Space Weather Research Articles

Modest space weather can also affect near Earth satellites

Modest space weather can also affect near Earth satellites

Evidence of Kelvin-Helmholtz and tearing mode instabilities at the magnetopause during space weather events

Introduction: Kelvin-Helmholtz (KH) and tearing mode (TM) instabilities are one of the most important mechanisms of solar wind energy, momentum and plasma transport within the magnetosphere.Methods: To investigate the conditions under which KHTM instabilities occur in the Earth environment it is fundamental to combine simultaneous multipoint in situ measurements and MHD simulations. We analyzed data from the THEMIS and Cluster spacecraft considering two Space Weather (SWE) events starting with an M2.0 flare event (hereafter Case-1) that occurred on 21 June 2015 and the most-intensive flare (X9.3) of solar cycle 24 that occurred on 6 September 2017 (hereafter Case-2).Results: Our analysis utilized a 2D MHD model for incompressible and viscous flow. The results from Case-1 indicate the presence of KH and TM instabilities, suggesting existence of observed low-amplitude oscillations at the nose of the magnetopause. However, the MHD simulations for Case-2 did not show any evidence of KH vortices, but did reveal the presence of “magnetic island” structures during a low-shear condition. The reconnection rate derived from the observations is compared with the computed one in the presence of developed instabilities inside the Earth’s magnetopause.

Acceleration of solar wind particles due to inertial Alfvén waves

Gaining an understanding of the effects and dynamics of the solar wind is crucial for the study of space weather, Earth's magnetosphere, spacecraft protection, the dynamics of the Solar System, and various other subjects. Observations show that Alfvén waves effectively transfer energy to resonant particles. This study demonstrates how inertial Alfvén waves deliver their energy to resonant plasma particles in different solar environments under certain conditions. The analysis shows that inertial Alfvén waves experience more rapid damping with increasing parallel wavenumber, ambient magnetic field strength, and particle number density, coupled with a decrease in temperature. The rate of energy transfer to resonant particles intensifies with higher temperatures and reduced parallel wavenumber and particle number density. Particles with higher initial velocities actively participate in Landau damping, especially in regions with a stronger ambient magnetic field.

Solar Weather Dynamics and the US Economy: A Comprehensive GVAR Perspective

Solar Weather Dynamics and the US Economy: A Comprehensive GVAR Perspective

Trends in childhood leukemia incidence in urban countries and their relation to environmental factors, including space weather

Leukemia is the most common cancer in children. Its incidence has been increasing worldwide since 1910th, suggesting the presence of common sources of the disease, most likely related to people’s lifestyle and environment. Understanding the relationship between childhood leukemia and environmental conditions is critical to preventing the disease. This discussion article examines established potentially-carcinogenic environmental factors, such as vehicle emissions and fires, alongside space weather-related parameters like cosmic rays and the geomagnetic field. To discern the primary contributor, we analyze trends and annual variations in leukemia incidence among 0-14-year-olds in the United States, Canada, Australia, and Russia from 1990 to 2018. Comparisons are drawn with the number of vehicles (representing gasoline emissions) and fire-affected land areas (indicative of fire-related pollutants), with novel data for Russia introduced for the first time. While childhood leukemia incidence is rising in all countries under study, the rate of increase in Russia is twice that of other nations, possibly due to a delayed surge in the country’s vehicle fleet compared to others. This trend in Russia may offer insights into past leukemia levels in the USA, Canada, and Australia. Our findings highlight vehicular emissions as the most substantial environmental hazard for children among the factors examined. We also advocate for the consideration of potential modulation of carcinogenic effects arising from variations in cosmic ray intensity, as well as the protective role of the geomagnetic field. To support the idea, we provide examples of potential space weather effects at both local and global scales. The additional analysis includes statistical data from 49 countries and underscores the significance of the magnetic field dip in the South Atlantic Anomaly in contributing to a peak in childhood leukemia incidence in Peru, Ecuador and Chile. We emphasize the importance of collectively assessing all potentially carcinogenic factors for the successful future predictions of childhood leukemia risk in each country.

