Marilia Samara, NASA Goddard Space Flight Center, Greenbelt, MD, United States, Robert Michell, University of Maryland College Park/ NASA GSFC, College Park, MD, United States, John W Bonnell, University of California, Berkeley, Space Sciences Laboratory, Berkeley, CA, United States, Donald Hampton, University of Alaska Fairbanks, Geophysical Institute, Fairbanks, AK, United States and Guy Alan Grubbs II, Catholic University of America, Washington, DC, United States