MIST

Magnetosphere, Ionosphere and Solar-Terrestrial

Latest news

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..
 

 

Outcome of SSAP priority project review

From the MIST mailing list:

We are writing to convey the outcome of this year’s priority project “light touch” review, specifically with reference to those projects within the remit of SSAP. We would like to thank all the PIs that originally submitted ideas, and those who provided updates to their projects over the summer. SSAP strongly believe that all the projects submitted are underpinned by strong scientific drivers in the SSAP area.

The “light touch” review was undertaken with a unified approach by SSAP and AAP, considering factors that have led to priority project development (in STFC or other research councils) or new funding for priority projects (1/51 projects in the STFC remit) in the last 12 months. After careful discussion, it was agreed by SSAP and AAP not to select any project where the remit clearly overlaps with UKSA (i.e. space missions or TRL 4+), reflecting STFC’s focus on ground-based observations, science exploitation and TRL 0-3 development. Whilst in no way reflecting the excellence of the science, or community scientific wishes, this approach has resulted in some changes to the list of SSAP priority projects. However, now, unlike at the time of the original call, it is clear that such projects cannot move forwards without UKSA (financial) support, and such funds are already committed according to UKSA’s existing programme. SSAP remain strongly supportive of mission-led science in solar-system exploration, so SSAP have strongly recommended that the high-level discussions between UKSA and STFC continue with a view to supporting a clear joint priority projects call in future, more naturally suited to mission and bi-lateral opportunities.

The priority projects (and PIs) identified by SSAP for 2019/20 are:

  • Solar Atmospheric Modelling Suite (Tony Arber)
  • LARES1: Laboratory Analysis for Research into Extra-terrestrial Samples (Monica Grady)
  • EST: European Solar Telescope (Sarah Matthews)

SSAP requested STFC continue to work with all three projects to expand their community reach and continue to develop the business cases for future (new) funding opportunities. In addition, SSAP have requested that STFC explore ways in which the concept of two projects—“ViCE: Virtual Centres of Excellence Programme / MSEMM Maximising Science Exploitation from Space Science Missions”—can be combined and, with community involvement, generate new funding for science exploitation and maximising scientific return in solar-system sciences. Initially this consultation will occur between SSAP and STFC.

We would like to thank the community again for its strong support, and rapid responses on very short timescales. A further “light touch” review will occur in 2020, with a new call for projects anticipated in 2021. SSAP continue to appreciate the unfamiliar approach a “call for proposals with no funding attached” causes to the community and are continuing to stress to STFC that the community would appreciate clearer guidance and longer timescales in future priority project calls.

Yours sincerely,

Dr Helen Fraser on behalf of SSAP

The Global Network for the Sustainability In Space (GNOSIS)

The Global Network for the Sustainability In Space (GNOSIS) is an STFC Network+ with the goal of helping researchers within the Particle, Nuclear and Astrophysics areas to engage with researchers from other research councils and industry to study the near Earth space environment. For more details, visit the GNOSIS website or see this issue of the GNOSIS newsletter.

Over the next few years we expect a large increase in the number of satellites in Earth orbit. This will lead to unprecedented levels of space traffic much of which will end as debris. The aim of this network is to understand the debris populations and its impact on space traffic management with a view to enabling a safer environment.

The free GNOSIS lunch event will be held on 18 November 2019 at the British Interplanetary Society at Vauxhall, London, with a video link to the Royal Observatory Edinburgh, to facilitate participation from across the UK. Tickets can be obtained here.

GNOSIS will be producing a programme of meetings for both space operations specialists and subject matter novices and will be able to support the development of collaborative ideas through project and part graduate student funding. Details of our first workshop will be announced in the next month.

If you are an academic with no direct experience but have knowledge of areas such as observations, data analysis, simulation or even law, then register your interest on our website. If you are a currently working in the space sector or if you are just interested in the aims and goals of the network please also register your interest and get involved.

