Magnetosphere, Ionosphere and Solar-Terrestrial

Latest news

RAS Awards

The Royal Astronomical Society announced their award recipients last week, and MIST Council would like to congratulate all that received an award. In particular, we would like to highlight the following members of the MIST Community, whose work has been recognised:
  • Professor Nick Achilleos (University College London) - Chapman Medal
  • Dr Oliver Allanson (University of Birmingham) - Fowler Award
  • Dr Ravindra Desai (University of Warwick) - Winton Award & RAS Higher Education Award
  • Professor Marina Galand (Imperial College London) - James Dungey Lecture

New MIST Council 2021-

There have been some recent ingoings and outgoings at MIST Council - please see below our current composition!:

  • Oliver Allanson, Exeter (This email address is being protected from spambots. You need JavaScript enabled to view it.), to 2024 -- Chair
  • Beatriz Sánchez-Cano, Leicester (This email address is being protected from spambots. You need JavaScript enabled to view it.), to 2024
  • Mathew Owens, Reading (This email address is being protected from spambots. You need JavaScript enabled to view it.), to 2023
  • Jasmine Sandhu, Northumbria (This email address is being protected from spambots. You need JavaScript enabled to view it.), to 2023 -- Vice-Chair
  • Maria-Theresia Walach, Lancaster (This email address is being protected from spambots. You need JavaScript enabled to view it.), to 2022
  • Sarah Badman, Lancaster (This email address is being protected from spambots. You need JavaScript enabled to view it.), to 2022
    (co-opted in 2021 in lieu of outgoing councillor Greg Hunt)

Charter amendment and MIST Council elections open

Nominations for MIST Council open today and run through to 8 August 2021! Please feel free to put yourself forward for election – the voting will open shortly after the deadline and run through to the end of August. The positions available are:

  • 2 members of MIST Council
  • 1 student representative (pending the amendment below passing)

Please email nominations to This email address is being protected from spambots. You need JavaScript enabled to view it. by 8 August 2021. Thank you!

Charter amendment

We also move to amend the following articles of the MIST Charter as demonstrated below. Bold type indicates additions and struck text indicates deletions. Please respond to the email on the MIST mailing list before 8 August 2021 if you would like to object to the amendment; MIST Charter provides that it will pass if less than 10% of the mailing list opposes its passing. 

4.1  MIST council is the collective term for the officers of MIST and consists of six individuals and one student representative from the MIST community.

5.1 Members of MIST council serve terms of three years, except for the student representative who serves a term of one year.

5.2 Elections will be announced at the Spring MIST meeting and voting must begin within two months of the Spring MIST meeting. Two slots on MIST council will be open in a given normal election year, alongside the student representative.

5.10 Candidates for student representative must not have submitted their PhD thesis at the time that nominations close.

SSAP roadmap update

The STFC Solar System Advisory Panel (SSAP) is undertaking a review of the "Roadmap for Solar System Research", to be presented to STFC Science Board later this year. This is expected to be a substantial update of the Roadmap, as the last full review was carried out in 2012, with a light-touch update in 2015.

The current version of the SSAP Roadmap can be found here.

In carrying out this review, we will take into account changes in the international landscape, and advances in instrumentation, technology, theory, and modelling work. 

As such, we solicit your input and comments on the existing roadmap and any material we should consider in this revision. This consultation will close on Wednesday 14 July 2021 and SSAP will try to give a preliminary assessment of findings at NAM.

This consultation is seeking the view of all members of our community and we particularly encourage early career researchers to respond. Specifically, we invite:

Comments and input on the current "Roadmap for Solar System Research" via the survey by clicking here.

Short "white papers" on science investigations (including space missions, ground-based experimental facilities, or computing infrastructure) and impact and knowledge exchange (e.g. societal and community impact, technology development). Please use the pro-forma sent to the MIST mailing list and send your response to This email address is being protected from spambots. You need JavaScript enabled to view it..

Quo vadis interim board


A white paper called "Quo vadis, European space weather community" has been published in J. Space Weather Space Clim. which outlines plans for the creation of an organisation to represent the European space weather community.
Since it was published, an online event of the same name was organised on 17 March 2021. A “Quo Vadis Interim Board” was then set up, to establish a mechanism for this discussion, which will go on until June 21st.

The Interim Board is composed of volunteers from the community in Europe. Its role is to coordinate the efforts so that the space weather (and including space climate) European community can:

  1. Organise itself
  2. Elect people to represent them

To reach this goal, the Interim Board is inviting anyone interested in and outside Europe to join the “Quo Vadis European Space Weather Community ” discussion forum.

