OPS2 – Severe Space Weather Events and Impacts of May 2024

Talks

OPS2.1 Wed 6/11 09:00-10:15, room C2D – Almedina

Chairs: Krista Hammond, Antonio Guerrero, Suzy Bingham

Author(s): Eelco Doornbos, Kasper van Dam, Kevin De hulsters, Mark ter Linden, Eelco Verduijn, Bert van den Oord

KNMI; KNMI; S&T; S&T; KNMI; KNMI

Abstract: On 10-11 May 2024, a sequence of merged interplanetary coronal mass ejections brought an extended period of high solar wind speed and strong southward directed interplanetary magnetic field to Earth’s magnetosphere, leading to the most powerful geomagnetic storm in recent history. A host of satellite and ground-based instrumentation was ready to observe and record the unique effects of this extreme event. We acknowledge the large effort of the teams behind making this data available to the community.
In this presentation, we will use the Space Weather Timeline Viewer to give a visual overview of a wide variety of data sources, focusing on events in Earth’s magnetic field and upper atmosphere. The timeline viewer tool has proven to be very useful, not only for monitoring real-time data streams as the events unfolded, but also for post-event assessment of forecast products, and for initial investigations of more complex scientific observations, including remote sensing of the aurora, that became available in the days and weeks following the storm. The flexibility of the timeline viewer also contributes to making comparisons between this and earlier events across the years, and helps to illustrate observational gaps.
The visualised data from May 10-11 will show, among others, the timing and locations of peak magnetic field perturbations, overhead aurora reaching 40 degrees magnetic latitude, the strong increase in satellite drag due to thermosphere expansion, as well as the nighttime F-region ionospheric fountain crests moving across mid-latitudes towards the auroral oval.

Author(s): Samantha Watson, Karen Shelton-Mur

Federal Aviation Administration; Federal Aviation Administration

Abstract: Space weather refers to the variable conditions on the Sun and in the space environment that can influence the performance and reliability of space and ground-based technological systems, as well as endanger human health. Primary space weather effects concerning aviation include radiation exposure and communication and navigational disruptions.
This presentation will delve into the threats space weather poses to aviation, particularly highlighting those felt during the May 2024 super storms. The Federal Aviation Administration’s (FAA) Aviation Weather Division received various anecdotes and reports following the G5 event, which was last reached in 2003. Aircraft technologies have drastically improved over those 21 years to make the national airspace safer and more efficient, but is aviation still vulnerable to space weather events? The launching of the new FAA Aviation Space Weather Research program in 2023 is timely with predicted solar maximum peaking over the next year. The program’s objectives are to conduct research to mitigate the impact of space weather on aviation, its passengers and crews, and to ensure continued safety for years to come.

Author(s): Ilja Honkonen, Tiera Laitinen, Elias Hirvonen, Mirjam Kellinsalmi, Petri Koskimaa, Sebastian Käki, Matias Takala, Ari Viljanen, Kirsti Kauristie

Finnish Meteorological Institute; Finnish Meteorological Institute; Finnish Meteorological Institute; Finnish Meteorological Institute; Finnish Meteorological Institute; Finnish Meteorological Institute; Finnish Meteorological Institute; Finnish Meteorological Institute; Finnish Meteorological Institute

Abstract: The Finnish Meteorological Institute (FMI) provides the Finnish public, industry and government with services on weather, sea, air quality, climate and near space. FMI’s space weather service started in 2014, consisting of 24/7 monitoring of space weather for potential hazards and daily aurora forecasts for the Finnish public. On November 7, 2019 FMI was the first to start providing space weather advisories for the International Civil Aviation Organization as part of PECASUS consortium, followed by NOAA SWPC on 19th and the ACFJ consortium on December 3.
We present the strong geomagnetic storm of May 2024 from the perspective of FMI space weather forecasters. We describe the basic structure of 24/7 space weather operations at FMI with the associated national and international duties. We recreate the FMI forecaster timeline for the Mother’s day storm starting from our warning of a potentially large geomagnetic storm to national customers at 5 UTC on May 8 and our first public mention of a potentially Earth-directed coronal mass ejection on our aurora forecast website approximately 3 hours later. We also present our timeline in the wider international context of forecasts from other space weather centers. We compare this storm to previous large geomagnetic storms using various FMI observations and global indices. Finally we show auroral images taken by our off-duty forecasters in the Helsinki metropolitan area.

Author(s): Fraser Baird, Fan Lei, Ben Clewer, Keith Ryden, Clive Dyer, Simon Machin, Krista Hammond

University of Surrey; University of Surrey; University of Surrey; University of Surrey; University of Surrey; Met Office; Met Office

Abstract: MAIRE+ is a model of the atmospheric ionising radiation field at aviation altitudes. Its purpose is to predict radiation dose rates and single event effect rates during both quiescent conditions and ground level enhancements (GLEs) of the radiation field. The real-time model has recently been delivered to the Met Office as part of the UK SWIMMR program.
In this contribution, the output of MAIRE+ during two recent space weather events is presented. The first event is the geomagnetic storm of March 25th 2024. This event was only brief, but caused some consternation in aviation communities due to two false ICAO severe radiation advisories, and one false GLE alert. The second event is the extreme geomagnetic storm of May 2024, which also featured the exceptionally small GLE 74.
For both events, the temporal and spatial structures of dose rates and single event effect rates are investigated. Furthermore, the behaviour of the MAIRE+ GLE trigger during both events is examined, as well as changes in predicted dose rates during the times of interest. Finally, the Met Office perspective on the challenges these events pose for space weather forecasting, and the capability added by MAIRE+, is discussed

Author(s): Eva Weiler, Christian Möstl, Emma E. Davies, Tanja Amerstorfer, Ute V. Amerstorfer, Hannah T. Rüdisser, Rachel L. Bailey, Julia Thalmann, Astrid Veronig, Noé Lugaz, Satabdwa Majumdar, Martin A. Reiss, Justin Le Louëdec, Maike Bauer

Austrian Space Weather Office, GeoSphere Austria, Graz, Austria; Institute of Physics, University of Graz, Graz, Austria; Austrian Space Weather Office, GeoSphere Austria, Graz, Austria; Austrian Space Weather Office, GeoSphere Austria, Graz, Austria; Austrian Space Weather Office, GeoSphere Austria, Graz, Austria; Austrian Space Weather Office, GeoSphere Austria, Graz, Austria; Austrian Space Weather Office, GeoSphere Austria, Graz, Austria; Institute of Physics, University of Graz, Graz, Austria; Conrad Observatory, GeoSphere Austria, Vienna, Austria; Institute of Physics, University of Graz, Graz, Austria; Institute of Physics, University of Graz, Graz, Austria; Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH, USA; Austrian Space Weather Office, GeoSphere Austria, Graz, Austria; Community Coordinated Modeling Center, NASA Goddard, Greenbelt, MD, USA; Austrian Space Weather Office, GeoSphere Austria, Graz, Austria; Austrian Space Weather Office, GeoSphere Austria, Graz, Austria; Institute of Physics, University of Graz, Graz, Austria

Abstract: On 2024 May 10-12, the strongest geomagnetic storm since 2003 took place. The event was caused by 5 interacting coronal mass ejections, launched from the Sun 2024 May 8-9, that drove the main geomagnetic activity. The fortunate passage of the STEREO-A spacecraft, 12 degrees away from the Earth and 0.05 AU closer to the Sun, provides the first possibility to study the method of sub-L1 monitoring for potential forecasting of a geomagnetic superstorm. We demonstrate with STEREO-A the extension of the prediction lead time, as the shock was measured 2.57 hours earlier at STEREO-A than at L1. We identify the 5 CMEs in the Wind and STEREO-A observations, which have interacted but not yet merged. Properties of CME-CME interaction are discussed, derived from the multipoint in situ observations, which may influence the forecasting capabilities of sub-L1 monitors. By deriving geomagnetic indices based on STEREO-A in situ data, we quantify how well the strength of a geomagnetic superstorm can be reproduced at this spacecraft separation distance, and the types of data that need to be measured in situ and how they affect the results.
Furthermore, we use the close encounter of STEREO-A and Wind from November 2022 to June 2024, when STEREO-A passed 0.05 AU ahead of Wind at ± 15 degrees heliospheric longitude. We apply a Dst model to STEREO-A in situ data and check whether we can reproduce the observed Dst in a range from moderate to severe geomagnetic storms (Dst < -80 nT to -412 nT) from this sub-L1 position. Given our current inability to reliably predict the southward magnetic field component of CMEs, sub-L1 monitors may be one way to address the Bz problem from an observational standpoint. With the statistics we obtain from our analysis, we are setting an unprecedented benchmark for future mission designs using upstream monitoring for space weather prediction.

OPS2.2 Thu 7/11 09:00-10:15, room C2D – Almedina

Chairs: Krista Hammond, Antonio Guerrero, Suzy Bingham

Author(s): Hannah Hermann, Teresa Nieves-Chinchilla, Tony Iampietro, Michelangelo Romano, Anna Chulaki, Carina Alden, Mary Aronne, Mary Pasanen, Mattie Anastopulos, Melissa Kane, Elizabeth Juelfs

NASA GSFC / CUA; NASA GSFC; NASA GSFC / Catholic University of America; NASA GSFC / Catholic University of America; NASA GSFC / Catholic University of America; NASA GSFC / Catholic University of America; NASA GSFC / George Mason University; NASA GSFC / ADNET Systems Inc.; NASA GSFC / Catholic University of America; NASA GSFC / Catholic University of America; NASA GSFC / George Mason University

Abstract: The Moon to Mars (M2M) Space Weather Analysis Office, located at NASA’s Goddard Spaceflight Center, conducts human-in-the-loop real-time space weather analysis to support NASA robotic missions and to support NASA’s Space Radiation Analysis Group (SRAG) with human exploration activities. The M2M Space Weather Analysis Office team works in close collaboration with both SRAG and the Community Coordinated Modeling Center (CCMC), as well as partnering with the NOAA Space Weather Prediction Center (SWPC). Efforts are focused on validating solar energetic particle (SEP) research model development, the transition of predictive capabilities from research to operations (R2O), monitoring space weather impacts to NASA robotic missions, and the transition from operations to research (O2R) by making real-time and post-analysis evaluations available in CCMC databases. The events of May 8-12, 2024 ushered in the highest levels of Earth-impacting space weather activity in Solar Cycle 25 thus far. The high level of activity, led by the Active Region 13664, included several coronal mass ejections (CMEs), X-class solar flares, two SEP events alongside the arrival of these CMEs, and the first extreme G5 geomagnetic storm observed and rated by NOAA SWPC since 2003. The M2M team adapted their routine activities for this exceptional event to provide longer and more comprehensive coverage and analysis for supported agencies. The team stressed the predictive models’ performance and monitored for potential impacts to NASA missions. Additionally, thanks to the low-latency data from the ESA/NASA Solar Orbiter Collaboration mission, located on the far side of the Sun, as well as the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission and the Perseverance Rover, both located at Mars, the M2M team was able to observe the progression of space weather events at multiple locations in the heliosphere. We will present an overview of the activities during this period along with the lessons learned for future events.

Author(s): Consuelo Cid, Manuel Flores-Soriano, Mario Cobos-Maestre, Armando Collado-Villaverde, David Fernández, Antonio Guerrero, Carlos Larrodera, Ivan Maseda, Pablo Muñoz, Antonio Reche, Elena Saiz

Universidad de Alcala; Universidad de Alcala; Universidad de Alcala; Universidad de Alcala; Universidad de Alcala; Universidad de Alcala; Universidad de Alcala; Universidad de Alcala; Universidad de Alcala; Universidad de Alcala; Universidad de Alcala

Abstract: On the morning of 8 May 2024 the University of Alcala (UAH) and the Spanish Air Force signed a cooperation agreement on space weather. That was a timely agreement because between 8 and 11 May the AR 13664 produced a series of intense flares and Earth-directed CMEs with an important impact on geospace. As in previous events, several space weather products were working in real time at the UAH servers and providing results through SeNMEs (the Spanish Space Weather Service) and the ESA Space Weather Portal. However, this was the first time that the Space Weather Group at the University of Alcala was working in an operational environment. In this presentation we will summarize how we worked, a showcase of the products’ assessment during the event, lessons learned and actions taken for future events.

