MIST

Magnetosphere, Ionosphere and Solar-Terrestrial

Latest news

Winners of Rishbeth Prizes 2023

We are pleased to announce that following Spring MIST 2023 the Rishbeth Prizes this year are awarded to Sophie Maguire (University of Birmingham) and Rachel Black (University of Exeter).

Sophie wins the prize for the best MIST student talk which was entitled “Large-scale plasma structures and scintillation in the high-latitude ionosphere”. Rachel wins the best MIST poster prize, for a poster entitled “Investigating different methods of chorus wave identification within the radiation belts”. Congratulations to both Sophie and Rachel!

As prize winners, Sophie and Rachel will be invited to write articles for Astronomy & Geophysics, which we look forward to reading.

MIST Council extends their thanks to the University of Birmingham for hosting the Spring MIST meeting 2023, and to the Royal Astronomical Society for their generous and continued support of the Rishbeth Prizes.

Nominations for MIST Council

We are pleased to open nominations for MIST Council. There are two positions available (detailed below), and elected candidates would join Beatriz Sanchez-Cano, Jasmine Kaur Sandhu, Andy Smith, Maria-Theresia Walach, and Emma Woodfield on Council. The nomination deadline is Friday 26 May.

Council positions open for nomination

  • MIST Councillor - a three year term (2023 - 2026). Everyone is eligible.
  • MIST Student Representative - a one year term (2023 - 2024). Only PhD students are eligible. See below for further details.

About being on MIST Council


If you would like to find out more about being on Council and what it can involve, please feel free to email any of us (email contacts below) with any of your informal enquiries! You can also find out more about MIST activities at mist.ac.uk.

Rosie Hodnett (current MIST Student Representative) has summarised their experience on MIST Council below:
"I have really enjoyed being the PhD representative on the MIST council and would like to encourage other PhD students to nominate themselves for the position. Some of the activities that I have been involved in include leading the organisation of Autumn MIST, leading the online seminar series and I have had the opportunity to chair sessions at conferences. These are examples of what you could expect to take part in whilst being on MIST council, but the council will welcome any other ideas you have. If anyone has any questions, please email me at This email address is being protected from spambots. You need JavaScript enabled to view it..”

How to nominate

If you would like to stand for election or you are nominating someone else (with their agreement!) please email This email address is being protected from spambots. You need JavaScript enabled to view it. by Friday 26 May. If there is a surplus of nominations for a role, then an online vote will be carried out with the community. Please include the following details in the nomination:
  • Name
  • Position (Councillor/Student Rep.)
  • Nomination Statement (150 words max including a bit about the nominee and your reasons for nominating. This will be circulated to the community in the event of a vote.)
 
MIST Council contact details

Rosie Hodnett - This email address is being protected from spambots. You need JavaScript enabled to view it.
Mathew Owens - This email address is being protected from spambots. You need JavaScript enabled to view it.
Beatriz Sanchez-Cano - This email address is being protected from spambots. You need JavaScript enabled to view it.
Jasmine Kaur Sandhu - This email address is being protected from spambots. You need JavaScript enabled to view it.
Andy Smith - This email address is being protected from spambots. You need JavaScript enabled to view it.
Maria-Theresia Walach - This email address is being protected from spambots. You need JavaScript enabled to view it.
Emma Woodfield - This email address is being protected from spambots. You need JavaScript enabled to view it.
MIST Council email - This email address is being protected from spambots. You need JavaScript enabled to view it.

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.

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 fill in the following form: https://forms.gle/Pn3mL73kHLn4VEZ66 and we will arrange a slot for you in the schedule. Nuggets should be 100–300 words long and include a figure/animation. Please get in touch!
If you have any issues with the form, please contact This email address is being protected from spambots. You need JavaScript enabled to view it.. 

Topology of turbulence within collisionless plasma reconnection

Bogdan Hnat (University of Warwick)

Collisionless magnetic reconnection [1] and plasma turbulence [2] are fundamental mechanisms that transfer energy across scales and between electromagnetic fields and particles. Stretched turbulent vortices and thin reconnection current sheets are prime sites of plasma heating and particle acceleration. Magnetic field line topology is central to both these processes.

