Following the Workshop, its output will be published as a volume in the Space Science Series of ISSI by Springer, in parallel with the publication of the papers in Space Science Reviews as a Topical Collection. It is expected that a total of about 8 review style and quality papers, submitted to the usual refereeing process will be published in the book. The papers will be based on talks presented at the Workshop and will reflect the discussions that will be held among the participants during the Workshop.