Two mechanisms for dayside polar cap auroral emissions under northward IMF

Jennifer Alyson Carter, University of Leicester, Leicester, LE1, United Kingdom, Steve E. Milan, University of Bergen, Birkeland Centre for Space Science, Bergen, Norway, Larry J Paxton, Applied Physics Laboratory Johns Hopkins, Laurel, MD, United States and Alexandra Fogg, University of Leicester, Department of Physics and Astronomy, Leicester, United Kingdom