MIST

Magnetosphere, Ionosphere and Solar-Terrestrial

Latest news

Nominations are open for MIST Council

We are very pleased to open nominations for MIST Council. There are three positions available (detailed below), and elected candidates would join Georgios Nicolaou, Andy Smith, Maria-Theresia Walach, and Emma Woodfield on Council. The nomination deadline is Friday 31 May.

Council positions open for nomination

2 x MIST Councillor - a three year term (2024 - 2027). Everyone is eligible.

MIST Student Representative - a one year term (2024 - 2025). 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. Two of our outgoing councillors, Beatriz and Sophie, have summarised their experiences being on MIST Council below.

Beatriz Sanchez-Cano (MIST Councillor):

"Being part of the MIST council for the last 3 years has been a great experience personally and professionally, in which I had the opportunity to know better our community and gain a larger perspective of the matters that are important for the MIST science progress in the UK. During this time, I’ve participated in a number of activities and discussions, such as organising the monthly MIST seminars, Autumn MIST meetings, writing A&G articles, and more importantly, being there to support and advise our colleagues in cases of need together with the wonderful council members. MIST is a vibrant and growing community, and the council is a faithful reflection of it."

Sophie Maguire (MIST Student Representative):

"Being the student representative for MIST council has been an amazing experience. I have been part of organizing conferences, chairing sessions, and writing grant applications based on the feedback MIST has received. From a wider perspective, MIST has helped to grow and support my professional networks which in turn, directly benefits my PhD work as well. I would encourage any PhD student to apply for the role of MIST Student Representative and I would be happy to answer any questions or queries you have about the role."

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 31 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:

  1. Name
  2. Position (Councillor/Student Rep.)
  3. Nomination Statement (150 words max including a bit about the nominee and focusing on your reasons for nominating. This will be circulated to the community in the event of a vote.)

MIST Council details

  • Sophie Maguire, University of Birmingham, Earth's ionosphere - This email address is being protected from spambots. You need JavaScript enabled to view it. 
  • Georgios Nicolaou, MSSL, solar wind plasma - This email address is being protected from spambots. You need JavaScript enabled to view it. 
  • Beatriz Sanchez-Cano, University of Leicester, Mars plasma - This email address is being protected from spambots. You need JavaScript enabled to view it.
  • Jasmine Kaur Sandhu, University of Leicester, Earth’s inner magnetosphere - This email address is being protected from spambots. You need JavaScript enabled to view it.
  • Andy Smith, Northumbria University, Space Weather - This email address is being protected from spambots. You need JavaScript enabled to view it. 
  • Maria-Theresia Walach, Lancaster University, Earth’s ionosphere - This email address is being protected from spambots. You need JavaScript enabled to view it. 
  • Emma Woodfield, British Antarctic Survey, radiation belts - 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. 

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)

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.. 

Revealing the process behind the limitation of electron fluxes in the heart of the outer radiation belt

Suman Chakraborty (Northumbria University)

The dynamics of the Earth’s outer radiation belts is highly complex arising from a delicate competition between different physical processes including acceleration, transport, and loss. During periods of enhanced geomagnetic activities, the outer radiation belt electron fluxes may vary by several orders of magnitude which can result in severe spacecraft damage, and in some extreme cases, may even lead to spacecraft failure. Therefore, understanding the processes that are responsible for the observed radiation belt variability remains an active topic of research. In this paper (see below for details), we provide direct observational evidence of the process that results in the limitation of outer radiation belt electron fluxes during geomagnetic storms. To conduct this study, we used electromagnetic wave and electron flux measurements from the Van Allen Probes during 70 isolated geomagnetic storms spanning the entire mission (2012 – 2019). We found that during the main phase of geomagnetic storms, when the flux of tens of keV electrons reaches close to or exceeds a theoretically predicted limiting flux value, intense chorus waves are generated having wave power 2 – 3 orders of magnitude larger than the pre-storm level. These intense chorus waves (wave power > 10-4 nT2, a value chosen from the superposed epoch response of the storms) rapidly scatter electrons into the loss cone causing atmospheric precipitation, thereby maintaining the fluxes at a value close to the limit predicted by Kennel and Petschek more than 50 years ago (see Figure 1). This study provides a significant advance in our understanding of the radiation belt variability as it shows that the electron fluxes cannot grow uncontrollably during geomagnetic storms, instead, they are capped through a chorus wave-driven flux-limitation process that is independent of the acceleration mechanism or source responsible for the flux enhancement.

