Ground-based Observations of Transient Phenomenon at the Dayside Magnetopause (Invited)

Satellite constellations (e.g., THEMIS and Cluster) capable of probing the bowshock, magnetosheath, magnetopause, and outer dayside magnetosphere have dramatically improved our understanding of transient phenomenon in those regions. Some of these transient processes cause distortions of the magnetopause which can drive magnetospheric field-aligned current (FAC) systems that close in the dayside high-latitude ionosphere. Prior to the THEMIS era, investigators of dayside transients had relatively few opportunities to study the full sequence of solar wind - magnetosphere - ionosphere coupling during these events. We report on recent studies and observations that begin to explore the necessary conditions (in each region) for the effective generation of dayside transient FACs (i.e., conditions for efficient coupling). We also highlight new ground-based capabilities that have improved our understanding of these phenomenon.