Measurement of Mass-Loading Effects On Transport Processes in the Earth's Magnetosphere

Sri International, Menlo Park CA

Investigators

Abstract

Variations in the mass density in the magnetosphere can have significant effects on a number of important magnetospheric phenomena. Mass loading is expected to effect the rate of magnetic reconnection and it effects the processes related to Ultra-Low Frequency (ULF) waves. Mass loading effects the growth rate and frequency of Kelvin-Helmholtz (K-H) oscillations at the magnetopause and in the low latitude boundary layer (LLBL). Although the effects are important, it has been difficult to get a quantitative measure of the mass loading and the associated effects. This project will develop a database of events for two classes of solar wind inputs. In each case, the event will begin with a prolonged period of northward interplanetary magnetic field (IMF), which will establish a "ground-state" of the magnetosphere. The first class of events that will be examined is Corotating Interaction Regions (CIRs) and the second class is periods of prolonged southward IMF. The mass loading effect on dayside magnetic merging will be examined by statistically comparing the rate of magnetic flux crossing the polar cap boundary as a function of the magnetospheric density. The project will use data from the Geotail and THEMIS satellite missions in conjunction with ground-based magnetometers and incoherent scatter radar data. The project will include research activities for a graduate student or advanced undergraduate student. The results will be of importance to the Geosapce Environment Modeling program as well as to our understanding and ability to forecast space weather events.