Using combined MHD/test particle simulations, we further explore characteristics of ion (proton) acceleration tailward of a near-tail reconnection site related to tailward moving plasmoids. In this paper we focus on local features, addressing specifically energy-time spectrograms, directional fluxes and phase space distributions, in comparison to some typical ion observations made by the "Acceleration, Reconnection, Turbulence and Electrodynamics of the Moon's Interaction with the Sun" mission near the plasma sheet boundary layer (PSBL) and in the central plasma sheet (CPS). In agreement with the observations, the simulations show boundary populations consisting of a core and an accelerated tailward beam, which decreases in speed but increases in intensity. While the core is found to be of PSBL or lobe origin the beam ions tend to include also origins in the central plasma sheet. Farther inward from the boundary, similar core/beam populations can also be found, both predominantly originating from the outer CPS. The rise in energetic ion fluxes is found to result from acceleration at or near the near-tail reconnection site. In contrast to the boundary populations, CPS distributions within the tailward moving plasmoid tend to be more isotropic, shifted by their bulk flow speed, again in agreement with observations.

Correlations between the electron fluxes in the Earth’s central plasma sheet and various solar wind and magnetospheric parameters are studied. Higher-energy fluxes (above approximately 2 keV) are the focus of the analysis. Flux measurements are taken during 950 current-sheet crossings in the central plasma sheet using 3-s-resolution electron measurements from the THEMIS-B and THEMIS-C spacecraft in the solar minimum years 2007–2010. The current-sheet crossings were from 10.8–30.6 RE downtail from the Earth. Plots of the Pearson linear correlation coefficient rcorr as a function of the instrument channel energy are examined. Even though all the solar wind variables are intercorrelated, which complicates the situation, indications are that the same element in the solar wind that drives magnetospheric activity is also what drives the fluxes of energetic electrons in the magnetotail plasma sheet. The correlation curves show that the energetic electron fluxes are related to the electron bulk temperature of the central plasma sheet. Accounting for the fact that magnetospheric activity moves the plasma sheet plasma earthward and systematically and adiabatically heats the plasma as a function of downtail distance, it is found that the electron temperature at a given downtail distance from the Earth is related to the level of magnetospheric activity at the time that the temperature is measured. The correlations of energetic electron fluxes with various common solar wind coupling functions are examined. The impact of measurement shot noise in the data is examined, and future work is outlined.

Energetic electrons in Earth's magnetosphere play a critical role in space weather processes and pose risks to spacecraft electronics. Combining measurements from multiple missions, such as Cluster and Time History of Events and Macroscale Interactions during Substorms (THEMIS), enhances our understanding of these populations but requires cross-calibration due to instrumental differences. This study presents a statistical comparison of 40-400 keV electron flux measurements from Cluster/Research with Adaptive Particle Imaging Detector (RAPID)/Imaging Electron Spectrometer (IES) and THEMIS/Solid State Telescope (SST) over 2007-2018. By analyzing the statistical distance between local flux distributions, we quantify discrepancies between the data sets and derive cross-calibration factors, covering radial distances up to 16 . Our results show that SST fluxes consistently exceed IES observations, with the difference increasing with energy. The derived correction factors enable the joint use of the Cluster and THEMIS energetic electron data for multipoint space weather studies.

Abstract Earth's magnetotail, a night‐side region characterized by stretched magnetic field lines and strong plasma currents, is the primary site for the release of magnetic field energy and its transformation into plasma heating and kinetic energy plus charged particle acceleration during magnetic reconnection. In this study, we demonstrate that the efficiency of this acceleration can be sufficiently high to produce populations of relativistic and ultra‐relativistic electrons, with energies up to several MeV, which exceeds all previous theoretical and simulation estimates. Using data from the low‐altitude ELFIN and CIRBE CubeSats, we show multiple events of relativistic electron bursts within the magnetotail, far poleward of the outer radiation belt. These bursts are characterized by power‐law energy spectra and can be detected during even moderate substorms.