Figure 1: Median (a, h) integrated chorus wave power (nT2; red) and difference of observed and calculated KP limiting flux for 33 keV (blue), 54 keV (green), and 80 keV (navy) electrons; probability distribution function (PDF) of (b, i) integrated chorus wave power and difference of observed and KP limiting flux for (c, j) 33 keV, (d, k) 54 keV and (e, l) 80 keV electrons in logarithmic scale; (f, m) percentage of finding integrated chorus wave power> 10−4 nT2 and observed flux greater than KP limiting flux for 33 keV (blue), 54 keV (green) and 80 keV (navy) electrons within the L range 4–5 (left panel) and 5–6 (right panel); and precipitating flux as observed by POES for > 30 keV electrons at (g) L = 4.5 and (n) L = 5.5 as a function of superposed epoch (in days) between 0 − 12 MLT. In each panel, the vertical dashed line marks the zero epoch, and the horizontal dashed lines in panels (c–e) and (j–l) indicate the observed flux being equal to the KP limiting flux. The colorbar at the right denotes the PDF so that the probability of finding events in each vertical slice adds up to 100%. In panels (g, n), the black scatter plot shows median electron flux and the error bars represent upper and lower quarterlies of the superposed epoch statistics.

 

Reference: Chakraborty, S., Mann, I.R., Watt, C.E.J., Rae, I.J., Olifer, L., Ozeke, L.G., Sandhu, J.K., Mauk, B.H., and Spence, H. Intense chorus waves are the cause of flux-limiting in the heart of the outer radiation belt. Sci Rep 12, 21717 (2022).https://doi.org/10.1038/s41598-022-26189-9.

 

Finding the Magnetopause Standoff Distance Using a Soft X-Ray Imager

By Andrey Samsonov (University College London)

The magnetopause standoff distance characterizes global magnetospheric compression and deformation in response to changes in the solar wind dynamic pressure and interplanetary magnetic field. We cannot derive this parameter directly from in situ spacecraft measurements because spacecraft cross the magnetopause rarely and in different regions along the magnetopause surface. However, it will be possible to obtain the time series of the magnetopause standoff distance in the near future using observations by soft X-ray imagers. In two companion papers (see below), we describe methods of finding the standoff distance from X-ray images. Soft X-rays are emitted in the magnetosheath and cusps as a result of charge exchange between heavy solar wind ions and exospheric neutrals. We use the results of MHD simulations to calculate the X-ray emissivity for different solar wind conditions. We simulate an artificial case with constant solar wind conditions and a case with an interplanetary coronal mass ejection (ICME) observed by the Wind spacecraft on 16-17 June 2012. Some MHD models predict relatively high density in the magnetosphere, larger than observed in the data. Correcting this, we develop magnetospheric masking methods to separate the magnetosphere from the magnetosheath and cusps.

We use the SXI_SIM numerical code developed at the University of Leicester to simulate the expected output of the Soft X-ray Imager (SXI) on board the forthcoming Solar wind Magnetosphere Ionosphere Link Explorer (SMILE) mission. Using the MHD results as input conditions, this code calculates the integrated emissivity along the Line-of-Sight (Ix) and SXI counts maps (see Figure 1). We verify the assumption that the maximum of the integrated emissivity is tangent to the magnetopause. Overall, the magnetopause is located close to the maximum Ix gradient or between the maximum Ix gradient and the maximum Ix depending on the method used. But since the angular distance between the maximum Ix gradient and the maximum Ix is relatively small (about 3°), the maximum Ix might be used as an indicator of the outer boundary of a wide magnetopause layer usually obtained in MHD simulations.

 

Eight panels showing the integrated emissivity and SXI count maps for different times during an ICME interaction with the magnetosphere. The emissivity is at first very bright and reliable due to the high number count, and then decreases.
Figure 1. Integrated emissivity (a,c,e, and g) and SXI counts maps (b,d,f, and h) with the exposure time of 5 min for different times in the case when an ICME interacts with the magnetosphere.

