NP6.3

How to cite: Agudelo Rueda, J. A., Verscharen, D., Wicks, R. T., Owen, C. J., Walsh, A. P., and Germaschewski, K.: Agyrotropy patterns in 3D small-scall turbulent reconnection, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11807, https://doi.org/10.5194/egusphere-egu22-11807, 2022.

Observations of Earth’s magnetosheath from the Magnetospheric Multiscale (MMS) mission have provided an unprecedented opportunity to examine the detailed structure of the multitude of thin current sheets that are generated by plasma turbulence, revealing that a novel form of magnetic reconnection, which has come to be known as electron-only reconnection, can occur within magnetosheath turbulence. These electron-only reconnection events occur at thin electron-scale current sheets and have super-Alfvénic electron jets that can approach the electron Alfvén speed; however, they do not appear to have signatures of ion jets. It is thought that electron-only reconnection can occur when the length of the reconnecting current sheets along the outflow direction is short enough that the ions cannot fully couple to the newly reconnected magnetic field lines before they fully relax. In this work, we examine how the correlation length of the magnetic fluctuations in a turbulent plasma, which constrains the length of the current sheets that can be formed by the turbulence, impacts the nature of turbulence-driven magnetic reconnection. Using observations from MMS, we systematically examine 60 intervals of magnetosheath turbulence – identifying 256 small-scale reconnection events, both with and without ion jets. We demonstrate that the properties of the reconnection events transition to become more consistent with electron-only reconnection when the magnetic correlation length of the turbulence is below ~20 ion inertial lengths. We further discuss the implications of the results in the context of other turbulent plasmas by considering observations of turbulent fluctuations in the solar wind.

How to cite: Stawarz, J. E., Eastwood, J. P., Phan, T., Gingell, I. L., Pyakurel, P. S., Shay, M. A., Robertson, S. L., Russell, C. T., and Le Contel, O.: Turbulence-driven magnetic reconnection and the magnetic correlation length in collisionless plasma turbulence, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11524, https://doi.org/10.5194/egusphere-egu22-11524, 2022.

We identify two coalescing flux ropes as squeezed by convergent ion flows near the magnetopause from the MMS observations. According to the electron distributions, we find that one flux rope is closer to the magnetosphere, while the other is closer to the magnetosheath. A current sheet with magnetic field reversal is found to sit at the interface between the two colliding flux ropes, and have magnetic reconnection occurring in the ion diffusion region (IDR). Due to the density asymmetry of flux ropes, the embedded magnetic reconnection event with a significant guide field component shows a large asymmetry in energy conversion across the reconnection site. On the side where the flux rope is closer to the magnetosphere with low density, we find that electrons gained energy from electromagnetic fields resulting in a parallel heating effect. In contrast, ions are found to obtain the energy from electromagnetic fields on the other side of the reconnection current sheet, where the flux rope is near the magnetosheath with high density.

How to cite: Luo, Q., He, J., and Cui, J.: Asymmetric magnetic reconnection between two coalescing flux ropes as squeezed by convergent flows, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-6722, https://doi.org/10.5194/egusphere-egu22-6722, 2022.

The internal dynamics of solar prominences have been observed for many decades to be highly complex, many of which also indicate the possibility of turbulence. Prominences represent large-scale, dense condensations suspended against gravity at great heights within the solar atmosphere. It is therefore of no surprise that the fundamental process of the Rayleigh-Taylor (RT) instability has been suggested as the potential mechanism for driving the dynamics and turbulence remarked upon within observations. We use the open-source MPI-AMRVAC code to construct an extremely high-resolution, 2.5D fully-resistive magnetohydrodynamic model, and employ it to explore the turbulent nature of RT-induced magnetic reconnection processes within solar prominences. The intermittent events of heating and energy dissipation are caused by magnetic reconnection. Furthermore, the strength of the mean magnetic field directed into the 2D plane, and its alignment with the plane itself, creates a system with varying turbulent behaviour. Based on low plasma beta (magnetic pressure dominant) evolution near the chromosphere and a higher value (plasma pressure dominant) evolution within the corona, the stratified numerical model generates different fluctuation statistics. Hence, we find the turbulent dynamics and prominence reconnection events to differ distinctly from those elsewhere within the solar corona.

