The May 2024 geomagnetic storm: UK experience and perspective

R. B. Horne; M. J. Angling; G. D. R. Attrill; C. Beggan; M. M. Bisi; P. S. Cannon; E. Clarke; C. Dyer; J. P. Eastwood; S. Elvidge; D. Gibbs; M. Gibbs; L. M. Green; M. A. Hapgood; M. Hofton; D. R. Jackson; B. Jones; S. Machin; C. N. Mitchell; H. Morgan; M. Owens; J. Preston; J. Rees; G. Routledge; K. A. Ryden; H. K. Sangha; R. J. Tanner; J. A. Wild; M. J. Willis

doi:10.1098/rsos.251943

The May 2024 geomagnetic storm: UK experience and perspective

R. B. Horne
, M. J. Angling
, G. D. R. Attrill
, C. Beggan
, M. M. Bisi
, P. S. Cannon
, E. Clarke
, C. Dyer
, J. P. Eastwood
, S. Elvidge
, D. Gibbs
, M. Gibbs
, L. M. Green
, M. A. Hapgood
, M. Hofton
, D. R. Jackson
, B. Jones
, S. Machin
, C. N. Mitchell
, H. Morgan

M. Owens, J. Preston, J. Rees, G. Routledge, K. A. Ryden, H. K. Sangha, R. J. Tanner, J. A. Wild, M. J. Willis

British Antarctic Survey
University of Birmingham
Defence Science and Technology Laboratory
British Geological Survey
Rutherford Appleton Laboratory
University of Surrey
Imperial College London
Civil Aviation Authority
The Met Office
University College London
National Energy System Operator
SolarMetrics Ltd.
Aberystwyth University
University of Reading
University of Essex
National Space Operations Centre
UK Health Security Agency
Lancaster University
UK Space Agency

Research output: Contribution to journal › Article › peer-review

Abstract

The May 2024 geomagnetic storm was the largest for over 20 years. The storm was categorized as a ‘low-level’ G5, where G5 is the highest on the National Oceanic and Atmospheric Administration (NOAA) scale for geomagnetic storms, yet the individual solar eruptive events were not particularly severe, and the observed impacts were relatively minor. The impacts that were observed were due to the combined and sustained effect of five successive earthward-directed coronal mass ejections (CMEs) which drove the storm. The event exposed the weakness of the current storm classification system which does not discriminate between low impact and high impact G5 events; it exercised the UK Met Office forecasting system, communications and UK preparedness; and it highlighted key areas that need to be addressed, particularly relating to national power supplies, space traffic management, aviation, forecasting and data gaps. Here, we set out what happened, record some of the key impacts, discuss what went well and what needs to be improved. We make 14 recommendations relevant to four government departments, so that the UK can be better prepared for a low-probability, high-impact space weather event described in the reasonable worst-case scenario that informs the national risk register.

Original language	English
Article number	251943
Number of pages	23
Journal	Royal Society Open Science
Volume	13
Issue number	4
Early online date	29 Apr 2026
DOIs	https://doi.org/10.1098/rsos.251943
Publication status	Published - 30 Apr 2026

Data Availability Statement

Data and imagery from the Atmospheric Imaging Assembly (AIA) instrument on the Solar Dynamics Observatory (SDO) spacecraft and the LASCO coronagraph instrument on the Solar and Heliospheric Observatory (SOHO) spacecraft used for figure 1 are available via jHelioviewer https://www.jhelioviewer.org. Data from the Hartland magnetometer are available via https://intermagnet.org. Data from the University of Surrey neutron monitor and the MAIRE-S model are available via https://spaceweather.surrey.ac.uk/surreyneutronmonitor.php. Data from the Oulu neutron monitor are available via https://cosmicrays.oulu.fi. GNSS observations used for figure 5 are available through the International GNSS Service (IGS) at https://igs.org/. Data from Space-Track (https://www.space-track.org) were used to assess changes to the ICESat-2 orbit following the storm.

Acknowledgements

We thank staff at the Met Office Space Weather Operations Centre for valuable information, Craig Rodger and the Solar Tsunami team for their information on the New Zealand power grid, and Hugh Evans and Ingmar Sandberg for helpful discussions on satellite data from LEO. We also thank two anonymous referees for
their helpful comments.

Funding

R.B.H. was supported by Natural Environment Research Council (NERC) grant NE/Y006178/1 PRESCIENT (2024-2028).

Keywords

geomagnetic storm
science policy
space weather

ASJC Scopus subject areas

General

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10.1098/rsos.251943Licence: CC BY

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Horne, R. B., Angling, M. J., Attrill, G. D. R., Beggan, C., Bisi, M. M., Cannon, P. S., Clarke, E., Dyer, C., Eastwood, J. P., Elvidge, S., Gibbs, D., Gibbs, M., Green, L. M., Hapgood, M. A., Hofton, M., Jackson, D. R., Jones, B., Machin, S., Mitchell, C. N., ... Willis, M. J. (2026). The May 2024 geomagnetic storm: UK experience and perspective. Royal Society Open Science, 13(4), Article 251943. https://doi.org/10.1098/rsos.251943

Horne, RB, Angling, MJ, Attrill, GDR, Beggan, C, Bisi, MM, Cannon, PS, Clarke, E, Dyer, C, Eastwood, JP, Elvidge, S, Gibbs, D, Gibbs, M, Green, LM, Hapgood, MA, Hofton, M, Jackson, DR, Jones, B, Machin, S, Mitchell, CN, Morgan, H, Owens, M, Preston, J, Rees, J, Routledge, G, Ryden, KA, Sangha, HK, Tanner, RJ, Wild, JA & Willis, MJ 2026, 'The May 2024 geomagnetic storm: UK experience and perspective', Royal Society Open Science, vol. 13, no. 4, 251943. https://doi.org/10.1098/rsos.251943

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The May 2024 geomagnetic storm: UK experience and perspective

Abstract

Data Availability Statement

Acknowledgements

Funding

Keywords

ASJC Scopus subject areas

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