MIST

Magnetosphere, Ionosphere and Solar-Terrestrial

Latest news

STFC Policy Internship Scheme now open

This year has proved the critical importance of science having a voice within Parliament. But how does scientific evidence come to the attention of policy makers? If you are a STFC-funded PhD student, you can experience this first-hand through our Policy Internship Scheme, which has just opened for applications for 2020/21. During these three-month placements, students are hosted either at the Parliamentary Office of Science and Technology (POST) or the Government Office for Science (GO Science).

POST is an independent office of the Houses of Parliament which provides impartial evidence reviews on topical scientific issues to MPs and Peers. Interns at POST will research, draft, edit and publish a briefing paper summarising the evidence base on an important or emerging scientific issue. GO Science works to ensure that Government policies and decisions are informed by the best scientific evidence and strategic long-term thinking. Placements at GO Science are likely to involve undertaking research, drafting briefing notes and background papers, and organising workshops and meetings.

The scheme offers a unique opportunity to experience the heart of UK policy making and to explore careers within the science-policy interface. The placements are fully funded and successful applicants will receive a three-month extension to their final PhD deadline.

For full information and to see case studies of previous interns, please see our website. The closing date is 10 September 2020 at 16.00.

Applied Sciences special issue: Dynamical processes in space plasmas

 

Applied Sciences is to publish a special issue on the topic of dynamical processes in space plasmas which is being guest edited by Georgious Nicolaou. Submissions are welcome until 31 March 2021, and submission instructions for authors can be found on the journal website. For general questions, This email address is being protected from spambots. You need JavaScript enabled to view it..

MIST elections in 2020

The election for the next MIST councillors opens today, and will run until 23:59 on 31 July 2020. The candidates are Michaela Mooney, Matt Owens, and Jasmine Kaur Sandhu. 

If you are subscribed to this mailing list you should receive a bespoke link which will let you vote on the MIST website, which will be sent by This email address is being protected from spambots. You need JavaScript enabled to view it.. If you don’t receive this link, please check your junk folder! The candidates’ platforms are on the voting platform, and also reproduced below for your convenience. 

Michaela Mooney

I’m a final year PhD student at MSSL standing for MIST Council as a student representative. During my PhD, I’ve been actively engaged in the department as a Student Rep in the Staff Student Consultation Committee and in the Equality, Diversity and Inclusion Committee. I’m an active member of the MIST research community through proposals for RAS Discussion meetings and NAM sessions on geomagnetic activity. 

My main goals as a MIST Council representative would be to:

  • lobby funding bodies to reduce the impact of the pandemic on PhD students.
  • facilitate the organisation of virtual conferences and careers days to ensure that students continue to have opportunities to present research and access to careers information.
  • support good practises in equality, diversity and inclusion within the MIST community.

My key priority would be to limit the impact of the pandemic on students and ensure equality of opportunities.

Matt Owens

Now, more than ever, it’s vital our community address its diversity problems. If anyone is standing for MIST council from an underrepresented demographic, I’d encourage you to vote for them; MIST needs their experience and insight. If not, I’ll seek to ensure MIST council continues to promote equality of opportunity and diversity in science.

MIST’s primary role is to represent our solar-terrestrial science within the wider discipline. I’m predominantly a heliospheric scientist, but keep a toe in the solar physics community. E.g., I’ve served in editorial capacities for both JGR and Solar Physics, and have a good deal of experience with both NERC and STFC funding. As such, I’d hope to see MIST working closely with UKSP, as we have a lot of common interest. I am also keen that the MIST community coordinate to make the most of the industrial and operational forecasting opportunities that are open to it. Finally, I’m a very recent convert to open science. I would seek to increase the prevalence of research code publication and use of community tools within our field, for reasons of both efficiency and reproducibility.

Jasmine Kaur Sandhu

I am a post-doctoral research associate at the Mullard Space Science Laboratory, UCL, with a research focus on inner magnetospheric physics. During my time as a Council member I have led a number of initiatives, primarily the MIST Student’s Corner, the MIST Nugget Series, and the MIST online seminar series. If elected, I will continue to focus on supporting early career researchers in ways that promote diversity of both science and the scientists within our community. This will include developing a set of up-to-date, comprehensive, and informative resources on funding opportunities available to early career researchers for travel funding and fellowships. This will be supported by a mentor-like scheme for assistance and guidance on applications.