Eligible European Space Weather Community members should register to the “Electoral Census” to be able to vote in June for the final choice of organisation.

This effort will be achieved through different actions indicated on the Quo Vadis webpage and special Slack workspace.

Nuggets of MIST science, summarising recent papers from the UK MIST community in a bitesize format.

If you would like to submit a nugget, please contact This email address is being protected from spambots. You need JavaScript enabled to view it. and we will arrange a slot for you in the schedule. Nuggets should be 100–300 words long, include a figure/animation, and include an affiliation with a UK MIST institute. Please get in touch!

Electron Bulk Heating At Saturn’s Magnetopause

By Matthew Cheng (University College London)

The magnetopause (MP) boundary is formed by the solar wind plasma flow interacting with a planetary magnetic field. Magnetic reconnection is an important process at this boundary as it energises plasma via release of magnetic energy. This process can lead to an “open” magnetosphere allowing solar wind and magnetosheath particles to directly enter the magnetosphere. At Saturn, the nature of MP reconnection remains unclear. Masters et al. (2012) hypothesised that viable reconnection under a large difference in plasma β across the MP also requires a high magnetic shear (i.e. magnetic fields either side of the boundary close to anti-parallel).

We used electron bulk heating (i.e. the scalar temperature change) at magnetopause crossings to test hypotheses about reconnection at open magnetopause locations, and the influence of magnetic shear and plasma β. The bulk temperature was determined using three different methods, related to properties of the observed energy distribution (including methods from Lewis et al. 2008). We compared the observed heating of magnetosheath electrons with the prediction based on reconnection, using the semi-empirical relationship proposed by Phan et al. (2013) which relates the degree of bulk electron heating to the inflow Alfven speed. Figure 1 shows that Δβ-magnetic shear parameter space discriminates well between events with evidence of energisation (right) and those without (left). Based on the magnetic shear measured locally by the spacecraft either side of the MP, we find 81% of events with no energisation were situated in the ‘reconnection suppressed’ regime, and up to 68% of events with energization lay in the ‘reconnection possible’ regime. These findings support the hypotheses that magnetic shear and plasma β play a role in the viability of magnetic reconnection.

Plots showing magnetic shear as a function of delta-beta, showing where events lie in this parameter space. Regions where reconnection is possible and reconnection is suppressed are marked. Two cases are shown: with and without energisation. The plots show the points lying in the suppressed reconnection when there is not energisation. More points lie in the possible reconnection region when there is energisation.

Figure 1. Assessment of diamagnetic suppression of reconnection, overlaid with electron heating ΔTe. The left and right panels show events without and with evidence of energization respectively.

Please see the paper for full details:

Cheng, I., Achilleos, N., Masters, A., Lewis, G., Kane, M., & Guio, P. (2021). Electron Bulk Heating at Saturn’s Magnetopause. Journal of Geophysical Research: Space Physics, 126, e2020JA028800. https://doi.org/10.1029/2020JA028800

Comparing electron precipitation fluxes calculated from pitch angle diffusion coefficients to LEO satellite observations

By Jade Reidy (British Antarctic Survey)

Trapped radiation belt particles can be pitch angle scattered into the loss cone by resonant wave-particle interactions and atmospheric collisions. This high-energy electron input into our atmosphere can affect the atmospheric chemistry and is a significant loss mechanism of particles from the radiation belts, which themselves pose a threat to satellites. Reidy et al (2021) calculates the precipitating flux that would be measured inside the field of view of an electron detector on board a low earth orbiting satellite (POES) using wave particle theory and compares to in-situ data. These calculations depend on diffusion coefficients for whistler mode chorus waves, plasmaspheric hiss waves and atmospheric collisions. The diffusion coefficients used in Reidy et al (2021) were derived for use in the British Antarctic Survey Radiation Belt Model (BAS-RBM). The analysis presented in this paper is a direct test of the how well the diffusion coefficients used in the BAS‐RBM are able to quantify the precipitating flux and therefore a first step toward testing the loss due to precipitation within the BAS‐RBM itself.

Figure 1 shows a global plot of the linear correlation between the calculated precipitating flux and that measured by the POES T0 >30 keV electron channel between 26–30 March 2013. Our results show the best correlation on the dawnside for L* > 5; this agreement is consistent with chorus waves being the dominant scattering mechanism in this MLT and L-shell zone, suggesting that chorus-driven scattering is well represented in the BAS-RBM. However, we consistently underestimate the precipitating flux on the duskside, suggesting we are likely missing some diffusion here; potential causes of this underestimate are discussed in the paper. Reidy et al (2021) also demonstrates the potential of using wave particle theory to reconstruct the total precipitating flux over the entire loss cone, some of which is missed by the POES detector due to its limited field of view, finding that the total precipitating flux can exceed that measured by POES by a factor of 10.