We have classified the magnetic field topology observed as the four MMS spacecraft fly through a well resolved reconnection site. The MMS spacecraft separation defines a spatial 'yardstick', which is of order of the ion inertial range di, for sampling magnetic field topology. However, spatial variation of the topology is indirectly captured on a much finer spatial scale due to high time resolution of the magnetic field measurements, 8192 samples per second.

We find two distinct types of the magnetic field line topology near and at the electron dissipation region (EDR). At the edges of the EDR turbulent-like topology, identical to the topology of stretched vortices in hydrodynamic turbulence, is dominant. It coincides with large high-frequency electromagnetic perturbations. At the EDR the topology departs from turbulence and the structures appear to be two-dimensional, coinciding with suppression of electromagnetic fluctuations. The topology of the magnetic field line directly orders electron acceleration and heating. Suprathermal electrons are absent where turbulent-like topology dominates, but the bulk electron temperature anisotropy is enhanced. Reduced two-dimensional topology at the EDR coincides with the suprathermal electrons. The turbulent-like topology can arise in EMHD in scales smaller than electron inertial scale when vorticity dominates the dynamics. We find that vorticity is indeed dominant at all times within our interval.

"Panels
Panels (a), (b) and (c): Time series of in situ observations of: (a) the magnetic field magnitude (black) and the electric field component E_N (blue) in the event LMN coordinates, (b) band pass filtered magnetic field components (blue) and magnetic field magnitude (black) within frequency range 64-256 Hz; the dashed red vertical lines mark the outer extent of large magnetic field fluctuations, and (c) the same quantity as panel (b) calculated for the electric field fluctuations. All traces are based on the reconnection region transit seen by MMS 3. The EDR is indicated with blue shading on all panels. Green shading indicates the time interval in which at least one spacecraft samples the EDR. Panel (d) shows the phase space of invariants of magnetic field gradient tensor. Elliptic (flux ropes) and hyperbolic (X-point) magnetic field lines are separated by the magenta line. Panel (c) shows phase space of invariants for the curl-free deformations of magnetic field lines. The red line is the boundary of possible invariants. The magenta line in panel (c) corresponds to triaxial deformations with eigenvalue ratios -3:-1:4 (Rs<0) and 3:1:-4 (Rs>0), as found in the strain tensor of a three dimensional hydrodynamic flow.


References:
[1] J. Birn, E.R. Priest, Reconnection of Magnetic Fields: Magnetohydrodynamics and Collisionless Theory and Observations (Cambridge University Press, New York, 2007).
[2] Matthaeus, W.H. and Velli, M.,Space Science Reviews, 160(1), pp.145-168 (2011).

 

See publication for further information:
Hnat, Bogdan, Sandra Chapman, and Nicholas Watkins. "Topology of turbulence within collisionless plasma reconnection." Scientific Reports 13.1 (2023): 18665.

Plasma vorticity in the high-latitude ionosphere

By Gareth Chisham (British Antarctic Survey)

Measurements of ionospheric plasma flow vorticity can be used for studying ionospheric plasma transport processes, such as convection and turbulence, over a wide range of spatial scales. This study presents an analysis of probability density functions (PDFs) of ionospheric vorticity for selected regions of the northern hemisphere high-latitude ionosphere as measured by the Super Dual Auroral Radar Network (SuperDARN) over a 6-year interval (2000-2005 inclusive). Making certain assumptions, the observed asymmetric vorticity PDFs can be decomposed into two separate components: (1) A single-sided function that results from the large-scale vorticity inherent in the ionospheric convection pattern, driven by magnetic reconnection; (2) A symmetric double-sided function that results from meso-scale vorticity that derives from fluid processes such as turbulence, and from measurement uncertainties.

Figure with three vertical panels. This figure demonstrates the decomposition of the probability density function (PDF) of ionospheric vorticity into its large-scale and meso-scale components. The data is from 73-77 degrees AACGM latitude and 0800-1100 MLT (dawn convection cell), for IMF By positive conditions, for the years 2000-2006 inclusive. (a) PDF of all the measured vorticity measurements; (b) Separated components of the PDF with model fits; (c) Percentage contribution of each component for different values of vorticity.
This figure demonstrates the decomposition of the probability density function (PDF) of ionospheric vorticity into its large-scale and meso-scale components. The data is from 73-77 degrees AACGM latitude and 0800-1100 MLT (dawn convection cell), for IMF By positive conditions, for the years 2000-2006 inclusive. (a) PDF of all the measured vorticity measurements; (b) Separated components of the PDF with model fits; (c) Percentage contribution of each component for different values of vorticity.