SWIMMR: A £19.9M programme of the UKRI Strategic Priorities Fund

Space Weather Instrumentation, Measurement, Modelling and Risk (SWIMMR) is a £19.9M programme of the UK Research and Innovation (UKRI) Strategic Priorities Fund.

MIST would like draw the attention of the research community to the potential opportunities which will become available as a result of this programme, which received final approval from the Department for Business, Energy and Industrial Strategy (BEIS) in August. The programme will run from now until March 2023 and is aimed at improving the UK’s capabilities for space weather monitoring and prediction. UKRI’s Strategic Priorities Fund provides a means for linking research council investment to governmental research priorities, hence the areas being emphasised in the programme reflect space weather threats to critical infrastructure, as reflected in the UK national risk register.

The programme will be delivered jointly by the STFC and NERC, mainly through open grant calls, but including some elements of commissioned work to be delivered through open competitive tenders. The first calls are expected to appear during the coming weeks. More information about the programme is available through the RAL Space website, and is forthcoming from the NERC web site.

To mark the official launch of the programme and provide more details of the planned activities, a kick-off meeting is being held in the Wolfson Library of the Royal Society on Tuesday 26 November 2019, from 10:30. Pre-registration is required for this event and can be done using this link. We hope that many of you will be able to attend.

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!

Plasma density gradients at the edge of polar ionospheric holes: the absence of phase scintillation

By Luke Jenner (Nottingham Trent University)

The high-latitude ionosphere is a highly structured medium. Large-scale plasma structures with a horizontal extent of tens to hundreds of kilometres are routinely observed and it is well known that these can disrupt radio waves such as those used for Global Navigation Satellite System (GNSS). One such structure, a polar ionospheric hole, is a sharp depletion of plasma density. In this paper polar holes were observed in the high-latitude ionosphere during a series of multi-instrument case studies close to the Northern Hemisphere winter solstice in 2014 and 2015. These holes were observed during geomagnetically quiet conditions and under a range of solar activities using the European Incoherent Scatter (EISCAT) Svalbard Radar (ESR) and measurements from GNSS receivers. The edges of the polar holes were characterised by steep gradients in the electron density. Such electron density gradients have been associated with phase scintillation in previous studies; however, no enhanced scintillation was detected within the electron density gradients at these boundaries. It is suggested that the lack of phase scintillation may be due to low plasma density levels and a lack of intense particle precipitation. In a review paper Aarons (1982) suggested that a minimum density level may be required for scintillation to occur, and our observations support this idea. We conclude that both significant electron density gradients and plasma density levels above a certain threshold are required for scintillation to occur.

Electric potential patterns with the phase scintillation and TEC overlaid 

Figure: Electric potential patterns inferred from the SuperDARN radars for 17:14 UT on 17 December 2014 as a function of geomagnetic latitude and magnetic local time. Magnetic noon is shown at the top of panels with dusk and dawn on the left- and right-hand sides respectively and magnetic midnight at the bottom. Magnetic latitude is indicated by the grey dashed circular lines at 10.0◦ increments. The grey lines show the location of satellite passes from GNSS satellites, assuming an ionospheric intersection of 350 km. The SuperDARN plot from 17:14 UT plot includes satellite passes from 16:58 to 17:28 UT. These time intervals were chosen as the inspection of the whole SuperDARN data set at a 2 min resolution indicated that the convection patterns were relatively stable during these intervals. The panels on the right half show the area around the satellite passes in more detail. Colours represent phase scintillation in the top right panel and TEC in the bottom right panel. The thick black line indicates the position of the polar hole observed using the 42 m dish of the EISCAT Svalbard Radar.

For more information, please see the paper:

Jenner, L. A., Wood, A. G., Dorrian, G. D., Oksavik, K., Yeoman, T. K., Fogg, A. R., and Coster, A. J.: Plasma density gradients at the edge of polar ionospheric holes: the absence of phase scintillation, Ann. Geophys., 38, 575–590, https://doi.org/10.5194/angeo-38-575-2020, 2020.

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