Conveners
SWR4 –Interactions in the Earth’s Magnetosphere-Ionosphere-Thermosphere System and their Space Weather Impact: Orals - Part 1
- Alan George Wood (University of Birmingham)
- Lucilla Alfonsi (Istituto Nazionale di Geofisica e Vulcanologia)
- Guram Kervalishvili (GFZ Helmholtz Centre for Geosciences)
- Daria Kotova (Department of Physics, University of Oslo)
SWR4 –Interactions in the Earth’s Magnetosphere-Ionosphere-Thermosphere System and their Space Weather Impact: Orals - Part 2
- Alan George Wood (University of Birmingham)
- Daria Kotova (Department of Physics, University of Oslo)
- Guram Kervalishvili (GFZ Helmholtz Centre for Geosciences)
- Lucilla Alfonsi (Istituto Nazionale di Geofisica e Vulcanologia)
SWR4 –Interactions in the Earth’s Magnetosphere-Ionosphere-Thermosphere System and their Space Weather Impact: Orals - Part 3
- Lucilla Alfonsi (Istituto Nazionale di Geofisica e Vulcanologia)
- Daria Kotova (Department of Physics, University of Oslo)
- Guram Kervalishvili (GFZ Helmholtz Centre for Geosciences)
- Alan George Wood (University of Birmingham)
SWR4 –Interactions in the Earth’s Magnetosphere-Ionosphere-Thermosphere System and their Space Weather Impact: Orals - part 4
- Daria Kotova (Department of Physics, University of Oslo)
- Guram Kervalishvili (GFZ Helmholtz Centre for Geosciences)
- Alan George Wood (University of Birmingham)
- Lucilla Alfonsi (Istituto Nazionale di Geofisica e Vulcanologia)
Description
The session focuses on the state-of-the-art understanding of the complex mechanisms ruling the Magnetosphere-Ionosphere-Thermosphere (M-I-T) coupling and how they translate into space weather impacts. Such an understanding is fundamental for the developing effective countermeasures against disruption, failure and deterioration of vulnerable technologies, including GNSS critical applications, HF/VHF/UHF radio communications and LEO satellite operations. It is essential to improve the prediction of both the underlying physical phenomena and how these are related to space weather impacts. This improved understanding is crucial for better forecasts, warnings, and mitigate measures for adverse space weather effects. Other crucial aspects of M-I-T coupling are the interhemispheric symmetric/asymmetric response to variable drivers, vertical coupling and coupling between different latitudinal regions which, if properly predicted, could support regional space weather modelling. This session seeks to encourage and foster dialogue between researchers studying the underlying physical phenomena and operators seeking to mitigate space weather impacts. As such, contributions are invited which address any aspect of M-I-T coupling and associated threats to systems at regional and global scales.
Auroral forms can provide information not only on the state of near-Earth space but also on conditions in the lower-thermosphere–ionosphere. The so-called dune aurora, consisting of brighter stripes forming a wave-like pattern in the dim, diffuse green aurora, has been hypothesised as being an optical signature revealing the presence of a large-scale atmospheric wave above or near the...
The center of the South Atlantic Magnetic Anomaly (SAMA) is located in the southern part of Brazil, where enhanced energetic particle precipitation (EPP) can occur, particularly during strong geomagnetic storms. Consequently, the sporadic auroral E layer (Esa), a feature typically observed in ionograms from high latitude auroral regions, can also be detected at stations near the center of the...
Geomagnetic storms during the declining phase of the solar cycle 24 were studied using the total electron content (TEC) data obtained from three geodetic receivers located in Portugal: Lisbon (Continental Portugal), Furnas (Azores) and Funchal (Madeira). Two of the receivers (Lisbon and Furnas) are located at about the same latitude (~39ºN) while the third receiver (Funchal, ~33ºN) is...
The main drivers of geomagnetic storms are interplanetary coronal mass ejections (ICMEs) and solar wind high-speed streams (HSSs) with stream interaction regions (SIRs). In this presentation, we show one example of both cases and study their effects on the high-latitude ionosphere-thermosphere (I-T) system. We use a multi-instrument approach with ground-based instruments (e.g., the EISCAT...