Being able to model ionospheric vorticity in this way will help to improve models of ionospheric plasma flow that are often used in larger-scale system models. At the present time, these plasma flow models typically only consider the larger-scale convection flow. Our observation of a significant meso-scale flow vorticity component due to turbulence will have implications for the fidelity of these models.

See paper for further details: Chisham, G. and Freeman, M. P. (2023). Separating contributions to plasma vorticity in the high-latitude ionosphere from large-scale convection and meso-scale turbulence. Journal of Geophysical Research: Space Physics, 128, e2023JA031885, https://doi.org/10.1029/2023JA031885.

Detection of the northern infrared aurora at Uranus using the W.M. Keck II Telescope and NIRSPEC instrument

By Emma Thomas (University of Leicester)

Three decades of searching for the infrared aurorae finally come to a successful conclusion as portions of the northern (IAU southern) aurorae have been confirmed at Uranus. The icy planet represents an enigma within our solar system, with the first and only visit by Voyager II in 1986, it remains one of the least documented planets in our solar system. This is exceptionally apparent with the planet’s history of auroral observations, where the UV aurorae have been observed a handful of times but no infrared (IR) counterpart has been confirmed, despite both aurorae appearing at Jupiter and Saturn. Analysis of IR aurorae at both Jupiter and Saturn have challenged what we know about magnetosphere-ionosphere coupling, highlighting a need for IR analysis at Uranus to uncover its mysteries. Since 2020 our team has meticulously analysed archived data of Uranus during 2006 from the Keck II telescope on Mauna Kea in Hawai’i. The timing of these observations was key, close to equinox, as it provided an optimal view of the predicted locations of the northern and southern aurorae. By examining the emission lines from these aurorae (the emitting ion being H3+) between 3.94 to 4.01 μm, we carried out a full spectrum best fit across 5 fundamental lines for each spatial pixel across the planet’s disk. By comparing these lines at specific locations, we were able to identify an average 88% increase in column ion densities with no significant temperature changes localised close to or at expected auroral locations for the northern aurora. With this confirmation at Uranus, we look forward to a new age of auroral investigations at both ice giant planets.

Measured H3+ Q(1,0-) intensity mapped across the upper atmosphere of Uranus against Uranian latitude and arbitrary longitude, (b) Total H3+ Emission calculated from the temperature and column density (explained in detailed in the Methods), (c) Estimated temperatures of the H3+ emissions from all five Q-branch lines and (d) Estimated column densities of H3+ emissions from all five Q-branch. The latitude is planetocentric whereas the longitude is arbitrary due to the loss of the Uranian Longitude System (ULS) since Voyager II. The solid black lines mark out the boundaries of E1 (on the left) and E2 (on the right). Within the boundaries, the Enhanced regions are unshaded, the Dim regions are shaded with dots, and the Intermediate regions are shaded with diagonal lines. Latitudes and/or longitudes that were not recorded during the observations have been greyed out.

References:

Thomas, E.M., Melin, H., Stallard, T.S. et al. Detection of the infrared aurora at Uranus with Keck-NIRSPEC. Nat Astron (2023). https://doi.org/10.1038/s41550-023-02096-5

A Model of High Latitude Ionospheric Convection derived from SuperDARN radar EOF Data

By Mai Mai Lam (British Antarctic Survey)

Variations in space weather in the ionized region of the Earth’s atmosphere (the ionosphere) can result in expansion of the atmosphere, increasing the atmospheric drag on objects, such as satellites, in the thermosphere. We aim to significantly improve the forecasting of the effects of atmospheric drag on satellites by more accurate modelling of space weather effects on the motion of ionized particles (plasma) in the ionosphere. We have developed a model of the variation in plasma motion using a small number of solar wind variables. The model was built using a solar cycle’s worth (1997 to 2008 inclusive) of 5-minute resolution Empirical Orthogonal Function (EOF) patterns derived from Super Dual Auroral Radar Network (SuperDARN) line-of-sight observations of the plasma motion in the high-latitude northern hemisphere ionosphere (Shore et al., 2021). The model is driven by four variables: (1) the interplanetary magnetic field component By, (2) the solar wind coupling parameter epsilon, (3) a trigonometric function of the day-of-year, and (4) the monthly solar radio flux at 10.7 cm (the F10.7 index). Our model is good at reproducing the original data set - if 0 indicates that there is no reproduction and 1 indicates exact reproduction, then our model scores 0.7. Data set reproduction is best around the maximum in the solar cycle and worst at solar minimum. This is mainly due to differences in the spatiotemporal data coverage between these times but possibly also due to the model’s specification of the physical processes coupling the Sun to the Earth’s ionosphere. Our model could easily be used to forecast the ionospheric electric field about 1 hour in advance, using the real-time solar wind data available from spacecraft located upstream of the Earth.