A Summary of the SWIMMR Kick-Off Meeting

The kick-off event for the Space Weather Innovation, Measurement, Modelling and Risk Study (one of the Wave 2 programmes of the UKRI Strategic Priorities Fund) took place in the Wolfson Library of the Royal Society on Tuesday November 26th. Seventy-five people attended the event, representing a range of academic institutions, as well as representatives from industry, government and public sector research establishments such as the UK Met Office. 

The morning session of the meeting consisted of five presentations, introducing the programme and its relevance to government, the Research Councils and the Met Office, as well as describing details of the potential calls. The presentations were as follows:

  •  Prof John Loughhead (Chief Scientific Advisor to BEIS) - Space Weather Innovation, Measurement, Modelling and Risk Programme (a governmental perspective). The slides from Prof John Loughhead's talk are available here.
  • Prof Chris Mutlow (Director of STFC RAL Space) - SWIMMR: Project funded by the Strategic Priorities Fund (a perspective from STFC).  The slides from Prof Chris Mutlow's talk are available here.
  • Jacky Wood (Head of Business Partnerships at NERC) - Space Weather Innovation, Measurement, Modelling and Risk (SWIMMR) - A NERC perspective.  The slides from Jacky Wood's talk are available here.
  • Dr. Ian McCrea (Senior Programme Manager for SWIMMR) -  SWIMMR: Space Weather Innovation, Measurement, Modelling and Risk: A wave 2 programme of the UKRI Strategic Priorities Fund.  The slides from Dr Ian McCrea's talk are available here.
  • Mark Gibbs (Head of Space Weather at the UK Met Office) - SWIMMR (Met Office perspective and detailed description of the calls.  The slides from Mark Gibb's talk are available here.

During the lunch break, the Announcement of Opportunity for the five NERC SWIMMR calls was issued on the NERC web site.  The afternoon therefore began with a brief introduction by Jacky Wood to the NERC Announcement of Opportunity, and the particular terms and conditions which it contained.

The remainder of the afternoon session was spent in a Question and Answer session in which attendees were able to ask questions to the speakers about the nature of the programme and the potential timing of future calls, and finally to an informal discussion session, in which participants gathered into groups to discuss the opportunities for funding which had been outlined. 

2019 RAS Council elections

As you may have seen, the nominations for RAS Council are currently open with a deadline of 29 November. MIST falls under the “G” (Geophysics) category and there are up to 3 councillor positions and one vice-president position available. MIST Council strongly encourages interested members of the MIST community to consider standing for election.
 
Clare Watt (University of Reading) has kindly volunteered to be a point of contact for the community for those who may wish to talk more about being on council and what it involves. Clare is a councillor on RAS Council, with her term due to complete in 2020, and This email address is being protected from spambots. You need JavaScript enabled to view it..
 

 

Nuggets of MIST science, summarising recent MIST papers 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 and include a figure/animation. Please get in touch!

On the Determination of Kappa Distribution Functions from Space Plasma Observations

by Georgios Nicolaou (Mullard Space Science Laboratory, UCL)

Solar wind plasma is often out of the classic thermal equilibrium and the particle velocities do not follow Maxwell distribution functions. Instead, numerous missions reported observations indicating that the velocities of plasma species follow kappa distribution functions which are characterized by narrow “cores” and elongated high-energy “tails”. In this study, we focus on the determination of these distributions by a novel calculation of statistical velocity and kinetic energy moments which we can potentially apply on-board to estimate the plasma parameters. We quantify this method by simulating and analyzing observations of typical solar wind protons. Moreover, we demonstrate how the instrument design affects the accuracy of the method and we suggest validation tests for future users. We highlight the importance of such a method for high time-resolution on-board analyses in space regions where the plasma is out of classic thermal equilibrium.

