The magnetopause as an intermediary between interplanetary structures and the Earth's inner magnetosphere

Observational studies using data from multipoint spacecraft combined with global modeling of the Earth's magnetosphere are presented to understand the magnetopause as an intermediary between interplanetary structures and the inner magnetosphere in response to a variety of solar-wind structures, such as Coronal Mass Ejections (CMEs), Corotating Interaction Regions (CIRs), interplanetary shocks, and pressure pulses. The importance of the magnetopause in the solar wind-inner magnetosphere coupling arises not only from its global motion, which determines the location of the magnetopause relative to the drift paths of outer radiation-belt particles, but also from physical processes occurring at the magnetopause boundary layer. Common physical processes occurring at the magnetopause boundary layer include Kelvin-Helmholtz waves and newly-identified velocity fluctuations, which both provide multiple channels to increase, decrease, or modulate inner-magnetospheric particle density/energy fluxes. We have surveyed the data sets, finding a number of events in which THEMIS observed magnetopause boundary waves while the Van Allen Probes observed flux enhancements in response to various solar-wind structures. Ultra-Low-Frequency (ULF) waves are often excited by, or enhanced, during these boundary fluctuations. Simultaneous intensifications and/or modulations in the energetic radiation belt and ring current populations are common. Amongst these events, we present categorized case studies in which inner-magnetospheric fluxes are regulated by different solar wind-magnetopause couplings. These results provide evidence that the energy from the interplanetary structures is transferred into the inner magnetosphere via magnetopause dynamics. We use measurements from multiple spacecraft including the Van Allen Probes and the THEMIS and global MHD simulations to track down the mechanisms by which this transport is implemented.