Date: Thursday, November 21, 2024
Time: 1:00 pm/CT
Advisor: Dr. Keiich Ogasawara
Understanding the Spatiotemporal Evolution of Subauroral Ion Drift and Oxygen Outflow from the Auroral Region through Multipoint Observations
Understanding the complex interactions between the ionosphere and magnetosphere dur-ing geomagnetic disturbances is crucial for advancing our knowledge of Earth’s near-space environment. This research focuses on key phenomena, such as subauroral ion drifts (SAIDs), the midlatitude trough, and ion outflows that shed light on the intricate cou-pling between these atmospheric regions.
- Spatiotemporal Evolution of SAID and Midlatitude Trough: SAIDs, characterized by rapid westward drift velocities and latitudinally narrow flow channels, are prominent dur-ing geomagnetic storms. Their dynamic behavior, including equatorward movement and broadening, remains poorly understood. This study utilize the multiple defense meteoro-logical satellite program (DMSP) satellites to investigate how SAIDs develop and how their evolution correlates with the midlatitude trough, a region of depleted plasma density. The findings aim to clarify how geomagnetic activity drives these phenomena and their impact on ionospheric plasma dynamics.
- Oxygen Ion Outflows in the Subauroral Region: While ion outflows from polar and auroral regions and their destinations are well studied, the subauroral zone remains less explored. SAIDs and subauroral polarization streams (SAPS) generate conditions for ion upflow, yet their contribution to oxygen ion outflows into the magnetosphere is not well quantified. By analyzing data from the magnetospheric multiscale (MMS) mission and DMSP satellites, this study seeks to determine whether subauroral ion upflows in the top-side ionosphere (~800 km) transition into sustained outflows and to assess their relative contributions compared to dayside cusp and auroral regions.
Novel Instrument Development for Ionospheric Observations: This work introduces a miniaturized three-dimensional ion velocity and mass imager (3DI). This innovative instru-ment will enhance the ability to distinguish ion species and analyze their distributions in mixed plasma environments, improving the accuracy of measurements in the topside iono-sphere.
These investigations will not only advance our understanding of magnetosphere-ionosphere coupling but also address unresolved questions about the spatial evolution of SAIDs and the role of subauroral regions in magnetospheric plasma populations, potential-ly informing future space weather modeling and prediction efforts.