrected geomagnetic latitude (MLAT) as functions of the interplanetary magnetic field (IMF), solar wind dynamic pressure, density, and velocity, and the SML, SMU, and SYM/H geomagnetic activity indices. Analyses were produced for premidnight and postmidnight events and for three ranges of time after the most recent substorm onset: (a) 0–30 min, (b) 30–60 min, and (c) >60 min. Of the solar wind and IMF parameters studied, only the IMF Bz component showed any consistent temporal variations prior to MPEs: a 1–2 h wide 1–3 nT negative minimum at all stations beginning ∼30–80 min before premidnight MPEs, and minima that were less consistent but often deeper before postmidnight MPEs. Median, 25th, and 75th percentile SuperMAG auroral indices SML (SMU) showed drops (rises) before pre‐ and post‐midnight type A MPEs, but most of the MPEs in categories B and C did not coincide with large‐scale peaks in ionospheric electrojets. Median SYM/H indices were flat near −30 nT for premidnight events and showed no consistent temporal association with any MPE events. More disturbed values of IMF Bz, Psw, Nsw, SML, SMU, and SYM/H appeared postmidnight than premidnight.

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Section: Discussionmentioning

confidence: 99%

Superposed Epoch Analysis of Nighttime Magnetic Perturbation Events Observed in Arctic Canada

et al. 2021

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“…Traditionally, geomagnetic field variations on the ground and magnetospheric magnetic field responses (especially on the nightside) are separated topics in observational studies, utilizing data from ground‐based observatories and spacecraft, respectively [ Villante and Piersanti , ]. Confined by limited and localized measurements, it is difficult to observationally relate the two phenomena occurring at largely separated locations.…”

Section: Introductionmentioning

confidence: 99%

The chain response of the magnetospheric and ground magnetic field to interplanetary shocks

et al. 2015

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(2015), The chain response of the magnetospheric and ground magnetic field to interplanetary shocks, J. Geophys. Res. Space Physics, 120, 157-165, doi:10.1002 Abstract In response to interplanetary (IP) shocks, magnetic field may decrease/increase (negative/positive response) in nightside magnetosphere, while at high latitudes on the ground it has two-phase bipolar variations: preliminary impulse and main impulse (MI). Using global MHD simulations, we investigate the linkage between the MI phase variation on the ground and the magnetospheric negative response to an IP shock. It is revealed that although the two phenomena occur at largely separated locations, they are physically related and form a response chain. The velocity disturbances near the flanks of the magnetopause cause the magnetic field to decrease, resulting in a dynamo which thus powers the transient field-aligned currents (FACs). These FACs further generate a pair of ionospheric current vortex, leading to MI variations on the ground. Therefore, we report here the intrinsic physically related chain response of the magnetospheric and ground magnetic field to IP shocks, and thus link the magnetospheric sudden impulse (SI) and ground SI together.

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Section: Discussionmentioning

confidence: 99%

Superposed Epoch Analysis of Nighttime Magnetic Perturbation Events Observed in Arctic Canada

Engebretson

Ahmed

Pilipenko³

et al. 2021

Preprint

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The threat to both spaceborne and ground-based technological systems posed by extreme events in Earth's space environment has led in recent years to numerous observational and modeling studies of the impact of dynamical processes in the solar corona that are conveyed to Earth via the solar wind plasma and interplanetary magnetic field that interact with Earth's magnetosphere and ionosphere.The influence of extreme solar phenomena on Earth was first documented for the Carrington event of 1859 (Carrington, 1859), in which a large and complex set of solar flares caused not only widespread auroral displays but also disturbances in telegraph systems over a large portion of Earth. Observations of similarly rare events since then, such as recent studies of the great magnetic storms of May 1921 and March 1989 and their effects (Boteler, 2019Hapgood, 2019;Love et al., 2019) have shown in more detail the ways in which "space weather" can have deleterious impacts on large-scale human technological systems, even to the extent of causing a blackout of the entire Hydro-Quebec electrical grid.The mechanisms by which these externally driven events caused dangerous electrical currents at Earth's surface are now known to be rapid variations in Earth's geomagnetic field -large unipolar or bipolar solitary pulses predominantly in the premidnight sector or Pi3 or Ps6 pulsations in the postmidnight sectorwith typical amplitudes |ΔB| of hundreds of nT and 5-10 min duration- (Belakhovsky et al., 2018;

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Sudden Impulses in the Magnetosphere and at Ground

Cited by 4 publications

References 38 publications

Superposed Epoch Analysis of Nighttime Magnetic Perturbation Events Observed in Arctic Canada

Superposed Epoch Analysis of Nighttime Magnetic Perturbation Events Observed in Arctic Canada

The chain response of the magnetospheric and ground magnetic field to interplanetary shocks

Superposed Epoch Analysis of Nighttime Magnetic Perturbation Events Observed in Arctic Canada

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