During a solar flare, the fluxes in various lines and continua of the solar spectrum increase, leading to enhanced ionisation of the illuminated part of the Earth’s ionosphere and an increase in the total electron content (TEC). It has been previously shown that nearly 50% of X-class solar flares exhibit a second peak in warm coronal lines, such as Fe XV and Fe XVI, (called the ”EUV late...
The bow shock current (BSC) plays an important role in supplying the magnetosphere with solar wind energy, in particular during times of low solar wind magnetosonic Mach numbers. Since the magnetic pile-up in the magnetosheath has to be maintained, the BSC cannot close locally, but must instead connect to magnetospheric current systems. However, the details of this closure remain poorly...
Changes in solar wind flow, typically associated with interplanetary coronal mass ejections (ICMEs) and high-speed streams (HSSs), directly impact the near-Earth space environment. These structures disturb the Earth’s magnetosphere and induce variability in the geomagnetic field. Rapid variations in the geomagnetic field, characterized by elevated values of dBH/dt, can lead to the generation...
The near-Earth space environment is strongly influenced by the solar wind and embedded interplanetary magnetic field. Therefore a thorough understanding of the upper atmosphere response during the passage of geoeffective solar wind transients, such as high-speed streams/stream interaction regions (HSS/SIR) and interplanetary coronal mass ejections (ICMEs) is crucial for accurate space weather...
The Low Frequency Array (LOFAR) is one of the most advanced radio telescopes in the world. When radio waves from a distant astronomical source traverse the ionosphere, structures in this plasma affect the signal. The high temporal resolution available (~10 ms), the range of frequencies observed (10-90 MHz & 110-250 MHz) and the large number of receiving stations (currently 52 across Europe)...
Sporadic-E, thin metallic ion layers in the lower ionosphere compressed via neutral wind shears or externally imposed electric fields, pose considerable challenges for High Frequency (HF) radio propagation modelling. As their name suggests, these layers can appear to be quasi-stochastic, requiring both an abundance of metallic ions and a mechanism through which to compress them into thin,...
Sudden Commencements (SCs) are rapid, near-impulsive changes of the geomagnetic field that are measured on the ground. SCs are caused by sudden increases of solar wind dynamic pressure (e.g., interplanetary shocks), that compress the Earth’s geomagnetic cavity (the magnetosphere). Such changes in the geomagnetic field, as measured on the surface of the Earth, result in the creation of...
AGATA (Antarctic Geospace and Atmosphere ReseArch) is a Scientific Research Programme (SRP) of the Scientific Committee on Antarctic Research (SCAR). The AGATA SRP was officially approved during the SCAR Delegates Meeting in August 2024, with scientific activities commencing in January 2025. The programme is designed to address key open questions concerning the coupling between the different...
Space weather events like solar flares cause enhanced absorption of radio waves in the ionosphere most notably in the lowest part of it, the D-region (ca. 60–100 km altitude range) which can weaken radio signals and can pose difficulties to radio communication at certain frequencies. There exist several methods to qualitatively or quantitatively assess the absorption in the layers of Earth’s...
Ionospheric indices play a crucial role in monitoring and understanding the dynamic behavior of the ionosphere. By examining the temporal and spatial variability of Total Electron Content (TEC) or electron density, we can detect and characterize ionospheric perturbations across various scales. Beyond their scientific value, these indices also help assess the potential impact of space weather...
Variations in the ionospheric currents can cause rapid disturbances in the magnetic field at the ground level, so called dB/dt spikes, and Geomagnetically Induced Currents (GICs) that can harm human infrastructure. When investigating dB/dt spike occurrence and GIC risks, the focus has typically been on geomagnetic storms. However, recently it has been argued that it is the substorm phenomena...
The solar wind causes a continuous modulation of the high-latitude ionosphere, namely in the electric field, thermosphere heating, plasma transport, thermospheric composition and circulation. The main goal of this study is to investigate the mechanisms that play a role in the response of the ionosphere-thermosphere system to the variations in the solar wind and to quantify the response time...
Our Sun starts processes with a strong impact on Earth’s magnetosphere that can cause strong magnetospheric and ionospheric perturbations. This can lead to the creation of intense fast-changing magnetospheric and ionospheric current systems, which provoke strong and fast fluctuations in the geomagnetic field. Time-varying magnetic fields interact with the Earth’s conductivity, resulting in an...
