MIST

Magnetosphere, Ionosphere and Solar-Terrestrial

Latest news

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.

Call for applications for STFC Public Engagement Early-Career Researcher Forum

 

The STFC Public Engagement Early-Career Researcher Forum (the ‘PEER Forum’) will support talented scientists and engineers in the early stages of their career to develop their public engagement and outreach goals, to ensure the next generation of STFC scientists and engineers continue to deliver the highest quality of purposeful, audience-driven public engagement.

Applications are being taken until 4pm on 3 June 2021. If you would like to apply, visit the PEER Forum website, and if you have queries This email address is being protected from spambots. You need JavaScript enabled to view it..

The PEER Forum aims:

  • To foster peer learning and support between early career scientists and engineers with similar passion for public engagement and outreach, thus developing a peer support network that goes beyond an individual’s term in the forum 
  • To foster a better knowledge and understanding of the support mechanisms available from STFC and other organisations, including funding mechanisms, evaluation, and reporting. As well as how to successfully access and utilise this support 
  • To explore the realities of delivering and leading public engagement as an early career professional and build an evidence base to inform and influence STFC and by extension UKRI’s approaches to public engagement, giving an effective voice to early career researchers

What will participation in the Forum involve?

Participants in the PEER Forum will meet face-to-face at least twice per year to share learning and to participate in session that will strengthen the depth and breadth of their understanding of public engagement and outreach.

Who can apply to join the Forum?

The PEER Forum is for practising early-career scientists and engineers who have passion and ambition for carrying out excellent public engagement alongside, and complementary to, their career in science or engineering. We are seeking Forum members from across the breadth of STFC’s pure and applied science and technology remit.

The specific personal requirements of PEER Forum membership are that members:

  • Have completed (or currently studying for – including apprentices and PhD students) their highest level of academic qualification within the last ten years (not including any career breaks)
  • Are employed at a Higher Education Institute, or a research-intensive Public Sector Research Organisation or Research Laboratory (including STFC’s own national laboratories)
  • Work within a science and technology field in STFC’s remit, or with a strong inter-disciplinary connection to STFC’s remit, or use an STFC facility to enable their own research
  • Clearly describe their track record of experience in their field, corresponding to the length of their career to date
  • Clearly describe their track record of delivering and leading, or seeking the opportunity to lead, public engagement and/or outreach
  • Can provide insight into their experiences in public engagement and/or outreach and also evidence one or more of
  • Inspiring others
  • Delivering impact
  • Demonstrating creativity
  • Introducing transformative ideas and/or inventions
  • Building and sustaining collaborations/networks
  • Are keen communicators with a willingness to contribute to the success of a UK-wide network
  • https://stfc.ukri.org/public-engagement/training-and-support/peer-forum/  

    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!

    The Global Distribution of Ultra‐Low‐Frequency Waves in Jupiter's Magnetosphere

    By Arthur Manners (Imperial College London)

    A key component to an understanding of Jupiter’s magnetosphere is how energy and momentum are transported through the system; how are perturbations communicated to regions many thousands of Earth radii distant? In the terrestrial magnetosphere, magnetohydrodynamic (MHD) waves with frequencies in the ultra-low-frequency band (~1mHz – 1Hz) play a key role in communication throughout the system, in some cases causing the magnetospheric cavity to resonate at its natural frequencies. The Jovian magnetosphere also seems to exhibit these phenomena but limited in-situ data has prevented a fuller picture from emerging. To remedy this, we have searched the heritage magnetometer data from Galileo, Ulysses, Voyager 1 & 2 and Pioneer 10 & 11 for ULF waves. The large plasma density in the equatorial magnetodisk and comparatively rarefied high-latitude regions means the Alfvén speed is orders of magnitude lower in the disk than elsewhere, effectively confining waves to the centremost region of the magnetic field lines.