Response of total electron content to the October 25, 2022 partial solar eclipse from high to low latitudes in the Euro-Asian region

Solar eclipses (SEs) pertain to high-energy sources. They are capable of causing significant disturbances in all geoshells and geophysical fields. Despite the almost century-long history of studying the influence of eclipses on geoshells, the task of observing and analyzing disturbances in them remains relevant. This is explained by the fact that the response of the media significantly depends on the state of atmospheric and space weather, the location and time of observation, the SE magnitude, etc. The aim of this paper is to present the results of a statistical analysis of the features of the total electron content (TEC) variations during the October 25, 2022 SE from high to low latitudes in the Euro-Asian region. Data from Global Navigation Satellite System were used for the analysis. The error in estimating TEC in the vertical column did not exceed 0.1 TECU. For the first time, the response of the ionosphere to an SE has been studied on a global scale (from the Reykjavik station to the Novosibirsk station) using methods of statistical analysis, including the time moments after sunset. The decrease in TEC reached 1.0–19.0 TECU, and the relative decrease was approximately –0.32. Changes in all TEC disturbance parameters depended in a complex manner on the relative obscuration area of the solar disk. This can be explained by non-monotonic changes in electron density during the daytime, by the intensification of the ionosphere–plasmasphere coupling, the disturbance of the ionospheric current system, vertical plasma drift in crossed electric and magnetic fields, as well as the generation of wave disturbances during the SE period. The delay time of the maximum ionospheric response (maximum |δV| value) with respect to the maximum magnitude of the eclipse was 15–25 min. The duration of the ionospheric response to the SE slightly exceeded the duration of the perturbing source influence.

Magnetospheric Time‐History in Storm‐Time Magnetic Flux Dynamics: A Global Simulation Campaign

AbstractThis paper aims to quantify the magnetospheric magnetic flux contents under moderate to intense space weather conditions using global simulations. This study is a companion to Akhavan‐Tafti, Atilaw, et al. (2023, https://doi.org/10.1029/2023JA031832) where magnetic flux evolution is presented for a catalog of storm events, using Heliophysics System Observatory (HSO) observations. For this study, we used the Space Weather Modeling Framework (SWMF) in Geospace configuration to study magnetic flux dynamics for a subset of their storm events (15 events). Simulations reliably resolve the storm‐time magnetic flux Bz and current density |J| asymmetries across the different storm phases. It is revealed that: relative to the quiet period, flux content is enhanced during the storm sudden commencement (SSC) phase in the dayside by ΔBz/Bz, quiet = +17%, and reduced in the nightside magnetosphere (r[RE] < −6 RE) by −15%. At the same time, the cross‐tail current is found to enhance (|J| = 2 nA/m2), which suggests the storm impact in the nightside magnetosphere is much earlier in the storm cycle than previously shown. Concurring with previous studies, a significant depletion of magnetic flux by up to −40%, with day‐night and dawn‐dusk asymmetries, can be seen during the main and recovery phases. This corresponds to the enhanced current density (|J| = 5–8 nA/m2) at ∼6 RE further confirming the role of ring current in driving magnetospheric dynamics during the main and recovery phases. This is in contrast with the SSC phase wherein the Chapman‐Ferraro and cross‐tail currents are the dominant current systems.

Magnetosheath Ion Field‐Aligned Asymmetry and Implications for Ion Leakage to the Foreshock

AbstractThe ion foreshock is highly dynamic, disturbing the bow shock and the magnetosphere‐ionosphere system. To forecast foreshock‐driven space weather effects, it is necessary to model foreshock ions as a function of upstream shock parameters. Case studies in the accompanying paper show that magnetosheath ions sometimes exhibit strong field‐aligned asymmetry toward the upstream direction, which may be responsible for enhancing magnetosheath leakage and therefore foreshock ion density. To understand the conditions leading to such asymmetry and the potential for enhanced leakage, we perform case studies and a statistical study of magnetosheath and foreshock region data surrounding ∼500 Time History of Events and Macroscale Interactions during Substorms mission bow shock crossings. We quantify the asymmetry using the heat flux along the field‐aligned direction. We show that the strong field‐aligned heat flux persists across the entire magnetosheath from the magnetopause to the bow shock. Ion distribution functions reveal that the strong heat flux is caused by a secondary thermal population. We find that stronger asymmetry events exhibit heat flux preferentially toward the upstream direction near the bow shock and occur under larger IMF strength and larger solar wind dynamic pressure and/or energy flux. Additionally, we show that near the bow shock, magnetosheath leakage is a significant contributor to foreshock ions, and through enhancing the leakage the magnetosheath ion asymmetry can modulate the foreshock ion velocity and density. Our results imply that likely due to field line draping and compression against the magnetopause that leads to a directional mirror force, modeling the foreshock ions necessitates a more global accounting of downstream conditions.