Dawnside auroral polarization streams (DAPS) are fast eastward flows in the dawn convection cell of Earth's ionosphere. With a steep flow gradient near the interface between Region 1 and 2 currents and a peak poleward of it, DAPS were suggested to be responsible for instabilities and dramatic events in the magnetosphere-ionosphere (M-I) system. To predict these events, it is important to investigate when and where DAPS prefer to occur and how they are related to other M-I phenomena. We conduct this investigation statistically using 10 years of Swarm data and find that DAPS under sunlit and dark ionospheric conditions exhibit different dependencies on magnetic local times and geomagnetic activities, reflecting a complicated interplay between magnetotail dynamics and ionospheric conductance. The statistical results also reveal a strong correlation between DAPS and embedded Region 2 currents. These findings provide new insights into the DAPS generation mechanism.

High‐speed plasma flows in Earth's magnetotail are important for the global dynamics of the magnetosphere. We survey 11 yrs of high‐speed plasma flows observed by the ARTEMIS spacecraft in Earth's distant magnetotail between X GSE = −52 R E and X GSE = −66 R E to investigate their properties for a wide range of solar and geomagnetic activity levels. We find that tailward and earthward high‐speed flows at these distances exhibit notable asymmetries, with higher ion temperatures and larger dawn‐dusk magnetic field magnitudes in tailward flows compared to earthward flows. These asymmetries suggest that a significant portion of tailward high‐speed flows originate from near‐Earth magnetotail reconnection, while earthward high‐speed flows originate from a distant magnetotail reconnection site tailward of ARTEMIS. The occurrence rate of high‐speed flows follows the solar cycle progression and is about twice as high during solar maximum compared to solar minimum. Furthermore, both tailward and earthward high‐speed flows have higher median ion and electron temperatures, outflow speeds, and dawn‐dusk magnetic fields during solar maximum. In addition to the solar cycle dependence, the ion and electron temperatures in the high‐speed flows increase with increasing geomagnetic activity, for both the Auroral Electrojet (AE) and the Disturbance Storm Time (Dst) indices. Interestingly, during large substorms (AE > 1,100 nT) and geomagnetic storms (Dst < −90 nT), only tailward high‐speed flows are observed at lunar distances in this data set. In essence, our results indicate that the properties of both near‐Earth and distant tail reconnection are functions of the solar cycle and geomagnetic activity.

Using particle data from the ELFIN satellites, we present a statistical study of 284 proton isotropy boundary events on the nightside magnetosphere, characterizing their occurrence and distribution in local time, latitude (L-shell), energy, and precipitating energy flux, as a function of geomagnetic activity. For a given charged particle species and energy, its isotropy boundary (IB) is the magnetic latitude poleward of which persistently isotropic pitch-angle distributions (J_prec/J_perp∼ 1) are first observed to occur. This isotropization is interpreted as resulting from magnetic field-line curvature (FLC) scattering in the equatorial magnetosphere. We find that proton IBs are observed under all observed activity levels, spanning 16 to 05 MLT with ∼100 These results are also compared with electron IB properties observed using ELFIN, where we find similar trends across local time and activity, with the onset in ≥50 keV proton IB occurring on average 2 L-shells lower, and providing between 3 and 10 times as much precipitating power. Proton IBs typically span 64^∘-66^∘ in magnetic latitude (5-6 in L-shell), corresponding to the outer edge of the ring current, tending toward lower IGRF latitudes as geomagnetic activity increases. The IBs were found to commonly occur 0.3-2.1 Re beyond the plasmapause. Proton IBs typically span <50 keV to ∼1 MeV in energy, maximizing near 22 MLT, and decreasing to a typical upper limit of 300-400 keV toward dawn and dusk, with peak observed isotropic energy increasing by ∼500 keV during active intervals. These results suggest that FLC in the vicinity of IBs can provide a substantial depletion mechanism for energetic protons, with the total nightside precipitating power from FLC-scattering found to be on the order of 100 MW, at times ≥10 GW.

To explore the asymmetry in ion and electron heating at Earth's magnetotail at mid-tail distances (X-GSM< -30 R-E), we analyze near-simultaneous observations of reconnection outflows from two opposite sides of reconnection sites at those distances using Magnetospheric Multiscale (MMS) and Acceleration, Reconnection, Turbulence and Electrodynamics of Moon's Interaction with the Sun (ARTEMIS) data. We report a pronounced temperature asymmetry between the earthward and tailward reconnection outflows. The asymmetry is more significant for electrons than for ions: Earthward moving ions are only three times hotter than tailward ones, but earthward moving electrons are 5-20 times hotter than tailward ones. The closed field-line topology on the earthward side of the reconnection region, as opposed to the open topology on the tailward side, is likely a critical contributor to this asymmetry. These findings cast light on the underlying mechanisms of particle heating and energization in magnetotail reconnection, highlighting the significant role of Earth's dipolar magnetic field. This study offers insights for refining magnetic reconnection models, emphasizing the importance of incorporating realistic magnetic field topologies to accurately simulate the heating and energization processes observed in space plasma environments.