    We focused our study to data where spacecraft traversed the magnetodisk and constructed a catalogue of large-amplitude ULF waves. We found several hundred events with periods spanning ~ 5 – 60 mins, with preferential periods at ~ 15 mins, ~ 30 mins and ~ 40 mins, consistent with case studies in the literature. The resultant distribution can be seen in Fig. 1. Regions close to the magnetopause at noon and along the dusk flank appear to host ULF waves most often, suggesting an external driver (Fig. 1a). However, the waves seem to be most powerful in the inner magnetosphere, close to the plasma torus, suggesting wave energy may accumulate in the region (Fig. 1b). Further study of the torus region is ongoing to further probe these findings. Overall, these results provide crucial information into large scale energy transport and pathways in Jupiter's complex magnetosphere, with significant implications for wider magnetospheric processes.

    Equatorial projections of the ULF wave samples, illustrating spatial variations in occurrence.

    Fig. 1: An equatorial-plane projection of: (a) the total time spacecraft spent in each bin; (b) the ULF bandpower averaged over the events in each bin; (c) the proportion of time spacecraft spent in each region where significant ULF activity was observed; (d) the same as (c) but for the subset of events where only a single significant period was observed. White bins signify where there are no available data, and gray bins signify regions where spacecraft visited but observed no events.

    Please see the paper for full details:

    Manners, H., & Masters, A. (2020). The global distribution of ultralow‐frequency waves in Jupiter's magnetosphere. Journal of Geophysical Research: Space Physics, 125, e2020JA028345. https://doi.org/10.1029/2020JA028345

    Using Dimensionality Reduction and Clustering Techniques to Classify Space Plasma Regimes

    By Mayur R. Bakrania (MSSL, UCL)

    Particle populations in collisionless space plasma environments are traditionally characterised by their moments. Distribution functions, however, provide the full picture of the state of each plasma environment. These distribution functions are not easily classified by a small number of parameters. We apply dimensionality reduction and clustering methods to particle distributions in pitch angle and energy space to distinguish between the different plasma regions. Dimensionality reduction is a specific type of unsupervised learning in which data in high-dimensional space is transformed to a meaningful representation in lower dimensional space. This transformation allows complex datasets to be characterised by analysis techniques with much higher computational efficiency. We use the following steps:

    1. An autoencoder to compress the data by a factor of 10 from a high-dimensional representation.
    2. A Principal Component Algorithm to further compress the data to a three-dimensional representation.
    3. The mean shift algorithm to determine how many populations are present in the data using this three-dimensional representation.
    4. An agglomerative clustering algorithm to assign each data-point to one of the populations.

    We use electron data from the magnetotail to test the effectiveness of our method. The magnetotail is traditionally divided into three different regions: the plasma sheet (PS), the plasma sheet boundary layer (PSBL), and the lobes. Starting with the ECLAT database with associated classifications based on the plasma parameters, we identify 8 distinct groups of distributions, that are dependent upon significantly more complex plasma and field dynamics. Fig. 1 shows the average electron differential energy flux distributions for each cluster. We see large differences in the average pitch angle/energy distributions. Each distribution differs by the: peak flux energy, peak flux value, or the pitch angle anisotropy. The lack of identical distributions shows mean shift has not overestimated the number of clusters. This novel technique reveals new information on the physical processes shaping magnetotail electron distributions, and has significant implications for analysing a wide range of plasma regimes.

    A multi-panel plot showing the distributions in pitch angle and energy space for each cluster.

    Fig. 1: Average electron differential energy flux distributions as a function of pitch angle and energy for each of the eight clusters (A–H) classified by the agglomerative clustering algorithm. Each cluster is assigned a magnetotail region (included in the sub-captions) based on our interpretation of their plasma and magnetic field parameters.