Comparison of the new Lam 2023 model velocities with the original radar EOF velocities. 5-min snapshots of the high-latitude flow in magnetic latitude (60 – 90 ºN) and magnetic local time (12 is towards the Sun), for times when Lam model can explain the variance of the original data very well (high P) and not very well (low P). The top row shows velocities at a time when the percentage of explained variance P is high (February 2001): (a) the SuperDARN radar EOF data patterns, (b) the Lam 2023 model. The bottom row is for a time of low P (June 1999): (c) the SuperDARN radar EOF patterns, (d) the Lam 2023 model. Colour is used to indicate speed.
Comparison of the new Lam 2023 model velocities with the original radar EOF velocities. 5-min snapshots of the high-latitude flow in magnetic latitude (60 – 90 ºN) and magnetic local time (12 is towards the Sun), for times when Lam model can explain the variance of the original data very well (high P) and not very well (low P). The top row shows velocities at a time when the percentage of explained variance P is high (February 2001): (a) the SuperDARN radar EOF data patterns, (b) the Lam 2023 model. The bottom row is for a time of low P (June 1999): (c) the SuperDARN radar EOF patterns, (d) the Lam 2023 model. Colour is used to indicate speed.


References:
Lam, M. M., Shore, R. M., Chisham, G., Freeman, M. P., Grocott, A., Walach, M.-T., & Orr, L. (2023). A model of high latitude ionospheric convection derived from SuperDARN EOF model data. Space Weather, 21, e2023SW003428. https://doi.org/10.1029/2023SW003428

Shore, R. M., Freeman, M., Chisham, G., Lam, M. M., & Breen, P. (2022). Dominant spatial and temporal patterns of horizontal ionospheric plasma velocity variation covering the northern polar region, from 1997.0 to 2009.0 - VERSION 2.0 (Version 2.0) [Dataset]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/2b9f0e9f-34ec-4467-9e02-abc771070cd9

Solar Energetic Particle Events Detected in the Housekeeping Data of the European Space Agency's Spacecraft Flotilla in the Solar System

By Beatriz Sánchez-Cano (University of Leicester)

Space Weather is the discipline that aims at understanding and predicting the state of the Sun, interplanetary medium and its impact on planetary environments. One source of Space Weather is Solar Energetic Particles (SEPs), which are emitted by the Sun and enhance the radiation and particles that flow in space. Predicting the motion of these particles is important but difficult as we need good satellite coverage of the entire inner Solar System, and only a limited number of spacecraft have the necessary instrumentation. Thanks to the European Space Agency flotilla in the solar system, that is, Venus Express, Mars Express, ExoMars-Trace Gas Orbiter, Rosetta, BepiColombo, Solar Orbiter, and Gaia, we performed a feasibility study of the detection of SEP events using engineering sensors in the main body of the spacecraft that were originally placed there to monitor its health during the mission. We explored how much scientific information we can get from these engineering sensors, such as the timing and duration of an SEP impacting the spacecraft, or the minimum energy of those particles to trigger a detection. The results of this study have the potential of providing a good network of solar particle detections at locations where no scientific observations are available.

Example of a solar energetic particle (SEP) event detected by Rosetta with housekeeping data (black line). Three different energy ranges of the SEP event are also shown in colours.
Example of a solar energetic particle (SEP) event detected by Rosetta with housekeeping data (black line). Three different energy ranges of the SEP event are also shown in colours.

Please see publication for further details: Sánchez-Cano, B., Witasse, O., Knutsen, E. W., Meggi, D., Viet, S., Lester, M., et al. (2023). Solar energetic particle events detected in the housekeeping data of the European Space Agency's spacecraft flotilla in the Solar System. Space Weather, 21, e2023SW003540. https://doi.org/10.1029/2023SW003540