How to cite: Changmai, M. and Keppens, R.: Exploring 2.5D magnetic reconnection due to Rayleigh-Taylor induced turbulence in solar prominences, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8160, https://doi.org/10.5194/egusphere-egu22-8160, 2022.

Turbulence, the self-generated turbulence by plasmas and magnetic field collective interaction, has been found to play an essential role in energizing charged particles in the large-scale reconnecting current sheet in the major solar eruption.

The typical large-scale CME/Flare events involve sudden bursts of particle acceleration from the sudden release of magnetic energy in a few minutes to a few tens of minutes. The X-rays emission and gamma rays burst produced by the combined result from the interactions of electrons, hydrogen, helium, and other heavier ions. Space and laboratory researchers are more inclined to believe that turbulence acceleration is belonged to shock acceleration. Solar and astrophysics researchers are more inclined to believe that turbulence acceleration is an independent acceleration mechanism that belongs to the flare acceleration. The evidence in both theories and observations from solar atmosphere activities shows that the acceleration is related to nonlinear resonant wave-particle interaction (e.g., Landau acceleration). So far, many-particle acceleration models consider turbulence acceleration as an effective way of generating energetic electrons, protons, and heavier ions. However, the detailed role of turbulence in this process remains unclear. More effort needs to invest in looking into particle accelerations by turbulence that occurs over a large range of the scale in space from the inertial scale of individual particles to the MHD scale.

In this work, applying the statistical treatment of plasma physics, combing with filter theory of turbulence, the actual ratio of the proton mass to the electron mass, and mass-to-charge ratios, we investigate the interaction of charged particles with the turbulent electric field and magnetic field in the large-scale CME/flare current sheet by applying the

We found the significant Langmuir turbulence acceleration (LTA) through the nonlinear resonant wave-particle interaction in the diffusion region via tracking the trajectories and analyzing the energy spectrum of energetic protons and electrons. The results show that protons and electrons could be efficiently accelerated simultaneously and that the way of LTA is similar to that of the shock acceleration}} but is much more efficient than the shock acceleration. This indicates that large-scale reconnection is a good candidate for the mechanism for the efficient acceleration of protons and electrons in the major solar eruption.

The acceleration of heavy ion considered Helium (3He/4He) and other heavy elements in 3He-rich flares burst would explore in the follow-up work series.

URL: https://pan.cstcloud.cn/s/drEdcjIaT8E

How to cite: Zhu, B., Li, Y., and Lin, J.: Investigations of Particle Accelerations by Turbulent Magnetic Reconnection in Large-Scale CME/Flare Current Sheet: I. Protons and Electrons, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-2116, https://doi.org/10.5194/egusphere-egu22-2116, 2022.

In the last decade, studies of solar wind plasma have shown that suprathermal populations (up to a few keV) are closely linked to wave turbulence and fluctuations at small (or kinetic) scales. We aim to identify those types of wave fluctuations observed at these scales scales, for which existing theories predict a major implication in particle acceleration and formation of suprathermal tails in the velocity distributions of plasma particles. On the other hand, it is currently believed that fluctuation power (magnetic, density, velocity) measured at ion scales and lower are generated by the turbulent cascade but also wave instabilities. Therefore, we also intend to discuss a number of recent results describing the kinetic instabilities driven by the anisotropy of velocity distributions (e.g., temperature anisotropy, field-aligned drifts), and how are these instabilities influenced by the suprathermal populations. These results help to understand the energy exchanges between particles and electromagnetic fields, not only in the solar wind but also in the coronal plasma ejections, with consequences for the space weather and terrestrial magnetosphere.

