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Session 33 - Dynamics of Solar Magnetic Fields.
Oral session, Tuesday, June 11
X-ray observations of the Sun's corona show it to be a hot-bed of energetic activity. Regions of strong magnetic field, in particular, are subject to sporadic, localized bursts of energy: flares and microflares. Using a simple three-dimensional model of the coronal magnetic field it is possible to demonstrate the occurrence of spontaneous magnetic singularities called current sheets. These singularities occur at boundaries defined by the topological inter-linkage of discrete flux tubes through the corona. Stresses applied to the corona through its photosphere boundary are focused at current sheet. This stress can be released through fast reconnection, which we hypothesize to occur when an instability threshold is crossed. Along these lines accumulation and release of stress at current sheets serves as a prototype of flares and microflares. Using this novel model it is possible to explain and quantify the local and sporadic nature of energy release in the corona.
This work was supported in part by NASA grant NAGW-3429, NSF grant AST-9218085, and Cal Space grant CS-17-95.
Program listing for Tuesday