A long-standing challenge to both basic space science and space weather capabilities is understanding what determines the amount of energy that goes into the CME (mass motions) versus the flare (plasma heating) in a solar eruptive event. It is also unclear what role thermodynamics plays in shaping CME dynamics. Although there have been many detailed observational studies of this issue using particular events, there have been very few quantitative theoretical studies due to the difficulty in keeping an accurate track of the energy released by the explosive reconnection during the flare impulsive phase. In this work, we conduct MHD simulations of the CME using an energy-conservative numerical scheme, which ensures energy conservation and accurate tracking of the energy release channels. The simulations are based on the Alfvén Wave Solar Model-Realtime (AWSoM-R). We used a simple photospheric magnetic field map composed of two dipoles. We then used the statistical injection of the condensed helicity model to generate CME eruptions. First, we analyzed the evolution of the magnetic, thermal, and kinetic energies during the CME eruption and found that the fraction of the released magnetic energy converted to thermal energy can be \approx 40 \%. We noticed that using the energy conservation scheme results in significantly more energy being converted to kinetic energy. The thermal energy leads to extremely high temperatures in the flare current sheet. We analyzed the evolution of density, electron temperature, and ion temperature in the flare current sheet. We found that extremely high temperatures hinder reconnection, resulting in a long-lasting current sheet. A second CME eruption is triggered due to this current sheet. Our results show that energy conservation and full thermodynamics play a key role in affecting the CME eruption process. We discuss the implications of our results for understanding energy release in a solar eruption and for interpreting observations of CMEs/eruptive flares.

Numerical models of the solar wind and coronal mass ejections (CMEs) utilize photospheric magnetic field observations to prescribe the inner boundary conditions for the plasma solutions. These magnetic field data are available to the community through various observational instruments, prepared via different methodologies and/or flux transport models. The solar wind solution driven by these maps provides the ambient plasma environment into which CMEs travel. Interaction with the surrounding solar wind impacts CME evolution and propagation in the solar corona and inner heliosphere. In this work, we use different input magnetic field maps for the same time period to drive the global Alfv & eacute;n Wave Solar atmosphere Model. We obtain the ambient solar wind conditions and compare the plasma properties and magnetic morphology in the corona domain to study the influence of the input maps. To understand how the resulting coronal solutions impact CMEs, we launch eruptions described by analytical flux ropes into these data-driven solutions and compare their evolution in the coronal domain (up to 24 R circle dot radially). The CMEs achieve varying speeds, deceleration rates, propagation directions, mass, and energies while coupling with the background solar wind. We quantify these differences to show that the different input driving maps can significantly impact the simulated CME propagation in the solar wind plasma. This also highlights the importance of understanding the uncertainties associated with data-driven modeling that become increasingly important in operational models and space weather prediction.

Strict energy conservation is, perhaps, the most basic principle in all physics, but has proven to be difficult to satisfy in numerical simulations of solar eruptions. The Alfvén Wave Solar atmosphere Model (AWSoM) is used to perform a rigorous comparison of CME simulations whose only difference is the use of a conservative vs. non-conservative scheme for the energy equation. A simple, symmetric active region is assumed for the initial magnetic field. As expected, the different numerical schemes result in very different plasma thermal energy, but surprisingly, we also find a factor >2 difference in the final kinetic energy, with the energy substantially larger in the energy-conservative scheme. The increase in thermal energy is comparable to the increase in kinetic energy in the conservative simulation. Our analysis reveals that the flare reconnection and increase of kinetic energy terminate earlier with the non-conservative scheme. We conclude that the plasma thermodynamics plays a critical role in the flare reconnection, with the thermal pressure gradient in the current sheet slowing down the reconnection. Our results imply that using strict energy-conservative numerics is critical for space weather modeling of CMEs and for understanding the CME energy budget partitioning.