Original articles for further detail:

Samsonov, A., Carter, J. A., Read, A., Sembay, S., Branduardi-Raymont, G., Sibeck, D., & Escoubet, P. (2022). Finding magnetopause standoff distance using a soft X-ray imager: 1. Magnetospheric masking. Journal of Geophysical Research: Space Physics,

127, e2022JA030848. https://doi.org/10.1029/2022JA030848

Samsonov, A., Sembay, S., Read, A., Carter, J. A., Branduardi-Raymont, G., Sibeck, D., & Escoubet, P. (2022). Finding magnetopause standoff distance using a Soft X-ray Imager: 2. Methods to analyze 2-D X-ray images. Journal of Geophysical Research: Space Physics, 127, e2022JA030850. https://doi.org/10.1029/2022JA030850

LOFAR Observations of sub-structure within a Travelling Ionospheric Disturbance at mid-latitude

By Gareth Dorrian (Space Environment & Radio Engineering, University of Birmingham)

Travelling ionospheric disturbances (TID) are ubiquitous wave-like propagations in the Earth’s ionosphere and are the ionospheric counterpart of neutral atmospheric gravity waves (AGW). AGW can be driven by numerous sources from both the terrestrial and space weather domain such as sunrise, auroral sub-storms, volcanic eruptions, or thunderstorms. Terrestrial drivers from the lower atmosphere are coupled to the thermosphere by upwards propagation of AGW (Hines, 1960).

We study the ionosphere using LOFAR observations of trans-ionospheric radio propagation from compact natural radio sources. This is advantageous as, unlike most artificial satellites, natural radio sources are inherently broadband emitters and LOFAR is a broadband receiver with high frequency and time resolution. The behaviour of radio scattering through the ionosphere can thus be observed simultaneously across many frequencies. 

Observations using the LOw Frequency ARray (LOFAR: van Haarlem et al., 2013) of trans-ionospheric radio propagation through a TID over the UK were made on 7 January 2019 (Figure 1). In LOFAR data, ionospheric variability manifests as rapid changes in the received signal from the radio source. Using this technique, internal sub-structure within the TID were clearly identified with dominant modes of oscillation on timescales of ~300s. At the observing geometries used these oscillations equated to sub-structure scale sizes of ~20 km. Contemporary GNSS and ionosonde data were used to provide the global parameters of the TID. At the observation frequencies used (25-65 MHz) the Fresnel scale is between 3-4 km; consequently the majority of the scattering features observed were lens-like refractions, rather than diffractive scintillation. Geomagnetic conditions at this time were very quiet, suggesting a terrestrial driver.

 


Figure 1: Left panels: LOFAR dynamic spectra from UK and Irish stations showing rapid variations in received signal power across the full observing band, caused by passage of TID internal substructure across raypath. Right panels: GNSS plasma anomaly maps from the observing period with the wave-like form of the TID clearly visible over the UK.

Original article for further details: 

Dorrian, G., Fallows, R., Wood, A., Themens, D. R., Boyde, B., Krankowski, A., et al. (2023). LOFAR observations of substructure within a travelling ionospheric disturbance at mid-latitude. Space Weather, 21, e2022SW003198. https://doi.org/10.1029/2022SW003198

 

References:

van Haarlem, M. P., Wise, M. W., Gunst, A. W., Heald, G., McKean, J. P., Hessels, J. W. T., et al. (2013). LOFAR: Low-frequency-array. Astronomy and Astrophysics, 556, A2. https://doi.org/10.1051/0004-6361/201220873

Hines, C. O. (1960). Internal atmospheric gravity waves at ionospheric heights. Canadian Journal of Physics, 38(11), 1441– 1481. https://doi.org/10.1139/p60-150

 

 

Fine‐Scale Electric Fields and Joule Heating From Observations of the Aurora

By Patrik Krcelic (University of Southampton)

Optical measurements from three selected wavelengths have been combined with modelling of emissions from an auroral arc to estimate the magnitude and direction of small-scale electric fields on either side of an auroral arc for an event at 22:47:45 UT on 21 December 2014. The temporal resolution of the estimates is 0.1 s, which is much higher resolution thameasurements from Super Dual Auroral Radar Network (SuperDARN) in the same region, with which we compare our estimates. The obtained electric fields have peak value of 88 ± 16 mV/m on the northern side of the arc and peak value of 66 ± 21 mV/m on the southern side of the arc. Additionally, we have used the Scanning Doppler Imager instrument to measure the neutral wind during the event in order to calculate the height integrated Joule heating. Joule heating obtained from small scale electric fields gives much larger values than that obtained from SuperDARN data. Results are briefly shown in the movie below, where the top two panels depict an observed and modelled auroral arc analyzed in current syudy, and the bottom plot depicts the evolution of Joule heating in time on each side of the auroral arc compared with the SuperDARN estimate. Our optical method for estimating electric fields, and consequently the Joule heating using ASK, has proven to be very valuable in understanding the local heating effects in the vicinity of auroral activity. Such high spatial and temporal resolution electric fields may play an important role in the dynamics of the magnetosphere-ionosphere-thermosphere system.