Understanding how solar wind parameters control ionospheric structure remains a fundamental challenge in space weather prediction. This study applies unsupervised machine learning techniques to analyse EISCAT Svalbard radar observations (1998-2023) during winter months, revealing unexpected hierarchies in solar wind-ionosphere coupling.
K-means clustering with UMAP dimensionality reduction...
Auroras can intuitively reflect the energy coupling between the Sun and the Earth and are an excellent indicator for monitoring and predicting space weather effects. Establishing an auroral oval model driven by the geomagnetic index, predicted up to three days ahead, can effectively assess energy transfer in space. Based on the data spanning from 2005 to 2016 obtained from DMSP/SSUSI, we...
Since the launch of ESA’s Swarm constellation, several physical quantities measured onboard the three satellites have been used to derive indices that support the study of near-Earth space processes. While multiple indices exist to quantify ionospheric plasma irregularities such as RODI (Rate Of change of electron Density Index), an analogous index for magnetic field fluctuations has not yet...
Space weather in the Arctic presents significant challenges for users of Global Navigation Satellite Systems (GNSS), particularly due to phase scintillations, which are rapid fluctuations in the signal phase, that can degrade positioning accuracy and in severe cases cause complete signal loss. The phase scintillation index serves as a standard metric for quantifying these fluctuations....
Investigations on ionospheric response during the super geomagnetic storm time (March 17 2015) are crucial. The VTEC predictability by regional/global ionospheric models (AfriTEC, IRI-2016, IRI-Plas 2017, GIM-CODE, and Nequick-G) is assessed by using root mean square error (RMSE) method and percentage deviation by comparing the GPS/GNSS-VTEC obtained from 10 IGS (International GNSS Service)...
In Brazil, equatorial plasma bubbles (EPBs) are the primary space weather phenomenon impacting the performance of Global Navigation Satellite Systems (GNSS), causing signal disruptions and positional inaccuracies in agricultural machinery used for mapping fields, guiding equipment, and ensuring accurate planting, chemical application, and harvesting. As a result, farmers and stakeholders face...
The impact of solar flares on the Earth’s ionosphere has been studied for many decades using both experimental and theoretical approaches. However, the accuracy of predicting ionospheric layer dynamics in response to variations in solar radiation remains limited. In particular, understanding the vertical redistribution of charged particles in the ionosphere during flares with different...
We observed O I red (630 nm) and green (557.7 nm) nightglow using a spectrograph that observed 28 deg to 44 deg elevation in the sky in the north-east direction over a month around February 2022. We applied a 2-D extension to the Global Airglow (GLOW) model on the dataset. We show that neutral and electron densities input to the GLOW model require modifications to reproduce the observed...
Auroral electrons are not energetic enough to penetrate down into the mesosphere, therefore the influence of auroral activity on the upper mesospheric temperature (~87km altitude) has not been studied extensively. Only a handful of studies have investigated the response of upper-mesospheric temperature to auroral activity, and possible temperature enhancements have been revealed in individual...
Climatological modeling of ionospheric plasma convection, driven by parameters such as solar wind velocity and density, interplanetary magnetic field (IMF) components, and geomagnetic indices, has been extensively investigated over the past decades. Interest in this topic continues to grow, both for its scientific importance, owing to the complex plasma processes it reveals, and for its...
Understanding ionospheric plasma dynamics under disturbed space weather conditions is critical for ensuring the reliability of satellite-based communication and navigation systems especially in the context of technological expansion into sensitive regions such as the Arctic. This study conducts a comparative investigation of ionospheric plasma responses to geomagnetic storm events during the...
In this study, we analyze and compare the Ionosphere-Thermosphere (I-T) response over Central Europe to the two severe geomagnetic storms occurred in October 2024 and January 2025. Ionosonde observations from Rome (41.8°N, 25.5°E) and Juliusruh (54.6°N, 13.4°E) were manually validated and used to characterize ionospheric variability and to retrieve thermospheric parameters—neutral composition,...
Ionospheric spatial TEC (total electron content) gradients can be computed using TEC maps. There are different types of TEC maps. For example, simple TEC maps use only ground-based GNSS TEC data; the global ionospheric maps (GIMs) that are created using both ground and space ionospheric data. Another significant difference between the two types of TEC maps is that the GNSS TEC maps have gaps,...