Dipolarizing flux bundles (DFBs) have been suggested to transport energy and momentum from regions of reconnection in the magnetotail to the high latitude ionosphere, where they can generate localized ionospheric currents that can produce large nighttime geomagnetic disturbances (GMDs). In this study we identified DFBs observed in the midnight sector from ~7 to ~10 RE by THEMIS A, D, and E during days in 2015-2017 whose northern hemisphere magnetic footpoints mapped to regions near Hudson Bay, Canada, and have compared them to GMDs observed by ground magnetometers. We found six days during which one or more of these DFBs coincided within ± 3 min with ≥ 6 nT/s GMDs observed by latitudinally closely spaced ground-based magnetometers located near those footpoints. Spherical elementary current systems (SECS) maps and all-sky imager data provided further characterization of two events, showing short-lived localized intense upward currents, auroral intensifications and/or streamers, and vortical perturbations of a westward electrojet. On all but one of these days the coincident DFB – GMD pairs occurred during intervals of high-speed solar wind streams but low values of SYM/H. In some events, in which the DFBs were observed closer to Earth and with lower Earthward velocities, the GMDs occurred slightly earlier than the DFBs, suggesting that braking had begun before the time of the DFB observation. This study is the first to connect spacecraft observations of DFBs in the magnetotail to intense (>6 nT/s) GMDs on the ground, and the results suggest DFBs could be an important driver of GICs.

The magnetotail current sheet plays a key role in the dynamics of Earth's magnetosphere. Specifically, the formation and subsequent reconnection of thin (ion-gyroscale) current sheets are critical components of magnetospheric substorms. However, the precise mechanisms governing the configuration and distribution of current density in these thin current sheets remain elusive. By analyzing a data set consisting of 453 thin current sheet crossings observed by the Acceleration, Reconnection, Turbulence and Electrodynamics of Moon's Interaction with the Sun (ARTEMIS) mission, we explore the statistical properties of the ion and electron pressures and current densities, Ji and Je, in the spacecraft rest frame. Using magnetotail flapping and magnetic field measurements to estimate the total current density, J0, we find that it agrees well with the sum of those from direct ion and electron measurements, Ji + Je, respectively. In 65% of thin current sheets, electrons were found to dominate the contribution to the total current density in the spacecraft frame, with a typical dawnward drift velocity of greater than or similar to 100 km/s. Diamagnetic drifts of electrons and ions estimated from their respective vertical pressure profiles (along the current sheet normal) reveal that the gradient of electron pressure alone cannot fully account for the observed high values of Je/Ji. Counter-intuitively, for most (52% of) thin current sheets the electron vertical pressure profile is wider than the ion pressure profile, again suggesting that electron diamagnetism is an insufficient contributor to the current density at such sheets. These findings suggest the presence of a significant E x B dawnward drift that the electrons can fully acquire but ions cannot, being partially unmagnetized. We compare our results with those previously reported for the near-Earth magnetotail and discuss them in the context of magnetotail current sheet modeling. We compare the contribution of electrons and ions to the total current density estimated from the flapping motion of the CSs at -60RE In 65% of thin current sheets, electron carriers dominate the total current at the spacecraft rest frame The diamagnetic drift associated with the pressure gradient of electrons, alone, is insufficient to explain the observed electron currents

The magnetotail current sheet's spatial configuration and stability control the onset of magnetic reconnection - the driving process for magnetospheric substorms. The near-Earth current sheet has been thoroughly investigated by numerous missions, whereas the midtail current sheet has not been adequately explored. This is especially the case for the long-term variation of its configuration in response to the solar wind. We present a statistical analysis of 1261 magnetotail current sheet crossings by the Acceleration, Reconnection, Turbulence and Electrodynamics of Moon's Interaction with the Sun (ARTEMIS) mission orbiting the moon (X~-60 RE), collected during the entirety of Solar Cycle 24. We demonstrate that the magnetotail current sheet typically remains extremely thin, with a characteristic thickness comparable to the thermal ion gyroradius, even at such large distances from Earth's dipole. We also find that a substantial fraction (~one quarter) of the observed current sheets have a partially force-free magnetic field configuration, with a negligible contribution of the thermal pressure and a significant contribution of the magnetic field shear component to the pressure balance. Further, we quantify the impact of the changing solar wind driving conditions on the properties of the midtail around the lunar orbit. During active solar wind driving conditions, we observe an increase in the occurrence rate of thin current sheets, whereas quiet solar wind driving conditions seem to favor the formation of partially force-free current sheets.

