Project highlights

  • Explore data from the new NASA TRACERS mission
  • Understand “Space Weather” and solar-planetary physics
  • Run experiments on state-of-the-art ionospheric radar systems.


At near-noon local times, at locations in the high arctic near 80 degrees North and South, the magnetic fields which originate in the conducting core of our planet extend upwards and are magnetically connected to the dayside magnetopause. This subsolar magnetopause is the point where the magnetic field of the Earth first touches the highly supersonic solar wind flow, and the interplanetary magnetic field of solar origin which is embedded in it. This creates the magnetospheric cusps, which are the primary entry points for energy of solar wind origin into the regions of space controlled by the terrestrial magnetic field, and the atmospheric regions which underlie them. This energy transfer occurs through a process called magnetic reconnection. As such, this crucial region of near-Earth space is fundamental to understanding the flow of energy, mass and momentum throughout the Earth’s magnetosphere, ionosphere and upper atmosphere, and hence in our understanding of “space weather”.

The magnetospheric cusps are longstanding areas of research interest, but their highly variable nature, in both space and time, makes them a highly challenging region to fully understand. This project is a multi-instrument research programme based around an exciting new NASA space mission, TRACERS (Tandem Reconnection & Cusp Electrodynamics Reconnaissance Satellites), due for launch in 2024. The TRACERS programme will operate in coordination with ground-based instrumentation in the Svalbard region. Around northern winter solstice Svalbard is in darkness at noon, and for ~10 days the moon is below the horizon. Such conditions offer a unique opportunity for multi-instrument cusp experiments involving cusp auroral optical observations. The project will also focus on data from the NERC-funded EISCAT Svalbard radar and the NERC-funded HAIRS (Hankasalmi Auroral Imaging Radar System) radar. HAIRS is a new state-of-the art digital imaging radar system currently under construction at the University of Leicester, which will look northwards from Finland, having a field of view centred over the Svalbard region. HAIRS will reveal the ionospheric cusp region electrodynamics at high spatial and temporal resolution over a ~1 million square kilometre region of the ionosphere.

Three graphics of terrestrial field lines, examples of measurements and data plots

Figure 1: Panel (a) shows a schematic of the evolution of terrestrial field lines from times T1 to T4, following reconnection at the subsolar point. The motion will separate out energised ions according to their velocity (an example is shown for a single spacecraft in Panel (b)). The TRACERS twin spacecraft will take time and space separated measurements of these particles at the field line footprints. The HAIRS radar will measure the surrounding electrodynamics (an example is shown in Panel (c); data plots taken from Provan et al., 2002).


University of Leicester


  • Climate and Environmental Sustainability
  • Dynamic Earth


Project investigator

Prof. T. K. Yeoman, University of Leicester ([email protected])


Prof. S. E. Milan, University of Leicester ([email protected])

How to apply


In this programme, low earth orbit measurements of energetic ions precipitating from the cusp region taken by the twin TRACERS spacecraft will provide measurements of the temporal and spatial structuring of the cusp reconnection processes. Magnetically conjugate measurements of the footprint of the reconnection line from HAIRS and associated ground-based instrumentation, will measure the length and the location of the reconnection line. HAIRS will provide an analysis of the boundary motion, and of the convection velocities detected near the boundary, allowing a calculation of the reconnection rate mapped down to the ionosphere. Such a combination of instrumentation will provide an unprecedented opportunity to understand the temporal and spatial behaviour of cusp reconnection and its role in controlling terrestrial space weather.

Training and skills

Students will be awarded CENTA2 Training Credits (CTCs) for participation in CENTA2-provided and ‘free choice’ external training. One CTC equates to 1⁄2 day session and students must accrue 100 CTCs across the three years of their PhD.

This project will offer the opportunity to gain skills in the analysis of data from in situ spacecraft measurements, and remote-sensed data from optical and radar systems. You will actively participate in the TRACERS science team, and will learn about the data and operations of the EISCAT 3D and HAIRS SuperDARN (Super Dual Auroral radar Network) radars through participation in the International workshops dedicated to those instruments. The Planetary science group has a large team of scientists with expertise in these systems and science areas, and you will work closely with this team.