Author(s): Maxime Grandin, Bea Gallardo-Lacourt, Mathieu Barthelemy, Emma Bruus, Rowan Dayton-Oxland, Eric Donovan, Katie Herlingshaw, Eero Karvinen, David Knudsen, Donna Lach, Les Ladbrook, Vincent Ledvina, Colin Legg, Carlos Martinis, Lena Mielke, Toshi Nishimura, Noora Partamies, Chris Ratzlaff, Margaret Sonnemann, Marjan Spijkers, Neethal Thomas, the ARCTICS collaborators

University of Helsinki, Finland; NASA/GSFC and Catholic University of America, USA; Université Grenoble Alpes, France; Sodankylä Geophysical Observatory, Finland; University of Southampton, UK; University of Calgary, Canada; University Centre in Svalbard, Norway; Citizen Scientist, Finland; University of Calgary, Canada; Citizen Scientist, Canada; Citizen Scientist, New Zealand; University of Alaska Fairbanks, USA; Citizen Scientist, Australia; Boston University, USA; University Centre in Svalbard, Norway; Boston University, USA; University Centre in Svalbard, Norway; Citizen Scientist, Canada; Citizen Scientist, Australia; Citizen Scientist, Netherlands; Sodankylä Geophysical Observatory, Finland

Abstract: The 10 May 2024 geomagnetic storm is one of the most extreme space weather events that occurred in over 20 years. In the era of smartphones and social media, numerous people from all around the world had been alerted about possibly exceptional auroral displays during those nights and hence got the opportunity not only to witness those but also to capture them in pictures. These observations, although not coming from traditional scientific instruments, can prove invaluable in obtaining data to characterise this exceptional event. In particular, many observers saw and photographed the aurora at midlatitudes, where ground-based instruments targeting auroral studies are sparse or absent. Moreover, the proximity of the event to the northern-hemisphere summer solstice implied that many optical instruments were not in operation due to the lack of suitably dark conditions.
The ARCTICS (Auroral Research Coordination: Towards Internationalised Citizen Science) collaboration, sponsored by the International Space Science Institute in Bern, set up an online survey and circulated it within the networks of aurora photographers to collect reports on observations of the aurora during this superstorm. In the span of three weeks, we obtained 677 reports by citizen scientists from over 30 countries, containing information such as time and location of aurora sightings as well as the observed colours. We present the results of the analysis of the collected data and discuss future avenues to leverage citizen science during exceptional space weather events.

Author(s): Baptiste Falque, Olivier Katz, François Colas, Jean Lilensten

COMEA; COMEA; CNRS – Observatoire de Paris; CNRS – IPAG – COMEA

Abstract: As part of a collaboration between COMEA (Alpine Space Weather Operationnal Centre) and the FRIPON (Fireball Recovery and Inter-Planetary Observation Network) project, we will present a re-analysis of the deployment of the auroral oval over Europe at the MotherDay Event on may 10th, 2024.
Thanks to the 283 full-sky cameras in the FRIPON network and COMEA’s observations of the event, an analysis of the images has enabled us to recreate the oval and details of the zones where the aurora appears in real time between 38°N and 55°N latitude, i.e. from Copenhagen (Denmark) to Tunis (Tunisia). The imagery seems to establish the presence of aurora at the zenith visible by the human eye at the lowest latitude of 48°N.
We will present a map of the oval recreated from the images and a spatiotemporal reanalysis of the oval’s deployment correlated with local magnetometer data. As COMEA’s speciality is forecasting, we will compare this analysis with forecasts based on data from satellites located at Lagrange 1, and show how this will enable us to adapt our future forecasts.

Author(s): Vincent Maget, Antoine Ferlin, Alexey Isavnin, Balazs Heilig, Christos Katsavrias, Constantinos Papadimitriou, Natalia Ganaushkina, Ingmar Sandberg, Ioannis Daglis, Joep Neijt, Kaspar Schiess, Janos Lichtenberger, Mark Dierckxsens, Sigiava Aminalragia-Giamini, Stefaan Poedts

ONERA; ONERA; Ray Of Space; ELTE; NKUA; SPARC; FMI; SPARC; NKUA; SOLENIX; SOLENIX; ELTE; BIRA-IASB; SPARC; KU LEUVEN

Abstract: In the frame of ESA Space Safety Programme, the Radiation Belt Forecast And Nowcast activity (RB-FAN) has been devoted in developing a framework to nowcast and enable a 3-day forecast of the particle populations and their dynamics within the (Van Allen or) Earth’s radiation belts.
The main objective of the RB-FAN framework, currently operating at https://swe.ssa.esa.int/onera-rb-fan-federated, is to provide the end-users with dedicated products, such as quick looks for specific orbits (LEO, GNSS, GEO and user pre-defined), radiation levels and risks assessment (internal charging and solar cell degradation).
RB-FAN relies on a dedicated global model chain based on the VSWMC infrastructure, and on available databases provided by ONERA, BIRA-IASB and SPARC supplemented by other external ones. The datasets used in this framework are retrieved in near real-time and are combined with the Salammbô codes (electron and proton) using data assimilation methods to provide the best nowcast. Solar wind structures are propagated from the Sun using the EUHFORIA model and the output estimated solar wind parameters and Kp values feed the Salammbô data assimilation codes which run with low energy boundary conditions provided by the IMPTAM model. The fluxes evolution produced by the Salammbô data assimilation codes  constitute the basic outputs of the RB-FAN framework.
The current developments of the RB-FAN framework involve improvements of the whole chain; from the models combined up to the end-user products. For that purpose, we are currently introducing new models to improve the forecast: EMERALD (NKUA, providing nowcast and forecast of radial diffusion coefficients), PLASMA (ELTE, providing nowcast and forecast of plasmasphere densities as well as plasmapause location) and UNSPELL (SPARC, providing nowcast and forecast of solar proton events).
In this context, the RB-FAN Team propose to discuss the severe Space Weather event of May as hindcasted and forecasted by the RB-FAN framework. We will discuss on the event characteristic as compared to past major events and present the behavior of the RB-FAN nowcasting components towards this event. We will then highlight on the expected benefit of its upgrade which is currently under development and discuss on the overall benefits when (relevant and) accurate science-based models are combined to a sophisticated forecasting framework. Finally, we will provide some insights of what type of inputs and improvements, based on the RB-FAN framework, could lead to improve further the forecasting of severe Space Weather events.

OPS2.3 Fri 8/11 09:00-10:15, room Auditorium

Chairs: Krista Hammond, Antonio Guerrero, Suzy Bingham

Author(s): Peter Wintoft, Magnus Wik, Kristoffer Hultgren, Markus Adolfsson

Swedish Institute of Space Physics; Swedish Institute of Space Physics; Swedish Civil Contingencies Agency; Swedish Civil Contingencies Agency

Abstract: In the beginning of May 2024 two solar active regions rotated into view that produced numerous X-flares and CMEs. Multiple CMEs during May 8 and 9, with the fastest associated with an X2.2 flare on May 9 caused a G5 event on May 10 and 11, the first since 2003. We utilised many international sources of information, such as SHARP solar magnetic features, identification and properties of CMEs, solar wind forecast for the arrival time of CMEs, and measured solar wind data at L1. This we combine with our SHARP-driven flare forecast models, forecast days ahead of G4 or higher from the solar wind forecast, hours-ahead of Kp and G levels driven by L1 data, 30-minute ahead forecast of dB/dt for northern Europe, and real-time monitoring of ground magnetic data. We describe here our monitoring and forecast of the event communicated with Swedish users before, during, and after the May 10-11 event. We also adress the impacts and actions taken by the Swedish Civil Contingencies Agency and concerned actors.

Author(s): Mamoru Ishii, Sergio Dasso

NICT/ISEE Nagoya University; Argentinean Space Weather Laboratory

Abstract: It is now important to know the relation between the severe space weather events and it’s social impact quantitatively for more precise social alert to civil activities.   The series of space weather events  in May 2024 and it’s social impacts were reported from all over the world.  These information are much precious to estimate the response function of social infrastructure with space weather events. We, International Space Environment Services (ISES) is a collaborative network of organizations providing space weather services around the globe. Each of ISES members has close communications with space weather end users in each region. We began to collect the information about the social impacts just after the events and prepare a report for further improvement of space weather services.
In this presentation, we will show an initial report about the regional space weather phenomena and social impacts and it’s analysis.

Author(s): Spogli Luca, Alberti Tommaso, Bagiacchi Paolo, Cafarella Lili, Cianchini Gianfranco, Coco Igino, Di Mauro Domenico, Ghidoni Rebecca, Giannattasio Fabio, Ippolito Alessandro, Marcocci Carlo, Pezzopane Michael, Pica Emanuele, Pignalberi Alessio, Perrone Loredana, Romano Vincenzo, Sabbagh Dario, Scotto Carlo, Spadoni Sabina, Viola Massimo, Cesaroni Claudio

INGV; INGV; INGV; INGV; INGV; INGV; INGV; Alma Mater Studiorum – Università degli studi di Bologna; INGV; INGV; INGV; INGV; INGV; INGV; INGV; INGV; INGV; INGV; INGV; INGV; INGV

Abstract: On 8 May 2024, the solar active region AR13664 started releasing a series of intense solar flares. Those of class X released between the 9 and 11 May 2024 gave rise to a chain of fast Coronal Mass Ejections (CMEs) that proved to be geoeffective. The Storm Sudden Commencement (SSC) of the resulting geomagnetic storm was registered on 10 May 2024 and it is, to date, the strongest event since November 2003. The May 2024 storm, named hereafter Mother’s Day storm, peaked with a Dst of -412 nT and stands out as a “standard candle” storm affecting modern era technologies prone to Space Weather threats. Moreover, the recovery phase exhibited almost no substorm signatures, making the Mother’s Day storm as a perfect storm example. in this paper we concentrate on the Space Weather effects over the Mediterranean sector, with a focus on Italy. In fact, the Istituto Nazionale di Geofisica e Vulcanologia manages a dense network of GNSS receivers (including scintillation receivers), ionosondes and magnetometers in the Mediterranean area, which facilitated for a detailed characterization of the modifications induced by the storm. Concerning the geomagnetic field, observatories located in Italy recorded a SSC with a rise time of only 3 minutes and a maximum variation of around 600 nT. The most notable ionospheric effect following the arrival of the disturbance was a significant decrease in plasma density on 11 May, resulting in a pronounced negative ionospheric storm registered on both foF2 and Total Electron Content. Another negative effect was recorded on 13 May, while no signatures of positive storm phases were reported. These negative ionospheric phases are ascribed to neutral composition changes and, specifically, to a decrease of the [O]/[N2] ratio. The IRI UP IONORING data-assimilation procedure, recently developed to nowcast the critical F2-layer frequency (foF2) over Italy, proved to be quite reliable during this extreme event, being characterised just by an overestimation during the main phase of the storm, when the electron density and the height of the F region, decreased and increased respectively. Relevant outcomes of the work related to the Rate of TEC change Index (ROTI), which shows unusually high spatially distributed values on the nights of 10 and 11 May. The ROTI enhancements on 10 May might be linked to Stable Auroral Red (SAR) arcs and an equatorward displacement of the ionospheric trough. Instead, the ROTI enhancements on 11 May might be triggered by a joint action of low-latitude plasma pushed poleward by the pre-reversal enhancement (PRE) in the post-sunset hours and wave-like perturbations propagating from the north. Furthermore, the storm generated immediate attention of the general public to Space Weather effects, including mid-latitude visible phenomena like SAR arcs. This paper outlines the report of the Space Weather Monitoring Group (SWMG) of the INGV Environment Department and its effort to disseminate information about this exceptional event.

Author(s): Hannah Grace Parry, Ian R. Mann, Darcy Cordell, Ryan MacMullin

University of Alberta; University of Alberta; University of Alberta; AltaLink LP

Abstract: Large space weather events like that seen on May 7-11th, 2024 have the potential to damage satellites and disrupt radio communications and Global Navigation Satellite Systems (GNSS). However, the threat to reliable electricity distribution and transmission from impacts of geomagnetically induced currents (GICs) on the power system could be considered the most socioeconomically impactful. GICs caused by geomagnetic disturbances (GMDs) are near DC currents that are induced in long conductive infrastructure including transmission lines. Preliminary results show that large GICs were driven in the Alberta electric power system during the May 2024 storm. Transformer neutral to ground current measurements provided by AltaLink, Alberta’s largest electric transmission company, show GICs greater than 150 A were seen at three transformers in Alberta. A high-fidelity, data-driven DC-equivalent network model, used magnetometer observations during the GMD to predict GIC across the Alberta power transmission network. A maximum GIC of approximately 150 A at a transformer substation in central Alberta west of Edmonton was modelled around 9:40 UT. The GIC measured on that transformer using a transformer neutral to ground Hall effect sensor reached 165 A at that time, and the correlation of the observed GICs with those from the data-driven model was 0.84. A differential magnetometer measurement was also used to estimate the GIC on an element of the grid North of Edmonton. The maximum GIC inferred on the double circuit transmission line using the DMM technique was approximately 93 A, seen around 11:00 UT. The timescale of this pulse is much shorter and was not seen in nearby transformer substation measurements, presumably due to the slower inertial timescale of induced currents in the network. The model also saw a large pulse at this time on that transmission line confirming that it was driven by space weather. Overall the model had a correlation of 0.78 with the DMM-inferred GIC. Through our partnership with AltaLink LP, we continue to assess the effects and potential impacts of the May 2024 geomagnetic storm on the electric power grid in Alberta, Canada.

Author(s): Ewelina Lawrence, Sarah Reay, Ellen Clarke, Ciaran Beggan, Gemma Richardson, Lauren Orr

British Geological Survey; British Geological Survey; British Geological Survey; British Geological Survey; British Geological Survey; British Geological Survey

Abstract: The 10th/11th May 2024 geomagnetic storm was the first G5 storm of the solar cycle 25 and the largest storm in over 20 years. The auroral electrojet, driven by a strong interplanetary magnetic field (IMF) of up to 50 nT, moved equatorward on the evening of the 10th May reaching the latitude of central England (below 54 degrees North) for several hours. Widespread sightings of the aurora were observed across the country, and rapid variations of the magnetic field were recorded in the UK.
Here we present the geomagnetic view of the storm using six UK-based British Geological Survey (BGS) magnetometer sites, as well as measurements from two geoelectric field monitors. Using the real-time magnetic data to drive a conductivity model of the UK, geomagnetically induced currents (GIC) in the high voltage power grid substations were estimated at up to 140 A in Wales and over 100 A in four sites in England. Since the storm effects moved swiftly to lower latitudes, measurements in Scottish substations did not record significantly large GIC values.
We compare the May 2024 storm with measurements from the September 2017, October 2003 and September 1859 Carrington storms to demonstrate the differences in magnitude, timings and latitudinal extent between these events. Although the duration of the May 2024 storm ranks it 3rd in the aa index, the lower ferocity (dB/dt and Dst index) of magnetic field rate of change brings it closer to a 1-in-30-year storm and hence, as expected, had relatively little impact on grounded technology in the UK.