Airglow phenomena serve as essential tracers for understanding the dynamics and interactions within the Earth's upper atmosphere. In this study, we introduce a machine learning-based approach for classifying airglow images captured by the all-sky camera at the Shigaraki (SGK) observatory. Our objective is to automate the identification of gravity wave signatures within these images,...
Flickering aurora, which appears in association with bright auroral arcs, consists of patchy structures a few kilometers in horizontal size that rapidly blink on and off at a frequency of about 10 Hz. Although the generation process of this phenomenon is not yet fully understood, the close similarity between the flickering period and the frequency of O^+ -mode electromagnetic ion cyclotron...
Geomagnetic substorms are major phenomena in the magnetosphere-ionosphere system that intensify the aurora and often pose a threat to technology on Earth and in geospace. Substorms are identifiable through a strong westward electrojet that forms to close the substorm current wedge, which creates a recognizable peak in the AL index. Global magnetohydrodynamics (MHD)-based models struggle to...
Currently, EISCAT are deploying EISCAT_3D, the most advanced volumetric imaging radar for atmospheric, ionospheric and near-Earth space investigations. The tri-static, phased-array incoherent scatter radar is located in Skibotn (inland from Tromsø, Norway), Karesuvanto (Finland, north of Kiruna), and Kaiseniemi (Sweden, west of Kiruna).
EISCAT_3D follows the long legacy of EISCAT radars,...
During the extreme geomagnetic storm on 10 May 2024, a pronounced super-fountain effect was triggered by prompt penetration electric fields (PPEF) and pre-reversal enhancement (PRE) electric fields. The SWARM-A satellite, with its favorable orbit through the dusk sector, captured detailed in-situ data revealing global-scale ionospheric responses. Strong equatorial uplift was observed,...
Understanding the coupling between the Earth's magnetosphere and ionosphere at local scales remains a key challenge in space weather research. This study examines the relationship between localized geomagnetic and ionospheric perturbations through a comparative analysis of two region-specific indices: the Local Disturbance index (LDi) and the Perturbed Total Electron Content index (PTEC). The...
Space weather poses a significant threat to critical technologies, including satellite communications, GPS navigation, and power grids, as demonstrated by past severe events like the 1989 Hydro-Quebec blackout and the 2003 'Halloween event'. With Solar Cycle 25 entering a particularly active phase since 2022, understanding and predicting these phenomena is crucial for mitigating economic...
Global navigation satellite systems (GNSS) are often used to provide positioning and timing for ground-based users. The low- and mid-latitude GNSS receivers are used to study periods where the Zambia GPS receiver observed high total electron content (TEC). To investigate the ionospheric changes, several receivers located in Namibia, Zambia, Kenya, and Uganda were utilised from 23 Feb to 1 Mar...
One of the most important scientific objectives is to comprehend the relationships between the sun, the space weather that generates storms, and the impacts on Earth. The ionosphere is greatly impacted by geomagnetic storms, which are very severe space weather phenomena. Ionospheric perturbations during intense geomagnetic storms caused the disturbance in Earth's magnetic field. A geomagnetic...
The Earth’s Magnetosphere-Ionosphere-Thermosphere (MIT) system is strongly controlled by the laws of electrodynamics, which include significant contributions from all three components. Today, we face a growing need for a better representation of this MIT system, at all latitudes due to the growing use of GNSS satellites for positioning, which face accuracy and forecasting challenges that are...
X-ray and EUV solar flare emission cause increases in the Earth's dayside ionospheric electron density. While the response of the lower ionosphere to X-rays is well studied, the delay between EUV flare emission and the response of the ionospheric F-region had not been investigated. Here we calculated the delays between incident He II 304 Å emission and the TEC response for 10 powerful solar...
This study investigates the response of the ionosphere–thermosphere system over Europe during the severe geomagnetic storm of May 2024. Between May 7 and 11, multiple X-class solar flares and at least five Earth-directed coronal mass ejections (CMEs) were observed. The initial CME impacted Earth at 12:30 UTC on May 10, triggering a geomagnetic disturbance that led to a pronounced negative...
The ionosphere affects trans-ionospheric radio signals even at GHz frequencies and in the bands that are used for satellite based positioning and navigation. Density measurements by Langmuir probes on the Swarm satellites at altitudes between about 450 and 510 km can be used to roughly characterize the total effects on GNSS signals during a period of about 12 years since the Swarm launch....