Accurate real-time and forecast of the space radiation environment caused by solar energetic particles (SEPs) is essential in supporting the human and robotic exploration activities in space. We implemented an automated and end-to-end pipeline based on the Solar Wind With Field Lines and Energetic Particles (SOFIE) model developed at the University of Michigan. SOFIE is a framework coupling several physics-based models that simulates the ambient solar wind, coronal mass ejections (CMEs), and SEPs. The ambient solar wind and the propagation of the CME is modeled using the Alfvén Wave Solar atmosphere Model–Realtime (AWSoM-R) model, a three-dimensional extended magnetohydrodynamic model that self-consistently accounts for Alfvén wave–driven heating and solar wind acceleration. The CME is generated by putting a Gibson–Low flux rope on the source region using the Eruptive Event Generator (EEGGL). The SEP acceleration and transport are modeled by the Multiple Field Line Particle Advection Model for Particle Acceleration (M-FLAMPA). We have implemented the SOFIE pipeline in which the ambient solar wind will be running continuously, ingesting hourly updated photospheric magnetic field observations to maintain an up-to-date solar wind solution in the heliosphere. When a CME is detected, the pipeline will launch a branched integrated CME and SEP simulation, in which the arrival of the Interplanetary Coronal Mass Ejection (ICME) and the complete SEP profiles at the energies of interest to the operation will be forecasted within a few hours of simulation time. The SOFIE pipeline is now fully automatic without human intervention. Model outputs and forecast products, including real-time solar wind conditions in the heliosphere, the forecasted arrival of the ICME and the proton fluxes will be made publicly available through the CLEAR website (https://solarwind.engin.umich.edu/). We will test the readiness and robustness of the pipeline and evaluate its performance during the Artemis-II mission.

We present a community effort to assess how open science can advance heliophysics and space weather modeling. Open science has the potential to enhance the quality and pace of scientific discovery, but its application to scientific modeling requires more careful consideration with respect to open data and open software guidelines, as complex scientific models are not ordinary software. We gathered feedback from modeling teams worldwide through a living survey and discussion sessions at the Open Science Workshop in College Park, USA, in 2024, and the COSPAR ISWAT Initiative Working Meeting in Cape Canaveral, USA, in 2025. We complement these findings with lessons learned from almost 25 years of experience at the Community Coordinated Modeling Center in enabling open use of models. We identify key roadblocks in current open science practices and guidelines and offer recommendations for future progress. Our findings are organized into four overlapping themes: open use of models and simulation results, open validation, open development, and open collaboration. An essential outcome of the discussion is the need for model developers and users to speak with a united voice and promote the role of models in future open science efforts. We introduce a new cross-domain community initiative called Heliophysics Open Modeling Environment (HOME), which will be integrated as an overarching activity within the COSPAR ISWAT Initiative. HOME will serve as a platform for modelers and model users to work together, facilitate community modeling, improve the scientific return on modeling investment, and advance innovation in heliophysics and space weather.

Solar eruptive events are generally believed to involve magnetic flux ropes (MFR), formed either in the pre-eruptive phase of the event or during the eruption itself. These MFR eruptions exhibit significant complexity and variations due to the interplay of the physical mechanisms involved, in particular magnetic reconnection and ideal instabilities. This work considers the effect of the background magnetic field on the nature of eruptions with pre-existing MFRs. We used a new MHD model to simulate the whole MFR eruption process, including the pre-eruptive stage and the initiation. Three simulations were performed, all of which used an identical bipolar active region, but with different background magnetic fields in the three cases. The simulations resulted in two successful eruptions (CMEs) and one failed eruption (a confined flare). We analyzed the energetics and the acceleration of the MFR in detail, and found a transition to a rapid exponential rise phase in two of the simulations. We also calculated the criterion for the torus instability and the timing of the breakout and flare reconnections. Our results show that the rapid exponential rise phase is likely due to breakout reconnection. We conclude that a background field antiparallel to the active-region field lowers the magnetic free-energy threshold for eruption; but, does not guarantee a successful eruption. We also found that an antiparallel background field leads to faster flare reconnection, but of shorter duration. Our findings underscore the importance of the background magnetic field in understanding CMEs.