Posters

Posters II  Display Thu 7/11 – Fri 8/11, room C1A – Aeminium

Authors in attendance: Thu 7/11 10:15–11:30, 15:15-16:15; Fri 8/11 10:15–11:30

Author(s): Brigitte.schmieder@obspm.fr, Guillaume Aulanier, Stefaan Poedts, Jin Han Guo

Observatoire de Paris; LPP, France; KuULeuven Belgique; KU Leuven, Be

Abstract: Many questions have to be answered before understanding the relationship between the emerging magnetic flux through the solar surface and the extreme geoeffective events. Which threshold determines the onset of the eruption? What is the upper limit in energy for a flare? Is the size of sunspot the only criteria to get extreme solar events?

Based on observations of previous solar cycles, and theory, the main ingredients for getting X ray class  flares and large Interplanetary Corona Mass Ejections e.g. the built up of the electric current in the corona, are presented such as the existence of magnetic free energy, magnetic energy/helicity ratio, twist and stress in active regions. The upper limit of solar  are energy in space research era and the possible chances to get super- flares and extreme solar events can be predicted using MHD simulation of coronal mass ejections.  Eruptive or confined flares are discussed in this context versus examples (e.g. events of September 2017).

Author(s): Alexander Mishev, N. Larsen, S. Koldobskiy, I. Usoskin

University Of Oulu, Finland; University Of Oulu, Finland; University Of Oulu, Finland; University Of Oulu, Finland

Abstract: The second ground-level enhancement (GLE) of solar cycle 25 was observed by the worldwide network of ground-based neutron monitors (NMs) on 11 May 2024. It has been identified as a GLE and data from the available NMs have been stored as the GLE #74 in the International GLE database. Here we report the observations and the study of this event using the global NM network and in-situ data from the GOES satellites. This event appeared very challenging to analyse because it occurred shortly after the deepest phase of a major Forbush decrease and during a severe geomagnetic storm with Dst < -400 nT. For a proper study of this event using NM data, we have first corrected the NM count rate for the variable background galactic cosmic rays and then explicitly modelled the acceptance, that is asymptotic cones, of the NMs explicitly considering  complex magnetospheric conditions, by employing the new magnetospheric tool OTSO within a combination of IGRF and Tsy01s models. Herein, we derived the characteristics of solar energetic particle fluxes during GLE # 74 and their dynamical evolution throughout the event.

Author(s): Ashot agassi Chilingarian

Yerevan Physics Institute

Abstract: This study investigates the modulation of particle fluxes at Earth’s surface influenced by the orientation and intensity of the “frozen” magnetic field within Interplanetary Coronal Mass Ejections (ICMEs). We examine how a southward Bz component, opposing Earth’s northward magnetic field, significantly enhances geomagnetic activity through magnetic reconnection. This reconnection facilitates increased penetration of solar wind particles into the magnetosphere, thus amplifying the fluxes registered by terrestrial particle detectors and enhancing particle fluxes through reduced cutoff rigidity (magnetospheric effect, ME). Conversely, the orientation of the Bz component is less crucial for a Forbush decrease (FD); instead, the strength of the ejecta’s scalar magnetic field (B) predominates, with a northward Bz component also potentially triggering a significant FD. The study methodically explores how these magnetic field variations influence the detector flux of neutrons and muons, effectively modifying the observed rates of cosmic ray influx. Comprehensive data from the WIND magnetometer and Aragats spectrometers underline the direct relationship between ICME magnetic configurations and variations in ground-level particle fluxes.
Moreover, the energy spectra of additional particles during ME are limited to 10 MeV due to the low energy of solar protons that generate secondary particles in the terrestrial atmosphere. In contrast, the energy spectra of the “missing” FD particles can extend up to 100 MeV, demonstrating that magnetic traps and cradles formed by interactions between ejecta and Earth’s magnetic fields can deflect high-energy solar protons. These insights advance our understanding of geomagnetic modulation of particle fluxes and bolster predictive models of space weather impacts on particle detection technologies.

Author(s): KANYA KUSANO, Yumi Bamba, Daikou Shiota

Nagoya University; National Institute of Information and Communications Technology; National Institute of Information and Communications Technology

Abstract: Solar active regions NOAA 13664 and 13697 produced many large flares, causing severe space weather events. We systematically analyzed the evolution of the three-dimensional magnetic field of this active region using the force-free field extrapolation technique and investigated the relationship between the magnetic field structure and flares. Through the analyses, we clarify the characteristics of this active region by comparing it with several major active regions in solar cycle 24. Furthermore, we apply the physics-based prediction scheme, kappa-scheme (Kusano et al. 2020), to this active region and discuss the predictability of the large flares in this region.

Author(s): Marie Cherrier, Philippe Yaya

CLS; CLS

Abstract: In mid-May 2024, a severe Space Weather event occurred and impacted the Earth environment. This event was mainly due to the strong activity coming from one particular active region, which grew in size and magnetic complexity throughout the days preceding the event. Several extreme flares and fast CMEs erupted from this region; many were geo-effective.
The resulting G5 geomagnetic storm, although producing wonderful auroras at latitudes rarely affected, had an impact on infrastructures around the globe. Furthermore, degradations were observed on satellites systems, with LEO satellite orbits being troubled due to drag mismodeling.
The purpose of the study is to analyze the impact of May 10th and 11th impact on the DORIS system, flying on board 9 civilian satellites. DORIS, standing for Doppler Orbitography by Radiopositioning Integrated by Satellite, is a French orbitography system whose ground network consists of around sixty beacons emitting a radio-frequency signal at 400 MHz and 2 GHz. The DORIS instruments perform Doppler shift measurements that allow precise orbit determination.
During strong solar events, such as this one, both DORIS channels can be impacted, and degradation might be observed on the system performance. The resulting degradations and disturbances impacting DORIS data and the derived orbits will be presented in this study.

Author(s): Germán Olivares-Pulido, Manuel Hernández-Pajares, Enric Monte-Moreno, Qi Liu, Heng Yang, Josep María Aroca-Farrerons, Victoria Graffigna

UPC-IonSAT; UPC-IonSAT; UPC-TALP; College of Geography and Environmental Science, Henan University; School of Electronic Information and Engineering, Yangtze Normal University; UPC-IonSAT; UPC-IonSAT

Abstract: During May 10th and 11th 2024, several high-energy Solar Flares (up to X6 class), and the following CMEs, triggered a NOAA-G5 geomagnetic storm that perturbed the ionosphere to limits not seen in over 20 years, during the Halloween Storm events in 2003. Since then, the number of GNSS ground receivers has vastly increased, thus offering a unique opportunity to study in great detail the impact of extreme geomagnetic storms on the ionosphere.
As GNSS technology and applications grow in complexity, so does our exposure to extreme solar events that may disrupt them. Therefore, in order to either prevent or mitigate the impact on GNSS technology, it is paramount to further understand the effect on the ionosphere.
In this work, we present an analysis and characterization of the state of the ionosphere. First, the real-time GNSS sensor SOLERAdrift provides information about the energy delivered by the geoeffective solar flares that preceded the geomagnetic storm. Then, during the storm, we analyze the state of the ionosphere with Global Ionospheric Maps (GIM) of Vertical Total Electron Content (VTEC), VTEC gradient GIMs, Rate Of TEC Index (ROTI) maps, the Ionospheric Storm Scale Index, IsUG, and the Global Electron Content (GEC).

Author(s): Pierrard Viviane, Winant Alexandre, Péters de Bonhome Maximilien, Krasniqi Faton

Royal Belgian Institute for Space Aeronomy; Royal Belgian Institute for Space Aeronomy; Royal Belgian Institute for Space Aeronomy; German National Metrology Institute

Abstract: The month of May 2024 was characterized by solar energetic particles events directed to the Earth, especially the big event causing a strong terrestrial geomagnetic storm during the night from 10 to 11 May 2024, with auroras observed everywhere in Europe. This was the strongest storm for the last 20 years with a Dst < -400 nT. In the present work, we show with observations of PROBA-V/EPT that this event was associated to the injection of energetic electrons in the outer belt, in the slot and the inner radiation belt, with important consequences for the South part of the South Atlantic Anomaly. Energetic protons detected by GOES and PROBA-V/EPT were also injected in the Earth’s magnetosphere at high latitudes. This event also influenced the ionization of the atmosphere and caused a decrease of ozone in the mesosphere. Using different observations including of neutron monitors at different latitudes and AtRIS simulations, we determine how this big event and others from 2024 disturbed the normal flux of the solar wind, the different regions of the magnetosphere, the ionosphere and the atmosphere.

Author(s): Richard Horne, Sarah Glauert, Pak Yin Lam, Matthew Lang, Alex Lozinski, Hugh Evans, Ingmar Sandberg, Dave Pitchford

British Antarctic Survey; British Antarctic Survey; British Antarctic Survey; British Antarctic Survey; UCLA; ESA; SPARC; CarringtonSpace

Abstract: The geomagnetic storm of 10-20 May 2024 is comparable to the Halloween storm of 2003 according to the Dst index, but the way in which events unfolded is quite different.  Here we review what happened to the electron and proton radiation belts.  We show results from the SaRIF system that operated reliably throughout the storm.  We show how the outer boundary of the Earth’s magnetic field (magnetopause) and last closed drift shell were “pushed” inside geostationary orbit.  This was confirmed by observations of a magnetic field reversal made by GOES 16 and 18 on the dayside of the Earth.  The BAS electron radiation belt model (BAS-RBM) predicted that the outer radiation belt would be depleted and re-formed much closer to the Earth filling the slot region.  This was confirmed later using observations from spacecraft in low earth orbit.  The model also showed that the flux increased in the slot region by about 4 orders of magnitude and that the charging current behind 0.5 mm of Al shielding exceeded NASA design guidelines for about 3 days.  We estimate that it would take between a few weeks to months for this high level of flux to decay.  Charging currents also reached high levels for Medium Earth Orbit where Galileo and GPS satellites orbit.  We also report results from the new BAS proton radiation belt model that shows that the proton flux between 5 – 30 MeV in the outer region (L > 2.0) decreased during the storm.  This was also confirmed by low altitude satellite data and is consistent with a reduction in single event upset rates reported by some spacecraft in MEO.  We attribute this decrease to a distortion of the magnetic field caused by the storm.  Data show that proton belt was enhanced at lower L but this was not reflected in the model.  We discuss the need to revise the models in the light of these results and to include new physics into the proton model.  Finally, we conclude that the changes in the electron and proton belts would increase radiation exposure to satellites undergoing electric orbit raising over the next few months.

Author(s): Vanessa Mercea, Lucia Kleint, Daniel Arnold, Adrian Jäggi

University of Bern; University of Bern; University of Bern; University of Bern

Abstract: In May 2024, a G5-class geomagnetic storm, the most intense since the Halloween solar storms of 2003, hit Earth. Over a dozen X-class flares were observed by GOES, and several Coronal Mass Ejections were launched towards Earth, as reported by the US National Oceanic and Atmospheric Administration. These events caused significant disturbances in the Earth’s upper atmosphere, impacting satellite orbits and causing auroras to be visible at mid-latitudes globally. The Space Objects Index of the United Nations Office for Outer Space Affairs lists nearly 12,000 satellites orbiting the Earth, while forecasts estimate over 10,000 additional launches by 2030. Our goal is to assess the critical impact of Space Weather on the decay of Earth-orbiting satellites at different altitudes.
We make use of semi-major axis data from a precise orbit determination method and publicly available two-line-element data, to which we apply a robust time series decomposition method iteratively to remove the most significant periodicity in the data and smooth the remaining component. We compute the orbital decay using this processed data, given the absence of accelerometer data, and analyze the correlation between orbital decay and solar wind parameters, solar activity proxies, and geomagnetic indices, accounting for the solar wind propagation time to the orbits.
For the first half of May, we observe a 15-hour delay between solar wind measurements and their effect on the orbits. We observe strong associations between orbital decay and several parameters. Consequently, we model orbital decay as a function of solar wind inputs and identify flow speed, electric field, proton densities, and magnetic field strength in the Z direction as the most impactful features. Despite challenges posed by satellite maneuvers and varying wind propagation times, we hypothesize that combining real-time orbital decay with these parameters could facilitate predicting its evolution.

