Statistical characterization of ionosphere anomalies and their relationship to space weather eventsChunming Wang, Irvin Gary Rosen, Bruce T. Tsurutani, Olga P. Verkhoglyadova, Xing Meng and Anthony J. MannucciJ. Space Weather Space Clim., 6 (2016) A5DOI: https://doi.org/10.1051/swsc/2015046