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 magnetopause booms like a drum due to impulses

    by Martin Archer (Queen Mary University of London)

    The abrupt boundary between a magnetosphere and the surrounding plasma, the magnetopause, has long been known to support surface waves which travel down the flanks. However, just like a stone thrown in a pond causes ripples which spread out in all directions, impulses acting on our magnetopause should also cause waves to travel towards the magnetic poles. It had been proposed that the ionosphere might result in a trapping of surface wave energy on the dayside as a standing wave or eigenmode of the magnetopause surface. This mechanism should act as a global source of magnetopause dynamics and ultra-low frequency waves that might then drive radiation belt and auroral interactions.

    While many potential impulsive drivers are known, no direct observational evidence of this process had been found to date and searches for indirect evidence had proven inconclusive, casting doubt on the theory. However, Archer et al. (2019) show using all five THEMIS spacecraft during their string-of-pearls phase that this mechanism does in fact occur.

    Figure: THEMIS observations and a schematic of the magnetopause standing wave.

    They present observations of a rare isolated fast plasma jet striking the magnetopause. This caused motion of the boundary and ultra-low frequency waves within the magnetosphere at well-defined frequencies. Through comparing the observations with the theoretical expectations for several possible mechanisms, they concluded that the jet excited the magnetopause surface eigenmode – like how hitting a drum once reveals the sounds of its normal modes.

    Hear the signals as audible sound here: https://www.youtube.com/watch?v=mcG03NBJf-s

    For more information please see the paper below:

    ‘Direct Observations Of A Surface Eigenmode Of The Dayside Magnetopause’. M.O. Archer, H. Hietala, M.D. Hartinger, F. Plaschke, V. Angelopoulos. Nature Communications. | https://doi.org/10.1038/s41467-018-08134-5

    Detecting the Resonant Frequency of the Magnetosphere with SuperDARN

    by Samuel J. Wharton (University of Leicester)

    The Earth’s magnetosphere is constantly being disturbed by ultralow frequency (ULF) waves. These waves transport energy and momentum through the system and can form standing waves on magnetospheric field lines. These standing waves have a resonant frequency which depends on the magnetic field strength and plasma distribution along the field line. The waves result in perturbations in the magnetic field and plasma in the ionosphere. These occur at the resonant frequency and can be directly observed with instruments on the ground. Being able to measure the resonant frequency can provide valuable information about the state of the magnetosphere.

    Traditionally, this can be done by applying a cross-phase spectral technique to ground-based magnetometers. It works by finding the frequency where the phase change with latitude is most rapid. This occurs at the local resonant frequency.

    The Super Dual Auroral Radar Network (SuperDARN) is a global consortium of 35 radars that observe radio waves backscattered from the ionosphere. The radars detect ULF waves by observing the movements of ionospheric plasma.

    For the first time, we have applied the cross-phase technique to SuperDARN. These radars have a much greater spatial resolution and coverage and provide more detailed information than can be achieved with magnetometers alone. In this study, we have used some notable techniques, such as developing a Lomb-Scargle cross-phase technique for uneven data and exploiting an improved fitting procedure Reimer et al. (2018).

    We have been able to apply these methods to several examples and validate the results with ground magnetometer estimations. When available, ionospheric heaters can be used to reduce the uncertainty in the backscatter location. However, the majority of SuperDARN data does not have a heater in the field of view and observes ‘natural scatter’. Figure 1 shows an example of the technique applied to natural scatter. The red band in Figure 1e lies at the resonant frequency. Hence, we can measure the resonant frequencies with and without an ionospheric heater.

    This study demonstrates that SuperDARN can be used as a tool to monitor resonant frequencies and therefore the plasma distribution of the magnetosphere. This opens up a new application for the SuperDARN radars.

    For more information, please see the paper below:

    Wharton, S. J., Wright, D. M., Yeoman, T. K., & Reimer, A. S. (2019). Identifying ULF wave eigenfrequencies in SuperDARN backscatter using a Lomb-Scargle cross-phase analysis. Journal of Geophysical Research: Space Physics, 124. https://doi.org/10.1029/2018JA025859

    Figure 1: This shows an example of the local resonant frequency being measured by SuperDARN. (a) and (b) show range-time-intensity plots for beams 12 and 15 of the Þykkvibær radar. (c) shows filtered line-of-sight velocities for range gates 10 and 9 on those beams respectively. (d) The cross-phase spectrum for data in (c). (e) The cross-phase spectrum from (d) smoothed.

    Current Density in Saturn’s Equatorial Current Sheet: Cassini Magnetometer Observations

    by Carley J. Martin (Lancaster University)

    Saturn’s rapidly rotating magnetosphere forms an equatorial current sheet that is prone to both periodic (i.e. flapping, breathing [see MIST nugget by Arianna Sorba]) and aperiodic movements (i.e. Martin & Arridge [2017]).

    Although the current density of the sheet structure has been discussed by many previous authors, the current density in the middle to outer magnetosphere has not been fully explored. To this end we analysed aperiodic wave movements of Saturn’s current sheet, determined using Cassini’s magnetometer observations. The data were fitted to a deformed current sheet model in order to estimate the magnetic field value just outside of the current sheet, plus the scale height of the current sheet itself. These values were then used to calculate the height integrated current density.

    We find a local time asymmetry in the current density, similar to the relationship seen at Jupiter, with a peak in current density of 0.04 A/m at ~ 3 SLT (Saturn Local Time). We then used the divergence of the azimuthal and radial current densities to infer the field-aligned currents that flow out from the equator pre-noon and enter the equator pre-midnight, similar to the Region-2 current at Earth. This current closure could enhance auroral emission in the pre-midnight sector by up to 11 kR.