How to cite: Lazar, M., Lopez, R., Shaaban, H., Poedts, S., Fichtner, H., and Yoon, P.: Suprathermal populations and small scale fluctuations in the solar wind, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-6084, https://doi.org/10.5194/egusphere-egu22-6084, 2022.

The structure of the solar wind plasma flow downstream of the ramp of the interplanetary and bow shocks was studied based on the BMSW plasma spectrometer installed onboard the SPEKTR-R spacecraft. Particular attention was paid to the overshoot region, where correlated oscillations of the ion flux and magnetic field are observed. They are formed by two populations of ions: the inflowing solar wind and the beam of coherent gyrating ions. Based on the statistical analysis it was shown that overshoots form both in supercritical and subcritical shocks. It is found that maximum values of the overshoot amplitudes are significantly influenced by the angle between the shock normal and magnetic field vectors, Mach number, plasma and magnetic compression at the shock front. It was established that the oscillation wavelength determined from the magnetic field measurements onboard the WIND spacecraft, on average, coincides with the oscillation wavelength determined from the ion flux on the SPEKTR-R, while the rates of relaxation of these oscillations can greatly differ. It was also shown that the estimates of the overshoot wavelength good correlate with the convected ion gyroradius.

How to cite: Borodkova, N., Sapunova, O., Eselevich, V., Zastenker, G., and Yermolaev, Y.: Overshoot dependence on the shock parameters, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3546, https://doi.org/10.5194/egusphere-egu22-3546, 2022.

In our study we analyzing fluctuations of the solar wind ion flux associated with the Earth bow shock using data obtained by the BMSW experiment, installed onboard the SPEKTR-R satellite. The high time resolution of the spectrometer (0.031 s for the plasma flux magnitude and direction and 1.5 s for velocity, temperature, and density) makes it possible to study fine structures in detail.

From 2011 to 2019 SPEKTR-R satellite crossed the Earth bow shock many times. In our work we analyzed more than 200 bow shock crossings including multiple ones. More than half of them had fluctuations near the Earth bow shock front.

It was shown that in 25% of events the frequencies of ion flux fluctuations were in the range of 3-4 Hz. In 5-7% of events the frequencies of ion flux fluctuations lay in the interval of 5-6 Hz. Just few cases had frequencies of ion flux fluctuations equal or more than 7 Hz. In other cases the frequencies of ion flux fluctuations were lower than 3 Hz or no fluctuations were observed at all.

We also observed low-frequencies fluctuations about 0.1 Hz and lower. These fluctuations were also visible by the 1.5 s plasma parameters: protons density and velocity; He++ (alpha particles) density and velocity (including helium abundance).

How to cite: Sapunova, O., Borodkova, N., Yermolaev, Y., and Zastenker, G.: Fluctuations of the solar wind ion flux near the Earth bow shock, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5222, https://doi.org/10.5194/egusphere-egu22-5222, 2022.

Identifying collisionless shock crossings in data sent from spacecraft has so far been done manually. It is a tedious job that shock physicists have to go through if they want to conduct case studies or perform statistical studies. We use a machine learning approach to automatically identify shock crossings from the Magnetospheric Multiscale (MMS) spacecraft. We compile a database of those crossings including various spacecraft related and shock related parameters for each event. Furthermore, we show that the shocks in the database have properties that are spread out both in real space and parameter space. We also present a possible science application of the database by looking for correlations between ion acceleration efficiency at shocks and different shock parameters such as the shock geometry and the Mach number.

How to cite: Khotyaintsev, Y., Lalti, A., Dimmock, A. P., Johlander, A., and Graham, D. B.: MMS bow shock crossings database, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9885, https://doi.org/10.5194/egusphere-egu22-9885, 2022.

