The Rate of Magnetic Reconnection Observed in the Solar Atmosphere

The Astrophysical Journal1996Vol. 472(2), pp. 864–873

Citations Over TimeTop 15% of 1996 papers

Abstract

The structure of the solar corona is often observed to evolve in a manner that is generally attributed to the process of magnetic eld line reconnection. The spatial and temporal scales for a variety of reconnection events have been examined on the basis of descriptions in the scientic literature. These events tend to fall into two general categories. In the rst category, reconnection proceeds as the corona adjusts itself to the emergence of new magnetic ux. In the second category, the eld lines have been explosively blown open by a are or mass ejection, and the eld lines eventually return to a more potential eld conguration by means of reconnection. Estimates of the density, temperature, and magnetic eld strength in the reconnection volume provide a basis on which to calculate the reconnection rate expected for resistive di usion, tearing mode reconnection, and reconnection at the Alfve n speed. The observed temporal and spatial scales of the reconnection events indicate that the rate of reconnection is on the order of 0.0010.1 of the Alfve n rate, the Alfve n speed divided by the observed length scale. This indicates that the e ective Reynolds number for large-scale structures in the corona is of the order of 10 1000. In none of the cases examined does the reconnection appear to be driven by external ows, but the process is more properly described as the relaxation of nonpotential magnetic eld congurations toward a potential conguration.

Citations Over TimeTop 15% of 1996 papers

Abstract

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