 

Figure 1. (Top left) The occurrence of the first order speed moment M1out and (lower right) the temperature Tout, as derived from the analysis of 1000 samples of plasma with n = 20 cm-3, u0=500 kms-1 towards Θ = 0° and Φ = 0°, T = 20 eV, and κ = 3. (Top right) Theoretical solutions of κout as a function of Tout and M1out. On each panel the blue lines indicate the input parameters and the black lines the derived parameters in our example.

Please see the paper for full details:

Nicolaou, G.; Livadiotis, G.; Wicks, R.T. On the Determination of Kappa Distribution Functions from Space Plasma Observations. Entropy 2020, 22, 212. https://doi.org/10.3390/e22020212

AE, DST and their SuperMAG Counterparts: The Effect of Improved Spatial Resolution in Geomagnetic Indices

By Aisling Bergin (University of Warwick)

Magnetometer stations on the ground are used to monitor and specify changes in the magnetosphere - ionosphere system. Geomagnetic indices based on measurements from these stations are used extensively and they have been recorded for many decades. Two examples are AE and DST , which are indices designed to measure the evolution and intensity of the auroral electrojets and the ring current, respectively. The SuperMAG collaboration have made new versions of these indices available, SME and SMR. They are based on a larger number of magnetometer stations than the original AE and DST indices.

Bergin et al. (2020) presents a statistical comparison of AE and DST geomagnetic indices with SME and SMR, their higher spatial resolution SuperMAG counterparts. As the number of magnetometer stations in the SuperMAG network increases over time, so does the spatial resolution of SME and SMR. Our statistical comparison between the established indices and their new SuperMAG counterparts finds that, for large excursions in geomagnetic activity, AE systematically underestimates SME for later cycles. The difference between distributions of recorded AE and SME values for a single solar maximum can be of the same order as changes in activity seen from one solar cycle to the next. We show that it in the case of AE and SME, it is not possible to simply translate between the two indices. We demonstrate that DST and SMR track each other but are subject to an approximate linear shift as a result of the procedure used to map stations to the magnetic equator. These results have demonstrated that important differences exist between the indices, and informs how and when these indices should be used.

Survival distributions show how the indices vary with solar cycle

Figure 1. Survival distributions of geomagnetic indices. (a) Sunspot number for the last five solar cycles are plotted (black); coloured regions indicate periods of solar maximum from which data are used for the statistical comparison of maxima of Cycles 21 (red), 22 (yellow), 23 (purple) and 24 (green). Corresponding dates of AE, SME, DST and SMR index data availability are indicated in the black line plot below. Survival distributions based on the empirical cumulative density function of electrojet indices (b) AE and (c) SME and ring current indices (d) DST and (e) SMR are plotted for each of the four solar maxima; uncertainties are estimated using the Greenwood error formula and are indicated by shading.

Please see the paper for full details:

Bergin, A., Chapman, S. C., & Gjerloev, J. W. (2020). AE, DST and their SuperMAG Counterparts: The Effect of Improved Spatial Resolution in Geomagnetic Indices. Journal of Geophysical Research: Space Physics, 125, e2020JA027828. https://doi.org/10.1029/2020JA027828

Temporal and Spectral Studies by XMM-Newton of Jupiter’s X-ray Auroras During a Compression Event

By Affelia Wibisono (Mullard Space Science Laboratory, UCL)

Out of all of Jupiter’s aurorae, its X-ray aurora is unique as it is produced by the interactions between the constituents of Jupiter’s atmosphere with both ions and electrons. Furthermore, the X-rays are emitted by the precipitating particles rather than the native Jovian species. The X-ray aurorae are fixed on Jupiter’s frame and often exhibit quasi-periodic oscillations (QPOs) with periods of tens of minutes (e.g. Dunn et al., 2017), however, the origins of the precipitating particles and the source of the QPOs remain to be fully understood.

Contemporaneous observations by XMM-Newton and Chandra of Jupiter’s X-ray aurorae occurred for five hours in June 2017 while Juno was at near apojove. XMM-Newton continued to survey the emissions for a further 18 hours. The southern aurora was visible to XMM-Newton three times while the northern aurora was only seen twice. The planet’s magnetosphere was shown to be compressed by the solar wind during this time.