CAMEL. II. A 3D Coronal Mass Ejection Catalog Based on Coronal Mass Ejection Automatic Detection with Deep Learning

Coronal mass ejections (CMEs) are major drivers of geomagnetic storms, which may cause severe space weather effects. Automating the detection, tracking, and three-dimensional (3D) reconstruction of CMEs is important for operational predictions of CME arrivals. The COR1 coronagraphs on board the Solar Terrestrial Relations Observatory spacecraft have facilitated extensive polarization observations, which are very suitable for the establishment of a 3D CME system. We have developed such a 3D system comprising four modules: classification, segmentation, tracking, and 3D reconstructions. We generalize our previously pretrained classification model to classify COR1 coronagraph images. Subsequently, as there are no publicly available CME segmentation data sets, we manually annotate the structural regions of CMEs using Large Angle and Spectrometric Coronagraph C2 observations. Leveraging transformer-based models, we achieve state-of-the-art results in CME segmentation. Furthermore, we improve the tracking algorithm to solve the difficult separation task of multiple CMEs. In the final module, tracking results, combined with the polarization ratio technique, are used to develop the first single-view 3D CME catalog without requiring manual mask annotation. Our method provides higher precision in automatic 2D CME catalog and more reliable physical parameters of CMEs, including 3D propagation direction and speed. The aforementioned 3D CME system can be applied to any coronagraph data with the capability of polarization measurements.

Development of a VLF receiver based on Red Pitaya for space weather studies

A new VLF (Very low Frequency) receiver has been developed by the Peruvian Space Agency (CONIDA) for space weather studies. The receiver has been designed based on a Red Pitaya board which performs an SDR (Software Defined Radio) to digitize, process and store the signal. The receiver is composed of a vertical antenna, a preamplifier to filter and amplify the incoming VLF signals from several transmitters located around the world. The receiver is able to cover a bandwidth from 1 up to 50 kHz and it has been developed in such a way as to be cost-effective, autonomous and solar-powered, making it suitable for installation in multiple locations with different geographic conditions. We show the performance of the receiver, the typical daily pattern of the lower ionosphere for the NAA VLF signal, as observed in Peru, and the first solar flares observed. The VLF amplitude curves recorded are validated by comparing them with data from SAVNET (The South American VLF Network) receiver installed in Peru. In a first effort to investigate the impact of solar flares on the lower ionosphere, we conducted a statistical analysis between VLF amplitude perturbations and 1–8 Å solar X-rays flux provided by GOES satellites, resulting in a linear relationship.

Earth’s Geomagnetic Environment—Progress and Gaps in Understanding, Prediction, and Impacts

