Here's the research paper: http://pubs.acs.org/doi/abs/10.1021/jp400001y

TLDR: The initial stages of the electrical discharge that produce this 'plasmoid' have many similarities to lightning. They're just electric arcs - in this case, electric arcs to the surface of this solution of electrolytes. And then what happens is this plasmoid emerges from it. Ball lightning is used almost generically to describe phenomena seen in nature that aren't described by normal lightning, bead lightning or things like 'St Elmo's fire', or aurora. And likely it's not one thing but several things that have similar observables. The US Air Force Academy team hopes its new approach can help science to better understand this strange spectacle.