A figure showing the correlation between calculated and precipitating flux as a function of space.

Figure 1: Linear correlation coefficient between calculated and measured precipitating flux in bins of 3 hour MLT and 0.5 L*, where noon is to the top and dawn to the right. The correlation is only shown where the confidence level is over 95%.

Please see the paper for full details:

Reidy, J. A., Horne, R. B., Glauert, S. A., Clilverd, M. A., Meredith, N. P., Woodfield, E. E., et al. (2021). Comparing electron precipitation fluxes calculated from pitch angle diffusion coefficients to LEO satellite observations. Journal of Geophysical Research: Space Physics, 126, e2020JA028410. https://doi.org/10.1029/2020JA028410

Simultaneous Observation of an Auroral Dawn Storm with the Hubble Space Telescope and Juno

By Ben Swithenbank-Harris (University of Leicester)

Jupiter’s dawn storms are bright enhancements of the dawn flank of the main auroral emission, and produce the most powerful auroral events in the Solar System. These events have been observed numerous times with the Hubble Space Telescope (HST), and more recently by the Juno spacecraft, but their exact origins and related magnetospheric dynamics are not fully understood. For example, although consistent observations of this phenomena near local dawn suggested a relationship with the impinging solar wind, previous studies have shown no correlation between storm occurrence and solar wind conditions. Additionally, prior to the arrival of the Juno spacecraft at Jupiter in July 2016, auroral observations of dawn storms had not been supported by magnetospheric data from spacecraft in the dawn magnetosphere.

In this work, we present the first simultaneous magnetospheric in situ and auroral observations of the onset of a dawn storm. Magnetometer readings reveal brief reversals in the azimuthal magnetic field and decreases in the radial and total field magnitudes around the time of storm onset (Figure 1a-d). Furthermore, concurrent JADE (Figure 1e-h) and JEDI (Figure 1k-n) particle measurements reveal an increase in high energy particle populations and acceleration of magnetospheric protons towards corotational speeds, as well as long-lived hot plasma populations which persist in the outer magnetosphere beyond the expected lifetime of the enhanced auroral emissions. Ultimately, we associate this dawn storm with significant plasma heating and acceleration following reconnection at earlier local times.

Multi-panel plot showing time series of Juno observations.

Figure 1: Overview of the Juno in situ data, showing (1a-d) the radial, north-south, azimuthal and total magnetic field strength (nT) in cylindrical polar coordinates, (1e-h) the JADE ion time-of-flight energy spectra, electron and proton temperatures (K), number densities (cm-3) and proton azimuthal velocities (km s-1), (1i-j) Waves high frequency and electric field continuum emissions, (1k-n) JEDI particle spectra showing the total particle and proton energies (k-l) and the proton and heavy ion pitch angle distributions (m-n), (1o) and the expected spacecraft distance from the centre of the current sheet (RJ), calculated using the method of Khurana (1992). The light grey shaded regions show the times of HST observations, with the dawn storm interval denoted by the yellow shaded region. The darker grey shading denotes a magnetopause crossing, and the three dotted vertical lines mark the times of several successive reversals in the azimuthal magnetic field.

Please see the paper for full details:

Swithenbank‐Harris, B.G., Nichols, J.D., Allegrini, F., Bagenal, F., Bonfond, B., Bunce, E.J., et al. (2021). Simultaneous Observation of an Auroral Dawn Storm with the Hubble Space Telescope and Juno. Journal of Geophysical Research: Space Physics, 126, e2020JA028717. https://doi.org/10.1029/2020JA028717 

Pro‐L* ‐ A probabilistic L* mapping tool for ground observations

By Rhys Thompson (University of Reading)

Both ground and space observations are used extensively in the modeling of space weather processes within the Earth's magnetosphere. The shape of the magnetic field is not fixed, however, and there is not a consistent relationship between the footprint location  of a ground measurement and its respective position in space. With no way to validate the global true magnetic field, numerous models exist to approximate it, allowing a subset of locations on the ground (mainly sub‐auroral) to be mapped along field lines to a location in space.