Understanding of Earth’s geomagnetic environment is critical to mitigating the space weather impacts caused by disruptive geoelectric fields in power lines and other conductors on Earth’s surface. These impacts are the result of a chain of processes driven by the solar wind and linking Earth’s magnetosphere, ionosphere, thermosphere and Earth’s surface. Tremendous progress has been made over the last two decades in understanding the solar wind driving mechanisms, the coupling mechanisms connecting the magnetically controlled regions of near-Earth space, and the impacts of these collective processes on human technologies on Earth’s surface. Studies of solar wind drivers have been focused on understanding the responses of the geomagnetic environment to spatial and temporal variations in the solar wind associated with Coronal Mass Ejections, Corotating Interaction Regions, Interplanetary Shocks, High-Speed Streams, and other interplanetary magnetic field structures. Increasingly sophisticated numerical models are able to simulate the magnetospheric response to the solar wind forcing associated with these structures. Magnetosphere-ionosphere-thermosphere coupling remains a great challenge, although new observations and sophisticated models that can assimilate disparate data sets have improved the ability to specify the electrodynamic properties of the high latitude ionosphere. The temporal and spatial resolution needed to predict the electric fields, conductivities, and currents in the ionosphere is driving the need for further advances. These parameters are intricately tied to auroral phenomena—energy deposition due to Joule heating and precipitating particles, motions of the auroral boundary, and ion outflow. A new view of these auroral processes is emerging that focuses on small-scale structures in the magnetosphere and their ionospheric effects, which may include the rapid variations in current associated with geomagnetically induced currents and the resulting perturbations to geoelectric fields on Earth’s surface. Improvements in model development have paralleled the advancements in understanding, yielding coupled models that better replicate the spatial and temporal scales needed to simulate the interconnected domains. Many realizations of such multi-component systems are under development, each with its own limitations and advantages. Challenges remain in the ability of models to quantify uncertainties introduced by propagation of solar wind parameters, to account for numerical effects in model codes, and to handle the special conditions occurring during extreme events. The impacts to technical systems on the ground are highly sensitive to the local electric properties of Earth’s surface, as well as to the specific technology at risk. Current research is focused on understanding the characteristics of geomagnetic disturbances that are important for geomagnetically induced currents, the development of earth conductivity models, the calculation of geoelectric fields, and the modeling of induced currents in the different affected systems. Assessing and mitigating the risks to technical systems requires quantitative knowledge of the range of values to be expected under all possible geomagnetic and technical conditions. Considering the progress that has been made in studying the chain of events leading to hazardous geomagnetic disturbances, the path forward will require concerted efforts to reveal missing physics, improve modeling capabilities, and deploy new observational assets. New understanding should be targeted to accurately quantify solar wind driving, magnetosphere-ionosphere-thermosphere coupling, and the impacts on specific technologies. The research, modeling, and observations highlighted here provide a framework for constructing a plan by which the international science community can comprehensively address the growing threat to human technologies caused by geomagnetic disturbances.

Terrestrial and Martian space weather: A complex systems approach

A comparative overview of Terrestrial and Martian space weather is presented, with emphasis on applying the tools of complexity and nonlinear dynamics to study the spatiotemporal dynamics and structures of sun-Earth and sun-Mars space environment. The following topics are reviewed: (1) complex systems approach to solar atmosphere and solar wind; (2) complex systems approach to planetary bow shock and magnetosphere-ionosphere; (3) Martian space weather, bow shock, and magnetosphere-ionosphere; (4) imaging planetary magnetosphere-ionosphere.

Joule Heating rate at high-latitudes by Swarm and ground-based observations compared to MHD simulations

We compare Joule Heating rates as derived from ground-based magnetic field and all-sky camera data, from Low Earth Orbit satellite data (ESA Swarm) and from a MHD simulation (GUMICS-5) with each other in a case study of an auroral arc system. The observational estimates of Joule Heating rates provide information on regional scales and with high spatial resolution (10–100 km). Their comparison with global MHD results is conducted for a quiet time interval of a few minutes, just before a magnetic substorm. Analysis of the ground-based observations yields electric field with dominating North-South component pointing towards the arcs and having maxima values in the range 20–35 V/km. Combining these values with Pedersen conductance estimates from optical data (5–10 S) yields Joule Heating rates in the range 2.5–3.5 mW/m2. Swarm electric field measurements are consistent in their direction and intensity with the ground-based estimates. They also show that heating is increased particularly in the region where the conductance is low. The total amount of Joule heating in the area between the Swarm A and C satellite footprints while crossing the all-sky camera field of view is estimated to be 46 MW and the total amount energy dissipation during the 80 s overflight is around 3.6 GJ (1000 kWh). GUMICS-5 estimate of the peak Joule Heating in the magnetic local time sector of the arc system is smaller than that from the ground-based data with a factor of 2.9. Comparisons of GUMICS-5 results with Space Weather Modelling Framework (SWMF), shows that the latter gives on average larger heating rates being thus more consistent with our regional observations. However, both MHD-codes yield smaller Joule Heating rates around the time of the arcs and during the following substorm than the CTIP-e code. CTIP-e has a more detailed description of ionosphere-thermosphere interactions than the MHD-codes and its convection electric field is enhanced with a randomly varying additional component mimicking small scale structures. GUMICS-SWMF comparisons of global Joule Heating patterns in the Northern polar area reveal that the two simulations have significant differences in their spatial distribution of heating rates. Main cause for these deviations is the difference in the derivation of ionospheric Pedersen conductance. Our results emphasize the fact that future estimates of the global energetics in the magnetosphere–ionosphere–thermosphere system require better knowledge on ionospheric conductivities, both by new measurement concepts and by better understanding on the background physics controlling conductivity variations.

