Kelvin-Helmholtz Instability and Magnetosonic Wave Emission Along Bursty Bulk Flow Channel Boudaries: Impacts on Near-Earth Plasma Sheet Dynamics During Substorms

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Substorms are key elements of space weather applications and fundamental processes of solar wind energy storage and release in Earth's magnetosphere. Understanding substorm dynamics is essential in preparing for extreme space weather events, which can cause strong disruption and damage to the performances and the reliability of space-borne and ground-based technological systems. Among many physical phenomena affecting the substorm dynamics, instabilities in the magnetotail have caught much attention in recent years. This project will investigate the evolution of Kelvin-Helmholtz Instability (KHI) and magnetohydrodynamics (MHD) wave emission along Bursty Bulk Flows (BBFs) and their potential impacts on the substorm dynamics. The project results will expand our understanding of MHD waves and instabilities in the magnetotail and their association with the substorm dynamics, which will contribute to a better understanding of the magnetosphere-ionosphere coupling. Therefore, the results of this project will have direct applications in the active development of Space Weather preparedness and building capabilities to forecast space weather effects, supporting the latest focus of the National Space Weather Action Plan. This project will also support an early career female scientist from an underrepresented group, which supports NSF's Strategic Goals in diversity and promoting the advancement of women in science. Furthermore, this project will contribute to NSF's goal of developing a diverse and globally competitive STEM workforce" by involving undergraduate students from Utica University (a primarily undergraduate institution) and high school students from minority groups in the greater Utica area as summer research students. The overarching questions that motivate this investigation are: Do MHD waves occur along BBFs, and if so, how do these MHD waves impact substorm dynamics? What is the relationship between the KHI and MHD waves emission along BBFs and associated substorm dynamics? Specifically: (1) What is the likely presence of MHD waves associated with BBFs? If they are present, which solar wind conditions are more favorable for the emission of these MHD waves? (2) If MHD waves are present, are they often accompanied by KHI evolution along the BBFs? If KHI evolution is absent during MHD wave emission, what other mechanisms might cause these waves? How often and under what conditions MHD wave emission occurs with KHI evolution? (3) What are the characteristics of these MHD waves, frequencies, periods, phase velocities, etc.? Do they agree with the observed ULF wave characteristics near BBFs? (4) How do these MHD waves affect BBFs' dynamics? (5) What are the signatures of these MHD waves in the ionosphere? The team will use CMIT-LFM coupled global MHD simulations code available at NASA's Community Coordinated Modeling Center (CCMC). Simulation results will be verified with observations from the Time History of Events and Macroscale Interactions during Substorms (THEMIS) and ground-based observations from the Canadian Array for Realtime Investigations of Magnetic Activity (CARISMA).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.