Ian G Richardson, University of Maryland College Park, Department of Astronomy, College Park, MD, United States, O C St Cyr, NASA GSFC, Greenbelt, MD, United States, Barbara J Thompson, NASA/GSFC, Greenbelt, MD, United States, Joan Burkepile, National Center for Atmospheric Research, High Altitude Observatory, Boulder, CO, United States and Hilary V Cane, University of Tasmania, Mathematics and Physics, Hobart, Australia