On some features characterizing the plasmasphere–magnetosphere–ionosphere system during the geomagnetic storm of 27 May 2017

Abstract

This paper presents how the magnetosphere–plasmasphere–ionosphere system was affected as a whole during the geomagnetic storm peaking on 27 May 2017. The interplanetary conditions, the magnetospheric response in terms of the magnetopause motion, and the ionospheric current flow pattern were investigated using data, respectively, from the WIND spacecraft, from GOES15, GOES13, THEMIS E, THEMIS D and THEMIS A satellites and from the INTERMAGNET magnetometer array. The main objective of the work is to investigate the plasmaspheric dynamics under disturbed conditions and its possible relation to the ionospheric one; to reach this goal, the equatorial plasma mass densities derived from geomagnetic field line resonance observations at the European quasi-Meridional Magnetometer Array (EMMA) and total electron content values obtained through three GPS receivers close to EMMA were jointly considered. Despite the complexity of physical mechanisms behind them, we found a similarity between the ionospheric and plasmaspheric characteristic recovery times. Specifically, the ionospheric characteristic time turned out to be ~ 1.5 days, ~ 2 days and ~ 3.1 days, respectively, at L ~ 3, L ~ 4 and L ~ 5, while the plasmaspheric one, for similar L values, ranged from ~ 1 day to more than 4 days.

From the Sun to Earth: effects of the 25 August 2018 geomagnetic storm

“…Interestingly, both GOES satellites show a huge increase of the B x component (panels b and c) and a negative and then positive variation in the B y component (panels d and e). This behaviour is the signature of a strong stretching and twisting of the magnetospheric field lines during the main phase of the geomagnetic storm (Piersanti et al, 2012(Piersanti et al, , 2017. This scenario is confirmed by a modified Tsyganenko and Sitnov (TS04 * ; 2005) model indicated by red dashed lines in Fig.…”

The development and validation of a ‘flux-corrected transport’ based solution methodology for the plasmasphere refilling problem following geomagnetic storms

“…In general, the imposition of boundary conditions in numerical models (Oran and Boris 2001) can be implemented in three different ways:…”

“…In this section, the plasmasphere refilling problem is modeled as a single ion species ( H + ions) along with electrons and refilling along a 1D flux tube, without considering the curvature of the tube and neglecting the effects from Coulomb collisions. The time-dependent continuity and momentum equations are given below (Oran and Boris 2001): where t is time, x the spatial coordinate, n i,e the ion/ electron concentration, u i,e ion/electron velocity, m i,e the ion/electron mass, p i,e = n i,e kT the partial ion/electron pressure, T the constant temperature along the flux tube, k the Boltzmann constant, E the electric field and g(x) the spatially dependent gravitational force. Imposing quasi-neutrality gives rise to n i = n e and neglecting the electron mass in the electron momentum equation gives rise to an expression for the electric field given by E = −(kT /en i )(∂n i /∂x) .…”

A Semikinetic Model of Plasmasphere Refilling Following Geomagnetic Storms and Comparison With Hydrodynamic Results

“…The lowermost region of the magnetosphere is the plasmasphere (Banks et al,1971;Carpenter & Park, 1973;Darrouzet et al, 2009;Goldstein et al, 2002;Gringauz, 1963;Millian & Thorne, 2007;Pezzopane et al, 2019). It has been described in literature (Rasmussen & Schunk, 1988;Singh et al, 1986) as a toroidal mass of cold, 1 ev plasma, corotating with the Earth.…”