Integration of Plasma Sheet Bubbles into the Inner Magnetosphere
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Team
W. Douglas Cramer (PI, University of New Hampshire)
Jimmy Raeder (Co-I, University of New Hampshire)
Christine Gabrielse (Co-I, Aerospace Corporation)
Mei-Ching Fok (Collaborator, NASA Goddard Space Flight Center)
Project Description
NSF Proposal (Attach:projectdescription.pdf)
Presentations
American Geophysical Union Fall 2020 Meeting (Attach:agu20_poster_cramer.pdf)
Project Summary
Overview
Solar wind disturbances, collectively known as space weather, are the primary driver of magnetospheric convection. Earthward-directed plasma injections from the tail region of the magnetosphere populate and energize the inner magnetosphere plasma population. When injections are numerous and powerful enough, they can cause geomagnetic storms and ionospheric disturbances which can impact power grids, communications, spacecraft, and astronaut health. Improving our current predictive capabilities is necessary in order to mitigate the potential negative effects of space weather. This first involves answering some of the unresolved questions about injections into the inner magnetosphere, which include: (1) the typical size and shape of injection fronts, (2) the magnitude of their associated flux increases, (3) the depth to which they penetrate into the inner magnetosphere, (4) the relationship between the initial observations in the plasma sheet and their effect on ring current energy and associated geomagnetic disturbances, as well as the factors that control those parameters.
In this study, we will use a newly-coupled global magnetosphere-inner magnetosphere model (OpenGGCM-CIMI) to investigate the integration of plasma sheet injections into the inner magnetosphere region. In particular, we will focus on the transient injections associated with regions of low flux tube entropy known as bubbles. The new model will provide novel capabilities for the analysis of plasma sheet injections, including: (1) the ability to track plasma sheet injections from birth in the plasma sheet to dissolution into the inner magnetosphere, (2) the preservation of pitch angle distribution information to track the position and evolution of the injection, and (3) the inclusion of the entire inner magnetosphere particle energy spectrum and most loss processes (to provide realistic behavior).
Satellite data will be used to validate model results. Data from the Van Allen Probes will be used to identify and characterize injections in the ring current region. Data from other spacecraft (THEMIS, GOES, Cluster, and MMS) will be used to analyze these bubble-driven
ows in the plasma sheet region. Where possible, conjunctions of spacecraft will be used to connect the observations.
Intellectual Merit
Plasma sheet injections and their influence on the energy and dynamics of the inner magnetosphere are not well understood. The development of a new coupled magnetosphere-ring current model that can simulate these phenomena with greater fidelity than current models will provide a global
view of these types of events from initial formation to dissolution. This project will shed light on ring current development and the interaction between near-Earth plasma sheet dynamics and the inner magnetosphere by evaluating the effects of plasma injections induced by the penetration of the plasma sheet BBFs/bubbles. With the completion of this study, we will have a quantitative understanding of how these particular plasma injections behave and how they affect the inner magnetosphere.
Broader Impacts
This study will improve the scientific community's magnetosphere modeling capability, which is crucial for being able to predict and mitigate the e ects geomagnetic storms and substorms on our society, including electrical power grids, orbiting spacecraft and astronaut health. This study will
will also provide funding for an early career female scientist.
