Martin Cafolla
Position: Final year PhD student
Supervisors: Prof. Sandra Chapman, Dr Nick Watkins
Project Title: Quantifying Space Weather Turbulence, Extremes and Risk at Earth
Teaching: 1st year undergraduate Physics problems classes
Overview of Research
Space Weather concerns the impact of the solar wind on the Earth's magnetic field environment, known as the Magnetosphere. Our dependence on satellite/space technologies makes it crucial to monitor these impacts. This PhD focuses on the Ionosphere, a region within the atmosphere composed of free electrons and ions as a result of exposure to solar radiation. The variability of intensity of this radiation, as well as the differing levels of geomagnetic activity, results in fluctuations in electron number density across the ionosphere, characterised by the Total Electron Content (TEC). Analysis of how TEC structures change over time can help mitigate the potential risks extreme space weather events pose on navigation and communication systems.
My main research project focuses on Global Ionospheric Maps (GIMs) produced by the Jet Propulsion Laboratory (JPL), which provide over 20 years of GNSS observations at a spatial resolution of 1◦ × 1◦ longitude/latitude every 15 minutes from 2003. We transform these maps into geomagnetic coordinates centered about the sub-solar point and isolate the top 1% of TEC values per map to define High Density Regions (HDRs) of TEC. We then construct an algorithm that isolates, detects and tracks these regions for 20 years of TEC data, producing a contiguous set of uniquely labelled space-time TEC HDRs. This analysis detects, labels and tracks HDR origin, path, areas, TEC intensities and duration. Below shows animated GIFs of example HDRs between 31/10/2003 00:00:00 UTC and 01/11/2003 23:45:00 UTC to demonstrate the detection/tracking algorithm:
For a given level of geomagnetic activity, our results show statistical trends in HDR formation location, duration and path taken. See Cafolla et al. (2025) for details.
We use this data to then analyse the relationship between the maximum TEC of these HDRs with the solar flux at 10.7cm (F10.7), commonly used as an input to ionospheric models. Previous work has shown that the global average TEC and F10.7 follow a linear relationship, however based on data from recent solar cycles (declination phase of cycle 23, cycle 24 and the ascending phase of cycle 25) we test both linear and non-linear functions to the data, investigating the saturation of TEC at high F10.7 (around solar maxima).
Further research will look at global Ionospheric Pierce Point (IPP) maps, where we compare the results of HDRs between these maps and GIMs from JPL. These maps also have a shorter time resolution of approximately 30s, offering better observations of fast-changing TEC structures.
Publications
Lead Author:
-
Cafolla, M. A., Chapman, S. C., Watkins, N. W., Meng, X., & Verkhoglyadova, O. P. (2025). Dynamics of TEC high density regions seen in JPL GIMs: Variations with latitude, season and geomagnetic activity. Space Weather, 23, e2024SW004307. DOI: 10.1029/2024SW004307
- Preprint: Martin Anthony Cafolla, Sandra C Chapman, Nicholas Wynn Watkins, et al. Dynamics of Space-Time TEC Enhancements seen in JPL GIMs: Variations with Latitude, Season and Geomagnetic Activity. ESS Open Archive . December 19, 2024. DOI: 10.22541/essoar.173463008.89578977/v1Link opens in a new window
Co-author:
- Meng, X., Verkhoglyadova, O. P., Chapman, S. C., Watkins, N. W., & Cafolla, M. (2024). Statistical characteristics of total electron content intensifications on global ionospheric maps. Space Weather, 22, e2023SW003695. DOI: 10.1029/2023SW003695
Talks and Poster Sessions
| Conference | Date | Location | Presentation Type |
|---|---|---|---|
| Autumn MIST 2023 | 02/12/23 | Burlington House, London, UK | Oral |
| EGU 2024 | 15/04/24 - 20/04/24 | Austria Center, Vienna, Austria | Poster |
| UK SWSE 2024 | 09/09/24 - 12/09/24 | Sandy Park, Exeter, UK | Oral |
| ESWW 2024 | 04/11/24 - 08/11/24 | Convento São Fransisco, Coimbra, Portugal | Oral |
| Autumn MIST 2024 | 29/11/24 | The Exchange, Birmingham, UK | Poster |
| AGU 2024* | 09/12/24-13/12/24 | Walter E. Washington Convention Center, Washington D.C., USA | Poster |
| Spring MIST 2025 | 07/04/25-09/04/25 | College Court, Leicester, UK | Oral |
| EGU 2025 | 28/04/25-02/05/25 | Austria Center, Vienna, Austria | Oral |
* Conference not attended, presented by supervisor on my behalf
Undergraduate Degree
MSci in Mathematics and Physics within the Natural Sciences Programme, Durham University (2018-2022)
Master's Project (2021-22): Modelling Smoothed Particle Hydrodynamics on a Quantum Computer
3rd Year Computing Project (2020-21): The Impact of the Cosmological Constant on the Maximum Mass of Neutron Stars
Contact
Email: martin.cafolla.1@warwick.ac.uk
Office: PS1.17
Address: Department of Physics, University of Warwick, Coventry, CV4 7AL
LinkedIn: LinkedIn
ORCID: 0009-0000-8215-2339