HR: 09:15h
AN: SH51D-05    [Abstracts]
TI: Reconnection in the solar corona: probing the fundamental scales
AU: * Longcope, D W
EM: dana@solar.physics.montana.edu
AF: Montana State University, Dept. of Physics, Bozeman, MT 59717 United States
AB: Magnetic reconnection is generally believed to play a crucial role in solar coronal activity. A central paradox is that magnetic reconnection must occur at very small scales in order to be fast enough but must directly affect the largest scales in order to matter. In a natural scenario for this cross-scale coupling, the large-scale coronal field spontaneously develops thin current concentrations (current sheets) where magnetic reconnection then occurs. It has recently been hypothesized that in order to proceed at Alfvenic speeds reconnection must be somehow localized to a small portion of that sheet. Global properties of the current sheet, such as its net current, are set by the global magnetic geometry independent of the small scales. Small scale structure, such as the sheet's thickness, depends on how the microphysics adapts to this imposed global structure. An example is presented of how global properties can be established using present solar observations and models. In this example it is possible to quantify both the net flux transfer and energy release from reconnection and to observe their respective effects on the large scales. One puzzling conclusion is that current sheets seem to persist for extended periods before reconnection begins within them. To understand this apparent latency it is necessary to directly observe the microscales on which the reconnection occurs --- scales that can be estimated by modeling the response to the global context. Observations at these scales, resolvable by the proposed Reconnection and Microscale (RAM) Probe, would reveal the nature of the reconnection process, and thereby help explain the localization, latency and sudden initiation of current sheet reconnection.
DE: 7509 Corona
DE: 7519 Flares
DE: 7526 Magnetic reconnection (2723, 7835)
SC: SPA-Solar and Heliospheric Physics [SH]
MN: Fall Meeting 2005