Ramon E. Lopez

Solar eclipses provide unique opportunities to investigate geospace dynamics driven by rapid, localized reductions in solar radiation. On December , 2021, a total solar eclipse occurred over West Antarctica during substorms. While eclipse effects on Earth's upper atmosphere are widely studied, their subsequent impact on the magnetospheric configuration and feedback loops are less explored. Abrupt changes in conductivity can also affect interhemispheric asymmetry (IHA). In this study, an eclipse EUV mask was applied in the Global Ionosphere‐Thermosphere Model (GITM), driven by different high‐latitude forcing specifications. Using the Space Weather Modeling Framework, we examined how eclipse‐induced ionospheric conductance changes impact the magnetosphere and feed back to the I‐T system. Results show a −∼30% reduction in total electron content and −∼35% drop in ionospheric conductance compared to the no‐eclipse case, consistent with observations. This leads to an enhanced cross‐polar cap potential (CPCP) in both hemispheres (north vs. south: 36 vs. 40 kV). The eclipse reduced IHA in total field‐aligned currents and CPCP, bringing asymmetry close to zero after the shadow passed over the polar region. The magnetosphere also showed dynamic responses, including changes in plasma pressure and flow that shifted the magnetotail by up to 16 in the X ‐direction. Finally, by driving GITM with eclipse‐modified magnetospheric forcing, we found that magnetospheric feedback amplified thermospheric wind perturbations over the polar cap, even exceeding the direct effect of reduced solar EUV. These results demonstrate the critical role of ionospheric conductance in the coupled M‐I‐T system during solar eclipses.

The bow shock current (BSC) flows on the bow shock due to the compression of the interplanetary magnetic field (IMF) across the shock. Although previous studies have shown that the BSC can connect to magnetospheric current systems via the magnetosheath, it is still not known how this happens. For southward IMF, there is both numerical and observational evidence of BSC closure through the equatorial magnetosheath. For east‐west IMF (IMF dominated by the ‐component), the closure has instead been suggested to take place at higher latitudes, but this has yet to be investigated. In this paper we present the first hybrid‐kinetic simulation results in support of BSC closure through the high‐latitude magnetosheath, for east‐west IMF. Our simulations indicate large‐scale current closure away from (toward) the magnetosphere in the northern (southern) hemisphere, both in the dayside and nightside magnetosheath, for IMF . This is consistent with the north‐to‐south flowing BSC under such conditions. Moreover, our results suggest that the BSC primarily crosses the magnetosheath behind the quasi‐perpendicular bow shock.

The bow shock current (BSC) flows on the bow shock due to the compression of the interplanetary magnetic field (IMF) across the shock. Although previous studies have shown that the BSC can connect to magnetospheric current systems via the magnetosheath, it is still not known how this happens. For southward IMF, there is both numerical and observational evidence of BSC closure through the equatorial magnetosheath. For east-west IMF (IMF dominated by the By-component), the closure has instead been suggested to take place at higher latitudes, but this has yet to be investigated. In this paper we present the first hybrid-kinetic simulation results in support of BSC closure through the high-latitude magnetosheath, for east-west IMF. Our simulations indicate large-scale current closure away from (towards) the magnetosphere in the northern (southern) hemisphere, both in the dayside and nightside magnetosheath, for IMF By > 0. This is consistent with the north-to-south flowing BSC under such conditions. Moreover, our results suggest that the BSC primarily crosses the magnetosheath behind the quasi-perpendicular bow shock.

The Quantum for All project has developed instructional materials and a professional development program to expand Quantum Information Science education in precollege education. In this paper, we discuss the background for Quantum Science education in the United States. We then discuss the design of the professional development plan and the development of the materials by the Leadership Team, and the workshops for teachers to learn and utilize this content. We will examine growth in teacher knowledge and confidence and examine the variation of these things across content domains as represented by the instructional modules.

This exploratory study examines the classroom deployment of aiPlato, an AI-enabled homework platform, in a large introductory physics course at the University of Texas at Arlington. Designed to support open-ended problem solving, aiPlato provides step-wise feedback and iterative guidance through tools such as "Evaluate My Work" and "AI Tutor Chat", while preserving opportunities for productive struggle. Over four optional extra-credit assignments, the platform captured detailed student interaction data, which were analyzed alongside course performance and end-of-semester survey responses. We examine how students engaged with different feedback tools, whether engagement patterns were associated with performance on the cumulative final exam, and how students perceived the platform's usability and learning value. Students who engaged more frequently with aiPlato tended to achieve higher final exam scores, with a mean difference corresponding to a standardized effect size of approximately 0.81 between high and low engagement groups after controlling for prior academic performance. Usage patterns and survey responses indicate that students primarily relied on iterative, formative feedback rather than solution-revealing assistance. As a quasi-experimental pilot study, these findings do not establish causality and may reflect self-selection effects. Nonetheless, the results demonstrate the feasibility of integrating AI-mediated, step-wise feedback into authentic physics homework and motivate future controlled studies of AI-assisted tutoring systems.