Abstract The CLEAR Space Weather Center of Excellence's solar energetic particle (SEP) model, SOlar wind with FIeld lines and Energetic particles (SOFIE), was run and evaluated on‐site during the Space Weather Prediction Testbed (SWPT) exercise at the National Oceanic and Atmospheric Administration's Space Weather Prediction Center (NOAA/SWPC) in May 2025. As a physics‐based SEP model, SOFIE simulates the acceleration and transport of energetic particles by the coronal mass ejection (CME)‐driven shock in the solar corona and inner heliosphere, and has been validated against historical events. However, questions remain regarding whether a physics‐based model, traditionally considered computationally expensive, could meet operational needs. The SWPT exercise offered a valuable opportunity to evaluate SOFIE under simulated operational conditions. On‐site interactive feedback from SWPC forecasters, Space Radiation Analysis Group (SRAG) console operators, Community Coordinated Modeling Center (CCMC) personnel, and Moon‐to‐Mars Space Weather Analysis Office (M2M SWAO) analysts led to significant strategic improvements in the model configuration. The simulation grid was optimized by combining a coarser background grid with higher‐resolution regions along the CME path and toward Earth, reducing computational cost without compromising accuracy. In this work, we present the simulated operational performance of SOFIE and its capability to predict SEP fluxes significantly faster than real time. During the SWPT exercise, SOFIE completed a 4‐day SEP simulation within 5 hr using 1,000 central processing unit cores, although the earliest SEP forecast was obtained a few hours after CME onset. This marks a milestone in demonstrating SOFIE's operational usefulness and robustness to support future human space exploration.

Magnetic reconnection in coronal current sheet(s) is widely believed to be the main energy release process powering solar eruptive events, such as flares, coronal mass ejections (CME), and coronal jets. Modeling this process and determining the channels for the energy release, mass motions and heating, has long been a major goal in space science. We present results from a two-fluid MHD simulation of an eruptive flare/CME using a newly developed Strategic Capability, SCEPTER, which is based on the well-validated and widely used Space Weather Modeling Framework. SCEPTER incorporates two major advances in numerical capability. First, we use the STITCH formalism for the energy buildup, so that we start with a potential-field minimum-energy state and slowly form a sheared filament channel over a polarity inversion line as is observed on the Sun. Second, we use a new formulation of the plasma energetics that is explicitly energy conserving while calculating separate electron and ion temperatures and separate parallel and perpendicular pressures, as desired. For this first simulation with our new model, we opted for the non-adiabatic heating to go solely into the protons and for an isotropic pressure. We discuss the resulting energetics of the reconnection and, in particular, the plasma heating in the reconnecting current sheets, mass acceleration, and shock formation. We also discuss the implications of our results for understanding solar eruptions, in general. This work was supported by the NASA Living With a Star Program.

Advancing space weather forecasting for human space exploration requires not only advanced scientific models, but also demonstration of their operational readiness, validation in realistic environments, and sustained feedback between research and operations (R2O2R). The CLEAR Space Weather Center of Excellence (CLEAR center) focuses on developing and transitioning advanced solar energetic particle (SEP) forecasting capabilities into operationally viable, real-time systems to support future missions.In this presentation, we will describe the research to operation activities conducted within the CLEAR center, with an emphasis on the past testbed-based exercise, operational co-development, and real-time implementation. The CLEAR center actively participated in the 2025 Space Weather Prediction Testbed Exercise in support of Human Space Exploration and the Artemis-II Mission, which provided a realistic operational context to assess model performance under constraints relevant to flight decision support, including latency, robustness, automation, interpretability, and uncertainty communication.We will also report on the deployment of the CLEAR center’s physics-based, empirical, and machine-learning SEP models into an automated, near-real-time forecasting framework, designed to operate continuously during mission-critical periods. Particular attention is given to operational architecture, including data acquisition, computational optimization, automation and fail-safe design, enabling timely delivery of prediction products for Artemis launch windows. Feedback from operators and forecasters has directly informed pipeline design, product placement, delivery timing, and visualization - closing the O2R loop.This work demonstrates how sustained engagement with operational partners accelerates the transition of SEP research into actionable forecasting capabilities. The CLEAR experience provides a concrete example of effective R2O2R pathways for next-generation space weather modeling in support of Moon and Mars exploration.