Collisionless shocks are ubiquitous throughout the universe in near-Earth and astrophysical plasma environments. The behavior of collisionless shocks in terms of their structure and energy dissipation has been the subject of extensive research over many decades, but many open questions remain. Recent studies have demonstrated that the Earth's bow shock can exhibit ripples that propagate along the shock surface. However, their occurrence, dependence on shock parameters, and their role in shock dynamics is still under investigation. One signature of rippling is the presence of phase space holes in reduced ion distribution (integrated along the tangential plane of the shock). Such ion phase space holes are also observed in association with the shock reformation. It is unclear at what part of the parametric space these ion phase space holes are expected. In this study, we have focused on characterizing ion phase space holes at the Earth’s bow shock using MMS observations. We analyze more than 500 shock crossings observed by the MMS spacecraft and establish a systematic procedure to find the shocks exhibiting phase space holes. We investigate the key shock physical processes responsible for the existence of these phase space holes (e.g. ripples and reformation) and study the association to shock parameters such as Mach number and geometry. We present the first statistical study of this nature, and these results are important to understanding the non-stationary behavior of collisionless shocks. 

How to cite: Lotekar, A., Khotyaintsev, Y., Graham, D., Dimmock, A., Lalti, A., and Johlander, A.: Statistical study of the ripples and reformation in the collisionless shocks using MMS observation, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5560, https://doi.org/10.5194/egusphere-egu22-5560, 2022.

Previous numerical works on electron/ion foreshocks observed upstream of a curved shock have been already performed within a self-consistent approach based on 2D PIC simulation (Savoini et Lembege, 2010, 2013, 2015), but are restricted to a supercritical regime only. Present two dimensional PIC (Particle in cell) simulations are used in order to analyze the features of a curved shock and associated foreshocks in a subcritical regime. In order to investigate the dynamic of each electron and ion backstreaming populations, we used test-particles in a pre-computed electromagnetic field (issued from 2D PIC simulations) which allows us to define precisely the characteristic of each population in terms of initial velocity and/or their upstream position to the  θ_Bn angle (angle between the local shock normal and the interplanetary magnetic field IMF). Then, results allow to clarify the following questions: what is the impact of the subcritical regime (i) on the persistence of each electron/ion foreshock respectively ?, (ii) in the case the persistence is confirmed,  how the location (along the curved front) and the angular direction of each foreshock edge are affected ?, and (iii) how the mapping of upstream local  distribution functions are impacted ? Preliminary results will be presented and compared with those already obtained for a supercritical shock.

How to cite: Savoini, P. and Lembege, B.: Analysis of a curved shock front microstructures and associated electron/ion foreshock for a subcritical shock regime, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3631, https://doi.org/10.5194/egusphere-egu22-3631, 2022.

In supercritical shocks a substantial fraction of ions is reflected at the steep shock ramp. The beam of reflected ions carries a considerable amount of energy and momentum. As a consequence, different plasma populations can co-exist within the same foot region, which constitutes a source of micro-instabilities excited by the relative drifts between incoming ions, reflected ions, and electrons across the ambient magnetic field B_o . With the help of a spectral periodic 2D PIC code, we investigate the resulting micro-turbulence. Three different waves with different frequency/wave number ranges can be excited simultaneously: Bernstein waves and whistler waves near the lower-hybrid frequency as well as the electron cyclotron frequency. The present work is a 2D extension of a previous analysis (Muschietti et Lembege, Ann. Geophys. 2017) and allows to self-consistently include the mutual interaction between the different instabilities/waves which propagate in different directions with respect to B_o and are at different stages of their respective linear/nonlinear phases. In order to clarify their intricate synergies, a new filtering procedure (low or high pass filter of a given wave number range) has been developed. Taking thus advantage of the spectral nature of the code, we can include/exclude at will the impact of a given instability on the other ones. We have performed several times the simulation with exactly the same initial conditions yet with different filtering ranges. The procedure allows us to illuminate the role played by each instability in the scenario when all are included. Recent results will be presented. 

