Professor Tim Yeoman

I graduated from the University of Bristol in 1985 and went on to the University of York gaining a D.Phil. in the Physics of Ultra Low-Frequency waves observed in the Earth's magnetosphere in 1988. I joined the University of Leicester as a PDRA that year and joined the Academic staff here as a Lecturer in 1992. I was promoted to Reader in 2000 and was awarded a personal Chair in Magnetospheric Physics in 2007. I was Academic Director of the College of Science and Engineering from 2013-2016.

My research centres on the analysis and interpretation of data from spacecraft particle and field instruments and ground-based magnetometer and ionospheric radar data.

Current research activities include:

ULF waves: Ultra low frequency (ULF) waves are an important coupling mechanism between the magnetosphere and the ionosphere since they transfer both energy and momentum. The waves also act as an important diagnostic of magnetospheric morphology and dynamics. High-frequency radio experiments such as SuperDARN and spacecraft such as the van Allen probes and Arase are providing exciting new information on ULF waves and we also explore the ULF wave populations of other solar system bodies such as Mercury.

Solar wind-magnetosphere-ionosphere coupling: The large-scale transport of mass momentum and energy into the Earth's magnetosphere-ionosphere system from the solar wind is mainly controlled by processes at the dayside magnetopause in the cusp region. These processes cause transient flows in the high latitude ionosphere which can be studied with the SuperDARN radars and auroral emissions which may be imaged from the ground or by space-borne auroral imagers. 

 

See https://orcid.org/0000-0002-8434-4825

Selected recent publications:

M. K. James, T. K. Yeoman, P. Jones, J. K. Sandhu, and J. Goldstein (2021) The Scalable Plasma Ion Composition and Electron Density (SPICED) model for Earth's inner magnetosphere. Journal of Geophysical Research:Space Physics. https://doi.org/10.1029/2021JA029565

A. S. Kalishin, N. F. Blagoveshchenskaya, T. D. Borisova, and T. K. Yeoman (2021). Ion Gyro-Harmonic Structures in Stimulated Emission Excited by X-Mode High Power HF Radio Waves at EISCAT. Journal of Geophysical Research: Space Physics 126.8. https://doi.org/10.1029/2020JA028989

C. Moser, J. LaBelle, S. Hatch, J. I. Moen, A. Spicher, T. Takahashi, C. A. Kletzing, S. Bounds, K. Oksavik, F. Sigernes, and T. K. Yeoman (2021). The Cusp as a VLF Saucer Source: First Rocket Observations of Long-Duration VLF Saucers on the Dayside. Geophysical Research Letters 48.2. https://doi.org/10.1029/2020GL090747

A. R. Fogg, M. Lester, T. K. Yeoman, A. G. Burrell, S. M. Imber, S. E. Milan, E. G. Thomas, H. Sangha, and B. J. Anderson (2020). An Improved Estimation of SuperDARN Heppner-Maynard Boundaries Using AMPERE Data. Journal of Geophysical Research: Space Physics 125.5, https://doi.org/10.1029/2019JA027218

C. M. Michael, T. K. Yeoman, D. M. Wright, S. E. Milan, and M. K. James (2020). A ray tracing simulation of HF ionospheric radar performance at African equatorial latitudes. Radio Science 55.2, e2019RS006936.  https://doi.org/10.1029/2019RS006936

S. J. Wharton, I. J. Rae, J. K. Sandhu, M.-T. Walach, D. M. Wright, and T. K. Yeoman (2020). The Changing Eigenfrequency Continuum During Geomagnetic Storms: Implications for Plasma Mass Dynamics and ULF Wave Coupling. Journal of Geophysical Research: Space Physics 125.6, https://doi.org/10.1029/2019JA027648

M. K. James, S. M. Imber, T. K. Yeoman, and E. J. Bunce (2019). Field Line Resonance in the Hermean Magnetosphere: Structure and Implications for Plasma Distribution. Journal of Geophysical Research: Space Physics 124.1, pp. 211-228. https://doi.org/10.1029/2018JA025920

S. J. Wharton, D. M. Wright, T. K. Yeoman, M. K. James, and J. K. Sandhu (2019). The Variation of Resonating Magnetospheric Field Lines With Changing Geomagnetic and Solar Wind Conditions. Journal of Geophysical Research: Space Physics 124.7, pp. 5353-5375.  https://doi.org/10.1029/2019JA026848

J. K. Sandhu, T. K. Yeoman, R. C. Fear, and I. Dandouras (2016a). A statistical study of magnetospheric electron density using the Cluster spacecraft. Journal of Geophysical Research-Space Physics 121.11, 11042-11062. https://doi.org/10.1002/2016JA023397

M. K. James, T. K. Yeoman, P. N. Mager, and D. Y. Klimushkin (2013). The spatio-temporal characteristics of ULF waves driven by substorm injected particles. Journal of Geophysical Research-Space Physics 118.4, pp. 1737-1749. https://doi.org/10.1002/jgra.50131

ULF wave process in the magnetospheres of the Earth Mercury Jupiter and Saturn.

Solar wind ionosphere-magnetosphere coupling at the Earth

High frequency radar operations and their uses in providing diagnostics of ionospheric processes

Magnetospheric substorms and their interaction with energetic particles in the Earths radiation belts 

I teach on all the school's undergraduate degree programmes and currently contribute to the following modules: PA1120, Light and Matter; PA2240, Electromagnetic Fields; PA3603, The Space Environment; PA3280, Physics Challenge; and PA4980, Physics Special topics. I also regularly offer Pair and Group Projects in the 3rd year and Specialist Research Projects and Literature Review Projects in the 4th year. 

High frequency radar systems, the plasma environments of the planets, the Earth’s space environment, space weather.