Energetic (greater than or similar to 50 keV) electron precipitation from the magnetosphere to the ionosphere during substorms can be important for magnetosphere-ionosphere coupling. Using conjugate observations between the THEMIS, ELFIN, and DMSP spacecraft during a substorm, we have analyzed the energetic electron precipitation, the magnetospheric injection, and the associated plasma waves to examine the role of waves in pitch-angle scattering plasma sheet electrons into the loss cone. During the substorm expansion phase, ELFIN-A observed 50-300 keV electron precipitation from the plasma sheet that was likely driven by wave-particle interactions. The identification of the low-altitude extent of the plasma sheet from ELFIN is aided by DMSP global auroral images. Combining quasi-linear theory, numerical test particle simulations, and equatorial THEMIS measurements of particles and fields, we have evaluated the relative importance of kinetic Alfven waves (KAWs) and whistler-mode waves in driving the observed precipitation. We find that the KAW-driven bounce-averaged pitch-angle diffusion coefficients D-alpha 0 alpha 0 near the edge of the loss cone are similar to 10(-6)-10(-5) s(-1) for these energetic electrons. The D-alpha 0 alpha 0 due to parallel whistler-mode waves, observed at THEMIS similar to 10-min after the ELFIN observations, are similar to 10(-8)-10(-6) s(-1). Thus, at least in this case, the observed KAWs dominate over the observed whistler-mode waves in the scattering and precipitation of energetic plasma sheet electrons during the substorm injection.

Although energetic particle (EP) injections are commonly thought to be formed by the flow burst intrusion from the magnetotail, important details and quantitative aspects of their transport, acceleration and flow braking need further investigation and understanding. Motivated by frequent observations of short transient EP injections being not associated with substorms, we analyze high-resolution Rice Convection Model simulations of a short (5-min long) localized (similar to 3R(E) width) density depletion (evacuating 90% of flux tube content) initiated at the tailward simulation boundary (similar to 18R(E)) and allowed to evolve within an otherwise typical plasma sheet environment. We note that, driven by betatron-like acceleration, the peak EP flux at fixed energy dramatically increases in a couple of minutes when the bubble head enters the inner magnetosphere at r < 8-10 R-E giving rise to a localized injection of subsequently drifting EP clouds. Here the 50-200 keV electron flux reaches values as high as #10(5) (cm(2) s sr keV)(-1), and even higher energies (up to 1 MeV) may briefly appear. Surprisingly, at a later stage of bubble penetration, after termination of bubble jet from the tail, the injection boundary of high energy (HE) particles detaches from the bubble earthward boundary while the latter continues moving inward. Time History of Events and Macroscale Interactions during Substorms multi-spacecraft mission observations of a short bubble-like flow burst at the spacecraft cluster located near the flow stopping point, show much similarity with simulation results but also reveal important differences between responses of HE protons and electrons attributed to the finite gyroradius effect.

Relativistic electron precipitation to the Earth's atmosphere is an important loss mechanism of inner magnetosphere electrons, contributing significantly to the dynamics of the radiation belts. Such precipitation may be driven by electron resonant scattering by middle-latitude whistler-mode waves at dawn to noon; by electromagnetic ion cyclotron (EMIC) waves at dusk; or by curvature scattering at the isotropy boundary (at the inner edge of the electron plasma sheet anywhere on the nightside, from dusk to dawn). Using low-altitude ELFIN and near-equatorial THEMIS measurements, we report on a new type of relativistic electron precipitation that shares some properties with the traditional curvature scattering mechanism (occurring on the nightside and often having a clear energy/L-shell dispersion). However, it is less common than the typical electron isotropy boundary and it is observed most often during substorms. It is seen equatorward of (and well separated from) the electron isotropy boundary and around or poleward of the ion isotropy boundary (the inner edge of the ion plasma sheet). It may be due to one or more of the following mechanisms: EMIC waves in the presence of a specific radial profile of the cold plasma density; a regional suppression of the magnetic field enhancing curvature scattering locally; and/or electron resonant scattering by kinetic Alfven waves. We report on observations of patterns of dispersed relativistic electron precipitation in the nightside inner magnetosphereThese precipitation patterns often show a clear energy versus L-shell dispersionThis new type of precipitation is observed equatorward of the electron isotropy boundary but near or poleward of the ion isotropy boundary