Figure: The top left panel depicts observed auroral arc emission at 730 nm, while the top right panel depicts the same modelled auroral arc emission. Contours on the observed images represent the 95% level of the modeled brightness. The red vectors in the modeled images represent ion drift obtained from our modeling technique on each side of the auroral arc. Note that the vectors are not scaled and are here for illustrative purposes. Bottom panel depicts the evolution of Joule heating obtained from small scale electric fields. The red line represents Joule heating south of the auroral arc, the blue line represents Joule heating north of the auroral arc and the black line represents Joule heating obtained from SuperDARN measurements. Dashed lines represent standard deviations.

Original article for further detail: 

Krcelic, P., Fear, R. C., Whiter, D., Lanchester, B., Aruliah, A. L., Lester, M., & Paxton, L. (2023). Fine-scale electric fields and Joule heating from observations of the aurora. Journal of Geophysical Research: Space Physics, 128, e2022JA030628. https://doi.org/10.1029/2022JA030628 

 

Modeling the Time-Dependent Magnetic Fields That BepiColombo Will Use to Probe Down Into Mercury's Mantle

By Sophia Zomerdijk-Russell (Imperial College London)

The interior structure of a magnetised planet can be determined by using electromagnetic induction processes that results from solar-wind-driven magnetopause variability. To determine a profile of conductivity through depth within a planet, a broad spectrum of inducing fields is needed, as each discrete frequency will probe to a certain depth.

In preparation for the arrival of BepiColombo at Mercury in 2025, we have identified the opportunity to use Helios data to assess how solar wind ram pressure forcing can drive magnetopause variability at Mercury, as Helios took measurements during a similar phase of the Solar Cycle that BepiColombo is expected to see on its arrival. We find that Mercury’s magnetosphere is bombarded by a highly variable and unpredictable solar wind with a broad range of frequency signals and that the inducing field generated in response to the variable solar wind ram pressure is non-uniform across the planet’s surface.

A solar wind ram pressure time series from Helios measurements and the KT17 Hermean magnetospheric field model (Korth et al., 2017) were then used to generate a ram pressure driven inducing field spectra at two points on Mercury’s surface. In power spectra of these example inducing field spectra, frequency signals were found to peak between ~5.510-5 and 1.510-2 Hz. Heyner et al. (2021) determined that signals with these frequencies should penetrate into Mercury’s crust and mantle.

Particular orbital configurations of the BepiColombo mission will have MPO inside Mercury’s magnetosphere and Mio measuring the upstream solar wind, see Figure 1. Therefore, the dual spacecraft nature of the BepiColombo mission will be well suited to investigate Mercury’s magnetosphere’s response to external solar wind variability and allow a conductivity profile through to the mantle to be derived from observations of solar wind driven inducing field spectra with timescales seen in this work.

Figure 1. Schematic showing particular BepiColombo MPO (purple) and Mio (orange) spacecraft orbital configurations that will be useful for utilising electromagnetic sounding techniques at Mercury. An average location of the magnetopause is shown in green. Magnetopause variability inducing field signals on the order of a few minutes to a few hours will be able to penetrate through Mercury’s crust and into the mantle, shown by the blue shaded region.

Original article for further detail:

Zomerdijk-Russell, S., Masters, A., Korth, H., & Heyner, D. (2023). Modeling the time-dependent magnetic fields that BepiColombo will use to probe down into Mercury's mantle. Geophysical Research Letters, 50, e2022GL101607. https://doi.org/10.1029/2022GL101607

References: 

Heyner, D., Auster, H.-U., Fornaçon, K.-H., Carr, C., Richter, I., Mieth, J. Z. D., Kolhey, P., Exner, W., Motschmann, U., Baumjohann, W., Matsuoka, A., Magnes, W., Berghofer, G., Fischer, D., Plaschke, F., Nakamura, R., Narita, Y., Delva, M., Volwerk, M., … Glassmeier, K.-H. (2021). The BepiColombo Planetary Magnetometer MPO-MAG: What Can We Learn from the Hermean Magnetic Field? Space Science Reviews, 217(4), 52. https://doi.org/10.1007/s11214-021-00822-x

Korth, H., Johnson, C. L., Philpott, L., Tsyganenko, N. A., & Anderson, B. J. (2017). A Dynamic Model of Mercury’s Magnetospheric Magnetic Field. Geophysical Research Letters, 44(20), 10,147-10,154. https://doi.org/10.1002/2017GL074699