MIST

By Juliane Huebert (British Geological Survey)

Geomagnetically induced currents (GICs) are a well-known consequence of increased geomagnetic activity due to solar storms. They pose the risk of damaging ground-based infrastructure like the high voltage power transmission network, gas pipelines and railways. Large-scale models of GICs in the UK exist, taking into account geomagnetic data, the induced ground electric fields and the configuration of the ground-based technologies. Validating these complex models is not easy and requires independent observations. To measure GICs in the HV voltage power network, we applied the Differential Magnetometer Method (DMM) at several sites in Britain. At each site, one magnetometer was placed under the power lines while a second one was located a few hundred meters away. By looking at the difference in the data between the two we can isolate the direct current flowing in the power lines. Data were recorded for several months, catching periods of increased geomagnetic activity. We then compared the measured current strength to the BGS GIC model developed from open source data sets of the UK power grid. The model also uses a measure for the ground electrical conductivity that is based on so-called magnetotelluric (MT) measurements which we performed in a country-wide campaign. MT data is necessary to characterize the spatial changes in the ground electric field due to local geology. We found our model and the field measurements to match very well, giving confidence that our simulations of the whole UK grid are very close to the correct values.

See full paper for further details:
Hübert, J., Beggan, C. D., Richardson, G. S., Gomez-Perez, N., Collins, A., & Thomson, A. W. P. (2024). Validating a UK geomagnetically induced current model using differential magnetometer measurements. Space Weather, 22, e2023SW003769. https://doi.org/10.1029/2023SW003769

By Jasmine Sandhu (University of Leicester)

Orbyts is a multi-award winning movement that partners scientists with schools to empower school students to undertake world-leading research. In this MIST nugget, we are delighted to present Orbyts very first Impact Report!

Read the Orbyts Impact Report 2017-2023 here: https://www.orbyts.org/impact

Over the past six years we have seen the programme enable a transformational impact on young people, researchers and teachers alike and we’re excited to share that with you here.

To date, Orbyts has created 100+ research partnerships, empowering 1500+ school students. We’ve increased inclusivity in post-16 STEM uptake, where students Orbyts engaged are 50+% girls, 50+% pupil premium, and identified from 48+ ethnicities. We have grown with new Hubs in North East England and Leicester, alongside expansion of our London Hub.

Read the report for all the statistics on Orbyts, spotlights on the ground-breaking research being led by students, and all the exciting plans for Orbyts in 2024!

We’d like to extend our thanks to all those who have and continue to support Orbyts, without whom this work would not be possible. In particular we would like to thank all the researchers and teachers for all their time and hard work. We also gratefully acknowledge support from all of our funders, including the UCL Access and Widening Participation Office, the Ogden Trust, UK Space Agency, European Research Council, EPSRC, and STFC.

Orbyts currently sits precariously positioned with no financial support beyond our upcoming 2024 programme. If you think that Orbyts might be something you would like to support, then we would love to hear from you at This email address is being protected from spambots. You need JavaScript enabled to view it..

Read the Orbyts Impact Report 2017-2023 for further details: https://www.orbyts.org/impact.

By Sachin Reddy (UCL / National Institute of Polar Research)

Jupiter’s moon Europa is exposed to a constant flow of plasma from its own ionosphere and the Jovian magnetosphere, which consists of a thermal and suprathermal population. As these particles flow onto the surface, an electrostatic potential forms in accordance with Kirchhoff’s current law. In this study, we investigate the electric charging of Europa’s icy surface using 3D particle-in-cell simulations via the Spacecraft Plasma Interactions Software (SPIS).

We find that surface potentials on Europa vary from -14 to -52 V. They change as a function of Europa’s four hemispheres, the solar illumination conditions, the plasma environment, and the properties of the surface itself. We reveal that the presence of an ionospheric plasma population reduces the surface potentials, producing a “dampening effect”. We also find that secondary electron emission is a crucial mechanism in Europan charging, shifting potentials by an order of magnitude for the same plasma properties. We argue that additional laboratory work into Europa-like-ice electron emission is necessary to reduce the uncertainties in the modelling. These results could be both corroborated and improved upon by the upcoming Europa Clipper and JUICE missions, and may be of use in the design of future missions to Europa’s surface (e.g. landers or other robotic explorers).

See full paper for further details:

Reddy, Sachin A., Nordheim, Tom N. and Harris, Camilla, D.K.,. "Surface Charging of Jupiter’s Moon Europa." The Astrophysical Journal Letters 962.2 (2024): L29. https://doi.org/10.3847/2041-8213/ad251e

By Ruoyan Wang (University of Leicester)

We have simultaneously observed line-of-sight ionospheric and thermospheric winds in Jupiter using the Keck II telescope and produced one of the first global maps of both ion and neutral flows in the same layer of any atmosphere. Since ionospheric currents are through the relative motion of ions within the neutral atmosphere, comparing these two maps produces a global map of the "effective" ion drifts, the E x B flows that drive upper ionospheric currents. To the surprise of the Jupiter community, this upper atmospheric "effective" ion drift is dominated by two sunward blue-shifted jets associated with the dawn and dusk main auroral region, highly reminiscent of ionospheric flows seen on Earth. This discovery is directly opposite to the expected rotationally symmetric breakdown in corotation driven by the plasma-heavy magnetosphere. Our result suggests that the asymmetric currents close in the upper ionosphere, while the closure of breakdown-in-corotation currents occurs deep in the lower ionosphere, resulting in powerful upward auroral currents penetrating through overlying regions of downward currents associated with the asymmetric currents. Such a mechanism could potentially explain the complex switching generation of Jupiter's main auroral emissions observed by the Juno mission. Moreover, this study highlights the importance of the neutral atmosphere and interactions between ions and neutrals on other planets, including Earth, making Jupiter an important global comparator for future studies of these interactions. 

See full paper for further details: 

Wang, R., Stallard, T. S., Melin, H., Baines, K. H., Achilleos, N., Rymer, A. M., Ray, R. C., Nichols, J. D., Moore, L., O'Donoghue, J., Chowdhury, M. N., Thomas, E. M., Knowles, K. L., Tiranti, P. I., Miller, S. (2023). Asymmetric Ionospheric Jets in Jupiter's Aurora. Journal of Geophysical Research: Space Physics, 128, e2023JA031861. https://doi.org/10.1029/2023JA031861.