CEDAR: Characterizing the Polar Cap Topside Ionosphere

Sri International, Menlo Park CA

Investigators

Abstract

This project addresses the polar cap topside ionosphere, a heretofore poorly characterized region of geospace, using novel experiments with the Resolute Bay Incoherent Scatter Radars (RISR-N and RISR-C) together with observations from the Enhanced Polar Outflow Probe (ePOP), observations from the three Swarm spacecraft, and numerical experiments using the Ionosphere/Polar Wind Model (IPWM). Although this project focuses on one region of geospace, it also relates to the connections between this region and other parts of the high-latitude geospace system. The polar cap topside ionosphere is a transition region with the magnetosphere through which ion upflows and outflows are transported. The polar cap is also a transition region between the dayside and the nightside, across which a significant amount of plasma is transported. A new pulse sequence will be developed for the incoherent scatter radars to enhance the sensitivity to the topside. The following specific questions will be addressed: (1) What are the typical properties of the polar cap topside ionosphere? (2) Which physical processes control the day-to-day, intraday, and patch-to-patch variability of the topside scale height and related quantities such as plasma temperature and ion upflow/downflow flux? (3) What do the polar cap topside observations imply about conditions upstream, e.g. in the cusp/cleft, and above in the polar wind?