Plasma sheet injections into the inner magnetosphere: Two‐way coupled OpenGGCM‐RCM model results

• Published in: Journal of geophysical research. Space physics 2017-05, Vol.122 (5), p.5077-5091
• Main Authors: Cramer, W. D., Raeder, J., Toffoletto, F. R., Gilson, M., Hu, B.
• Format: Article
• Language: English
• Subjects: BBF; Boundary conditions; bubble; Bubbles; Circulation; Climatology; Computer simulation; Convection modes; Coronal mass ejection; Corotating Interaction Regions (CIR); Coupling; Disturbances; Earth; Earth magnetosphere; Entropy; Environmental impact; Flux; General circulation; Geomagnetic field; Geomagnetic storms; Geomagnetism; Magnetic storms; Magnetism; Magnetohydrodynamics; Magnetosphere; Magnetospheres; Magnetotails; Mass transport; OpenGGCM; plasma sheet; RCM; ring current; Ring current models; Ring currents; Satellite data; Solar corona; Solar wind; Solar wind disturbances; Space weather; Storms; Strength
• ISSN: 2169-9380; 2169-9402
• DOI: 10.1002/2017JA024104

Plasma sheet injections associated with low flux tube entropy bubbles have been found to be the primary means of mass transport from the plasma sheet to the inner magnetosphere. This phenomenon has been primarily studied with satellite data and stand‐alone ring current models with artificial boundary conditions. This study introduces a new two‐way coupling between a kinetic ring current model (Rice Convection Model, or RCM) and a global magnetosphere MHD model (Open Geospace General Circulation Model, or OpenGGCM). Multiple geomagnetic storms and one period of quiet are modeled to track and characterize inward flow behavior. Simulations show that (1) there is a clear association of plasma sheet injections with bubbles, (2) the majority of inward plasma transport in the magnetotail beyond 6.6 RE is due to bubbles, regardless of storm activity, and (3) the average peak velocity of injections is higher for increasing downtail distances, stronger storms (when compared with storms having similar drivers), and storms driven by corotating interaction regions (when compared with coronal mass ejection‐driven storms of similar strength). Plain Language Summary Disturbances in the solar wind, most notably coronal mass ejections from the Sun, impact the plasma environment within the Earth's magnetosphere, the region where Earth's geomagnetic field dominates. This so‐called “space weather” transfers energy and plasma into the magnetosphere, which ultimately affects the near‐Earth plasma environment, or “inner magnetosphere.” Plasma is injected into this region from the nightside magnetosphere, or magnetotail, through a combination of steady and transient injections. There is significant debate about the relative importance of these processes, and the character of the injections themselves. In this study, we use simulations of the global magnetosphere to investigate transient injections to determine their relative importance in transporting plasma into the inner magnetosphere as well as the effect that different types of solar wind disturbances have. We find that transient injections are responsible for the vast majority of the plasma injected into the inner magnetosphere and that the velocity of these injections is dependent on the strength of the geomagnetic storm response and the type of solar wind disturbance. Key Points There is a clear association of plasma sheet injections with bubbles The majority of inward plasma transport in the magnetotail beyond geosynchrono