The Metis coronagraph onboard Solar Orbiter and the LASCO-C2 coronagraph onboard SoHO both acquire white light polarized brightness (pB) images of the solar corona. When the Sun–Solar Orbiter distance is less than 0.85 AU, i.e., outside orbital segments around aphelia, the range of elongations covered by the fields-of-view of the two instruments overlap significantly, allowing a quantitative comparison of their images. We report on such a comparison during September 2022, with images taken during a superior conjunction of the two spacecraft with the Sun, as well as close to that event. In each comparison, the two instruments observed the corona from opposite viewpoints, within ≈ 1^∘ in both Carrington longitude and latitude, with Metis at a distance of about half an astronomical unit from the Sun. We find that the Metis measurements are systematically larger than those of LASCO-C2 throughout the corona, with the Metis-to-C2 ratio of pB exhibiting a median value of ≈ 1.6 . The discrepancy is observed comparing essentially simultaneous observations, so it cannot be explained as an effect of coronal dynamics. Synthetic images of the solar corona computed from a stationary three-dimensional magneto-hydrodynamic model, replicating the geometry of the observations, are photometrically consistent. This rules out the small departure of the two instruments from observing from opposite viewpoints, or their different distance to the Sun, as the cause of their discrepant measurements. We conclude that the reported discrepancy has its root in the calibration methods of the two instruments, which should be further investigated.

AbstractForecasting the arrival time of Earth‐directed coronal mass ejections (CMEs) via physics‐based simulations is an essential but challenging task in space weather research due to the complexity of the underlying physics and limited remote and in situ observations of these events. Data assimilation techniques can assist in constraining free model parameters and reduce the uncertainty in subsequent model predictions. In this study, we show that CME simulations conducted with the Space Weather Modeling Framework (SWMF) can be assimilated with SOHO LASCO white‐light (WL) observations and solar wind observations at L1 prior to the CME eruption to improve the prediction of CME arrival time. The L1 observations are used to constrain the model of the solar wind background into which the CME is launched. Average speed of CME shock front over propagation angles are extracted from both synthetic WL images from the Alfvén Wave Solar atmosphere Model (AWSoM) and the WL observations. We observe a strong rank correlation between the average WL speed and CME arrival time, with the Spearman's rank correlation coefficients larger than 0.90 for three events occurring during different phases of the solar cycle. This enables us to develop a Bayesian framework to filter ensemble simulations using WL observations, which is found to reduce the mean absolute error of CME arrival time prediction from about 13.4 to 5.1 hr. The results show the potential of assimilating readily available L1 and WL observations within hours of the CME eruption to construct optimal ensembles of Sun‐to‐Earth CME simulations.

On 2022 September 5, a large solar energetic particle (SEP) event was detected by Parker Solar Probe (PSP) and Solar Orbiter (SolO) at heliocentric distances of 0.07 and 0.71 au, respectively. PSP observed an unusual velocity dispersion signature: particles below ∼1 MeV exhibited a normal velocity dispersion, while higher-energy particles displayed an inverse velocity arrival (IVA) feature, with the most energetic particles arriving later than those at lower energies. The maximum energy increased from about 20–30 MeV upstream to over 60 MeV downstream of the shock. The arrival of SEPs at PSP was significantly delayed relative to the expected onset of the eruption. In contrast, SolO detected a typical large SEP event characterized by a regular velocity dispersion at all energies up to 100 MeV. To understand these features, we simulate particle acceleration and transport from the shock to the observers with our newly developed SEP model—Particle ARizona and MIchigan Solver on Advected Nodes. Our results reveal that the IVA and delayed particle onset detected by PSP originate from the time-dependent diffusive shock acceleration processes. After shock passage, PSP’s magnetic connectivity gradually shifted due to its high velocity near perihelion, detecting high-energy SEPs streaming sunward. Conversely, SolO maintained a stable magnetic connection to the strong shock region where efficient acceleration was achieved. These results underscore the importance of spatial and temporal dependence in SEP acceleration at interplanetary shocks and provide new insights to understand SEP variations in the inner heliosphere.

