MIST

Magnetosphere, Ionosphere and Solar-Terrestrial

Latest news

New MIST Chair and Vice-Chair elected

Congratulations to John Coxon on becoming MIST Chair, and to Jasmine Sandhu on becoming MIST Vice-chair in a unanimous vote at a Council meeting last week.
 
MIST Council elects a new Chair whenever the previous Chair steps down, and in addition this year, the council has decided to elect a Vice-Chair for the first time.
 
On behalf of the MIST community, we would like to thank Ian McCrea for doing a superb job as Chair during his tenure on the Council.

EGU elections now open

The call for candidates for the EGU 2019 elections is currently open, with a deadline of 15 September 2019. The following roles are up for election: Union President, General Secretary, and the Division Presidents. More details about these roles and how you can nominate yourselves/colleagues can be found on the EGU website. 
 
MIST Council would like to emphasise that this is an excellent opportunity to contribute to and shape the field on an international scale, and we hope to see members from the MIST community putting themselves forward.

Summer Science Exhibition 2020

The Royal Society is currently accepting proposals for the Summer Science Exhibition 2020, and the deadline for proposals is 10 September 2019. Further details on applying can be found here.
 
MIST Council would like to highlight that this is an excellent opportunity for cross-institutional collaborations! The MIST community is involved in a number of projects with a particularly timely aspect (e.g. Solar Orbiter and SMILE), which would be very appropriate to propose to the Royal Society. If you are currently preparing a proposal that you are happy to invite community members to join or you have an idea for a proposal that you would like to work with the community on, then please email This email address is being protected from spambots. You need JavaScript enabled to view it. with a short outline by 9 August 2019. We hope to then share these projects with the community to build support for the proposals and involve the wider community!
 
We will be discussing this further and sharing ideas on the #public-engagement channel on the MIST Slack workspace. If you aren’t on the MIST Slack workspace then click here for details.

2019 Rishbeth prize winners announced

We are pleased to announce that the Rishbeth Prizes this year are awarded to Affelia Wibisono and Michaela Mooney , both of the Mullard Space Science Laboratory (UCL).
 
Affelia Wibisono wins the prize for the best MIST student talk, entitled “Jupiter’s X-ray Aurorae as seen by XMM-Newton concurrently with Juno”. Michaela wins the best MIST poster prize, for a poster entitled “Evaluating auroral forecasts against satellite observations”.
 
MIST Council would like to congratulate both Affelia and Michaela. As prize winners, Affelia and Michaela have been invited to write articles for Astronomy & Geophysics, which we look forward to reading.

Call for MIST/GEM Liaisons

There is a potential opening for a member of the MIST community to act as a liaison with the GEM (Geospace Environment Modelling) group. This will be an opportunity to act as a representative of the UK MIST community and inform GEM about relevant activities within the MIST community.

GEM liaisons will typically have the following responsibilities:

  1. Attend​​ a preponderance ​​of ​​GEM Steering ​​Committee ​​meetings​ ​at ​​summer​ ​workshop and​ ​mini-GEM​ ​​(June​ ​and​ ​December)
  2. Provide​​ written​​ annual​​ report​​ to​​ GEM Communications ​​Coordinator​​​ (by ​​April)
  3. Help ​​recruit ​​new​ ​GEM Steering​ ​Committee ​​members ​​​(as ​​needed)
  4. Provide ​​feedback​​ from​​ the​​ MIST community ​​and​​ share​​ with the GEM Chair/Vice​ ​Chair​ ​​(ongoing)

At this stage we would like to welcome any expressions of interest for this role from the community. If you are interested in being a GEM Liaison, then please This email address is being protected from spambots. You need JavaScript enabled to view it. including up to 100 words detailing why you would like to be a liaison and how your experience equips you for this role, and how often you would be able to attend GEM meetings.

If you have any further questions or would like more information about what the role would entail then please get in touch!

Statistical Planetary Period Oscillation Signatures in Saturn's UV Auroral Intensity

by Alexander Bader, Lancaster University, UK.

Saturn's highly dynamic auroras are generated by electrons precipitating along the magnetic field lines into the planet's polar ionospheres due to currents along the magnetic field lines. Therefore, the aurora provide information about the location and strength of these field-aligned currents. Two types of large-scale current systems have been observed in magnetic field measurements: one a quasi-static system associated with flow shears between plasma rotating at different speeds in the outer magnetosphere. The other significant type are field-aligned current systems rotating according to the planetary period oscillation (PPO) systems. Both the northern and the southern hemisphere are associated with one such system each, superimposed on the quasistatic system and causing roughly 10.7-hour periodic oscillations throughout the Kronian magnetosphere.

Upward and downward field-aligned currents in the northern ionosphere were found to be modulated by rotating patterns imposed by both the northern and southern PPO systems, the latter modulation being facilitated through interhemispheric current closure. The auroral intensity is hence also expected to be modulated accordingly, such that the northern aurora is brightest at roughly ΨN/S = 90°, where the currents have also been shown to maximize. Due to the two PPO systems rotating at slightly different angular velocities, this results in a double modulation.

In this study we analyzed the statistical behavior of Saturn's ultraviolet auroral emissions over the full Cassini mission using all suitable Cassini-UVIS images acquired between 2007 and 2017. This study shows for the first time that both hemispheres' auroral intensities are modulated by both the PPO system associated with the same hemisphere (primary system, Fig. 1a) and the opposite hemisphere (secondary system, Fig. 1b), relatively. The modulation by the primary system is found to be more intense than the one caused by the secondary system. This confirms that both PPO systems' field-aligned currents traverse the entire magnetosphere and close at least partly in the hemisphere opposite to where the generating perturbation is located.

For more information, see our paper below:

Bader, A., Badman, S. V., Kinrade, J., Cowley, S. W. H., Provan, G., & Pryor, W. R. (2018). Statistical planetary period oscillation signatures in Saturn's UV auroral intensity. Journal of Geophysical Research: Space Physics, 123, 8459–8472. https://doi.org/10.1029/2018JA025855

Figure 1: Average northern UV auroral intensity maxima per local time (4/3 h bin size) and PPO phase ΨN/S (20° bin size), shown in a logarithmic color scale. (a) Northern hemisphere auroral intensity ordered by the northern PPO system and (b) northern hemisphere auroral intensity ordered by the southern PPO system. Two Ψ phase cycles are plotted for clarity, the expected locations of maximum upward current are indicated by dashed white lines. On the top and to the side of each 2D histogram the averages of the mean intensity maxima over the ΨN/S and LT dimensions are shown in black, respectively. Separate histograms showing the PPO intensity modulation in the dawn-noon (blue) and dusk-midnight (red) regions are calculated from the parts of the histogram marked with colored boxes and shown to the right side (note the logarithmic intensity scale). The histogram over the full LT range (black) has been fitted with a simple sine (gray). Its maxima are marked with vertical dash-dotted lines, its peak-to-peak (pk-pk) amplitude and the ΨN angle with the highest intensity are given in the top right corner of each panel.