The Center for Geospace Storms (CGS) is a NASA DRIVE Science Center focused on geospace science. CGS is pursuing the goal of developing an understanding of the stormtime geospace as a complex system exhibiting strong coupling across physical regimes, domains and particle populations, which occurs across disparate spatiotemporal scales. CGS is tackling this problem via a concerted effort using both data analysis from heterogeneous sources (e.g., in situ, remote sensing and ground-based platforms) and physics-based modeling. In particular, the CGS team is developing the Multiscale Atmosphere-Geospace Environment (MAGE) model that couples all the relevant domains of geospace while doing it at sufficiently high resolution to capture key cross-scale interactions. In this presentation, we discuss recent work from the CGS team concentrating on high- to mid-latitude magnetosphere-ionosphere coupling in stormtime geospace. We discuss the novel model of energetic particle precipitation in MAGE, based on gray-box modeling of wave-induced particle precipitation, and its applications to high-resolution modeling of the aurora. We show examples of simulations of mesoscale auroral forms, such as giant undulations, and their connection to inner magnetosphere dynamics, including the subauroral polarization streams. We also review our recent efforts on developing a new high-resolution (in space and energy) inner magnetosphere model. Finally, we conclude the talk by emphasizing the interconnectedness of stormtime geospace using the May’24 superstorm as an example.

Auroral precipitation plays an important role in the magnetosphere-ionosphere-thermosphere (MIT) coupling. Various precipitation spectra have been observed and they are driven by different physical mechanisms. In this study, we report the Dragon King model which is used to characterize auroral precipitation and its consequent ionospheric conductance in the Multiscale Atmosphere-Geospace Environment (MAGE) model, a newly developed whole geospace model. Mono-energetic electron precipitation is derived from large-scale field-aligned currents and drift-physics informed loss cone rate, using the linearized Fridman-Lemaire relation. Diffuse electron precipitation is derived with a drift-physics based ring current model, in which electron lifetime due to interactions with chorus and hiss waves is obtained with an empirical table and electron loss rate is informed by drift physics and IGRF magnetic field. Broadband electron precipitation is derived from a statistical relationship between field-aligned Alfvénic Poynting flux and the precipitation energy flux and number flux. The Dragon King model is validated from different perspectives with various observational data, including the statistical pattern during different categories of solar wind driving conditions, and along-trajectory comparison with satellite measurements. The Dragon King model is further used to understand the drivers of different precipitation and their relative importance with MAGE simulations.

Accurately specifying polar ionospheric electrodynamics is essential for understanding energy and momentum exchange between space and the upper atmosphere and for improving simulations of the ionosphere and the thermosphere. Statistical models are commonly used to provide input for global circulation models (GCMs). However, maps derived from simultaneous multi-instrument observations better represent the actual state of the system. Such maps integrate measurements from ground-based magnetometers and radars, in situ plasma and magnetic field sensors at low-Earth orbit, and optical and particle observations of auroral precipitation. However, ionospheric data assimilation remains in its early stages. Current methods rely on restrictive assumptions to simplify equations and stabilize inverse problems, but these constraints limit applicability beyond polar regions, hinder the inclusion of time-dependent processes, and prevent independent estimation of ionospheric conductance. This review examines the physical foundations of ionospheric data assimilation, evaluates the limitations of existing approaches, and explores pathways toward more accurate and flexible techniques. Specifically, we discuss approaches to: (1) use a common dataset to estimate conductance and fields in a single inversion; (2) incorporate neutral winds instead of assuming they are zero; (3) account for a realistic main magnetic field geometry instead of assuming radial field lines; (4) eliminate a sharp boundary between polar and low-latitude regions; (5) use F-region density measurements to capture the history of ionospheric conductance and plasma transport; (6) account for the magnetic field of ground-induced currents in a more realistic way; (7) include ionospheric induction effects to stabilize time-dependent inversions; and (8) couple ionospheric electrodynamics with global magnetosphere simulations to model the physics of time variations.

