Browsing by Author "Sciola, Anthony"
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Item MMS Observations of Storm-Time Magnetopause Boundary Layers in the Vicinity of the Southern Cusp(Wiley, 2022) Burkholder, Brandon L.; Chen, Li-Jen; Fuselier, Stephen; Gershman, Daniel; Schiff, Conrad; Shuster, Jason; Zou, Ying; Walsh, Brian M.; Reiff, Patricia; Petrinec, Steve; Sciola, AnthonyDuring 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.Item Modeling the Space Weather Environment of Terrestrial Exoplanets(2021-04-28) Sciola, Anthony; Toffoletto, Frank; Alexander, DavidThe majority of currently known terrestrial exoplanets orbit close to their host stars, on the order of 0.05 AU. Such planets orbiting M Dwarf stars, assuming an Earth-like atmosphere, have the potential to possess liquid water on their surface, a key requirement for habitability of life as we are familiar with. However such close proximity to the star is also likely to result in the planet experiencing stellar wind pressures orders of magnitude greater than that at Earth. An understanding of whether the planet possesses an intrinsic magnetic field, or magnetosphere, and how this interacts with the extreme stellar wind, is necessary in order to constrain other parameters such as atmospheric loss rate. There is a unique radio emission which is expected to be commonly produced by magnetized planets, and is produced by every magnetized Solar System planet. Despite estimates predicting that such emission from Jupiter-sized set of exoplanets should be observable, there have been no confirmed detections thus far. This thesis utilizes magnetohydrodynamic (MHD) models coupled to the Rice Convection Model (RCM), originally developed to simulate Earth’s magnetosphere, to better understand the magnetic environments of terrestrial exoplanets. The first project adapts a coupled MHD+RCM model to simulate the environment of Proxima Centauri b, and estimates the rate of atmospheric loss via charge exchange. The second addresses the calculation of expected radio emission from a given exoplanetary environment, both analytically and numerically, which includes the effects of both ionospheric saturation, and secondary inner magnetosphere currents, on the radio signal’s location of emission and total signal power. This work may be used to better determine which star-planet systems may be more likely to produce observable radio emission, and are therefore better targets for future observation.