There have been a number of theories proposed concerning the loss of relativistic electrons from the radiation belts. However, direct observations of loss were not possible on a number of previous missions due to the large field of view of the instruments and often high-altitude orbits of satellites that did not allow researchers to isolate the precipitating electrons from the stably trapped. We use measurements from the ELFIN-L suit of instruments flown on Lomonosov spacecraft at LEO orbit, which allows us to distinguish stably trapped from the drift loss cone electrons. The sun-synchronous orbit of Lomonosov allows us to quantify scattering that occurred into the loss cone on the dawn-side and the dusk-side magnetosphere. The loss at MeV energies is observed predominantly on the dawn-side, consistent with the loss induced by the chorus waves. The companion data publication provides processed measurements.

The near‐Earth plasma sheet region is the main source of energetic (tens to hundreds keV) ion and electron populations transported by convection and injections into the inner magnetosphere. Energetic ions from the plasma sheet contribute to the ring current, whereas energetic electrons contribute to the radiation belt seed population for further acceleration to relativistic energies. Near‐Earth plasma sheet energetic fluxes have been traditionally used to set boundary conditions for radiation belt and ring current models. This study provides an empirical parametrization for ∼75 keV flux intensity as a function of the geomagnetic activity index auroral electrojet and the equatorial magnetic field B z . Such parametrization includes the dynamic magnetic field configuration in the near‐Earth plasma sheet and may be merged with empirical magnetic field models. We also provide models extending this parametrization to the [20, 300] keV of electron energy range and [75, 300] keV of ion energy range. The parametrization is developed based on THEMIS and Geostationary Operational Environmental Satellite measurements, and verified by comparison with MMS measurements in the near‐Earth plasma sheet. This parametrization incorporates meso‐scale transient flux variations associated with B z perturbations into ring current and radiation belt simulations.

The Earth's magnetotail at lunar distances ( R ≈ 60 R E ) serves as a unique laboratory to study plasma dynamics in a weak, highly fluctuating magnetic field with a strong magnetic field gradient. In particular, studies of the of quiet‐time plasma in the lunar‐distant magnetotail can inform us about plasma entry to the magnetosphere and sources of magnetospheric plasma populations. We use the data collected by the two lunar‐orbiting Acceleration, Reconnection, Turbulence and Electrodynamics of Moon's Interaction with the Sun (ARTEMIS) spacecraft during its 2013–2019 magnetotail traversals to infer the average thermodynamic and spectral properties of plasma populations in the quiet‐time (i.e., low geomagnetic activity and absence of fast plasma flows) magnetotail at lunar distances. We found that plasma temperature and density in the quiet‐time magnetotail at R ≈ 60 R E are organized by the magnetic field. Three distinct regions with plasma β ≫ 1, β ∼ 1, and β ≪ 1, the central plasma sheet (CPS), outer plasma sheet (OPS), and lobes are sampled. We found that temperatures and energy spectra of ion populations in CPS, OPS, and lobes regimes are different: the hotter CPS temperatures scale with the kinetic energy of solar wind protons; cold OPS/lobe ions are, likely, of ionospheric origin. The ion and electron particle spectra in CPS, OPS, and lobes are nonthermal and reasonably well fitted by the Kappa function, with κ exponent varying between 2.5 and 3.5.