How to cite: Muschietti, L., Lembege, B., and Decyk, V.: How to define the interplay between different instabilities excited within the foot of a supercritical shock : 2D PIC simulations, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8962, https://doi.org/10.5194/egusphere-egu22-8962, 2022.

Fast coronal mass ejections (CMEs) drive shock waves ahead of them. The turbulent sheath region between the shock and the CME itself contains magnetic field and velocity fluctuations on a broad spectrum of frequencies. In this work we aim to characterise the direction and source of solar wind fluctuations at MHD fluid scales in CME-driven sheaths near Earth. One possible source for these fluctuations is velocity shear, which are common occurrences in CME-driven sheaths. Here we first identify velocity shear as it occurs and then relate that to signatures of new fluctuations being created locally in the sheath. Turbulence parameters such as cross helicity, residual energy, Elsasser ratio, and Alfvén ratio are calculated, and they are correlated against large-scale signatures of velocity shear. Findings indicate a clear association between velocity shear and locally generated fluctuations, as well as a balance in the directionality of these new fluctuations, i.e., they tend to propagate equally towards and away from the Sun. In contrast, most solar wind is typically dominated by anti-sunward fluctuations.

How to cite: Soljento, J., Good, S., Osmane, A., and Kilpua, E.: Turbulence modified by velocity shear in coronal mass ejection sheaths, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11945, https://doi.org/10.5194/egusphere-egu22-11945, 2022.

We model the development of plasma turbulence in the near-Sun solar wind with high-resolution fully-kinetic particle-in-cell (PIC) simulations, initialised with plasma conditions measured by Parker Solar Probe during its first solar encounter (ion and electron plasma beta ≤ 1 and a large amplitude of the turbulent fluctuations). The power spectra of the plasma and electromagnetic fluctuations are characterized by multiple power-law intervals, with a transition and a considerable steepening in correspondence of the electron scales. In the same range of scales, the kurtosis of the magnetic fluctuations is observed to further increase, hinting at a higher level of intermittency. We observe a number of electron-only reconnection events, which are responsible for an increase of the electron temperature in the direction parallel to the ambient field. The total electron temperature, however, exhibits only a small increase due to the cooling of electrons in the perpendicular direction, leading to a strong temperature anisotropy. We also analyse the power spectra of the different terms of the electric field in the generalised Ohm’s law, their linear and nonlinear components, and their alignment, to get a deeper insight on the nature of the turbulent cascade. Finally, we compare our results with those from hybrid simulations with the same parameters, as well as with spacecraft observations.

How to cite: Franci, L., Papini, E., Micera, A., Matteini, L., Stawarz, J., Lapenta, G., Burgess, D., Hellinger, P., Landi, S., Verdini, A., and Montagud-Camps, V.: Fully kinetic simulations of the near-Sun solar wind plasma: turbulence, reconnection, and particle heating, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8705, https://doi.org/10.5194/egusphere-egu22-8705, 2022.

Solar wind, a supersonic flow of plasma embedded in the magnetic field, exhibits turbulent behavior. The character of turbulent fluctuations has been investigated through low cadence measurements of particle distribution function and high cadence magnetic field measurements. One of the most frequently adopted approach in the analysis of the ‘measured’ time series of any particular quantity is the estimation of its power spectral density (PSD). The shape of the PSD then may infer which physical mechanisms govern the evolution of turbulent fluctuations. Generally, every ‘measured’ time series is ‘noisy’ and it differs from the ‘true’ one (measured by an ideal instrument). In turn, the shape of PSD is affected as well. In this paper, we focus on a special case where the signal and noise are independent, i.e., the noise is additive and therefore, the PSD of measured signal can be expressed as a sum of ‘true’ and ‘noise’ PSDs. Moreover, we define a so-called local slope in the framework of continuous wavelet transform as the finite difference derivative between the two consequent values of a global PSD. Employing this technique, we show that the noise of magnetic field measurements of the MFI instrument on board the Wind spacecraft is additive. Finally, we applied the technique to measurements of the Parker Solar Probe close to the Sun. Our preliminary results suggest that our technique may lead to a more accurate estimations of the kinetic range spectral indices.

