Properties of the Reconnecting Current Sheets in CME/Flare Events

Analyzing the data from the UVCS and other instruments on board SOHO, we studied the plasma features of current sheets observed in various temperatures. The results suggest a thick current sheet with small interior structures, which implies the development of plasma instabilities in the sheet. Direct measurements yielded the sheet thickness d between 5.0 x 10(4) and 4.6 x 10(5) km, increasing with both time and altitude. The possibility that large apparent d results from projection effects is examined and rejected. We derive theoretical scaling laws relating d to other observables that corroborate this conclusion and thus help confine both d and the electric resistivity eta(c) to a reasonable range.