Low‐altitude observations of magnetospheric particles provide a unique opportunity for remote probing of the magnetospheric and plasma states during active times. We present the first statistical analysis of a specific pattern in such observations, energetic electron flux dropouts in the low‐altitude projection of the plasma sheet. Using 3.5 years of data from the ELFIN CubeSats we report the occurrence distribution of 145 energetic electron flux dropout events and identify characteristics, including their prevalence in the dusk and premidnight sectors, their association with substorms and enhanced auroral activities, and their correlation with the region‐1 (R1) field‐aligned current region. We also investigate three representative dropout events which benefit from satellite conjunctions between ELFIN, GOES, and THEMIS, to better understand the magnetospheric drivers and magnetic field conditions that lead to such dropouts as viewed by ELFIN. One class of dropouts may be associated with magnetic field mapping distortions due to local enhancements and thinning of cross‐tail current sheets and amplification of R1 field‐aligned currents. The other class may be associated with the increase in perpendicular anisotropy of magnetospheric electrons due to magnetic field dipolarizations near premidnight. These plasma sheet flux dropouts at ELFIN provide a valuable tool for refining magnetospheric models, thereby improving the accuracy of field‐line mapping during substorms.

In this paper we present PARAGON, a mission concept that provides predictive understanding of geomagnetic disturbances at systems level, by connecting global evolution to mesoscale dynamics and kinetic-scale effects.PARAGON introduces a paradigm shift in the way we observe geospace by utilizing coordinated: i) unprecedented spatial and temporal resolution imaging of the ring current, near-Earth plasma sheet, aurora, and plasmasphere and ii) in-situ plasma, energetic particles and magnetic field measurements, from different platforms, in order to discover, quantify and understand the global impact of mesoscale processes in the development of major geomagnetic disturbances.Since the beginning of the space age, we have ventured extensively into Earth's immediate surroundings, and have learned how geospace is a coupled system of systems, including the magnetosphere, the ionosphere and the upper atmosphere in which the ionosphere is embedded.Just like terrestrial weather disturbances, such as cyclones, evolve as a collection of processes at different spatial and temporal scales in the atmosphere, so too do geomagnetic storms transfer energy, mass, and momentum throughout geospace at local, mesoscale, and global scales.Multiple missions over the years have targeted either the local or global nature of geospace with in-situ probes or global imaging, respectively.However, understanding geomagnetic disturbances to the level of predictability remains elusive, because we still do not understand the bridge between the local and global geospace, that is, the mesoscale (1000 km to few R E in the magnetotail, ~10s-100s km in the ionosphere) processes and their global implications.PARAGON will determine under what conditions mesoscale processes in the coupled Magnetosphere-Ionosphere (M-I) system become geoeffective, by observing the global system in mesoscale resolution.PARAGON addresses fundamental questions about mesoscale processes that are observed throughout the solar system, from the fast rotating magnetospheres of Jupiter and Saturn to the supra-arcade downflows in the eruptive solar flares.Earth's accessible space environment provides the perfect laboratory for these processes to be explored in detail.With the outstanding question of the global impact of mesoscale processes still being at the forefront of magnetospheric physics, and considering the technological advancements over the last decade, PARAGON can and should be of the highestpriority for implementation in the upcoming decade.

We investigate an unusual sequence and peculiar features of magnetotail changes during a storm‐range substorm initiated by the interplanetary shock. Auroral observations and measurements at several favorably distributed magnetospheric spacecraft allowed the construction of an adaptive time‐dependent magnetospheric model to quantitatively characterize the configurational changes and mapping variations. Several passages of low‐altitude spacecraft in polar orbits near midnight help reveal the magnetic configuration of the nightside tail‐dipole transition region. In this event, an intense auroral and convection activity (accompanied by an up to 1,500 nT increase in the SuperMag AL‐index index) emerged in the highly compressed magnetosphere after the passage of interplanetary shock followed by strongly southward interplanetary magnetic field (IMF). This directly driven phase of the activity continued for an hour and resulted in the formation of a hybrid magnetic configuration with dipolarized midtail and stretched field lines in the transition region. Observations of energetic particle isotropy boundary latitudes near midnight are consistent with the modeled magnetic configuration. In concert with a downward turn of the solar wind (SW) flow, and weakening of the IMF driver and convection, an unusual stretching signature of the inner magnetosphere magnetic field was observed as close as at r ∼ 5 to 7 Re; which resulted mostly from an increasing downward tilt of the thin azimuthal current. Classic substorm breakup signatures commenced at fairly low, ∼60° magnetic latitude, deep in the closed field line region, in association with the current sheet upward motion. It was followed by strong stepwise poleward auroral expansion. We discuss how these signatures deviate from standard substorm scenarios and may be potentially imparted by the aforementioned changes in SW flow direction and pressure.