This study provides a comprehensive investigation into the ionospheric response over the African sector during the extreme (G5 scale) geomagnetic superstorm of 10 May 2024. The storm was characterized by a dramatic depression in the SymH index to nearly
$-518\,nT$, highlighting its extraordinary intensity. To examine the ionosphere's behavior under such extreme conditions, we utilized...
Pole-to-pole VTEC data from the Madrigal GNSS network on May 10–12 and October 10–12, 2024, were analyzed to diagnose the ionospheric response during the May superstorm and the October severe storm. VTEC, superimposed with S4 and Sigma-phi scintillation, was used to study the spatiotemporal evolution of small-scale irregularities, while ROTI data from the ISEE GNSS network complemented the...
Magnetosheath jets, transient plasma structures of enhanced dynamic pressure, can excite ultra-low frequency (ULF) waves in the magnetosphere impacting the magnetopause. These ULF waves transport energy into the ionosphere, making it essential to quantify their contribution to ionospheric energy deposition. In this study, we combine observations from the Magnetospheric Multiscale (MMS)...
We present an analysis of the strongest geomagnetic storm of Solar Cycle 25 (SYM-H < −518 nT), known as the Mother’s Day Storm, which occurred between 10 and 15 May 2024.
The study is based on data from a stand-alone system for measuring geomagnetic field variations at Talos Dome (TLD), a remote site on the Antarctic plateau, about 300 km from TNB,the Italian geomagnetic observatory at Mario...
Geomagnetically induced currents (GIC) are among the most hazardous forms of space weather impacts. Finnish Meteorological Institute has a long history of GIC measurements and real-time GIC modeling, with products also being delivered to the ESA Space Weather Service Network. Our latest research focuses on GIC estimation during the extreme Halloween geomagnetic storm, which caused the...
Dual-frequency GNSS ground observations are commonly used to compute precise ionospheric total electron content (TEC) maps also known as Global Ionospheric Maps (GIMs). Precise ionospheric maps are useful in mitigating atmospheric effects in GNSS navigation, positioning and timing (PNT) applications. The estimation of ionospheric TECs, and the satellite and receiver Differential Code Biases...
Polar cap is the source region of the space weather disturbances, which expand to mid and low latitudes. Large southward IMF Bz leads to strong cross polar cap potential generating intense Joule heating from ion neutral collisions. To understand how much Joule heating is generated, one must know the thermospheric winds. Over the years, NCAR has been operating ground based Fabry Perot...
In the present study, we analyzed the Earth's magnetospheric dynamics in response to the intense geomagnetic storm of 19th December 2015, marked by a substantial decrease in the SYM-H index to -188 nT. We focushere on the variations of the magnetic flux content (MFC) within closed magnetic shells in the inner magnetosphe up to a distance roughly corresponding to the magnetopause. During this...
Modeling extreme storm response on the ground, for the purpose of preparing for a worst-case scenario, sometimes takes the form of scaling up observed ground response from historical storms. This approach assumes that a simple scaling of the ground response can capture the complexities and non-linearities inherent in the solar wind-magnetosphere interaction. As part of the Solar Tsunamis...
Sub-ionospheric Very Low Frequency (VLF) signal propagation serves as a powerful diagnostic tool for probing the lower ionosphere, particularly the D-region, during various space weather phenomena. In this study, we present an unified, autonomous modeling framework to investigate VLF signal perturbations induced by two distinct solar events: the 2024 Total Solar Eclipse (TSE-2024) and selected...
The solar wind (SW), as a primary space weather driver, exhibits significant temporal and spatial variations in the properties of heliospheric plasma. The mass, energy, and flux transfer from the SW to Earth's magnetosphere and upper atmosphere occurs through strong coupling between the magnetosphere and ionosphere, primarily mediated by field-aligned current (FAC) systems. Earth’s coupled...
The South Atlantic Magnetic Anomaly (SAMA) represents a unique low-intensity region of the geomagnetic field, where the inner radiation belt approaches the upper atmosphere, enhancing particle precipitation and ionospheric conductivity. In this work, we investigate how SAMA modulates the ground magnetic response during Sudden Commencements (SCs) and associated Pc5 pulsations. Using data from a...