    Please see the paper for full details:

    M. R. Bakrania, Rae I. J., Walsh A. P., Verscharen D. and Smith A. W. (2020). Using Dimensionality Reduction and Clustering Techniques to Classify Space Plasma Regimes. Front. Astron. Space Sci. 7:593516. https://doi.org/10.3389/fspas.2020.593516

    Polytropic Behavior of Solar Wind Protons Observed by Parker Solar Probe

    by Georgios Nicolaou (MSSL, UCL)

    The polytropic equation relates the density and temperature of a fluid through the polytropic index. The polytropic index is a crucial parameter in understanding the physical mechanisms acting on the fluid. In this study, we investigate the large time-scale and the short time-scale fluctuations of the plasma proton density and temperature in order to determine their polytropic index. The large time-scale fluctuations which are associated with the plasma expansion within the heliosphere, follow a polytropic model with a polytropic index ~5/3. The specific behavior is consistent with an adiabatic expanding plasma protons with three degrees of freedom. The radial profile of the density follows in general, the model for a spherical expansion with a constant radial speed (see Figure 1). However, the short time-scale fluctuations, which are associated with plasma turbulence, follow a polytropic model with a polytropic index ~2.7. Interestingly, the short time-scale polytropic index is found to be correlated with the interplanetary magnetic field. We discuss the possibly of a mechanism that supplies/retains energy from the plasma protons in these short time-scales, or a mechanism that restricts the effective degrees of freedom of the protons. We finally highlight the importance of future studies that examine the polytropic index along with the characteristics of the full 3D distributions of the plasma ions and electrons.

    Plots showing how the proton density and proton temperature vary with radial distance.

    Figure 1. Two-dimensional histograms of (top) the proton density and (bottom) the proton temperature as functions of the radial distance for time interval 1. The magenta line in the top panel shows the expected density for an expansion model with constant speed, n  r-2. In the lower panel, the magenta line shows the expected temperature of a polytropic radial expansion model with γ = 5/3 while the blue lines represent expansion models with γ = 2.7. The grey line illustrates the slope determined by Huang et al. 2020 for the parallel proton temperature of fast solar wind observed by SPC.

    Please see the paper for full details:

    Nicolaou, G., Livadiotis, G., Wicks, R. T., Verscharen, D., Maruca, B. A., (2020). Polytropic Behavior of Solar Wind Protons Observed by Parker Solar Probe. The Astrophysical Journal, 901, 1, https://doi.org/10.3847/1538-4357/abaaae.

    Evaluating the ionospheric mass source for the magnetospheres of Jupiter and Saturn

    By Carley J. Martin (Lancaster University)

    Ionospheric outflow is a flow of plasma initiated by a loss of equilibrium along a magnetic field line. This induces an electric field due to the separation of electrons and ions in a gravitational field. At Earth, this process is initiated by dayside reconnection in the Dungey cycle. But, is this the case at the gas giants?  

    Valek+ (2019) show that there is an increased outflow on field lines which map between the moon Io and the auroral oval at Jupiter, and very little in the actual polar cap. Hence, in our analysis, we evaluate over these latitudes at Jupiter and Saturn. This also means we must consider a different driver than the Dungey cycle! 

    We developed a model which estimates the number of charged particles that flow from the ionospheres of Jupiter and Saturn. We also look at the effects of field aligned currents (FACs) and centrifugal forces on the total source rates of the outflow. At Saturn, the inclusion of these effects increase the total flux from the ionosphere, and it is now comparable to in situ measurements by Cassini CAPS. At Jupiter, the total particle source is found to be comparable to Io as a source of plasma in the magnetosphere.  We find that the downward FACs and centrifugal force act to increase the flow of electrons from the ionosphere, and conversely upward FAC’s act to decrease outflow (see Figure below).  

    The additional mass flux into the inner and middle magnetospheres of Jupiter and Saturn can substantially affect the dynamics and composition and so must be included in any future assessment! 

    Figure shows how electron flux at the equator varies with radial distance, comparing the inclusion and exclusion of field-aligned currents.

    Figure shows an example of results for the electron flux mapped to the equator; solid green is with field‐aligned currents; dotted green is without field‐aligned currents. The insert shows the shape of the field‐aligned currents themselves. The electron flux is highly modified by the field‐aligned currents present, where it is enhanced by a downward current and retarded by an upward current in the auroral regions.

