The aurora has been active during the past few nights and has been well seen here at Tarbatness in Highland Scotland. Most of the auroral forms are very mobile and fleeting with many occuring simultaneously, these make up the entire display. However there are some beams and rays which are long lasting. Last night a beam appeared at the end of the auroral arc which seemed almost stationary to the naked eye and persisted for more than 14 minutes. I have seen one of these long lasting stationary beams earlier this year in a display in April. I asked around to see if anyone knew the cause of these unusual features and one suggestion was a proton beam. Can any one give me an explanation of this phenomena. Gordon Mackie of Thurso also imaged this feature last night and his excellent image is attached. The single beam looked like a a bright comet tail in the sky. A wonderful sight.
There is a discussion and images here http://www.orbiter-forum.com/showthread.php?t=36047 on proton beams aurora (plus images) . Need to sort out my library (book stacks) for Neil Bone’s and Akosofu’s auroral books, There should be something in those .Hope this links help a bit.