<p>Coupling of the solar wind and Earth’s magnetosphere is strongest during intervals of the southward interplanetary magnetic field (IMF), when magnetic reconnection at the subsolar magnetopause, with subsequent reconnection in the distant magnetotail, sets off a global convection cycle that transfers magnetic flux from the dayside into the magnetotail and then back to the dayside magnetosphere. Plasma sheet convection from the distant reconnection line to the inner magnetosphere exhibits a wide range of coupled multi-scale processes. Non-monotonic features in the plasma sheet magnetic terrain, such as minima, tailward gradients, or bumps in the northward component of the magnetic field lead to instabilities and<span class="Apple-converted-space">  </span>energy from transfer from large scale (~100 Earth radii) to mesoscale (~Earth radii) structures and earthward plasma flows. These in turn generate a wide range of kinetic scale (~100 km) phenomena which energize particles beyond 100 keV and produce bursts of particle precipitation into the atmosphere. In this paper we explore the properties and the role of mesoscale convection in the transport and acceleration of energetic electrons and ions from the magnetotail to the inner magnetosphere, from direct injections of particles into the radiation belt and the ring current, to generation of velocity instabilities that provide the pathway for the energy cascade from global to kinetic processes. We employ test-particle simulations in our Conservative Hamiltonian Integrator of Magnetospheric Particles (CHIMP) one way coupled to a high-resolution magnetohydrodynamic (MHD) simulations of plasma convection in the magnetotail. For the latter we use the Grid Agnostic MHD for Extended Research Applications (GAMERA) global magnetospheric model. We then use new modeling results and understanding of individual properties and impacts on plasmasheet dynamics to discuss Heliophysics Systems Observatory capabilities that would enable a system-wide view of cross-scale convection in Earth’s magnetotail.<span class="Apple-converted-space"> </span></p>

Supporting information for "The contribution of plasma sheet bubbles to stormtime ring current buildup and evolution of the energy composition" by Sciola et al. 2023 submitted to the Journal of Geophysical Research: Space Physics

During geomagnetically active periods plasma is transported from the magnetotail into the inner magnetosphere to become the ring current. The transpot of plasma into the ring current occurs at different spatial and temporal scales, from global quasi-steady convection to bursty bulk flows (BBFs), with typical cross-tail extents of 1-3 Earth radii. During its enhancement, the ring current plays a critical role in magnetosphere-ionosphere coupling. Ring current ions build up plasma pressure in the inner magnetosphere and will drive field-aligned currents which must close in the ionosphere, while electrons will lead to diffuse precipitation and enhanced ionospheric conductance which shape the ionospheric path of current closure. Current closure in the ionosphere will couple to the thermospheric neutral population, via Joule heating, and alter the dynamics of the plasmasphere, via the penetration electric field in the inner magnetosphere. Understanding the relative role of convection at different spatial scales in both the buildup of the ring current and its broader effects on geospace coupling is an area of active interest and one of the core science questions of the Center for Geospace Storms. In this talk I will describe how addressing this question has informed the development of the Multiscale Atmosphere Geospace Environment (MAGE) model and highlight several recent modeling studies which illustrate the central role of mesoscale processes.

George Clark, Jim Kinnison, Dan Kelly, Peter Kollmann, Wen Li, Allison Jaynes, Lauren Blum, Robert Marshall, Drew Turner, Ian Cohen, Sasha Ukhorskiy, Barry Mauk, Elias Roussos, Quentin Nénon, Sasha Drozdov, Xinlin Li, Emma Woodfield, Will Dunn, Grant Berland, Ralph Kraft, Peter Williams, Todd Smith, Kareem Sorathia , Anthony Sciola, George Hospodarsky, Xin Wu, Paul O’Brian, Mark Looper, Angelica Sicard, Andy Santo, Meagan Leary , Amanda Haapala, Fazle Siddique, Michelle Donegan, Ben Clare, Derek Emmell, Kim Slack, John Wirzburger, Daniel Sepulveda, Lew Roufberg, Jackie Perry, John Schellhase, Darrius Pergosky, Liz Able, Mike O’Neill, Cris Fernandes, Deb Chattopadhyay, Samuel Bibelhauser, Seth Kijewski, Joe Pulkowski, and Mike Furrow

High-resolution global magnetohydrodynamics (MHD) simulations include both meso- and global-scale processes occurring at the magnetopause, which interact to determine the time-dependent orientation of the day-side x-line (DXL). This study demonstrates that the global orientation of the DXL in GAMERA global MHD simulations varies on a time scale of minutes during steady southward interplanetary magnetic field conditions. This behavior manifests in observational data when reconnection outflows indicate that the direction to the x-line is opposite to the prediction from a steady-state model of the reconnection location. Because steady-state models of the DXL do not capture dynamics that are independent of solar wind variations, particularly surface waves and flux transfer events, they represent a time-averaged state of the system.

During a storm‐time interval around winter solstice, observations by the Magnetospheric Multi‐Scale (MMS) Mission show multiple distinct magnetopause boundary layers (BLs) in the vicinity of the southern cusp. The microphysics of the solar wind‐magnetosphere interaction during storm times are not well understood, because the observations are relatively lacking. This event enables the opportunity to probe the storm‐time magnetopause, and observations support that MMS was near a reconnection site equatorward of the southern cusp, suggesting active reconnection in close proximity to closed magnetic flux regions in the BL. The Grid Agnostic magnetohydrodynamics (MHD) for Extended Research Applications global MHD simulation shows evidence for transient secondary reconnection sites near the southern cusp, demonstrating mechanisms to form closed field line regions of the BL.