Previous studies on the interaction of Mars’ un-magnetized space environment with the solar wind have shown that the structural morphology of Mars’ hybrid magnetosphere and the plasma dynamical processes occurring within are strongly driven by its solar wind conditions. This unique interaction is highly complex during quiet solar wind periods, let alone extreme solar wind conditions such as the encounter of CMEs or other transient solar wind structures. This emphasizes the importance of accurate knowledge of the upstream solar wind conditions when any spacecraft is inside the hybrid magnetosphere. However, all planetary missions to Mars consist of only one spacecraft, which further highlights the need for a solar wind model to accurately predict the upstream solar wind conditions. Here, we aim to validate and assess the capability of the physics-based Alfvén Wave Solar atmosphere Model (AWSoM) developed at the University of Michigan in predicting the solar wind interplanetary magnetic field (i.e. B) and plasma conditions (i.e. velocity, temperature and density) by comparing its simulated outputs with the solar wind data from the MAVEN spacecraft; MAVEN has been in orbit around Mars since 2014. We surveyed and identified multiple Carrington rotations across 10 years of MAVEN solar wind observations whenever MAVEN is upstream of the martian bow shock, and compared them with the simulated outputs from AWSoM using the dynamic time warping technique as a metric tool. Preliminary results indicate that AWSoM was able to accurately predict the magnitude of each solar wind parameter but did not perform as well when predicting the time of occurrence for observed solar wind structures (i.e. time-shift between observed and simulated). We further investigated the quality of our data-model comparison between consecutive solar maximum of Solar Cycle 24 and current Solar Cycle 25, and the solar minimum in-between. The data-model comparison methods and results presented in this study contribute to the overall space weather efforts to improve the accuracy and precision of the physics-based AWSoM solar wind predictions over large heliocentric distances, including Mercury and Earth.

We present an unprecedented simulation of how two large-scale heliospheric transients—a coronal mass ejection (CME) and a corotating stream interaction region—collide, producing a dramatic increase in the complexity of the CME due to formation of mesoscale flux ropes. These structures are captured for the first time by a numerical simulation using high-resolution numerical grids. The circumstances that lead to the formation of these complex structures occur during solar maximum. At the time of the solar maximum taken for this study, 2014 September, the heliospheric current sheet is vertically inclined running over the poles, allowing the CME to impact a preceding slow-fast stream interaction region. The simulation is performed with the Alfvén Wave Solar Atmosphere Model (or AWSoM), with which we initiate a fast CME from active region (AR) 12158 by applying a Gibson–Low magnetic flux rope. Magnetic reconnection within the leading extremity of the CME results in the formation of mesoscale flux ropes, which contain sufficiently strong magnetic fields (∼30 nT) to affect planetary magnetospheres. Finally, we use a tetrahedral configuration of four virtual probes, corresponding to the Space Weather Investigation Frontier mission concept, to show that the mission can uniquely resolve the spatial characteristics and temporal evolution of reconnecting current sheets within the CME, as well as the resulting mesoscale structures.

Solar energetic particles (SEPs) can pose hazardous radiation risks to both humans and spacecraft electronics in space. Numerical modeling based on first principles offers valuable insights into the underlying physics of SEPs and provides synthetic observables for SEPs at any time and location in the inner heliosphere. In this work, we present a numerical scheme, which conserves the number of particles based on integral relations for Poisson brackets, to solve the kinetic equation for particle acceleration and transport processes. We implement this scheme within the Space Weather Modeling Framework, developed at the University of Michigan. In addition, we develop a new shock-capturing tool to study the coronal mass ejection-driven shock originating from the low solar corona. These methodological advancements are applied to conduct a comprehensive study of a historical SEP event on 2013 April 11. Observations from multiple spacecraft, including the Solar and Heliospheric Observatory, Solar Dynamics Observatory, Geostationary Operational Environmental Satellite, Advanced Composition Explorer near Earth, and STEREO-A/B, are used for model–data comparison and validation. We show synthetic observables, including extreme ultraviolet and white-light images, proton time–intensity profiles, and energy spectra, and discuss their differences and probable explanations compared to observations. Our simulation results demonstrate the application of the Poisson bracket scheme with a particle solver to simulating a historical SEP event. We also show the capability of extracting the complex shock surface using our shock-capturing tool and understand how the complex shock surface affects the particle acceleration process.

