MIST

Magnetosphere, Ionosphere and Solar-Terrestrial

Latest news

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!

ESA Voyager 2050

As was touched upon at the business lunch at NAM, ESA has launched the next in its series of milestones to shape long-term scientific planning, which is called Voyager 2050.
 
The next milestone in this process is a call for white papers, and this is outlined in detail here. In short, 20 page proposals are invited describing clear science questions and explaining how a space mission would address those questions. The deadline is 5 August 2019.
 
MIST Council hopes that members of the MIST community are planning to submit white papers to this call, and we would be very interested to hear from those who are planning to do this, or those who have already applied to be part of the Topical Teams also outlined in the call.

MIST Council election results

Following a call for nominations, Greg Hunt (Imperial College London) and Maria-Theresia Walach (Lancaster University) have been elected unopposed to MIST Council. We congratulate the two new MIST councillors!

We would also like to express our thanks and appreciation to both Ian McCrea and Sarah Badman who are leaving MIST Council, for their invaluable contributions and commitment to the MIST community.

UK Space Agency call for nominations for the position of Chair of the Science Programme Advisory Committee

The UK Space Agency (UKSA) is seeking a new Chair for the Science Programme Advisory Committee (SPAC). The position of Chair of the Science Programme Advisory Committee will become vacant on 1 July 2019.

The UK Space Agency welcomes applications from the UK space science community. The full position and person specifications are on the Government's website.

 

Exploring Key Characteristics in Saturn’s Infrared Auroral Emissions Using VLT-CRIRES: H3+ Intensities, Ion Line-of-Sight Velocities, and Rotational Temperatures

by Nahid Chowdhury (University of Leicester)

Saturn’s aurorae are generated by interactions between high-energy charged particles and neutral atoms in the upper atmosphere. Infrared observations of auroral emissions make use of H3+ – a dominant hydrogen ion in Saturn’s ionosphere – that acts as a tracer of energy injected into the ionosphere.

We analysed observations taken in May 2013 of Saturn’s northern infrared auroral emissions with the Very Large Telescope in Chile using the CRIRES instrument. The use of adaptive optics, combined with the high spectral resolution of VLT-CRIRES (100,000), meant that this dataset offered an unprecedented spatially and spectrally resolved ground-based view of Saturn's infrared aurora. Using discrete H3+ emission lines, we derived dawn-to-dusk auroral emission intensity, ion line-of-sight velocity, and thermospheric temperature profiles, allowing us to probe the physical properties of Saturn’s polar atmosphere.

Our analysis showed an enhancement in the dawn-side auroral emission intensity, a common feature that is known to be linked with solar-wind compressions in the kronian magnetosphere, and the presence of a localised dark region in the aurora very close to the pole. The ion line-of-sight velocity profile revealed previously unknown smaller-scale structures in the ion flows. In particular, the ion flows near the centre of the pole (at position B in Figure 1) could be consistent with the behaviour of a relatively small ionospheric polar vortex whereby the ions are interrupting the general dawn-to-dusk trend in movement to instead adopt a very sharp shearing motion of ions first toward midnight and then almost immediately back toward noon. Our thermospheric temperature derivations also reveal a very subtle temperature gradient that increases from 350 K on the dawn-side of the pole to 389 K on the dusk-side.

This work has bought to light complex features in the behaviour of H3+ ions in Saturn’s upper atmosphere for the first time and highlights the need for additional analyses of two-dimensional scanned maps of Saturn’s auroral regions with a view to addressing some of the major outstanding questions surrounding Saturn’s thermosphere-ionosphere-magnetosphere interaction.

For more information, please see the paper below:

Chowdhury, M. N., Stallard, T. S., Melin, H., & Johnson, R. E. ( 2019). Exploring key characteristics in Saturn's infrared auroral emissions using VLT‐CRIRES: H3+intensities, ion line‐of‐sight velocities, and rotational temperatures. Geophysical Research Letters, 46. https://doi.org/10.1029/2019GL083250.

 Plot showing the ion line-of-sight velocities and emission intensity as a function of colatitude.

Figure 1: The ion line-of-sight velocity and auroral emission intensity profiles are plotted as a function of co-latitude on the planet. Evidence for ion flows possibly consistent with the behaviour of an intriguing ionospheric polar vortex is adjacent to the area marked by the letter B, between approximately 0⁰ and 5⁰ co-latitude on the dawn-side of Saturn’s northern pole.