Author(s): Sota Nanjo, Kazuo Shiokawa

The University of Electro-Communications / Swedish Institute of Space Physics (IRF); Nagoya University

Abstract: On May 10, 2024, an extreme G5-class geomagnetic storm displayed auroras that were visible globally in mid- to low-latitude regions. In Japan, auroras were observed not only from Hokkaido, the northernmost island, but also from the northern and central parts of Honshu, the main island. Thanks to the improved quality of personal digital cameras, numerous high-resolution images of these auroras were shared on social media. This study focuses on the blue aurora observed during a storm-time substorm on this day. (1) Several field-aligned structures that were captured by citizen scientists. (2) Using timelapse videos captured by two photographers at different locations, the location and longitudinal extent of this aurora were estimated at a magnetic latitude of 40 degrees and magnetic local time of 23 h, spanning about 1200 km longitudinally and ranging in altitude from 400 km to at least 900 km. (3) Simultaneous photometric measurements indicated that the blue luminosity was due to emissions at 427.8 nm. Although previous studies have identified 427.8 nm emissions in low-latitude auroras, this is the first time that spatial structures of low-latitude blue aurora have been visualized. This finding might challenge the existing hypothesis that blue emissions in low-latitude auroras are produced by energetic neutral atoms from the ring current. The existence of field-aligned and small-scale longitudinal structures may require alternative explanations for the generation of blue low-latitude auroras.

Author(s): Ilja Honkonen, Max van de Kamp

Finnish Meteorological Institute; Finnish Meteorological Institute

Abstract: We investigate real-time energetic particle observations by Geostationary Operational Environmental Satellite (GOES) during the Mother’s day geomagnetic storm of 2024. On 2023-05-11 an X class flare peaking at 1:15 UTC apparently resulted in a solar energetic particle event, with 10+ MeV proton flux eventually rising to slightly above 100 pfu at around 9 UTC. Interestingly, real-time 500+, 100+, 60+ and 50+ MeV fluxes at Earth started increasing simultaneously at approximately 1:45 UTC, although there is 5 to 10 min uncertainty in exact timings. Nevertheless, a significant discrepancy exists between first arrival of high energy protons and arrival time based on field-aligned travel time. For example, first 500+ MeV protons arrived up to 19 min later than would be suggested by their 11 min travel time, or even 29 min later if they were accelerated as soon as X-ray flux started increasing. Based on real-time data from GOES, advanced composition explorer and neutron monitor database, we propose that the simultaneous increase of 50+ to 500+ MeV proton fluxes on 2024-05-11 at approximately 1:45 UTC is due to one or more prior coronal mass ejections (CME) passing Earth just before. Once the CME(s) had passed Earth, magnetic connection to the flare region was restored and fluxes of high energy protons with an order of magnitude difference in energies started increasing simultaneously at GOES.

Author(s): Maria Gerontidou, Norma Crosby, Helen Mavromichalaki, Pavlos Paschalis, Maria Papailiou, Dimitra Lingri, Mark Dierckxsens

Nuclear and Particle Physics Department, Physics Faculty, National and Kapodistrian University of Athens, Greece; Royal Belgian Institute for Space Aeronomy, Brussels, Belgium; Nuclear and Particle Physics Department,Physics Faculty, National and Kapodistrian University of Athens, Greece; Nuclear and Particle Physics Department,Physics Faculty, National and Kapodistrian University of Athens, Greece; Nuclear and Particle Physics Department,Physics Faculty, National and Kapodistrian University of Athens, Greece; Nuclear and Particle Physics Department,Physics Faculty, National and Kapodistrian University of Athens, Greece; Royal Belgian Institute for Space Aeronomy, Brussels, Belgium

Abstract: On May 11, 2024, during a period of intense solar activity and highly disturbed geomagnetic conditions, a Ground Level Enhancement (GLE) was detected by several stations of the worldwide ground-based neutron monitor network. This event, classified as GLE74, occurred during the recovery phase of a deep Forbush decrease, resulting from multiple, at least seven, Coronal Mass Ejections (CMEs) that had been occurring since May 7. On May 11, a powerful solar flare of importance X5.8 reached its maximum at 01:32 UT. This was followed by an abrupt increase in proton flux with energies >100 MeV peaking at 02:45 UT as recorded by GOES satellites. This Solar Energetic Particle (SEP) event consisted of both impulsive and gradual components, where the high energy tail of the gradual component was recorded by several neutron monitors. Approximately fifteen minutes after the onset of the SEP event (E >100 MeV) and 40 min prior to its peak, an alert was issued at 02:05 UT by the GLE Alert++ system of the Athens Neutron Monitor Station (A.Ne.Mo.S.) available as a federated product on the ESA SWE Portal under the Space Radiation Expert Service Centre. The neutron monitor stations that triggered this alert were Oulu (OULU), South Pole (SOPO) and Lomnicky Stit (LMKS). The alert signal lasted for several minutes until 02:19 UT. One minute after the initial alert, a new polar station, South Pole B (SOPB), also entered into Alert mode.  Afterwards the GLE Alert++ system switched to Warning status until 02:52 UT because OULU and LMKS had returned to Quiet status, while polar stations SOPO and SOPB continued to be in Alert mode. Characteristics of this complex GLE74 event, as well as its detection by the GLE Alert++ system, are presented in this study. This work was performed in the frame of ESA Space Safety Programe’s network of space weather service development and pre-operational activities, and was supported under ESA Contract 4000134036/21/D/MRP.

Author(s): Paul Loto’aniu, Sarah Auriemma, Alessandra Pacini, Daehyeon Oh, Aspen Davis, Alison Jarvis, Fadil Inceoglu

University of Colorado-CIRES / NOAA-NCEI; University of Colorado-CIRES / NOAA-NCEI; University of Colorado-CIRES / NOAA-NCEI; Korea Meteorological Administration; University of Colorado-CIRES / NOAA-NCEI; University of Colorado-CIRES / NOAA-NCEI; University of Colorado-CIRES / NOAA-NCEI

Abstract: We present observations and model results from 10 May 2024 showing the response of Earth’s magnetopause to the arrival of coronal mass ejections (CMEs). On this day, the NOAA GOES-16 and GOES-18 satellites were well positioned to observe the compression of the magnetopause on the dayside, while the Korean Meteorological Administration (KMA) GEO-KOMPSAT-2A (GK-2A) satellite was located post local midnight and therefore able to observe the nightside responses. Around 17:30 UT GOES-16 observed the magnetopause compress below geostationary orbit, while the Shue et al. model results indicate the magnetopause compression reached about 3 Earth radii. This is likely the strongest compression that we have observed since the Halloween 2003 storms. The GK-2A observations show a near instantaneous response on the nightside followed by strong lower frequency variations probably due to multiple reconnection events, bursty bulk flows and tail flapping. Observations suggest a wide dayside reconnection X-line and propagation of this reconnection region along the low latitude dayside magnetopause. We also present the GOES-R magnetopause crossing operational product results and CCMC magnetospheric model runs of the event and compare the model results to observations.

Author(s): Shantanu Jain, Tatiana Podladchikova, Galina Chikunova, Karin Dissauer, Astrid M. Veronig, Amaia R. Lizarraga

Skolkovo Institute of Science and Technology, Moscow, Russia; Skolkovo Institute of Science and Technology, Moscow, Russia; Hvar Observatory, University of Zagreb, Croatia; Skolkovo Institute of Science and Technology, Moscow, Russia; Northwest Research Associates, Boulder, USA; University of Graz, Kanzelhöhe Observatory for Solar and Environmental Research, Kanzelhöhe 19, 9521 Treffen, Austria; University of Graz, Kanzelhöhe Observatory for Solar and Environmental Research, Kanzelhöhe 19, 9521 Treffen, Austria

Abstract: On May 8, 2024, solar active region 13664 produced an X-class flare, several M-class flares, and multiple Coronal Mass Ejections (CMEs) directed towards Earth. The initial CME resulted in coronal dimmings, characterized by localized reductions in extreme-ultraviolet (EUV) and soft X-ray emissions, indicative of mass loss and expansion during the eruption. This study utilizes the DIRECD method (Jain et al. 2024) to analyze the expansion of observed coronal dimming as a marker for early CME propagation. Our approach incorporates 3D simulations of CMEs employing a geometric cone model, investigating parameters such as width, height, source location, and deflection from the radial direction during the impulsive phase, where the CME remains connected to the dimming in the low corona. We derived CME parameters by matching CME projections on the solar sphere with the dimming geometry. By extrapolating the best-fit cone and CME outer edge heights to STEREO-A COR2 times, we found that the cone closely matches the CME shape, with fainter CME parts corresponding to far-side cone projections. These findings provide valuable insights into early CME propagation, essential for enhancing space weather forecasting and mitigating its impacts.

Author(s): Amaia Razquin, Astrid M. Veronig, Karin Dissauer, Tatiana Podladchikova, Shantanu Jain, Galina Chikunova, Julia. K. Thalmann, Mateja Dumbović

University of Graz, Institute of Physics, Universitätsplatz 5, 8010 Graz, Austria; University of Graz, Institute of Physics, Universitätsplatz 5, 8010 Graz, Austria; NorthWest Research Associates, 3380 Mitchell Lane, Boulder, CO 80301, USA; Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, bld. 1, 121205 Moscow, Russia; Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, bld. 1, 121205 Moscow, Russia; Hvar Observatory, Faculty of Geodesy, University of Zagreb, Kaciceva 26, 10000 Zagreb, Croatia; University of Graz, Institute of Physics, Universitätsplatz 5, 8010 Graz, Austria; Hvar Observatory, Faculty of Geodesy, University of Zagreb, Kaciceva 26, 10000 Zagreb, Croatia

Abstract: Coronal dimmings are regions of transiently reduced emissions observed in extreme ultraviolet (EUV) and soft X-ray (SXR) wavelengths interpreted as the decrease of coronal density and plasma evacuation due to the onset of coronal mass ejections (CMEs). As such, they are important diagnostics for CME activity (in particular for Earth-directed CMEs) and provide insights on the accompanying physical processes in the low corona. During the first half of May 2024, Active Region AR13664 was the source of 11 X class flares and was associated with a number of CMEs. The high number of CMEs launched in quick succession caused the largest geomagnetic storm since two decades. Accompanying these eruptive phenomena, coronal dimmings were also observed. We present a study of the main coronal dimmings as observed by the AIA instrument onboard the Solar Dynamics Observatory between the 3th and 14th of May 2024. We consider 5 X class flares with a dimming observed on disk and 3 X class flares observed off limb. In addition, we also include M class flares with significant dimmings on disk and off limb. We compare the dimming parameters (area, brightness, magnetic flux) with key characteristics of the observed CMEs, and study their global characteristics in order to investigate large-scale magnetic connections revealed by coronal dimmings.

Author(s): Evangelos Paouris, Angelos Vourlidas, Manolis Georgoulis, Elena Provornikova, Evangelia Samara, Nour Raouafi

Johns Hopkins University Applied Physics Laboratory; Johns Hopkins University Applied Physics Laboratory; Johns Hopkins University Applied Physics Laboratory; Johns Hopkins University Applied Physics Laboratory; NASA Goddard Space Flight Center; Johns Hopkins University Applied Physics Laboratory

Abstract: The first two weeks of May 2024 were characterized by the most significant space weather phenomena since the Halloween events more than 20 years ago. NOAA Active Region (AR) 13644 produced numerous M- and X-class solar flares and Earth-directed Coronal Mass Ejections (CMEs), triggering the most intense geomagnetic storm since October 2003. This AR, in terms of size, was comparable to the AR responsible for the Carrington event and was long-lived, reappearing during the next Carrington rotation with an even larger size.
In this work, we combine observations from multiple viewpoints (SOHO, STEREO, Solar Orbiter) and in situ data points (Wind, ACE, STEREO), simulations, and modeling of the propagation of CMEs in the inner heliosphere, as well as retrospective forecasts of the CMEs’ arrivals at Earth. We begin our analysis by examining the characteristics of the AR, utilizing Space-weather HMI Active Region Patches (SHARPs). Specifically, we calculate the effective connected magnetic field strength parameter, known as Beff, an index of magnetic complexity, which we found to achieve a record-high value of nearly 9000 Gauss. We then analyze the kinematic properties of the halo CMEs and, in combination with the flare magnitude, we estimate the probability of a Solar Energetic Particle (SEP) event through the application of a recently published machine learning model (see Paouris et al., 2023). The extraordinary strength of the persistent geomagnetic storm led us to simulate the propagation of CMEs using MHD modeling by means of the GAMERA model. Through these simulations, we attempt to explain the storm’s intensity based on the characteristics of the interaction and compression between the CMEs. Finally, we address the obvious question: “Why were the CMEs not as extraordinary as the parent AR?”, considering that one might expect CMEs with extreme characteristics in terms of speed and mass.

Author(s): Yihua Zheng, Mei-Ching Fok, Alexander Drozdov, Dmitri Kondroshov,, Vania Jordanova, Steven Morley, Janet Green, T. Paul O’Brien, Donglai Ma, Lutz Rastaetter, Mostafa El Alaoui, Yuri Y. Shprits

NASA Goddard Space Flight Center; NASA Goddard Space Flight Center; UCLA; UCLA; LANL; LANL; Space Hazards Applications; Aerospace Corporation; UCLA; NASA Goddard Space Flight Center; CUA/NASA Goddard Space Flight Center; GFZ German Research Centre for Geosciences, University of Potsdam, UCLA

Abstract: The super geomagnetic storm of 10-16 May 2024, driven mostly by a series of Coronal Mass Ejections (CMEs), has captivated both the scientific community and the public due to its intense auroral displays visible across almost the entire globe on 10-11 May. The primary sources of these CMEs were Active Region (AR) 13664, with additional contributions from a filament eruption near AR 13667. This event presents a significant opportunity for the Heliophysics Big Year Solar Max effort and for the entire heliophysics science and user communities. This presentation focuses on the inner magnetosphere response and behavior during the May storm from a system science perspective.
Several models at CCMC (Model Catalog | CCMC) will be used to analyze the ring current and radiation belt dynamics, including:
CIMI (Comprehensive Inner Magnetosphere-Ionosphere)
RAM-SCB (Ring current-Atmosphere interactions Model with Self-Consistent magnetic field)
VERB (Versatile Electron Radiation Belt) Code
SHELLS (Specifying High-altitude Electrons using Low-altitude LEO Satellites)
ORIENT (Outer RadIation belt Electron Neural net model)
IMPTAM (Inner Magnetosphere Particle Transport and Acceleration Model)
The analysis will focus on:
Model and Data Comparison: Assessing the performance of each model by using the previously identified essential space environment quantities (ESEQs)
Inter-Model Comparison: Identifying consistencies and discrepancies among the different but similar models.
Inner Magnetosphere Response: Investigating how the near-Earth region responds to the unique characteristics/nuances of the solar drivers (e.g., multiple CMEs, the role of filament eruption near AR 13667).