    Overall, the results provide important information into the asymmetries of the current sheet, and the characteristics of the current sheet suggest important field-aligned current systems that shape Saturn’s auroral emissions.

    For more information, please see the paper below:

    Martin, C. J., & Arridge, C. S. (2019). Current density in Saturn's equatorial current sheet: Cassini magnetometer observations. Journal Geophysical Researcher: Space Physics, 124, 279–292. https://doi.org/10.1029/2018JA025970

    Figure: Divergence of height-integrated perpendicular current density (which infers the field-aligned current density). The coloured blocks show the average value of the divergence projected onto the X-Y plane in KSM (Kronocentric Solar Magnetospheric) coordinates. A range of magnetopause positions is shown using Arridge et at. (2006) along with the orbits of Titan (20 RS) and Rhea (9 RS), all shown in grey.

     

    Observations of magnetic reconnection in Earth’s bow shock

    by Imogen Gingell (Imperial College London)

    The bow shock is a thin transition between super-sonic solar wind flows and sub-sonic flows in the Earth’s magnetosheath, during which the plasma is rapidly compressed and heated. In space plasmas, particle collisions cannot provide sufficient energy dissipation to slow the flow to sub-sonic speeds. Instead, nonlinear, electromagnetic plasma processes must be responsible.

    Recent simulations (hybrid and fully kinetic particle-in-cell) have shown that current sheets and magnetic islands may be generated within the bow shock’s thin transition region (see Gingell et al 2017). This implies that magnetic reconnection, i.e. a localised change in the topology of the magnetic field, may be among the nonlinear processes responsible for heating in the shock transition layer. However, reconnection is not currently included in shock models.

    Using data provided by NASA’s Magnetospheric Multiscale mission (MMS), we have now detected signatures of reconnection occurring at current sheets embedded in the shock. These signatures include a reversal of the magnetic field direction over ion inertial scales and a coincident super-Alfvénic jet of electrons corresponding the outflow from the reconnection site (see Fig 1). The increase in the electron temperature is consistent with previous observations of reconnection at the magnetopause. However, the lack of an ion jet or heating is similar to recent observations within the magnetosheath.

    Now that we have confirmed that reconnection can occur within the bow shock, we must assess the broader impact of reconnection on heating and particle acceleration at shocks, explore the evolution of reconnecting structures as they convect downstream, and determine the parameter regime over which shock reconnection can occur.

    For more information, please see the paper below:

    Gingell, I., Schwartz, S. J., Eastwood, J. P., Burch, J. L., Ergun, R. E., Fuselier, S., et al. (2019). Observations of magnetic reconnection in the transition region of quasi‐parallel shocks. Geophysical Research Letters, 46. https://doi.org/10.1029/2018GL081804

    Fig 1. (i) schematic of the structure of a reconnecting current sheet, showing magnetic field (black), current density (green), electron outflow jets (blue) and spacecraft trajectory for the observed event (red). (ii) observations of a current sheet in the bow shock, showing (a) magnetic field, (b) electron and ion bulk velocities, and (c) electron ion temperatures.

    The surprisingly variable current system inside Saturn’s D ring

    by Gabby Provan & Stan Cowley (University of Leicester)

    During Cassini’s Grand Finale, the spacecraft made 22 daring “proximal” periapsis passes between the denser layers of Saturn’s upper atmosphere and the inner edge of the planet’s innermost D ring (Figure 1a). This region had never previously been explored.  On every pass Cassini’s magnetometer observed unanticipated perturbations in the azimuthal magnetic field component, confined to field lines that pass through and inside of the D ring in the equatorial plane, peaking typically at a few tens of nano-Tesla.  Since the fields are near-symmetric about the magnetic equator, they are consistent with interhemispheric currents flowing along the near-equatorial magnetic field lines, as illustrated in Figure 1b. 

    Here we examine the azimuthal field perturbations on all the proximal passes, and show that they are surprisingly variable in form and magnitude.  While a third of the passes indicate a unidirectional current flow, and a further third shows multiple sheets of oppositely-directed currents.  The remaining passes present diverse signatures, including two passes showing reverse currents, and two with only small and fluctuating perturbations. This variability is not related to the spacecraft trajectory or organized by any known rotational period of the Saturnian system (i.e. the phase of the Saturn’s planetary period oscillations or the rotational phase of the D68 ringlet).

    Khurana et al. (2018) suggested that these currents are generated by differential zonal thermospheric wind drag acting in the ionosphere at the two ends of these inner field lines.  If so, these results show that either Saturn’s ionospheric zonal winds or ionospheric conductivity, or both, are very variable over the ~6.5 day orbital period of these periapsis passes.  Our results add to the body of evidence showing that there is a significant and variable dynamical interaction between the material in Saturn’s D ring and the planet’s equatorial atmosphere.

    For more information, please see the paper below:

    Provan, G., Cowley, S. W. H., Bunce, E. J., Bradley, T. J., Hunt, G. J., Cao, H., & Dougherty, M. K. (2019). Variability of intra–D ring azimuthal magnetic field profiles observed on Cassini's proximal periapsis passes. Journal of Geophysical Research: Space Physics, 124. https://doi.org/10.1029/2018JA026121

    Figure 1: (a) The spacecraft trajectory of two example proximal passes.  The planet is shown in orange, and the arrowed black lines show model magnetic field lines.  The A to C rings are shown in dark blue, and the D ring in lighter blue. The suggested intra-D ring current system is shown in green in panel (b).