This thesis explores how space weather affects the orbits of Earth satellites. In particular, how changes in geomagnetic activity disturb satellite paths in any possible way, including atmospheric density, and solar radiation, but also Lorentz force perturbation. The study compares satellites at very different orbital heights: CHAMP in low-Earth orbit, MetOp-A in mid-Earth orbit, the geodetic...
The ionospheric F2 layer plays a crucial role in radio wave propagation and is significantly influenced by various factors. Understanding its long-term variations is essential for analyzing Solar-Terrestrial dynamics and improving ionospheric models. This study uses the critical frequency of the F2 layer (foF2) and the height of the peak electron density (hmF2) from 1964 to 2019. Both...
The partial solar eclipse on 29th March 2025 had become an opportunity to conduct radio observations from a stratospheric balloon platform, simultaneously and as an aid to the ground-based observations by the LOFAR radiotelescope station in Borówiec near Poznań. The stratospheric flight conditions were chosen as a mean to mitigate the influence of the man-made radio noise; the experiments’...
This study focuses on the mid- and low-midlatitude ionospheric response to the 2024 Mother’s Day superstorm, utilizing ground-based and Swarm satellite observations. The ground-based ionosonde measured F1, F2-layer, B0 and B1 parameters, as well as isodensity data, were used. The ionospheric absorption was investigated with the so-called amplitude method, which is based on ionosonde data....
The ionosphere is a complex plasma medium characterised by electron density fluctuations spanning a wide range of spatial and temporal scales. Its dynamics are determined by complex interactions with the magnetosphere, solar wind, and thermosphere, forming a tightly coupled system. These external and internal factors cause variability that is often nonlinear and anisotropic, making it...
The ionosphere is a highly complex plasma containing electron density structures with a wide range of spatial scale sizes. The ionosphere is coupled to the Earth’s magnetosphere and the solar wind, as well as to the neutral atmosphere. Variability within the ionosphere is highly dependent on the driving processes. Thus, modelling the ionosphere and capturing its full dynamic range considering...
Space It Up! (SIU) is a major research and innovation program funded by the Italian Space Agency (ASI) and the National Recovery and Resilience Plan. It brings together a consortium of 33 Italian entities from both the research and industry operating in the space sector. SIU aims at fostering innovation and technological development in space exploration. The project is structured into thematic...
The first DTM_nrt (near real time), developed in 2013, used exospheric temperature corrections inferred from observed densities essentially for debiasing. We have started the development of an updated DTM_nrt, which uses the more precise DTM2020 as background model, and more precise density data (CHAMP, GRACE, GOCE, Swarm-A, and GRACE-FO) calculated by TU Delft, as well as updated Stella...
The Hunga Tonga-Hunga Ha’apai Volcano, located in the Pacific Islands, erupted on 15 January 2022. The eruption triggered both a tsunami and a meteotsunami, impacting areas around the Pacific Ocean. Lamb waves from the eruption, travelling at a speed of approximately 310 m/s, reached eastern Indonesia (~5000 km from Tonga) within 4 hours and arrived in Malaysia (Borneo region) about 6 hours...
The ionosphere, extending from approximately 60 to 1000 km altitude, is a dynamic plasma environment critical for radio wave propagation and the performance of Global Navigation Satellite Systems (GNSS). Its variability is strongly influenced by solar activity, notably during coronal mass ejections (CMEs) and intense solar flares, which inject energetic particles and disturbances into the...
Graz University of Technology processes thermospheric neutral densities for several satellite missions, primarily using accelerometer measurements and GNSS observations (POD). Additionally, we recently began calculating long-term variations from SLR observations of passive satellites. Combining these techniques yields a dataset spanning approximately 25 years, which is ideal for studying the...
The analysis of low-latitude magnetograms, essential for space weather monitoring, is generally affected by the presence of noise. Our initial investigation focused on quantifying this impact by applying the Discrete Wavelet Transform (DWT) to data from South American geomagnetic stations. The results demonstrated that common noise features, such as Gaussian white noise, compromise the...
The ionosphere exhibits complex, non-stationary behaviors driven by atmospheric, solar, and geomagnetic influences. To effectively analyze such variability, this study employs wavelet spectral analysis on high-resolution data obtained from the Tromsø Dynasonde. Continuous wavelet transforms (CWT) were applied to key ionospheric parameters, including vertical plasma drift velocities and...