Author(s): Patrik Pinczes, Attila Hirn

HUN-REN Centre for Energy Research; HUN-REN Centre for Energy Research

Abstract: The Hungarian 3-unit technology demonstration CubeSat RADCUBE, conducted under the auspices of the European Space Agency CubeSat programme, was launched in August 2021 to a sun-synchronous low-Earth polar orbit. The satellite hosted the combined space radiation and magnetic field measuring instrument package (RadMag). The radiation monitor part comprises two silicon detector telescopes to measure the flux of energetic protons, electrons and heavier ions. Although the main mission lasted until April 2022, the instrument was also switched on in early May 2024 to observe the effects of the space weather event. The BUDA neutron monitor station in Budapest, Hungary was put into operation in August 2023.
In our talk we present the flight data measured with the radiation monitor part of the Radmag instrument package on RADCUBE  during the severe space weather events in early May 2024 and compare them with the RadMag measurements during the solar energetic particle event on the 28th of March 2022. Results of the on-ground measurements with the BUDA neutron monitor station are also presented and compared with other neutron monitor stations of similar geomagnetic cutoff and altitude above sea level.

Author(s): Lauren Orr, Juliane Hübert, Ciarán Beggan

British Geological Survey; British Geological Survey; British Geological Survey

Abstract: Extreme geomagnetic activity can cause problems to grounded technological systems, via the induced geoelectric fields, potentially with massive economic cost. To plan for and mitigate against this hazard we need to quantify the occurrence probability and magnitude of severe space weather events. The May 2024 storm was the largest event in the past 20 years, but it is important to understand how this compares to other extreme storms and how likely it is to experience a storm of similar magnitude. Extreme value statistics is a method by which we can estimate how large a 1-in-100-year event could be. In the UK there are >40 years of digitised magnetometer measurements with 1 minute cadence available which have previously been used to estimate extreme events but only at the three geomagnetic observatory locations. Recently collected long-period magnetotelluric (MT) data allows us to extend this coverage. Measuring the local geomagnetic and geoelectric field variations at >50 sites across the UK, we derived the MT impedance tensor which is then used alongside interpolated magnetic field measurements to estimate the geoelectric field at each of the locations since 1983. With this new dataset we have UK wide coverage of geoelectric field for our extreme value statistics. We find the highest magnitude 1-in-100-year geoelectric field values to occur along the central longitude of England between 54-56 degrees latitude. The analysis also allows us to put the May 2024 storm into context. We find sites in the south of England have an estimated geoelectric field with a return period of 10-20 years whereas higher latitude sites would see similar magnitudes every 2-5 years.

Author(s): Hervé Lamy

BIRA-IASB

Abstract: On Friday night 10 May and Saturday 11 May, a historic geomagnetic storm impacted the Earth and caused a very rare occurrence of strong and dynamic aurora visible to latitudes as low as the South of France. This geomagnetic storm reached G5 extreme conditions. The aurora display was largely observed by many people and optical cameras in Belgium.
BRAMS (Belgian RAdio Meteor Stations) is a Belgian radio network aimed at detecting and characterizing meteors using forward scatter techniques. It is made of a dedicated transmitter which sends a circularly polarized CW wave at 49.97 MHz with a power of ~ 350 Watts, and about 50 receiving stations spread in Belgium and neighboring countries.
At the time of the aurora, all these receiving stations were strongly affected by a large increase of “noise”, preventing the detection of most meteor echoes. The spectral distribution of this “noise” has a width lower than 1 KHz and several distinct peaks evolving rapidly, which might be compatible with the characteristics of an auroral emission.
We will present these observations at different stations with largest separations in latitude and longitude.  We will also provide an estimate of the total power associated with these events. All these results will be discussed in the context of a possible auroral emission near 50 MHz, which to our knowledge has never been detected before.

Author(s): Jens Berdermann, Martin Kriegel, Erik Schmölter, Volker Wilken, Claudia Borries, Mainul Hoque

German Aerospace Center; German Aerospace Center; German Aerospace Center; German Aerospace Center; German Aerospace Center; German Aerospace Center

Abstract: Severe Space weather can influence or even damage important systems and services such as GNSS or HF communication as well as ground and space-based infrastructures such as power grids or satellites. The highly interdisciplinary topic of space weather is therefore not only scientifically challenging, but is also becoming increasingly important for industry and service providers. Since we are reaching the peak of activity within the 25th solar cycle, Space Weather events occur more frequent and with increased intensity. In our presentation we discuss Space Weather effects on satellite navigation and communication services based on moderate and severe events of the recent solar cycle. We present real time and post-processed observations from the Ionosphere Monitoring and Prediction Center (IMPC) of DLR and related scientific analyses. We further focus on the “Motherday” event of 10-14 May 2024 and provide insight into its impact on operational services. Finally, we provide an outlook on interactive web-applications and performance indicators, that could help users assess the impact of severe space events on their operational system.

Author(s): Krauss Sandro, Temmer Manuela, Drescher Lukas, Strasser Andreas, Barbara Süsser-Rechberger

Graz University of Technology, Institute of Geodesy; Universität Graz, Institut of Physics; Graz University of Technology, Institute of Theoretical and Computational Physics; Graz University of Technology, Institute of Geodesy; Graz University of Technology, Institute of Geodesy

Abstract: With the strong rise of the current solar cycle 25, the number of solar eruptions, such as solar flares and coronal mass ejections (CMEs), is also increasing. These solar events can trigger geomagnetic storms. On 10 May 2024, one of the most severe storms in decades occurred. The storm was triggered by six CMEs hurled towards Earth by the giant sunspot AR3664. We show the successful prediction of the forecasting tool SODA (Satellite Orbit DecAy), which has been part of ESA’s Space Safety Programme (Ionospheric Weather I.161) since July 2023 (portal release 3.7.0). SODA is based on an interdisciplinary analysis of geodetic observations and in-situ solar wind measurements and was developed in cooperation between the University of Graz and the Graz University of Technology. It allows the prediction of the impact of CME events on the altitude of low Earth orbiting satellites with a lead time of 20 hours. For the geomagnetic storm in May 2024, SODA predicted an orbit decay for LEO satellites at 490 km of the order of 30 m, corresponding to a strong G4 near G5 storm. In addition to the prediction, we present a validation based on accelerometer measurements of the GRACE-FO-C satellite and kinematic orbits for the SWARM satellite mission. Finally, first results of the upcoming SODA Release 2.0 will be presented. This includes additional altitude layers (400 km, 450 km) produced using data from the CHAMP mission, as well as updated display options for the user and an extended CME event list.

Author(s): Nhlanzeko Lindingcebo Mbhele

South African National Space Agency

Abstract: Geomagnetic storms cause large-scale disturbances in the Earth’s magnetic field which are measured using geomagnetic activity indices. Since the local K-index varies through regions due to local variation in the magnetic field, it will be used to study the response of the South African National Space Agency (SANSA) magnetic observatories to the Mother’s Day storm event which occurred on 10 – 11 May 2024 in Southern Africa. This storm was notable for producing visible auroras over Southern Africa, a phenomenon unseen since 1989. A large coronal mass ejection (CME) associated with an X1.0 solar flare that occurred at 08/21:40 UT that originated from a sunspot region AR3664 resulted in a G4/Severe to G5/Extreme geomagnetic storms with planetary K (Kp) index of 9 and a minimum disturbance storm time (Dst) index of -412 nT. Four stations will be used for this study, namely Hermanus (HER), Hartebeesthoek (HBK), Tsumeb (TSU), and Keetmanshoop (KMH) which are located in the mid-latitude region.

Author(s): Sylvie Benck, Stanislav Borisov

UCLouvain; UCLouvain

Abstract: The satellite PROBA-V with the Energetic Particle Telescope (EPT) onboard, was launched on 7 May 2013 onto a polar Low Earth Orbit of 820 km altitude. Since then, EPT has provided quasi continuously flux spectra data for electrons (0.5–8 MeV), protons (9.5–248 MeV) and α-particles (38–980 MeV) with a time resolution of 2 seconds. Hence, the EPT data set covers presently a full solar cycle period of ~11 years, starting around maximum of solar cycle 24. Now that we are approaching the maximum of solar cycle 25, it obviously can be observed that the solar activity is getting higher. The trend indicates that not only the frequency of events increases but also their intensity, and the effect of those space weather events on the LEO environment are clearly monitored by EPT. Within this presentation we will show how the light charged particle population at LEO evolved during the last solar cycle period and to what extend an event like the one in May 2024 can inject particles into the inner magnetosphere and disturb the radiation belts structure for many months.

Author(s): Trisani Biswas, Ashik Paul

Institute of radio Physics and Electronics, University of Calcutta; Institute of Radio Physics and Electronics, University of Calcutta

Abstract: With the Sun approaching towards the maxima of current solar cycle 25, recent space weather events have also gained justified attention due to occurrence of major phenomena. In second week of May 2024, the Earth was hit by one of the strongest solar storms of entire Space Age, which led to a geomagnetic super-storm of massive magnitude and impacts. During May 08-12, multiple M-class and X-class flares, along with several coronal mass ejections (CMEs) were observed to be emitted from a detected solar active region (Region 3664). As a result, the most intense geomagnetic storm of several decades was unleashed on Earth. Adhering to the classifications of NOAA scales [NOAA Space Weather Scales | NOAA / NWS Space Weather Prediction Center], it was an extreme (G5 class) storm, where the Kp index reached 9- and 9 respectively on May 10 and May 11 [https://kp.gfz-potsdam.de]. A geomagnetic storm of this magnitude is certain to impart impacts which are detectable from space-based and ground-based state-of-the-art radio instruments [Ray et al., Journal of Geophysical Research: Space Physics, 2017; Zhang et al., Journal of Geophysical Research: Space Physics, 2019; Spogli et al., Journal of Geophysical Research: Space Physics, 2021]. Additionally, being intricately connected with the global Magnetosphere-Ionosphere, an event like this necessitates diverse analysis and investigation from across latitudes.
In this study, efforts are made to portray the response of the low-latitude/equatorial ionosphere to the extreme geomagnetic storm, using space-based as well as ground-based observations. Ground-based observation includes characterization of the Total Electron Content (TEC) from 6 IGS stations (IISc, IITK, JDPR, SGOC, SHLG, LCK4) distributed within the geographical range of 5°-27° N and 70°- 92° E over the Indian longitudes, along with station Calcutta (22.58° N, 88.38° E geographic; magnetic dip 34.54°), located near the northern crest of the Equatorial Ionization Anomaly (EIA). Additionally, space-based probing of the mentioned area, has been conducting using SWARM satellite passes. Data has been analyzed for the period of May 09-15, 2024. During the event, the Dst index reached -135 nT at 19 UT of May 10, after which it gradually decreased to reach the peak minima of -412 nT at 02 UT of May 11. The TEC maps and contours generated from the ground-based measurements, reveal a gradual equatorward (southward) shift of the peak of ionization during the event. The result was cross-verified with data from SWARM B, which also reveals the F2 layer peak plasma density to gradually shift towards lower latitudes during May 11-12. The impact of the storm on GNSS was studied from Calcutta by analyzing the receiver position error during May 09-15, 2024. Results show maximum position error registered on May 11 with a 15 m deviation in latitude, followed by on May 10, with a 10 m deviation in latitude, while for the rest of days, the deviation value was less than 6 m. Adding to these initial results, a complete analysis of the event brings out intricate details which are crucial for understanding the phenomena from a global perspective.

