  "Streamers, sprites, leaders, lightning: from micro- to macroscales" was the
theme of a workshop in October 2007 in Leiden, The Netherlands; it brought
researchers from plasma physics, electrical engineering and industry,
geophysics and space physics, computational science and nonlinear dynamics
together around the common topic of generation, structure and products of
streamer-like electric breakdown. The present cluster issue collects relevant
articles within this area; most of them were presented during the workshop. We
here briefly discuss the research questions and very shortly review the papers
in the cluster issue, and we also refer to a few recent papers in other
journals.