Solar eclipses provide unique opportunities to investigate geospace dynamics driven by rapid, localized reductions in solar radiation. On December 4th, 2021, a total solar eclipse occurred over West Antarctica during substorms. While eclipse effects on Earth’s upper atmosphere are well studied, their influence on the coupled magnetosphere-ionosphere-thermosphere (M-I-T) system remains less understood. Abrupt changes in conductivity can also affect interhemispheric asymmetry (IHA). In this study, an eclipse EUV mask was applied in the Global Ionosphere-Thermosphere Model (GITM), driven by different high-latitude forcing specifications. Using the Space Weather Modeling Framework, we examined how eclipse-induced ionospheric conductance changes impact the magnetosphere and feed back to the I-T system. Results show a ~30% reduction in total electron content (TEC) and ~35% drop in ionospheric conductance compared to the no-eclipse case, consistent with TEC observations. This leads to an enhanced cross-polar cap potential (CPCP) in both hemispheres (north vs. south: 36 kV vs. 40 kV). The eclipse reduced IHA in total FACs and CPCP, bringing asymmetry close to zero after the shadow passed over the polar region. The magnetosphere also showed dynamic responses, including changes in plasma pressure and flow that shifted the magnetotail by up to 16 RE in the X-direction. Finally, by driving GITM with eclipse-modified magnetospheric forcing, we found that magnetospheric feedback amplified thermospheric winds perturbations over the polar cap, even exceeding the direct effect of reduced solar EUV. These results demonstrate the critical role of ionospheric conductance in the coupled M-I-T system during solar eclipses.

As physics‐based global magnetosphere‐ionosphere‐thermosphere models enter operations for space weather forecasting, it is imperative that the sources of uncertainty in model outputs are thoroughly investigated. Global magnetosphere models rely on a set of input solar wind conditions to drive the model; such inputs are often propagated from upstream in the solar wind where the interplanetary magnetic field and plasma parameters can be constantly monitored. Generally, this data is provided by the OMNI data set, a set of observations of the solar wind typically collected near the Lagrange point and propagated to Earth's bow shock nose. The actual solar wind conditions outside the bow shock may differ from the OMNI data, leading to erroneous model inputs. Erroneous model inputs will lead to erroneous model outputs, and contribute to poor predictions of space weather phenomena. We present a study on the effects of variability in OMNI solar wind propagation accuracy on ionosphere‐thermosphere model outputs at the individual grid cell level. Models are driven with OMNI and ARTEMIS (Acceleration, Reconnection, Turbulence & Electrodynamics of the Moon's Interaction with the Sun) solar wind time series for three events at varying levels of correlation between both inputs (Pearson Correlation Coefficient = 0.95, 0.82, and 0.58). Thermospheric neutral densities at three heights (200, 400, and 600 km) are compared for each simulation at grid cells over Kennedy Space Center, Florida, USA, and College Magnetometer Station, Alaska, USA.

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 understood. For east–west interplanetary magnetic field (IMF) it has been hypothesized that the BSC partly closes to the high‐latitude ionosphere, as field‐aligned currents (FACs) on open field lines, but there is still no statistical evidence of this. In order to investigate this hypothesis, we use 9 years of Defense Meteorological Satellite Program (DMSP) data to construct normalized FAC maps of the northern hemisphere polar cap. We sort them according to different IMF clock angles, IMF magnitudes and magnetosonic Mach numbers. By separating opposite polarity FACs, we show that, on average, a unipolar FAC exists in the dayside polar cap when the IMF , regardless of the sign of the IMF . This current flows out of (into) the ionosphere in the northern hemisphere for IMF and is thus of the correct polarity to connect to the north–south component of the BSC. Moreover, it is strongest when the BSC flows predominantly in the north–south direction. These results constitute the first statistical evidence in support of at least a partial closure of the BSC to the ionosphere during non‐zero IMF .

As physics-based global magnetosphere-ionosphere-thermosphere models enter operations for space weather forecasting, it is imperative that the sources of uncertainty in model outputs are thoroughly investigated. Global magnetosphere models rely on a set of input solar wind conditions to drive the model; such inputs are often propagated from upstream in the solar wind where the IMF and plasma parameters can be constantly monitored. Generally, this data is provided by the OMNI dataset, a set of observations of the solar wind typically collected near the L1 Lagrange point and propagated to Earth’s bow shock nose. The actual solar wind conditions outside the bow shock may differ from the OMNI data, leading to erroneous model inputs. Erroneous model inputs will lead to erroneous model outputs, and contribute to poor predictions of space weather phenomena. We present a study on the effects of variability in OMNI solar wind propagation accuracy on ionosphere-thermosphere model outputs at the individual grid cell level. Models are driven with OMNI and ARTEMIS solar wind time series for three events at varying levels of correlation between both inputs (Pearson Correlation Coefficient = 0.95, 0.82, 0.58). Thermospheric neutral densities at three heights (200 km, 400 km, 600 km) are compared for each simulation at grid cells over Kennedy Space Center, Florida, USA and College Magnetometer Station, Alaska, USA.