How to cite: Pitna, A., Safrankova, J., Nemecek, Z., Pi, G., Franci, L., and Park, B.: Local slope of magnetic field power spectrum in inertial and kinetic ranges of solar wind turbulence, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-1740, https://doi.org/10.5194/egusphere-egu22-1740, 2022.

The measurements of the longitudinal velocity were performed in an open-circuit suction wind tunnel installed at the laboratory of the Max-Planck Institute for Dynamics and Self-Organization in Gottingen, using hot wire anemometer at different positions in turbulent flow generated by a traditional fractal square grid (FSG) and by a spaced fractal square grid (SFSG) with similar physical properties have shown that the self-similarity is present. The statistical description of this complex turbulent system was performed using Extended Self Similarity (ESS). We propose a complementary methodology suitable for non-homogeneous turbulence based on the analysis of the energy transfer hierarchy. The signature of the non-homogeneous characteristics of a turbulent field, indicated by nonlocal dynamics, is separated from those usually assigned as being only due to the intermittency. We propose a physical interpretation of the observed scale independence of the relative scaling exponents in such non-homogeneous flows by means of the compensation effect of the energy transfer on the difference between the strong coherent turbulent events and the background less intense turbulence. This procedure is able to distinguish whether the intermittency arises from the small scales or is linked to coherent structures. The practical interest of this type of turbulent excitation concerns several fields of aeronautical and space application and energy or environmental problems of noise reduction of mixers in combustion or for the numerical models of prediction of the dispersion of pollutants in the atmosphere.

How to cite: Ben Mahjoub, O. and Ouadoud, A.: Intermittency in turbulence generated by traditional fractal square grid and spaced fractal square grid, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-1997, https://doi.org/10.5194/egusphere-egu22-1997, 2022.

We consider a simple 1-D planar equilibrium model with piece-wise constant density. We completed analytical computations in incompressible MHD. First, we derived mathematical formulas for the wave energy density, the rate of energy dissipation, and the energy cascade damping time. Following that, we developed an analytical model to estimate the damping time for the evolution of uniturbulence in surface Alfvén waves. According to the derived equation, the damping time is inversely proportional to the perpendicular wavenumber and the amplitude of the surface Alfvén waves. Next, we determined the numerical energy dissipation rate using the Fourier transform through numerical simulations. Finally, we approximated the damping time using the fundamental mode of a perpendicular wavenumber.
Consequently, we compared our theoretical model to a series of 3D ideal MHD simulations and observed a remarkable resemblance. The numerical findings demonstrate, in particular, that the damping time is inversely related to the density contrast and amplitude of surface Alfvén waves. Besides, we studied third-order structure-function (Yaglom's law) for Uniturbulence. We compared Yaglom's law (predicted energy dissipation) statistics obtained through simulation with our analytical model. In addition, we estimated the inertial range of the turbulent flow.

How to cite: Ismayilli, R. and Van Doorsselaere, T.: Uniturbulence due to non-linear damping of surface Alfvén waves, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7371, https://doi.org/10.5194/egusphere-egu22-7371, 2022.

Magnetosheath ion transport across the night-side magnetopause can be contributed by ion cross-field diffusion due to wave-particle scattering. In this presentation we focus on such scattering mechanism for the most intense magnetosheath wave emission, kinetic Alfven waves (KAWs). These waves carry a finite field-aligned electric field and potentially can accelerate particles along magnetic field lines. In the fast plasma flows these waves are usually observed as a wide Doppler-shifted electromagnetic spectrum characterized by strong electric fields in high wave-number range. Dense frequency spectrum leads to overlapping of particles resonances with waves and causes particle diffusion in pitch-angle and energy space. We investigate particles diffusion caused by interactions with KAW turbulence in a realistic model of the Earth flank magnetopause with nonuniform ambient magnetic field fitting the tangential discontinuity. The KAW spectrum is determined by a sum of a several thousand plane waves with different frequencies and propagation angles. We estimate diffusion coefficients as function of ion pitch-angle and energy for different distances from the magnetopause and discuss the expected cross-field transport rate for this model.