As radio astronomy enters a golden age, ground-based observatories are reaching sensitivities capable of unlocking a new and exciting field of exoplanet observation. Radio observation of planetary auroral emission provides unique and complementary insight into planetary science not available via orthodox exoplanet observation techniques. Supplying the first measurements of planetary magnetic fields, rotation rates, and orbital obliquities, we gain necessary and crucial insight into our understanding of the star–planet relationships, geophysics, composition, and habitability of exoplanets. Using a stellar-wind-driven Jovian approximation, we present analytical methods for estimating magnetospheric radio emission from confirmed exoplanets. Predicted radio fluxes from cataloged exoplanets are compared against the wavelengths and sensitivities of current and future observatories. Candidate exoplanets are downselected based on the sky coverage of each ground-based observatory. Orbits of target exoplanets are modeled to account for influential orbit-dependent effects in anticipating time-varying exoplanet radio luminosity and flux. To evaluate the angular alignment of exoplanetary beamed emission relative to Earth’s position, the equatorial latitude of exoplanetary auroral emission is compared against Earth’s apparent latitude on the exoplanet. Predicted time-dependent measurements and recommended beamformed observations for ground-based radio arrays are provided, along with a detailed analysis of the anticipated emission behavior for τ Boo b.

We present calculations of auroral radio emission for an Earth-like planet produced by field-aligned current (FAC) driven electron acceleration using a coupled global magnetohydrodynamic (MHD) and inner magnetosphere model, extending the capabilities of previous works which focus solely on the direct transmission of magnetic energy between the stellar wind and ionosphere. Magnetized exoplanets are expected to produce radio emission via interaction between the host star’s stellar wind and planetary magnetosphere-ionosphere system. The empirically derived Radiometric Bode’s Law (RBL) is a linear relation between the magnetic solar wind power and total emitted radio power from magnetized Solar System planets, and is often extrapolated to extreme exoplanet systems. It has been shown that the magnitudes of the FACs coupling the stellar wind to planetary ionospheres are likely to be significantly limited (often referred to as ionospheric saturation), resulting in an estimated radio power up to several orders of magnitude less than that predicted by RBL. In this paper, we demonstrate the significance of intense, sporadic FACs, driven by nightside magnetic reconnection and inner magnetosphere plasma flow, to the total radio power produced by wind–ionosphere interaction in terrestrial planets. During periods of strong stellar wind variability, the contribution from these secondary currents can be over an order of magnitude greater than the primary current systems that previous models describe. The results highlight the role of the variability of the stellar wind on the magnitude and location of the resulting emission, subsequently affecting the conditions for detectability.

Recently, there has been a growing interest in robotic systems that are able to share workspaces and collaborate with humans. Such collaborative scenarios require efficient mechanisms to communicate human requests to a robot, as well as to transmit robot interpretations and intents to humans. Recent advances in augmented reality (AR) technologies have provided an alternative for such communication. Nonetheless, most of the existing work in human-robot interaction with AR devices is still limited to robot motion programming or teleoperation. In this paper, we present an alternative approach to command and collaborate with robots. Our approach uses an AR interface that allows a user to specify high-level requests to a robot, to preview, approve or modify the computed robot motions. The proposed approach exploits the robot's decision-making capabilities instead of requiring low-level motion specifications provided by the user. The latter is achieved by using a motion planner that can deal with high-level goals corresponding to regions in the robot configuration space. We present a proof of concept to validate our approach in different test scenarios, and we present a discussion of its applicability in collaborative environments.

We employ a flux transport model incorporating observed stellar activity relations to characterize stellar interplanetary fields on cycle timescales for a range of stellar activity defined by the Rossby number. This framework allows us to examine the asterospheric environments of exoplanetary systems and yields references against which exoplanetary observations can be compared. We examine several quantitative measures of star?exoplanet interaction: the ratio of open to total stellar magnetic flux, the location of the stellar Alfvn surface, and the strength of interplanetary magnetic field polarity inversions, all of which influence planetary magnetic environments. For simulations in the range of Rossby numbers considered (0.1?5 Ro(Sun)), we find that (1) the fraction of open magnetic flux available to interplanetary space increases with Rossby number, with a maximum of around 40% at stellar minimum for low-activity stars, while the open flux for very active stars (Ro?0.1?0.25 Ro(Sun)) is ?1?5%; (2) the mean Alfvn surface radius, R-A, varies between 0.7 and 1.3 R-A,R-Sun and is larger for lower stellar activity; and (3) at high activity, the asterospheric current sheet becomes more complex with stronger inversions, possibly resulting in more frequent reconnection events (e.g., magnetic storms) at the planetary magnetosphere. The simulations presented here serve to bound a range of asterospheric magnetic environments within which we can characterize the conditions impacting any exoplanets present. We relate these results to several known exoplanets and discuss how they might be affected by changes in asterospheric magnetic field topologies.