Thursday, August 6, 2020

Congratulations to Assistant Research Scientist Dr. David Hartley who was awarded $625,000 from NASA to study the “Angular Distribution and Propagation Trajectories: Chorus Near Plumes (ADaPT:CNP)”

Project Description:

Angular Distribution and Propagation Trajectories: Chorus Near Plumes (ADaPT: CNP)

This project is a collaborative effort between Dr. Hartley here at the University of Iowa and Prof. Lunjin Chen at the University of Texas at Dallas. Our recent work identified chorus sources located in the vicinity of plasmaspheric plumes as a necessary criterion if a substantial fraction of chorus wave power is to propagate into the plasmasphere and become a source of plasmaspheric hiss. As such, direct investigation of chorus waves in the vicinity of plasmaspheric plumes is crucial to determining the coupling mechanism between chorus and hiss. No such studies have taken place, and the variation of chorus wave properties and propagation characteristics in the vicinity of plasmaspheric plumes have not been directly evaluated. This funding will allow us to directly address this subject area through a dual approach of analyzing the extensive Van Allen Probes data, coupled with ray tracing simulations. Specifically, we will i) characterize the angular distribution of chorus waves in the vicinity of plasmaspheric plumes, and investigate how this distribution varies with separation distance from the plume, ii) quantify the initial conditions required for chorus waves to propagate into the plasmasphere from sources located close to plasmapsheric plumes, and investigate how these conditions vary for different plume structures, and iii) determine whether the angular distribution of plasmaspheric hiss in/near plumes be explained by using chorus as a source.