Further details

Informal enquiries welcome to Prof. Tim Yeoman ([email protected])

If you wish to apply to the project, applications should include:

  • A CV with the names of at least two referees (preferably three and who can comment on your academic abilities)

Applications to be received by the end of the day on Wednesday 11th January 2023. 

Possible timeline

Year 1

Prior to the launch of TRACERS, you will learn how to design experiments and analyse data from the EISCAT 3D and HAIRS radars, and plan the experimental campaigns to be run in conjunction with TRACERS. Data from historical spacecraft conjunctions will provide intervals for new science analysis.

Year 2

Coordination and running of experiments with ground-based data from optical and radar instrumentation, analysis and interpretation of the data collected and publication of the science investigations using the new instrumentation.

Year 3

Continue running experimental campaigns, but with increased focus on the analysis, interpretation and publication of the multi-instrument studies of the cusp region.

Further reading

Amm, O., Lester, M., Wild, J. A., et al. (2005), ‘Coordinated studies of the geospace environment using Cluster, satellite and ground-based data: an interim review’, Ann. Geophys., 23, 2129–2170,

Chisham, G., S. E. Milan, M. Lester, et al. (2008), ‘Remote sensing of the spatial and temporal structure of magnetopause and magnetotail reconnection from the ionosphere’, Rev. Geophys., 46, RG1004,

G. Chisham, M. Lester, S. E. Milan, M. P. Freeman, W. A. Bristow, A. Grocott, K. A. McWilliams, J. M. Ruohoniemi, T. K. Yeoman, P. L. Dyson, R. A. Greenwald, T. Kikuchi, M. Pinnock, J. P. S. Rash, N. Sato, G. J. Sofko, J.-P. Villain, and A. D. M. Walker (2007). ‘A decade of the Super Dual Auroral Radar Network (SuperDARN): scientific achievements, new techniques and future directions’. Surveys in Geophysics 28.1, pp. 33–109.

McWilliams, K. A., G. J. Sofko, T. K. Yeoman, S. E. Milan, D. G. Sibeck, T. Nagai, T. Mukai, I. J. Coleman, T. Hori, and F. J. Rich (2004), ‘Simultaneous observations of magnetopause flux transfer events and of their associated signatures at ionospheric altitudes’, Annales Geophysicae 22.6, pp. 2181–2199,

Provan, G., S. E. Milan, M. Lester, T. K. Yeoman, and H. Khan (2002), ‘Simultaneous observations of the ionospheric footprint of flux transfer events and dispersed ion signatures’, Annales Geophysicae 20.2, pp. 281–287.

Trattner, K. J., S. A. Fuselier, T. K. Yeoman, C. Carlson, W. K. Peterson, A. Korth, H. Reme, J. A. Sauvaud, and N. Dubouloz (2005), ‘Spatial and Temporal Cusp Structures Observed by Multiple Spacecraft and Ground Based Observations’, Surveys in Geophysics 26.1-3, pp. 281–305.

Yeoman, T. K., D. M. Wright, M. J. Engebretson, M. R. Lessard, V. A. Pilipenko, and H. Kim (2012), ‘Upstream-generated Pc3 ULF wave signatures observed near the Earth’s cusp’, Journal of Geophysical Research-Space Physics 117.

Virginia Tech (no date) SuperDARN Available at: (Accessed 09 September 2022).

EISCAT Scientific association (no date) Welcome to EISCAT Scientific Association Available at: (Accessed 09 September 2022).

University of Iowa (no date) TRACERS (Tandem Reconnection & Cusp Electrodynamics Reconnaissance Satellites). Available at: (Accessed 09 September 2022).

University of Leicester (no date) Planetary science at the University of Leicester. Available at: (Accessed 09 September 2022).


It is anticipated that this project will run within the office space within the Planetary Science group at Leicester. In the event of disruption through a covid resurgence, we have considerable experience in mitigating such circumstances. The instrumentation required for the project will run regardless, and the data is electronically transmitted to Leicester. Analysis of the data will always be possible on the Leicester high performance computer systems, and alternative virtual supervision and collaboration systems are in place