Wibisono et al., 2020 applied discrete wavelet and Fast Fourier Transforms (FFT) on the XMM-Newton auroral lightcurves from both poles. Figure 1 shows the power spectral density (PSD) plots from the FFT analysis in chronological order. QPOs were not found in the southern lights when it was first in view hence why its PSD plot is not included. The first rotation in the north had a strong pulse with a period of 27 minutes; a result that Chandra agrees with (Weigt et al., 2020). There is a secondary, less powerful beat at 23 minutes that is also observed in the south and then again in the north. This period lasts for a total duration of 12.5 hours, marking it the first time that both poles are seen to pulsate with the same period, at the same time and for more than one Jupiter rotation. The period increased to 33 minutes in the final rotation. The observed periods indicate that ultra-low frequency waves are a likely cause of the pulsations.

Power spectral densities for multiple rotations.

Figure 1: The power spectral density (PSD) plots after the Fast Fourier Transform was applied on the time intervals when regular pulsations occurred. PSDs A and C are for the entire first rotation and start of the second rotation of the northern aurora respectively. PSDs B and D are for the beginning of the second and entire third rotation of the southern aurora respectively. The dashed, dashed-dot and dotted black lines mark the 66th, 90th and 99th percentiles which were calculated by using Monte Carlo methods to produce 10 000 simulated lightcurves and determining the frequency of a periodicity of the observed power was randomly generated. The vertical red dashed lines show when the period is equal to 23 minutes. There were no regular pulsations in the first rotation in the south.

Spectral analysis of the XMM-Newton dataset gave the surprising result that during this particular magnetospheric compression event, the precipitating ions were from inside Jupiter’s magnetosphere. This outcome provides an insight into what drives Jupiter’s X-ray aurorae that have significant implications for our understanding of the wider magnetospheric dynamics at Jupiter.

For more details, see the paper:

Wibisono, A. D., Branduardi‐Raymont, G., Dunn, W. R., Coates, A. J., Weigt, D. M., Jackman, C. M., et al ( 2020). Temporal and Spectral Studies by XMM‐Newton of Jupiter's X‐ray Auroras During a Compression Event. Journal of Geophysical Research: Space Physics, 125, e2019JA027676. https://doi.org/10.1029/2019JA027676

Chandra Observations of Jupiter's X-ray Auroral Emission During Juno Apojove 2017

By Dale Weigt (University of Southampton)

Jupiter has dynamic auroral X-ray emissions, first observed over 40 years ago. A key characteristic of Jupiter’s aurora are “hot spots” of soft X-rays at the poles, which we observe from the Chandra X-ray Observatory (CXO) with high spatial resolution. These non-conjugate northern (Gladstone et al. 2002 + others) and southern auroral hot spots (Dunn et al. 2017 + others) are found in several observation campaigns to flare quasi-periodically. However, the driver of the X-rays (and hence their link to solar wind and magnetospheric conditions) is currently unknown.

In the Weigt at. (2020) case study, we analyse CXO data from 18th June 2017 during a 10-hour observation where Juno was near its apojove position. An XMM-Newton observation overlapped the latter half of this observation (Wibisono et al. 2020). From the particle data, we find that Juno crossed the magnetopause several times preceding the Chandra observation. Using the closest crossing and amagnetopause model, we inferred a compressed magnetosphere during this interval. Using a numerical threshold to define spatial regions of concentrated photons, we find that the hot spot in the north appeared twice during the observation with a more extended morphology. Using Rayleigh testing, we find significant quasi-periodic oscillations (QPO) during both instances the hot spot was in view at ~ 37 min and 26 min respectively. The 26-min QPO was also observed by XMM-Newton and was found to remain for a further two Jupiter rotations. Using the Vogt et al. (2011, 2015) flux equivalence model, we map the origin of the QPOs and X-ray driver to be on the dayside-dusk magnetopause boundary, considering the caveats of the model. The timescales of the periods found suggest that the driver may be linked to magnetospheric processes producing ultra-low frequency waves (ULF).

X-ray aurora at Jupiter's northern pole are mapped to their magnetospheric origins.