Author(s): Laura Rodríguez García, Marco Pinto, Francisca Santos, P. Goncalves, Hajdas Wojtek, Olivier Witasse, Christina Cohen, Erika Palmerio, Nina Dresing, Raúl Gómez Herrero, Laura Balmaceda, Jan Giesler, Beatriz Sánchez Cano

ESA; ESA; Univ. Lisboa; LIP; PSI; ESA; Caltech; Predictive Science; University of Turku; Universidad de Alcalá; George Mason University; University of Turku; Leicester

Abstract: During 2024 May the Sun gave rise to a series of flares and coronal mass ejections (CMEs) that attracted the attention of the scientific community. On 2024 May 11, an X5.8 class flare erupted from active region AR13664 located on the south-west hemisphere of the Sun as seen from the Earth (W44S17). A CME was related to the event, reaching a speed of ~1300 km/s. JUICE, STEREO-A, and near-Earth spacecraft were well magnetically connected to the AR and observed a solar energetic particle (SEP) event, with ion flux increases up to 100 MeV. JUICE and STEREO-A, located 12 degrees west of the Earth, were only separated by 1 degree in longitude and 0.1 au in radial distance to the Sun. We present in this study the particle observations of these fleet of spacecraft, focusing on JUICE and STEREO-A observations.
JUICE was launched in April 2023, and it is now in its cruise phase to Jupiter, where it will arrive in July 2031. JUICE carries a RADiation hard Electron Monitor (RADEM) to measure protons, electrons, and ions detecting particles coming from the anti-Sun direction. In this SEP event, the proton detector measured particles above 50 MeV, being the largest intensity registered at these energies by the instrument so far.  Taking advantage of the small distance between JUICE and STEREO-A, we reconstructed the RADEM flight count rate using STEREO-A HET spectral data. This work is the first in-depth analysis of RADEM SEP observations representing a key milestone in the instrument characterization. Additionally, ongoing comparisons with STEREO-A for other events aim to further validate and refine these comparisons, ensuring a robust and comprehensive understanding of the detector’s performance. As an additional result, this study will enable the inter-calibration of RADEM with other particle instruments on board different spacecraft.

Author(s): Daniel Matthiä

German Aerospace Center (DLR), Institute of Aerospace Medicine

Abstract: A number of space weather events occurred during a very active phase of the Sun in May 2024 including several strong M and X class X-ray flares. Following these X-ray flares and the associated coronal mass ejections, elevated levels of highly energetic protons were measured in Earth Orbit, that have the potential to increase the dose rate at aviation altitudes. One of the events, however, also caused a temporary reduction in the intensity of galactic cosmic radiation measured by ground-based neutron monitors during a Forbush decrease. During this period of temporary decreased intensity of cosmic radiation, another event in turn lead to a small increase in neutron monitor count rates, a ground level enhancement, the first of its kind since October 2021.
The complex evolution of the different components of these space weather events was analysed with the PANDOCA model, developed at the German Aerospace Center for the assessment of radiation exposure in aviation. The expected impact on the radiation field and the related variations in the effective dose at aviation altitudes were calculated and compared to quiet space weather conditions. The calculations were based on measurements of the integral proton flux by the Geostationary Operational Environmental Satellites (GOES) and count rates of ground-based neutron monitors during the critical phases of the events.

Author(s): Joshua Dreyer, Nicolas Bergeot, Jean-Marie Chevalier

Royal Observatory of Belgium; Royal Observatory of Belgium; Royal Observatory of Belgium

Abstract: We describe the recent efforts to expand the near real-time VTEC maps produced by the ROB-IONO software (Bergeot et al., 2014) from multi-constellation GNSS data to a global scale. For this purpose, we use median polish kriging to interpolate a small percentage of VTEC data and compare the derived global map products to those of other services and the entire global VTEC dataset for validation.
We then utilise the generated maps to study the recent geomagnetic storm which commenced on 10 May 2024, with a focus on identifying storm-time signatures in the VTEC maps by comparing to the median maps from the preceding solar rotation period. Additionally, we investigate trends in the ionospheric and plasmaspheric contributions to the total VTEC before and during the storm.

Author(s): Bernd Heber, Henrik Dröge, Malte Hörlöck, Stefan Jensen, Alexander Kollhoff, Patrick Kühl, Holger Sierks

Christian-Albrechts-Universität Kiel; Christian-Albrechts-Universität Kiel; Christian-Albrechts-Universität Kiel; Christian-Albrechts-Universität Kiel; Christian-Albrechts-Universität Kiel; Christian-Albrechts-Universität Kiel; MPS

Abstract: The SOlar and Heliospheric Observatory (SOHO) was launched November 1995 with the Electron Proton Helium INstrument (EPHIN) measuring electrons from 150 keV to several MeV and protons and helium in the energy range from 4 MeV/amu to above 50~MeV/amu. However, applying the dE/dx-dE/dx-method we extended the energy range to above 600~MeV. From 2017 onwards the instrument was reprogrammed to provide better statistic for measurements of protons above 50 MeV, allowing a more detailed investigation of the energy spectra and its temporal evolution. Using the bow-tie method we were able to derive several energy channels between 50 MeV and about 1~GeV.
The solar activity in May 2024 to June 2024 led to 5 SEP events that accelerated protons above 100 MeV that were also observed at STEREO A and partially at Solar Orbiter.
In this contribution we present the observations and compare them with measurements from other missions.
The SOHO/EPHIN project is supported under Grant 50 OC 2102 by the German Bundesministerium für Wirtschaft through the Deutsches Zentrum für Luft- und Raumfahrt (DLR). This study has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 101004159 (SERPENTINE) and No. 101135044 (SPEARHEAD)

Author(s): Abdalla Shaker, Hassan Noor-Eldeen, Amira Hussein

Egyptian Space Agency (EgSA); Egyptian Space Agency (EgSA); Egyptian Space Agency (EgSA)

Abstract: On 8 May 2024, the solar active region AR13664 began producing a series of solar X flares and releasing multiple Interplanetary Coronal Mass Ejections (ICMEs) that proved to be geoeffective. The resulting geomagnetic storm had its Storm Sudden Commencement (SSC) on 10 May 2024 and is, to date, the strongest since the November 2003 geomagnetic storm. The May 2024 storm, named the Mother’s Day storm, peaked at a Dst of -412 nT and stands out as a “standard candle” for storms affecting modern-era technologies prone to Space Weather threats. Moreover, the recovery phase showed almost no signatures of substorms, making the Mother’s Day storm a perfect example of a severe geomagnetic storm.
Despite numerous interesting modifications to the near-Earth environment that are still under investigation, this abstract focuses on the Space Weather effects over the North-East Africa sector, particularly Egypt. Utilizing data from 45 GNSS stations across Egypt, operated by the Egyptian Space Weather Center at the Egyptian Space Agency, we present the Egyptian Ionospheric Map Model (EGIMM). This model provides a comprehensive analysis of the ionospheric changes before, during, and after the May 2024 geomagnetic storm and assesses its impact on various services over the North-East African region.
Our analysis focuses on several critical parameters: Total Electron Content (TEC), scintillation indices (S4), Rate of TEC change Index (ROTI), and vertical ionospheric delay. The data reveal significant parameter alterations, with marked deviations observed during the storm period. The most notable effect observed in the ionosphere over North-East Africa is a significant decrease in plasma density on 11 May following the arrival of the disturbance, resulting in a pronounced negative ionospheric storm visible in TEC. Another negative effect was recorded on 13 May, while no signatures of positive storm phases were reported.
Relevant outcomes of the work include findings related to ROTI, which showed high and unusually spatially distributed values on the nights of 10 and 11 May. ROTI enhancements on 11 May might be triggered by joint action of low-latitude plasma pushed by the pre-reversal enhancement in the post-sunset hours and wave-like perturbations propagating from the north.
Our findings underscore the necessity for continuous monitoring and advanced modeling to understand space weather effects and develop robust mitigation strategies. By improving our predictive capabilities and preparedness, we can better protect critical infrastructure and services in North-East Africa from future space weather events.

Author(s): Francois-Xavier Bocquet, David Jackson, Ian McCrea, Si Machin, Richard Horne, Huw Morgan, Ciaran Beggan, Sean Elvidge, Keith Ryden

Met Office; Met Office; STFC UKRI; Met Office; BAS; Aberystwyth university; BGS; University of Birmingham; University of Surrey

Abstract: On May 10th 2024, the arrival of a series of CMEs led to the largest geomagnetic storm of solar cycle 25, resulting in auroras observed worldwide up to very low latitudes, as well as to a range of reported impacts on engineered systems. This presentation focuses on the forecasting of this event at the Met Office Space Weather Operations Centre and outlines the enhanced forecasting capability from the pre-operational models delivered to the Met Office as part of the SWIMMR research-to-operations program, covering the heliosphere, the magnetosphere and the radiation belts, the aviation radiation environment, and the evolution of the geo-electric field at ground level. These physical models are also associated to impact models tailored to a range of sectors such as satellite operations, aviation, and power grid operations. A preliminary assessment of the performance these models will be provided and linked to reported impact of the event on technological systems.
Once fully operational, these models will enhance the forecasters’ ability to forecast these extreme events and to provide advance warning of anticipated impacts to end-users in a variety of sectors, allowing them to enact mitigation strategies.

Author(s): Alexis Rouillard, Athanasios Papaioannou, Rami Vainio, Mateja Dumbovic, Manon Jarry, Victor Réville, Alexander mishev, P. Kühl, Athanasios Kouloumvakos, B. Heber, A. Warmuth, Ilya Usoskin, Jan Gieseler, A. Anastasiadis, G. Vasalos, Illya Plotnikov

IRAP, Université Toulouse III – Paul Sabatier, CNRS, CNES, Toulouse, France; Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing (IAASARS), National Observatory of Athens, Penteli, Greece; Department of Physics and Astronomy, University of Turku, FI-20014 Turku, Finland; University of Zagreb, Faculty of Geodesy, Hvar Observatory, Zagreb, Croatia; IRAP, Université Toulouse III – Paul Sabatier, CNRS, CNES, Toulouse, France; IRAP, Université Toulouse III – Paul Sabatier, CNRS, CNES, Toulouse, France; Space Physics and Astronomy Research Unit and Sodankylä Geophysical Observatory, University of Oulu, Oulu, Finland; Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24118 Kiel, Germany; The Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA; Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24118 Kiel, Germany; Leibniz Institute for Astrophysics Potsdam (AIP), 14482 Potsdam, Germany; Space Physics and Astronomy Research Unit and Sodankylä Geophysical Observatory, University of Oulu, Oulu, Finland; Department of Physics and Astronomy, University of Turku, FI-20014 Turku, Finland; Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing (IAASARS), National Observatory of Athens, Penteli, Greece; Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing (IAASARS), National Observatory of Athens, Penteli, Greece; IRAP, Université Toulouse III – Paul Sabatier, CNRS, CNES, Toulouse, France

Abstract: A strong shock and complex solar ejecta hit the Earth’s magnetosphere on 10th May 2024 leading to the strongest geomagnetic storm since the 2003 Halloween superstorm. Upon the arrival of the Coronal Mass Ejections (CMEs) at Earth, ground-based neutron monitors around the globe recorded a strong Forbush decrease in response to the shielding effects of these CMEs on the galactic cosmic ray fluxes. As the cosmic ray fluxes reached a minimum on May 11 at 01:00UT, a Ground-Level Enhancement (GLE) was suddenly detected together with a powerful Solar Energetic Particle (SEP) event measured at the Lagrange L1 point and the Solar-Terrestrial Relations Observatory Ahead (STEREO-A). This GLE has the official number 74 and the ground-based neutron monitor data are collected at the International GLE Database (https://gle.oulu.fi). It was triggered by an X5.8 flare and a fast CME (>1500 km/s) originating in the complex active region NOAA13668 (S15W55). We first present an observational analysis of this complex sequence of events including the state of the interplanetary medium during this powerful radiation storm and the properties of the measured GLE. We give a timing analysis of the in-situ particle recordings at L1. We then show modeling results of the coronal and interplanetary medium leading to this GLE including energetic particle transport.
This work was carried out as part of the on-going EU SPEARHEAD project under grant agreement No 101135044.

Author(s): Chigo Ngwira

NASA GSFC

Abstract: Space weather causes geomagnetic disturbances that can affect critical infrastructure. Understanding the dynamic response of the coupled solar wind-magnetosphere-ionosphere system to severe space weather is essential for mitigation purposes. This paper reports on a detailed analysis of the most recently observed May 10, 2024, storm. Preliminary results in the American sector show that the most extreme mid-latitude response was associated to substorm related activity. We further discuss how this storm response compares with other historical storms.

Author(s): Irina Zakharenkova, Iurii Cherniak, John Braun, Qian Wu, Jan-Peter Weiss, Douglas Hunt, Teresa Vanhove

COSMIC Program Office, UCAR; COSMIC Program Office, UCAR; COSMIC Program Office, UCAR; HAO, UCAR; COSMIC Program Office, UCAR; COSMIC Program Office, UCAR; COSMIC Program Office, UCAR

Abstract: As we approach the maximum of the 25th solar cycle, multiple intense geomagnetic storms occurred during the years 2023-2024. Following an X-class solar flare and geoeffective CME, the most powerful space weather event of the current cycle took place on May 10, 2024, causing a Dst excursion down to -410 nT. The May 2024 G5 severe geomagnetic storm resulted in auroras extended from high to middle latitudes in both hemispheres, but significant ionospheric disturbances occurred in low latitudes as well.
Launched in 2019, COSMIC-2 is the largest equatorial multi-satellite constellation of six full-size satellites to study the equatorial ionosphere. The scientific payload of the mission includes the advanced GNSS receiver supporting multiple observation types including multi-GNSS TEC, radio occultation electron density profiles, amplitude (S4) and phase (sigma phi) scintillation indices, as well as an Ion Velocity Meter (IVM) instrument to measure the in-situ ion densities along the satellite orbits of ~550 km altitude.
For the cases of March and April 2023 geomagnetic storms, we utilized multi-instrumental COSMIC-2 observations in combination with ground-based GNSS measurements to investigate the development of the equatorial ionospheric irregularities induced by prompt penetration of electric fields of magnetospheric origin, which were progressively developed over a great longitudinal range and expanded from equatorial to middle latitudes.
For the May 2024 superstorm, combination of low-Earth-orbit satellites and ground-based ionospheric measurements allowed us to reveal dramatic changes in the global distribution of ionospheric plasma, development of broad plasma density depletions near the F2 layer peak and the presence of strong plasma density gradients surrounding these depletions. Furthermore, evidence of strong vertical redistribution and enhancements in plasma density were observed in the upper ionosphere and plasmasphere.
We discuss potential space weather drivers and physical processes responsible for dramatic storm-time ionospheric effects developed in low and middle latitude regions, as observed with multi-satellite and ground-based observations.

