Flow Channels in the Magnetosphere:

Recent work, both observational and theoretical, have brought the role of flow channels in magnetospheric dynamics into closer focus. The flow channels have also variously been called bursty bulk flows (BBF's), dipolarization fronts, and bubbles. They link together a number of components of the magnetosphere-ionosphere system: tail reconnection, mid-tail dynamics and convection, the ionosphere, and the ring current. This coupling occurs through the injection of low entropy ( PV^γ ) plasma carried by the flow channels into the inner magnetosphere. In this talk we present results of high resolution simulations of flow channels and their interaction with the inner magnetosphere and ionosphere. These simulations were performed with the Lyon-Fedder-Mobarry (LFM) code coupled with the Rice Convection Model through the use of the MIX ionospheric coupler. The resolution in the midtail is ∼ 1/4 R_E. The low entropy flux tubes form in the tail reconnection region and propagate inward through an interchange instability. We will discuss four major features revealed in these calculations: 1.) the formation of the ``bubbles'' in the tail reconnection region and the dynamics of their acceleration toward the Earth; 2.) The behavior of the flow channels as they break in the region nearer the Earth; 3.) the incorporation of the plasma transported into the ring current and the ring current's evolution; and 4.) the coupling of the flow channels with the ionosphere and the channels' auroral signatures.