Tianlin Wang, University of Michigan Ann Arbor, Ann Arbor, MI, United States, Valery U Zavorotny, NOAA/OAR/ESRL (retired), Boulder, CO, United States, Joel Johnson, Ohio State University, Electroscience Lab, Columbus, OH, United States, Yuchan Yi, The Ohio State University, Division of Geodetic Science, School of Earth Sciences, Columbus, OH, United States and Christopher S Ruf, University of Michigan Ann Arbor, Climate and Space, Ann Arbor, MI, United States