Supported by the Space Weather with Quantified Uncertainty (SWQU) NSF program, we have been developing the Next Generation Space Weather Modeling Framework at the University of Michigan for three years. The main goal of the project is to provide useful probabilistic forecast of major space weather events about 24 hours before the geospace impact occurs. We are using the first-principles models in the Space Weather Modeling Framework (SWMF) in combination with uncertainty quantification and data assimilation. Using the advanced MaxPro experimental design and fully automated Python scripts, we have performed thousands of solar wind background and coronal mass ejection (CME) simulations with the solar corona, inner heliosphere and eruptive event generator based on the Gibson-Low fluxrope (EEGGL) models of the SWMF. Our CME initiation model is at the surface of the Sun, so the CME can interact with the background solar wind and the magnetic field of the erupting active region. Based on these simulations, we have performed the uncertainty quantification analysis using the Bayesian inversion formula and a newly defined distance metric adapted to solar simulations. One important finding is that the physically meaningful range of the background solar wind model parameters depends on the solar cycle. We have identified the three most important parameters that impact the background solar wind model and two more parameters (the strength and helicity of the magnetic field of the fluxrope) that impact the CME eruption model. The reduced dimensionality of the parameter space enables reducing the size of the ensemble. Data assimilation provides further opportunity to improve the predictions. We are using in-situ observations at L1 prior to the CME to constrain the background solar wind and coronal white-light image observations right after the eruption to find the optimal flux rope parameters. We find that the CME arrival time error is significantly reduced to less than 5 hours by the data assimilation based on three events. Using an ensemble of simulations also provides a likely range for the various quantities of interest, including arrival time, solar wind speed and density and the BZ component of the magnetic field. The main product of the project, the Michigan Sun-to-Earth Model with Quantified Uncertainty and Data Assimilation (MSTEM-QUDA) is available as an open-source distribution at https://github.com/MSTEM-QUDA

The Eruptive Event Generator – Gibson-Low (EEGGL) generates an unstable 3D flux rope from a given synoptic solar magnetogram that can be inserted into magnetohydrodynamic (MHD) coronal simulations for coronal mass ejection (CME) initiation. This model has been used extensively for CME simulation, both for studying the evolution of the CME itself and for generation of solar energetic particles that propagate throughout the heliosphere. EEGGL relies on empirical fitting of test events to find the relationship between the magnetogram, CME parameters, and flux rope geometry and strength. As part of the CLEAR NASA Center of Excellence at the University of Michigan, validation and enhancement of EEGGL is a key deliverable. In this presentation, we provide results from the updated EEGGL with improvements to enhance the robust nature of the code. A statistical validation is performed comparing synthetic white-light coronal images generated by the simulation to coronagraph observations, focusing on CME speed and strength. While past publications have occasionally optimized the flux rope based on a priori knowledge, we use larger statistics from agnostic runs to evaluate model performance. Such steps prepare the model for running in a fully-automated low-latency configuration.

Magnetic reconnection in a flare current sheet is widely believed to be the main energy release process powering solar flares and coronal mass ejections (CMEs). Modeling this process and determining the channels for the energy release, mass motions, and heating has long been a major goal in space science. We present results from a two-fluid magnetohydrodynamic simulation of an eruptive flare/CME using a newly developed version of the Space Weather Modeling Framework that incorporates two major advances in numerical capability. First, we use the STatistical InjecTion of Condensed Helicity formalism for the energy buildup, so that we start with a potential-field minimum-energy state and slowly form a sheared filament channel over a polarity inversion line as is observed on the Sun. Second, we use a new formulation of the plasma energetics that is explicitly energy conserving while calculating separate electron and ion temperatures and separate parallel and perpendicular pressures, as desired. For this first simulation with our new model, we opted for the nonadiabatic heating to go solely into the protons and for an isotropic pressure. We discuss the resulting energetics of the reconnection and, in particular, the plasma heating in the reconnecting current sheets, mass acceleration, and shock formation. We also discuss the implications of our results for flare/CME observations and for understanding solar eruptions in general.