Events in Physics
Alexander Russell (Dundee):'Solar flares, coronal implosions, MHD waves and sunquakes'
Solar flares are exciting, important and, I believe, a rich area for application of magnetohydrodynamics (MHD). Let me acknowledge straight away that placing “flare” and “MHD” in the same sentence can be polarising: flare experts rightly point out that non-thermal particles are central to flares, so one should be highly sceptical about applying MHD to key parts of the flaring Sun, however, this has not stopped the enthusiastic development of a high-profile and highly-developed industry in solar MHD where researchers simulate 3-d active region instabilities and claim correspondence of subsequent magnetic reconnection to real flares. I will not be settling the debate that occurs when strong views from these two perspectives collide. Instead, this talk makes a less controversial proposition that flares have effects in places and times where MHD remains a good description, and since many of these have not been explored with the tools of MHD, they are fertile new ground for MHD and flare theorists to collaborate on. I will sample a few flare topics where MHD has recently been applied for the first time that are part of my own research: coronal implosions, their connection to transverse loop oscillations, and (separately) some brief comments on magnetic excitation of sunquakes as an MHD wave-coupling problem. I hope to persuade you that novel discoveries await when MHD is applied to flares in new ways, and that flare science has much to gain from collaboration with MHD.