Short-term Classification of Strong Solar Energetic Particle Events Using Multivariate Time-series Classifiers

Solar energetic particle (SEP) events are one of the most crucial aspects of space weather that require continuous monitoring and forecasting. Their prediction depends on various factors, including source eruptions. In the present work, we use the Geostationary Solar Energetic Particle data set covering solar cycles 22, 23, and 24. We develop a framework using time-series-based machine-learning (ML) models with the aim of developing robust short-term forecasts by classifying SEP events. For this purpose, we introduce an ensemble learning approach that merges the results from univariate time series of three proton channels (E ≥10, 50, and 100 MeV) and the long-band X-ray flux (1–8 Å) channel from the Geostationary Operational Environmental Satellite missions and analyze their performance. We consider three models, namely, time series forest, supervised time series forest (STSF), and Bag-of-Symbolic Fourier Approximation Symbols. Our study also focuses on understanding and developing confidence in the predictive capabilities of our models. Therefore, we utilize multiple evaluation techniques and metrics. Based on that, we find STSF to perform well in all scenarios. The summary of metrics for the STSF model is as follows: the area under the ROC curve = 0.981, F 1-score = 0.960, true skill statistics = 0.919, Heidke skill score = 0.920, Gilbert skill score = 0.852, and Matthew’s correlation coefficient = 0.920. The Brier score loss of the STSF model is 0.077. This work lays the foundation for building near-real-time short-term SEP event predictions using robust ML methods.

Identification of Geomagnetic Pulsations in SQUID Data for Space Weather Research

Identification of Geomagnetic Pulsations in SQUID Data for Space Weather Research

The impact of moderate solar flare activity on ionospheric response from august 5th to 7th, 2023

This study investigates the ionospheric response to a period of heightened solar flare activity from August 5th to August 7th, 2023, by analysing ground-based observations of various ionospheric parameters. The data includes detailed information on solar flare events, including their class, start time, maximum time, and end time, along with solar activity indicators such as sunspot numbers, solar radio flux, and solar zenith angles. On August 5th, multiple C-class, M-class, and an X1.63 flare were recorded, with the X-class flare being the most intense event. Ionospheric measurements revealed enhancements in electron temperatures, reaching a peak of 2104K at 6 UT, coinciding with the onset of an M1.6 flare. Additionally, a pronounced increase in total electron content (TEC) was observed, peaking at 34 TEC units at 6 UT, suggesting increased ionization due to the flare's influence. On August 6th, an M5.51 flare was the most significant event. Notably, the peak electron temperature of 2097K and the TEC maximum of 35.9 units were recorded at 6 UT, several hours before the flare's maximum phase, indicating potential preconditioning effects from the flare's preparatory stages. August 7th witnessed an X1.51 flare, along with multiple M-class flares. The peak electron temperature of 2088K and the TEC maximum of 35.3 units were observed at 7 UT, again preceding the X1.51 flare's peak, suggesting the influence of precursor effects. Throughout the observation period, the data exhibited typical diurnal patterns in ion temperatures and TEC, consistent with regular ionospheric behavior driven by solar radiation intensity variations. The study's findings provide evidence of the ionosphere's responsive nature to intense solar flare activity, with significant enhancements in electron temperatures and TEC observed during flare events. Notably, the effects were evident not only during the peak flare phases but also several hours prior, potentially due to the arrival of energetic particles or precursor electromagnetic radiation, indicating the influence of preconditioning processes. Furthermore, the data suggests that solar flares can impact the ionosphere's chemistry and dynamics, as inferred from changes in the "Ion Percentage" parameter, representing relative ionospheric compositions. Continuous monitoring and analysis of such events across different geophysical conditions are crucial for advancing the understanding of solar-terrestrial interactions and their impacts on space-based technologies, contributing to the development of improved space weather prediction and mitigation strategies.

