M. Karlicky
Astronomical Institute of the Academy of Sciences of the Czech
Republic, 25165 Ondrejov, Czech Republic
First, theoretical expectations are summarized. Current sheets formed by slow evolution of the active region, stochastic current sheets in stressed active region, and the current sheet formed in the CME-flare phenomenon are shown. Then, we present their observational evidence: a) UV current sheets behind CMEs and b) X-ray plasmoid ejection. After examples of MHD and PIC modelling of these processes we discuss their radio and X-ray diagnostics, considering drifting pulsation structures, narrowband dm-spikes, lace bursts, and X-ray loop-top sources.