    Please see the papers for full details:

    Martin, C. J., Ray, L. C., Felici, M., Constable, D. A., Lorch, C. T. S., & Kinrade, J., et al. (2020). The effect of field‐aligned currents and centrifugal forces on ionospheric outflow at Saturn. Journal of Geophysical Research: Space Physics, 125, e2019JA027728. https://doi.org/10.1029/2019JA027728

    Martin, C. J., Ray, L. C., Constable, D. A., Southwood, D. J., Lorch, C. T. S., & Felici, M. (2020). Evaluating the ionospheric mass source for Jupiter's magnetosphere: An ionospheric outflow model for the auroral regions. Journal of Geophysical Research: Space Physics, 125, e2019JA027727. https://doi.org/10.1029/2019JA027727 

    Saturn’s Nightside Dynamics During Cassini’s F Ring and Proximal Orbits: Response to Solar Wind and Planetary Period Oscillation Modulations

    By Tom J. Bradley (University of Leicester)

    In this study we examined the final 44 Cassini spacecraft orbits that traversed the midnight sector of Saturn’s magnetosphere to distances of ~21 Saturn radii, in order to investigate responses to heliospheric conditions inferred from model solar wind and Cassini galactic cosmic ray (GCR) flux data.

    Clear responses to anticipated magnetospheric compressions were observed in magnetic field and energetic particle data, together with Saturn kilometric radiation (SKR), auroral hiss, and ultraviolet auroral emissions. Most compression events were associated with corotating interaction regions, as shown by the periodic model solar wind parameters and Forbush-like decreases in GCR fluxes in Figure 1.

    Overview of the dataset showing time series of solar wind data, particle fluxes, and PPO phase. 

    Figure 1: Overview of full dataset. Figure 1a shows a RPWS spectrogram, and Figures 1b-1e show model solar wind dynamic pressure (nPa), IMF strength (nT), LEMMS channel E6 count rate (GCR flux of >120 MeV protons), and LEMMS channel P2 count rate (GCR flux as well as SEP flux of 2.3-4.5 MeV protons). Figure 1f shows the PPO beat phase (deg modulo 360°). The superposed red and green shaded vertical bands (white dashed lines in Figure 1a) show intervals of magnetospheric compression defined by criteria given above. Red corresponds to major events with an extended LFE interval (longer than one planetary rotation) and green to minor events without such an extended LFE interval. The superposed grey shaded vertical bands show intervals of relative magnetospheric quiet when energetic particle fluxes were at near-minimum values.

    Each compression tended to produce ~2-3.5 day intervals of magnetospheric activity that were typically recurrent with the ~26 day solar rotation period (one or two such events per rotation). However, the responses were somewhat variable (as is shown in greater detail in the article), and were thus divided into “major” and “minor” events. Major events (red shaded bands) are those with SKR low frequency extension (LFE) intervals with durations greater than ~one planetary rotation (11 out of 20 events, or 55%), while minor events (green shaded bands) either have no noticeable LFE interval (7 out of 20 events, or 35%), or one whose duration is one planetary rotation period or less (2 out of 20 events, or 10%)

    These two types of responses were found to be modulated by Saturn’s planetary period oscillations (PPOs), as follows.

    1. Major events are favoured when the two PPO systems are roughly in anti-phase, where they act together to thin and thicken the tail plasma sheet during each PPO cycle. The anti-phase conditions during major events result in thin plasma sheet conditions (once per rotation), that are most unstable to tail reconnection, producing energetic nightside particle injections and poleward contractions of dawn-brightened auroras.
    2. Minor events are favoured when the PPOs are in phase, where they act together to stabilise the plasma sheet and inhibit tail collapse, resulting in less obvious magnetospheric responses.

    Overall, the results emphasize how strongly activity in Saturn’s magnetosphere is modulated by both the concurrent heliospheric conditions and the PPO modulations.

    Please see the paper for full details:

    Bradley, T. J., Cowley, S. W. H., Bunce, E. J., Melin, H., Provan, G., & Nichols, J. D., et al. (2020). Saturn's nightside dynamics during Cassini's F ring and proximal orbits: Response to solar wind and planetary period oscillation modulations. Journal of Geophysical Research: Space Physics, 125, e2020JA027907. https://doi.org/10.1029/2020JA027907