Author(s): Yana Maneva, Judith de Patoul, Jennifer O’Hara and the SIDC SWOP team

Solar Terrestrial Centre of Excellence/Royal Observatory of Belgium; Solar Terrestrial Centre of Excellence/Royal Observatory of Belgium; Solar Terrestrial Centre of Excellence/Royal Observatory of Belgium

Abstract: The Solar Influences Data analysis Centre (SIDC) based at the Royal Observatory of Belgium has a long term experience in space weather service provision, combining various modelling with solar observations. The Space Weather OPerations (SWOP) team within the SIDC has more than 20 years of experience in space weather forecasting and product developments, and since 2019 is heavily involved in 24/7 operational space weather service provision to aviation within the framework of PECASUS consortium. Combining our daily space weather forecasting and operational service provision efforts with model expertise provided in-house or by partnering institutions we propose to present our perspective on the recent severe space weather event, leading to multiple periods of extreme geomagnetic conditions with diverse impacts. We will follow the event from the solar surface origin to the impacts on Earth, combining solar observations with prediction models and including modelled and observed impacts regarding problems with high-frequency radio communications, navigation and radiation environment. We will briefly mention other impacts, such as observed auroras over Belgium, as well as some reported power outages over US.

Author(s): D. Lario, F. Carcaboso, M. R. Kane, A. Chulaki, J. G. Mitchell, D. Berghmans, L. Y. Khoo, C. M. S. Cohen, J. Verniero, C. O. Lee, I. G. Richardson, C. O. G. Waterfall, V. Krupar, S. Krucker, H. Collier, A. Hutchinson, T. S. Horbury, E. R. Christian

NASA/GSFC; NASA Postdoctoral Program Fellow NASA/GSFC; CUA/NASA-GSFC; CUA/NASA-GSFC; NASA/GSFC; Royal Observatory of Belguim (ROB); Princeton University; CalTech; NASA/GSFC; University of California at Berkeley; Universitu of Maruland/NASA-GSFC; UCAR/NASA-GSFC; UMBC/NASA-GSFC; FHNW; FHNW; UMBC/NASA-GSFC; Imperial College; NASA/GSFC

Abstract: The intense level of solar activity recorded from 2024 May 8 to 2024 Jun 17 led to unusually elevated energetic particle intensities observed in the inner heliosphere. The fleet of spacecraft distributed in the inner (<~1 AU) heliosphere offers us the opportunity to track the effects of the active region AR 13664 (later numbered AR 13697) over a wide range of heliolongitudes. We combine remote-sensing observations from Solar Orbiter, STEREO-A, and near-Earth spacecraft (GOES, SOHO, SDO) to track the location and activity of AR 13664 for two solar rotations. Solar Orbiter was moving from a heliocentric radial distance of 0.67 au to 0.93 au and separated from Earth by 166-170 degrees in longitude, whereas STEREO-A was at 0.95 from the Sun and 12-16 degrees west of Earth. This distribution of spacecraft allows us to monitor the far side of the Sun and determine the origin of the solar energetic particle (SEP) events observed by near Earth spacecraft (GOES, SOHO, ACE), Solar Orbiter, and Parker Solar Probe (moving from 0.73 au to 0.46 au and at about 90 degrees west from Earth) during this intense period of solar activity. Energetic particle data at these three locations display multiple particle intensity enhancements associated with individual SEP injections and with the arrival of shocks driven by coronal mass ejections (CMEs). The result was a long-time interval (>40 days) with elevated (>10 MeV) proton intensities observed at these well separated heliolongitudes. The most intense >10 MeV proton intensity enhancement measured by Solar Orbiter and Parker Solar Probe during this period was associated with a backside (as seen from Earth) fast halo CME (with an estimated speed of ~2000 km/s) that occurred on May 20 together with an intense X-ray flare (with an estimated X12 GOES class flare). This SEP event resulted in a long-lasting period of elevated period of SEP intensities at the three locations with the peculiarity of a hard energy spectrum observed by near-Earth spacecraft.

Author(s): B. Tezenas du Montcel, A. Trouche, A. M. Castillo-Tibocha, S. Bianco, D. Wang, J. Forest, Y. Y. Shprits

Artenum, Toulouse, France; Artenum, Toulouse, France; GFZ, Postdam, Germany; GFZ, Postdam, Germany; GFZ, Postdam, Germany; Artenum, Paris, France; GFZ, Postdam, Germany

Abstract: Modern space-weather frameworks are able to provide fine maps of different particles parameters in the near-Earth environment today. European PAGER project (Prediction of Adverse effects of Geomagnetic storms and Energetic Radiation), provides indexes allowing a first concrete estimation of the charging risk for in-flight space systems (i.e. platforms and payloads). It is made possible thanks to the innovating plugging of internal charging models taking into account the spacecraft geometry downstream to the environment models.
For this, Artenum has developed a complete modelling chain able to simulate, in a reasonable time, both surface and internal charging processes on any kind of simplified but realistic space devices. This service has been plugged downstream the VERB (3D & 4D) environment model developed by GFZ and is freely available on the PAGER Web site since mid 2023. To build this framework Artenum was able to rely on its SpaceSuite software suite which includes some of the most advanced software in modeling satellite loading effects, such as SPIS-SC and SPIS-IC on for 3D analyses on realistic geometry, and SCOne and ICOne for simplified 1D approaches.
The PAGER framework’s recent success in forecasting solar storms which are occurring with the maximum of this solar cycle approaches, including events such as the May 10-11, 2024 solar storm. underscores its efficiency in simulating and assessing the charging states of studied platforms. An analysis of the charging risks forecast during these intense solar events and a comparison with quieter periods has been carried out. Outcomes further validate the framework’s operational capabilities and its potential role in future scenarios involving extreme space weather events.

Author(s): Paolo Romano, Abouazza Elmhamdi, Alessandro Marassi, Lidia Contarino

INAF – Osservatorio Astrofisico di Catania; KSU – Department of Physics and Astronomy; INAF – Osservatorio Astronomico di Trieste,; INAF – Osservatorio Astrofisico di Catania

Abstract: Active Region (AR) 13664, observed in May 2024, exhibited characteristics similar to those of the AR responsible for the historic Carrington Event of 1859. This AR produced multiple X-class solar flares, triggering a severe G5-class geomagnetic storm. Our study investigates the magnetic field emergence and horizontal motions within AR 13664 using high-resolution HMI/SDO data. We identify a sequence of emerging bipoles at the same latitude and longitude, followed by converging and shear motions, as critical factors in the rapid intensification and complexity of the magnetic field. These findings offer new insights into the formation of compact active regions and their potential to cause extreme space weather events.

Author(s): Yamauchi M, Nanjo S, Brandström U, and Wintoft P.

Swedish Institute of Space Physics (IRF), Kiruna

Abstract: (1) Kiruna B recorded local BX = + 1300 nT at around 12 UT (14 MLT), which corresponds to local K index of 9. Unlike the sudden commencement spikes (total duration of few minutes), total duration was about 1 hour. The positive dBx in the afternoon sector in the northern hemisphere means a sunward return convection, which is opposite from the cusp convection.
(2) According to AE_QL and SuperMAG polar plots, this dBx>0 deviation is seen only at Scandinavia (14 MLT, 60-70 Mlat), and is immediately followed by a strong negative excursion in the Pacific sector. It is difficult to examine if the large dBX>0 extends to the evening sector because no data is available in the evening sector for both arctic (Russian arctic stations) and antarctic (corresponds to the Pacific Ocean). On the other hand, stations at < 55° Mlat in the arctic evening sector (including Russian INTERMAGNET stations) shows consistent 200-300 nT for 14-24 MLT. If the big dBx>0 bay extends to the midnight (for which we cannot confirm with currently available data), it would be consistent with the growth phase signature for the next substorm onset that followed immediately after this big dBx>0 bay.
(3) We examined all Kiruna data since 1962 (past 60 years), and only two occasions were similar (dBx > + 1000 nT near noon (9-13 UT).
1967-05-25 (cf. Kp = 8+), dX around +950 nT with simultaneous dZ ≈ -900
2001-11-24 (cf. Kp = 8-), dX around +1400 nT
2024-05-11 (cf. Kp = 9), dX around +1300 nT
All cases have a lifetime of 30-60 min, with the peak at around 12 UT (14 MLT). The AE profiles show big AU followed by big AL for both this event and 2001-11-14 event.  AE is not available for the 1967-05-25 events.
(4) For more completeness, we examined AU data since 1978 when the AU minute values are available. While many cases registered > +1200 nT, only three days registered AU > 1200 nT between 9-14 UT (midday in European sector):
2001-11-24 (about 1300 nT at 11-12 UT)
2000-06-08 (about 1200 nT at 10-11 UT)
1994-02-21 (about 1500 nT at 09-10 UT)
AU station in the European sector might register lower deviation than the other sector. The similar asymmetry is seen for Kp=9 (9 and 9-) occurrence since 1932: it is much rare at 09-15 UT than the other UT.
(5) For the region where unusual low-altitude aurora was reported (Japan, Arizona), the magnetic dBx < 0 is gradually increasing toward lower latitudes.  Such “gradually” diverging dB in the northern hemisphere means conversing Jp, and hence wide-spread upward field-aligned current.  This is consistent with precipitation of massive low energy electron, which produces diffuse aurora.
Acknowledgment: We used provisional AE, SuperMAG, INTERMAGNET data which were produced unusually quick after this event. For statistics, we also used Kp in addition to AE and SuperMAG. We thank all the effort and all contributing observatories for SuperMAG and INTERMAGNET station (AE and Kp stations are INTERMAGNET stations).

Author(s): Bernard V. Jackson, Matthew Bracamontes, Kazumasa Iwai, Jackie Davies, Mario M. Bisi, Ken’ichi Fujiki

Department of Astronomy and Astrophysics, University of California, San Diego, 9500 Gilman Drive #0424, La Jolla, CA 92093-0424, USA; Department of Astronomy and Astrophysics, University of California, San Diego, 9500 Gilman Drive #0424, La Jolla, CA 92093-0424, USA; Institute for Space-Earth Environmental Research, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan; RAL Space, United Kingdom Research and Innovation, Science & Technology Facilities Council, Harwell Campus, Oxfordshire, OX11 0QX, UK; RAL Space, United Kingdom Research and Innovation, Science & Technology Facilities Council, Harwell Campus, Oxfordshire, OX11 0QX, UK; Institute for Space-Earth Environmental Research, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan

Abstract: UCSD’s iterative time-dependent three-dimensional (3-D) reconstruction program has characterized solar wind topology throughout the inner heliosphere based on interplanetary scintillation (IPS) and Thomson scattering brightness observations since the year 2000. Several years ago this system was adapted for use with Thomson scattering brightness from STEREO HI data. These STEREO HI-based reconstructions have been made available in near real ever since on a UCSD website (now https://stereo.ucsd.edu). The 3-D reconstruction system proceeds with the use of outward solar wind flow speeds that are obtained from the Institute for Space-Earth Environmental Research (ISEE), Japan IPS arrays. Analysis of Thomson scattering brightness data provides far higher 3-D heliospheric density reconstruction resolutions over time than are possible from the analysis of IPS data alone due to the far more abundant image line of sight values present. The closest approach of the STEREO A spacecraft to Earth in August 12, 2023 allows extremely good 3-D reconstructions of the solar wind densities near the ecliptic along the Sun-Earth line to the east of STEREO A. Retrospectively these analyses can provide density resolutions of 1 x 1 degree in latitude and longitude, one-hour cadence, and solar distances of 0.02 AU. Here we show these high-resolution heliospheric analyses during the time period prior to 10 May 2024 in order to help identify the associated interplanetary CME structure present that was responsible for the superstorm.

Author(s): Veronika Haberle, Rachel Bailey, Roman Leonhardt, Eva Weiler, Christian Möstl, Ute Amerstorfer, Tanja Amerstorfer, Sandro Krauß, Werner Pötzi, Manuela Temmer, Rumi Nakamura, Hyangpyo Kim, David Fischer, Georg Achleitner, Philipp Schachinger, Alexander Fröhlich, Andreas Pfoser, Gregor Möller

Conrad Observatory, GeoSphere Austria; Conrad Observatory, GeoSphere Austria; Conrad Observatory, GeoSphere Austria; Austrian Space Weather Office, GeoSphere Austria; Austrian Space Weather Office, GeoSphere Austria; Austrian Space Weather Office, GeoSphere Austria; Austrian Space Weather Office, GeoSphere Austria; Graz University of Technology, Institute for Geodesy; Kanzelhöhe Observatory for Solar and Environmantal Research, University of Graz; Institute of Physics/IGAM, University of Graz; Space Research Institute, Austrian Academy of Sciences; Space Research Institute, Austrian Academy of Sciences; Space Research Institute, Austrian Academy of Sciences; Austrian Power Grid AG; Austrian Power Grid AG; Institute of Electrical Power Systems, Graz University of Technology; Austro Control GmbH; Department of Geodesy and Geoinformation, TU Wien

Abstract: The space weather events from beginning of May 2024 included the most severe geomagnetic storm within the past 20 years, reaching the maximum level G5 of the NOAA scale. The positive side of the event were aurora displays all around the globe providing a great opportunity to bring the topic of space weather closer to the broad public. However, this event was also accompanied by negative impacts, not only in space and at high latitudes.
The Space Weather Austrian Platform (SWAP) is aimed at bringing space weather stakeholders all over Austria together to create a national competence group. The extreme event of May 2024 provided an excellent opportunity to leverage this network for observation and forecasting capabilities and to determine impacts of the event, as well as to refine the communication channels and needs of stakeholders.
In this contribution, the May storm of 2024 is evaluated from the national perspective of Austria including images from the solar surface, forecast of the propagation and impact of the ICME, variations within the magnetosphere, ionosphere and thermosphere, as well as effects on end-users covering GNSS users, transmission system operators and aviation.

