The energetics of geomagnetic storms and magnetospheric substorms continue to be controversial problems in the space community. Multi-point investigations of the physical processes responsible for these phenomena are especially timely due to the increasing availability of multi-point measurements from ground-based stations and distributed satellites within the magnetosphere. Understanding of these phenomena would answer fundamental questions on impulsive particle acceleration in space plasmas. Since magnetospheric substorms occur in other planetary bodies and may be akin to solar flares, understanding substorm process will also provide valuable insights into energetic processes occurring throughout our solar system and would assist space weather forecasting. This project is based on an extensive database from remote-sensing and in situ measurements of these phenomena in the magnetosphere. The project will examine: (1) the association between dipolarization and plasma flow, (2) the propagation of the pressure reduction front during substorms to differentiate whether the pressure reduction is associated with plasma bubble or a rarefaction wave, (3) the plasma flow reversals during substorms to determine whether or not the flows are indicative of f a single plasma source (magnetic reconnection site) or varying contributions from multiple activity sites, and (4) the transport characteristics of magnetic reconnection activity using a multi-component approach. The PI will continue to undertake outreach activity in mentoring high school teachers and students during the period of the program.
Space disturbances pose hazards to space assets and societal activities. The intellectual merit of proposed activity is to fundamental understanding of the physical processes responsible for these space disturbances. This goal is accomplished by synthesizing multi-satellite observations synergistically among the space programs in USA and Europe. The proposed project benefits the society at large in the prediction of space weather hazards. Several important outcomes are (1) finding strong evidence for a plasma instability to redirect large electric currents in space to the ionosphere during space disturbances known as substorms – this result refutes the conclusion reached in a Science article published in 2008; (2) discovering a new feature in the diffuse auroral emission that is related to plasma flow vortices (similar to tornadoes on the ground) in space; (3) developing a unique technique to reconstruct space environment around a satellite path; (4) determining three categories of magnetic structures in space environment, one of which is found in solar wind and is responsible for causing large geomagnetic disturbances at Earth known as geomagnetic storms. In terms of broader impacts, the project investigates a fundamental problem of impulsive energization process that would benefit many branches of physics. For integration of education and research, the proposed project includes mentoring some high school students as well as training younger scientists on data analysis techniques used in space research.