We often envision the radiation belts in a fixed coordinate system representative of the motions of the trapped particles. Often considered a proxy for distance is L*, a quantity related to the radial motion of electrons. Once an observation's respective location in the magnetic field is approximated it can be transformed into L*, provided the electrons at the measurement's physical location remain trapped by the Earth’s magnetic field.

Dependency of L* on magnetic field model accuracy is therefore paramount, however these models can significantly disagree on mapped L* values for a single point on the ground, during both quiet times and storms.

We present a state‐of‐the‐art tool, Pro‐L*, which for any ground observation provides the probabilities of corresponding L* values. Usage is highlighted for both event studies (a simple demonstration can be seen in Figure 1) and statistical models, and we demonstrate a number of potential applications. Pro-L* may be accessed as a freely available Python package at https://github.com/Rhyst223/pro-lstar.git.

Timeseries during a geomagnetic storm. Panels show the level of activity and the L* value according to multiple models at different geomagnetic latitudes.

Figure 1: The L* response of magnetic field models to the 17-18 March 2013 storm enhancement, for a selection of magnetic latitudes at 330 degrees magnetic longitude, where ground observations are frequently of interest. The median probabilistic L* is also given provided that at least 3 magnetic field models return an L* value. All returned L* are normalised by their respective constant dipole approximation for comparison of latitudes on the same scale. The Dst and Kp indices are also provided over the given time period. Shaded bars indicate times where observed values are on the nightside.

Please see the paper for full details:

Thompson, R. L., Morley, S. K., Watt, C. E. J., Bentley, S. N., & Williams, P. D. (2020). Pro‐L* ‐ A probabilistic L* mapping tool for ground observations. Space Weather, 18, e2020SW002602. https://doi.org/10.1029/2020SW002602 

Comparative Analysis of the Various Generalized Ohm’s Law Terms in Magnetosheath Turbulence as Observed by Magnetospheric Multiscale

By Julia E. Stawarz (Imperial College London)

Complex, highly nonlinear, turbulent dynamics play an important role in particle acceleration and plasma heating throughout the Universe by transferring energy from large-scale to small-scale fluctuations that can be more easily dissipated. Electric fields (E) in these plasmas are responsible for mediating energy exchange between the magnetic fields and particle motions and, therefore, can provide key insight into both the nonlinear dynamics of the turbulence and the processes responsible for dissipating the fluctuations. In the collisionless plasmas often found in space, E is described by generalized Ohm’s law, displayed in Fig. 1.

In Stawarz et al. (2021), we directly measure nearly all the terms in generalized Ohm’s law for several intervals in Earth’s magnetosheath and, for the first time, examine how Ohm’s law shapes the turbulent E at different length scales. Many terms in Ohm’s law, require the computation of small-scale gradients, and, therefore, the unique high-resolution, multi-spacecraft measurements from NASA’s Magnetospheric Multiscale mission were necessary to perform the study. As seen in Fig. 1, we find that, at scales larger than the proton inertial length, the observed E is given by the ideal magnetohydrodynamic term, while, at sub-proton scales, a combination of the Hall and electron pressure terms control E, as expected. Other terms, related to the difference between proton and electron inertia and the finite mass of electrons, remain small across the observable scales. Within the paper, we explore the interplay of the various terms in further detail by examining the correlation between the Hall and electron pressure terms, which provides insight into the types of sub-proton-scale structures formed, and by exploring the relative contribution of linear and nonlinear terms in Ohm’s law at different scales.

The Figure shows an equation for the Generalised Ohm's law at the top. Below a plot shows spectra of the terms in Ohm's law.

Fig.1: (Top) Generalized Ohm’s law for a collisionless, two species plasma, highlighting the different dynamical effects that can support E. (Bottom) Spectra of the terms in Ohm’s law and the observed E for an interval of turbulence in Earth’s magnetosheath. Vertical lines denote the proton and electron gyroradii (ρi/e), inertial lengths (di/e), and spacecraft formation size.

Please see the paper for full details: 

J. E. Stawarz, L. Matteini, T. N. Parashar, L. Franci, J. P. Eastwood, C. A. Gonzalez, I. L. Gingell, J. L. Burch, R. E. Ergun, N. Ahmadi, B. L. Giles, D. J. Gershman, O. Le Contel, P.-A. Lindqvist, C. T. Russell, R. J. Strangeway, and R. B. Torbert (2021). Comparative Analysis of the Various Generalized Ohm’s Law Terms in Magnetosheath Turbulence as Observed by Magnetospheric Multiscale. J. Geophys. Res., 126, e2020JA028447, doi:10.1029/2020JA028447.