Figure 1: (c) polar plot of Jupiter’s north pole showing the observed mapped and unmapped photons (black dots and orange triangles respectively)at the beginning of the observation interval. (d) The photons are mapped to their magnetospheric origins using the Vogt et al. (2011, 2015) model, where error bars show the estimated mapping errors. The red dashed line indicates the magnetopause boundary inferred from the Juno data during the Chandra observation. The location of Juno during this time is denoted by the yellow star. 

These results demonstrate the capabilities of CXO data in understanding the “hot spots” in Jupiter’s aurora, and can provide important contextual information to Juno observations. This study is also the first to find two significant QPOs in the northern hot spot over timescales less than a Jupiter rotation.

For more details, see the paper:

Weigt, D. M., Jackman, C. M., Dunn W. R., Gladstone G.R., Vogt M. F., Wibisono A. D., et al (2020). Chandra Observation of Jupiter’s X-rays Auroral Emission During Juno Apojove 2017 Journal of Geophysical Research: Planets, 125, e2019JE006262. https://doi.org/10.1029/2019JE006262 

Jupiter’s X-ray Emission 2007 Part 1 and Part 2

By William Dunn (Mullard Space Science Laboratory, UCL; The Centre for Planetary Science at UCL/Birkbeck; Harvard‐Smithsonian Center for Astrophysics)

The solar minimum from 2007-2009 was the lowest and longest of the space age. In February 2007, the New Horizons spacecraft was approaching Jupiter measuring the conditions in the solar wind. At this time, a rich multi-instrument observing campaign was conducted, including X-ray, UV and Radio observations. In 2 accepted JGR: Space Physics papers we explore these campaigns, particularly focussing on the X-ray observations. 

The first paper concentrates on the X-ray emissions in the context of solar minimum. We explore the spectral and spatial morphologies of Jupiter’s X-rays using the Chandra and XMM-Newton (XMM) observatories. We show that the Jovian equatorial emission varies with solar cycle and may be utilised as a diagnostic of the disk-integrated solar spectrum at a given time. 

X-ray aurora projected onto Jupiter's northern pole

Figure showing variability in Jupiter’s X-ray aurora as recorded by Chandra ACIS during the 2007 campaign.  Each plot shows a projection on Jupiter's North pole of the X-ray aurora. The logarithmic color bar indicates the number of X-rays in bins of 3 degree by 3 degree of S3 latitude-longitude. Dashed grey lines of longitude radiate from the pole, increasing clockwise in increments of 30 degree from 0 degree at the top. Concentric grey circles outward from the pole represent lines of latitude in increments of 10 degree. Thin green contours with white text labels indicate the VIP4  [Connerney et al. 1998] model magnetic field strength in Gauss. Thick gold contours show the magnetic field ionospheric footprints of field lines intersecting the Jovigraphic equator at 5.9 RJ (Io's orbit), 15 RJ and 45 RJ [Grodent et al. 2008; Vogt et al. 2015] from equator to pole respectively.

The second paper compares the UV, Radio and X-ray auroral emissions in the context of the solar wind conditions, identifying shared behaviours between the emissions. Generally, we find that Jupiter’s X-ray aurora is best fit by ion lines from precipitating magnetospheric plasma, but during some magnetospheric expansions the spectrum is very different. At these times, the spectral models require the inclusion of a precipitating solar wind ion population, suggesting that additional solar wind ions gain access to the outer magnetosphere or directly to the pole during magnetospheric expansions. During these expansions we also observe a new type of X-ray aurora, which coexists with the other aurorae. We label this new aurora as ‘flickering X-ray aurora’ based on its temporal behaviour. 

The papers lay important groundwork in X-ray aurora spectral modelling and in attempting to understand the unification of the different multi-waveband auroral emissions and their relationship to solar wind conditions.

For more details see:

Dunn, W. R. et al. Jupiter’s X-rays 2007 Part 1: Jupiter’s X-ray Emission During Solar Minimum. J. Geophys. Res. Sp. Phys. https://doi.org/10.1029/2019JA027219

Dunn, W. R. et al. Jupiter’s X-ray Emission 2007 Part 2: Comparisons with UV and Radio Emissions and In-Situ Solar Wind Measurements. J. Geophys. Res. Sp. Phys. https://doi.org/10.1029/2019JA027222