Dayside Auroral Pulsations and their Association with Outer Magnetospheric Dynamics

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The Earth's magnetosphere interacts continuously with the incoming solar wind plasma flow, transfers its energy and momentum from outer layers down to the ionosphere and upper atmosphere. These physical processes take place mainly on the Earth's dayside, generating electromagnetic waves in the outer magnetosphere that likely act as key agents in causing and/or modulating precipitation of energetic electrons responsible for the dayside auroral pulsations. For better understanding of these physical processes laying underneath the dayside auroral pulsations, it is essential to examine associations of the auroral structure variations with the dayside outer magnetospheric dynamics. This award will significantly advance our understanding of the ultra-low frequency electromagnetic wave dynamics in the outer magnetosphere and their connection to the Earth's ionosphere and respective processes taking place there. This research was motivated by recent case studies that suggested connections between the dynamical behavior of daytime auroral pulsations being modulated by the kilo-electron-volts electron precipitation caused by the earthward-propagating compressional Pc3 waves of the upstream origin. This study will conduct the first critical observational test of the above hypothetical scenario via characterization of spatiotemporal properties of the dayside auroral pulsations in the two-dimensional perspective that will help addressing their association with the dynamic of outer magnetosphere layers. More specifically, the following science questions will be addressed: (a) what are the spatiotemporal properties of the dayside auroral pulsations, and (b) what are their occurrence rate, period, propagation direction, and correlation with the geomagnetic pulsations observed from the ground in the polar regions.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.