Author(s): Simon Thomas, Izarra Rodriguez-Bilbao, Mohamed Ouraini, Quentin Lenouvel, Aurelien Pujol, Julien Dupuy

ESSP; ESSP; ESSP; ESSP; ESSP; ESSP

Abstract: The ionosphere is one of the main contributors to Global Navigation Satellite System (GNSS) positioning errors. The European Geostationary Navigation Overlay Service (EGNOS) provides a satellite-based augmentation system service to the Global Positioning System (GPS) Standard Positioning Service, by supplying correction data and integrity information to improve positioning navigation and timing services over Europe. EGNOS provides three kinds of service, the Open Service, the EGNOS Data Access Service, and the EGNOS Safety of Life (SoL) services.  In this work, we focus on the SoL service which is geared primarily towards civil aviation and gives the necessary level of accuracy, integrity and continuity of service. We investigate the impact of exceptional ionospheric events observed over Europe on the performance of EGNOS SoL by focusing on the Mother’s Day storm on 10-11th May 2024, when we observed significant ionospheric perturbations over Europe. The event affected satellite-based augmentation systems, including EGNOS and WAAS, due to the ionospheric disturbances present within their service coverage areas. Notably, the recent deployment of EGNOS Service Release 242B has strengthened the system’s response to ionospheric scintillation, particularly in the northern regions.

Author(s): Charles Constant, Laura Aguilar, Indigo Brownhall, Eliot Dable, Santosh Bhattarai, Anasuya Aruliah, Marek Ziebart

University College London; University College London; University College London; University College London; University College London; University College London; University College London

Abstract: The May 2024 Gannon geomagnetic storm, characterized by multiple X-class solar flares and Earth-directed coronal mass ejections (CMEs), resulted in a G5-level event, the most severe since the October 2003 storms. This extreme space weather event caused widespread auroras and substantial disruptions to space-based systems and critical infrastructure worldwide. This study bridges research and operational considerations by addressing the primary source of uncertainty during geomagnetic storms—atmospheric density—and its impact on space operations.
An analysis of the thermosphere’s behaviour during the storm is conducted using data from multiple independent sources, including ground-based Fabry-Perot interferometer (FPI) observations, precise orbit determination (POD) data from GRACE-FO and TerraSAR-X satellites, and four operational atmospheric density models (WAM-IPE, NRLMSISE-00, DTM2000, and JB08). This evaluation explores the capabilities of both physics-based and empirical density models to accurately capture extreme variations in atmospheric density induced by the storm.
The impact of the storm on satellite tracking accuracy is assessed by using precise orbits derived from satellites in densely populated altitude shells (GRACE-FO, TerraSAR-X, Sentinel-1A, and Sentinel-2B) as reference orbits to evaluate the effect of the geostorm on the quality of space object tracking by the U.S. Space Surveillance Network. This analysis provides insights into how geomagnetic storms degrade the accuracy of space object tracking, primarily due to errors in atmospheric density modelling.
To quantify the operational demands on satellite operators, the number of manoeuvres required and the observed decay rates of satellites and debris within the 250-1250 km altitude range are evaluated. This assessment highlights the increased operational workload during and after the storm and illustrates the role of geomagnetic storms in accelerating the natural decay of space debris, suggesting a potential benefit for long-term space sustainability.

Author(s): Zbyšek Mošna, Petra Koucká Knížová, Kateřina Podolská, Daniel Kouba

Institute of Atmospheric Physics, Czech Academy of Sciences; Institute of Atmospheric Physics, Czech Academy of Sciences; Institute of Atmospheric Physics, Czech Academy of Sciences; Institute of Atmospheric Physics, Czech Academy of Sciences

Abstract: We present observations from ground-based measurements at the Czech ionospheric station in Pruhonice. We compare visual observations of the Aurora Borealis with simultaneous Digisonde measurements, identifying the ionospheric regions where Auroras occur. We analyzed the event and incorporated amateur photographs into a dissemination paper published in the Czechoslovak Journal of Physics, aimed at teachers, students, scientists, and the general public.

Author(s): Roberta Forte, Raffaele Crapolicchio, Enkelejda Qamili, Nicola Comparetti, Lorenzo Trenchi, Anja Stromme, Klaus Scipal

Serco for ESA; Serco for ESA; Serco for ESA; Serco for ESA; Serco for ESA; ESA; ESA

Abstract: ESA Earth Explorers missions pioneer new space technology and observe our planet to help answer key science questions about Earth’s systems, and in some cases, they can go behind the original scientific purpose and be beneficial to other field of science. Moreover, they allow to develop synergies which open to further applications in different fields.
An example of a fruitful synergy between two completely different missions, that fosters new objectives behind their original ones, is Swarm and SMOS. Both these Earth Explorer missions may be advantageous for Space Weather applications: their distinctive characteristics is the possibility to observe Space Weather phenomena from different point of view.
SMOS mission is dedicated to Soil moisture and salinity measurements, but within these measurements, the on-board Microwave Imaging Radiometer captures a signal from the Sun, that allows to derive the Solar Flux in L-band, with its polarization component.
Swarm original purpose is to characterize Earth’s geomagnetic, ionospheric and electric fields and their temporal variation, through measurements of Earth’s magnetic field and plasma parameters with a peculiar constellation configuration of 3 satellites. With its new “Fast” processing chain, Swarm is able to provide data with a minimum delay with respect to acquisition time, making this mission eligible for Space Weather application.
Moreover, both Swarm and SMOS provide measurements of Total Vertical Electron Content (VTEC), very useful to evaluate impact of Space Weather phenomena on the ionosphere.
A combined observation of SMOS and Swarm measurements reveals new possible applications: an example of this collaboration is the observation of the same event, the geomagnetic storm occurred in May 2024 so-called Mother’s Day Super storm.
This poster aims to demonstrate how these two missions can enhance their contributions to Space Weather by combining their distinct observations. The results of the analysis of the same event observed by SMOS and Swarm are presented: the variation in Solar flux in L-band,
including its circular polarization component, and the detection of Solar Radio burst measured by SMOS, compared with GNSS effects and radio blackouts on the ground, combined with the variations in geomagnetic field, plasma density and temperature, and Field Aligned Currents measured by Swarm.

Author(s): Roberta Tozzi, Tommaso Alberti, Igino Coco, Paola De Michelis, Fabio Giannattasio, Mirko Piersanti

Istituto Nazionale di Geofisica e Vulcanologia; Istituto Nazionale di Geofisica e Vulcanologia; Istituto Nazionale di Geofisica e Vulcanologia; Istituto Nazionale di Geofisica e Vulcanologia; Istituto Nazionale di Geofisica e Vulcanologia; Università degli Studi dell’Aquila

Abstract: On 10 May 2024, a storm sudden commencement recorded around 17 UT marked the beginning of the Mother’s Day storm that turned out to be the second most intense geomagnetic storm of the XXI century, reaching a minimum Sym-H index of –518 nT. In this study, we present some analyses of  ground-based geomagnetic data recorded by the European quasi-Meridional Magnetometer Array (EMMA). In detail, we use data from 22 stations of the EMMA array to investigate the ground effects of the storm. Selected stations cover Northern magnetic latitudes from approximately 36° to 66°. We estimate indices able to provide information on the potential buildup  of geomagnetically induced currents as well as their amplitude dependence on time and geomagnetic latitude during the period from 9 May to 13 May 2024.

Author(s): Yongliang Zhang, Larry Paxton, Robert Schaefer

The Johns Hopkins University / APL; The Johns Hopkins University / APL; The Johns Hopkins University / APL

Abstract: The May 10-11, 2024 superstorm created significant disturbances in the auroral and thermosphere activities.  The auroral oval expanded to ~40 Mlat during the storm. In addition to many known features (dawn-dusk asymmetry, detached ring current aurora, ENA aurora, undulation at equatorward edge, arcs etc.), there are also new features, such as undulation on the poleward edge, arcs in the auroral oval cavity, penetration of plasma sheet energetic particles into the dayside polar cap, etc.  The strong particle and Joule heating led to significant O/N2 depletion and NO enhancement extending down to the equatorial regions with a weak longitude dependence at 8:30 LT (TIMED/GUVI observation) and clear longitude variation at ~16:00 LT (DMSP/SSUSI). The enhancement in NO recovered in 4 days while the O/N2 depletion recovered at a slower pace.

Author(s): Ljubomir Nikolic

Natural Resources Canada

Abstract: Several Coronal Mass Ejections (CMEs) coming from the Active Region (AR) 13664 were observed during May 2024, causing a significant geomagnetic storm with the Disturbance Storm Time (Dst) index reaching -412 nT on 11 May. While the Dst index of this geomagnetic storm is low, it is still well above the Dst index of the 13-14 March 1989 storm which caused a blackout of the Hydro-Québec (Canada) power system. With the Dst index reaching -589 nT on 14 March, the March 1989 event represents the biggest geomagnetic storm of the space age.
Here, the Canadian space weather forecasts and numerical modelling during the May 2024 event and a comparison with the March 1989 event are discussed. The focus is on solar disturbances which caused the storms. While a CME associated with a long duration X class flare on 10 March 1989 was the basis for the major geomagnetic storm forecast at that time, the evidence suggests that multiple CMEs were involved in the event and produced geomagnetic disturbances. Thus, both events, May 2024 and March 1989, represent compound events. While AR13664 exhibited fast growth and started to produce significant eruptions on 8 March, after crossing the central meridian of the sun (e.g. S18W17), the region AR5395 responsible for the March 1989 event produced significant eruptions starting from its appearance on the east limb, with the most geoeffective eruptions on the east side from the central meridian and a relatively high latitude (e.g. N31E22).
During the May 2024 event, simulations of the CME arrivals were performed, including a run with 9 CMEs from the 8-11 May period. The disturbance arrival time from the CME simulations, around 22:00 UT, was in relatively good agreement with the observed shock in the solar wind at 16:35 UT on 10 May. Numerical modeling of events suggests propagation of CMEs through the interplanetary space far from the Heliospheric Current Sheet (HSC) during the May 2024 event, while solar eruptions responsible for the March 1989 event were close to HSC. This suggests more complex interactions in interplanetary space during the March 1989 event.
Due to solar activity 8-9 May 2024, the Canadian Space Weather Forecast Center (CSWFC) issued a major geomagnetic storm watch. While global geomagnetic disturbances at the same level as the March 1989 storm were not expected, it should be noted that the Hydro-Québec blackout happened early in the March 1989 event, on 13 March at 7:44 UT, when the Dst index was around -138 nT, which is much higher than the Dst minimum of the May 2024 storm. Considering the importance of the 13-14 March 1989 event, particularly from the Canadian perspective, work is underway at the CSWFC to compare all aspects of the May 2024 and March 1989 events, including ionospheric and ground effects.

Author(s): Ingmar Sandberg, Hugh Evans, Richard Horne, Constantinos Papadimitriou, David Pitchford, Sigiava Aminalragia-Giamini, Melanie Heil, Kimon Tsilias

1. Space Applications and Research Consultancy, 2. Department of Aerospace Science and Technology, National and Kapodistrian University of Athens; ESA/ESTEC; British Antarctic Survey; Space Applications and Research Consultancy; SES; Space Applications and Research Consultancy; ESA/ESOC; Space Applications and Research Consultancy

Abstract: In this work we report significant long-term enhancements in the flux intensities of energetic protons in the inner belt region resulted from the May 2024 severe SW events. The observations are based on the measurements of the ESA Next Generation Radiation Monitor (NGRM) unit on-board EUMETSAT Sentinnel-6, launched in November 2020, which operates at an altitude of 1,336 km and inclination 66.0°.
In the L-shell region centred around L=2, we observe long-term enhancements of flux intensities of protons with energy in a range of 5-30 MeV while in the L-shell region centred around L=1.4, we observe long-term enhancements of flux intensities of protons with energies above 30-40 MeV. The increased proton flux levels in the inner belt are expected to last several months and lead to a relatively significant increase of radiation effects attributed to energetic protons, such as Single Event Effects and Solar cell degradation.
Measurements from the ESA Sentinel-6/NGRM unit are presented and explained with the support of third-party observations. In addition, we present results and comparisons with standardly used space radiation environment and effect tools to evaluate the impact of the May 2024 proton belt formation.
Acknowledgements:  This work is supported by the SSA P3-SWE-XXI NGRM Data Processing activity led by SPARC under ESA Contract No 4000127954/19/D/CT.