NSF Award
9119516
Experiments are proposed using the incoherent scatter radar facility at Sondre Stromfjord, Greenland, and to study plasma processes on magnetic field lines connected to the dayside auroral oval and discrete arcs in the evening sector. Recent upgrades to the radar have made several new operating modes possible that will enable measurements of ionospheric properties such as vertical and horizontal ion drift, electron densities, and ion and electron temperatures with greatly improved temporal and spatial resolution. A carefully planned experimental program will be conducted that takes advantage of these new capabilities as well as additional data from other ground-based instruments and satellites. The objectives are (1) to study the spatial and temporal variations of ionospheric properties in the dayside auroral oval, (2) to characterize the source region for ions that are transported from the dayside oval to populate the magnetosphere, and (3) to develop radar methods for observing plasma properties at high altitudes on field lines connected to auroral arcs. The dayside observations will be used to define the initial conditions for theoretical modeling of upward ion fluxes and their effects on magnetospheric pressure balance in the near-Earth plasma sheet. The high altitude measurements on auroral field lines will be used to determine the presence of coherent echoes from plasma turbulence associated with the auroral acceleration region. The results of these experiments will establish a firm observational framework for ground-based studies of auroral precipitation and will have important implications for our understanding of magnetosphere/ionosphere coupling on the dayside and how it relates to auroral substorm processes.