How to cite: Lukin, A., Artemyev, A., and Petrukovich, A.: Model of KAW contribution to cross-magnetopause ion transport, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3868, https://doi.org/10.5194/egusphere-egu22-3868, 2022.

The Jovian magnetosphere is loaded internally with material from the volcanic moon of Io, which is ionised and brought into co-rotation forming the Io plasma torus. Plasma is removed from the torus mainly via ejection as energetic neutrals and by bulk transport into sink regions in the outer magnetosphere.

There are two physical processes that are implicated in the bulk transport process, these are diffusion and the radial-interchange (RI) instability. The latter is analogous to the Rayleigh-Taylor instability, but with centrifugal force replacing gravity. This allows magnetic flux tubes containing hot, tenuous plasma to exchange places with tubes containing cool, dense plasma, moving material from the inner to outer magnetosphere whilst returning magnetic flux to the planet. Observational data does not currently provide strong evidence to favour either process and indeed they may be non-linearly coupled. Furthermore, current state-of-the-art simulations do not permit an understanding of non-linear phases of the instability nor the effect of magnetosphere-ionosphere coupling on small length scales.

In order to examine the bulk transport process we have developed a full hybrid kinetic ion, fluid-electron plasma model in 2.5-dimensions, JERICHO. The technique of hybrid modelling allows for probing of plasma motions from the scales of planetary-radii down to the ion-inertial length, considering constituent ion species kinetically as charged particles and forming the electrons into a single magnetised fluid continuum. This allows for insights into particle motions on spatial scales below the size of the magnetic flux tubes. We are particularly interested in exploring a) bulk transport on spatial scales not currently accessible with other state-of-the-art models; b) the relative contributions from diffusive motions against those from RI instabilities; and c) non-linear effects generated by RI instabilities and the impact of these on plasma transport from the inner to outer magnetosphere. In this presentation we will examine the latest simulation results from JERICHO, initialised with a range of Jovian parameters, examining the evolution of the RI instability on differing spatial and temporal scales.

How to cite: Wiggs, J. and Arridge, C.: Examining Radial-Interchange in the Jovian Magnetosphere using JERICHO: a Kinetic-Ion, Fluid-Electron Hybrid Model, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9788, https://doi.org/10.5194/egusphere-egu22-9788, 2022.

High frequency electrostatic oscillations are one of the most fundamental players in energy conversion in collisionless plasmas. Whether at collisionless shocks, turbulence energy cascades or reconnection, small scale Debye length processes  are at the heart of irreversible energy exchange between particles and fields. MMS is one of the most advanced still active spacecraft, with high resolution field and particle instruments. The electric field instrument (EDP) on board of MMS is formed of 3 axial double probes positioned in a perpendicular configuration allowing for the measurement of the 3D electric field. In this study we probe the limitations of the EDP instrument in measuring Debye-scale electrostatic oscillations. In particular we show that at such small wavelengths the electric field is attenuated due to the finite probe-to-probe separation. Furthermore, we propose a method to correct for the electric field attenuation based on the single spacecraft interferometry technique which will allow us to properly determine the observed wave modes.

How to cite: Lalti, A., Khotyaintsev, Y., Graham, D., Steinvall, K., and Johlander, A.: Measurement of short  (Debye length) scale electrostatic waves with MMS EDP instrument:  Problems and possible mitigation, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5068, https://doi.org/10.5194/egusphere-egu22-5068, 2022.