PASAT: pathfinder in solar adaptive telescope

In the forefront of quantitative solar physics research using large-aperture ground-based solar optical telescopes, high-contrast observation along with high-accuracy polarimetric measurement in the solar active region are required. In this paper, we propose a novel high-contrast imaging telescope construction with a 60 cm medium aperture, namely, the PAthfinder in Solar Adaptive Telescope (PASAT), in which a deformable secondary mirror is used as the adaptive optical correction device and a symmetrical optical path design is employed, leading to the least Muller matrix polarization instruments. The telescope can provide a high-resolution magnetic field with high accuracy for the solar active regions, as well as high-contrast images with a superior signal-to-noise ratio and photometric accuracy of the solar photosphere and chromosphere. These data will be directly used for a better understanding of the evolution and release of magnetic energy, which will help in improving space weather forecasting. Meanwhile, PASAT will accumulate the relevant techniques for constructing similar, larger solar telescopes in the future.

SWOL2023: Report of Space Weather Observations Throughout Latinoamerica: Filling the Southern Gaps

AbstractThe “Space Weather Observations throughout Latinoamerica: Filling the Southern gaps” Workshop took place in Ushuaia, Argentina, from 2 to 4 October 2023. This event was exclusively dedicated to Space Weather (SWx), gathering leading international academic and governmental agencies focused on the subject. The meeting addressed the field of SWx from three perspectives: driving phenomena occurring in the solar atmosphere, evolution in the interplanetary environment, and interaction with the Earth. In addition, emphasis was placed on identifying key research directions in solar and space physics that warrant development in Argentina and across the region in the forthcoming years. The workshop also focused on the current observational infrastructure that supports SWx studies, and how to improve and develop it through strategic international partnerships, stressing on the need for real‐time data. The conference fostered discussion among different partners involved in SWx studies, that is, researchers and potential space weather service providers, and the need to include in this debate potential users of space weather services.

Solar Filament Detection Based on an Improved Deep Learning Model

Solar filaments are good tracers of space weather and magnetic flux ropes in the corona. Identifying and detecting filaments helps to forecast space weather and explore the solar magnetic field. Many automatic detection methods have been proposed to process the large number of observed images. Current methods face issues of unreliable dataset annotations and poor anti-interference capability. First, to address the issue of unreliable dataset annotations, we built a solar filament dataset using a manual annotation method. Second, we introduced Transformer into Convolutional Neural Networks. Transformer, with the ability to extract more global features, can help counter interference. In addition, there is large disparity in the size of solar filaments. Therefore, a multi-scale residual block is designed to extract features across various scales. Deformable large kernel attention and a res path are used to better integrate encoder and decoder information. Results show that this method outperforms the existing solar filament detection methods (improved U-Net and improved V-Net), achieving an F1 score of 91.19%. In particular, our results show lower interference by sunspots and background noise than existing methods. The ability to counter interference is improved.

Impact of flight route changes on cosmic ray exposure: consequences of the conflict between Ukraine and the Russian federation.

This work investigates the impact on cosmic ray exposures to aircrew due to changing flight routes operated in the context of the recent conflict between Ukraine and the Russian Federation. All analyses were done based on Paris-Tokyo and Tokyo-Paris flights taken as examples, and differences in radiation exposures were quantified by comparing the situation before and after the beginning of the conflict. Regarding space weather scenarios, a quiet solar period and an extreme solar event (ground level enhancement (GLE) 5) were considered in the study. Analyses showed that the new Paris-Tokyo flight route established after the beginning of the conflict results in a smaller radiation dose to aircrew than that operated before the conflict, particularly during solar events. In contrast, for Tokyo-Paris flights the new high-latitude route crossing the Atlantic Ocean and North America increases the dose significantly (+ 50% in the worst case). Although this analysis is limited only to flights connecting Paris and Tokyo, it allowed for an evaluation of the consequences of new routes (particularly polar ones) on ambient dose equivalent values.