Semi-annual, annual and Universal Time variations in the magnetosphere and in geomagnetic activity: 1. Geomagnetic dataMike Lockwood, Mathew J. Owens, Luke A. Barnard, Carl Haines, Chris J. Scott, Kathryn A. McWilliams and John C. CoxonJ. Space Weather Space Clim., 10 (2020) 23DOI: https://doi.org/10.1051/swsc/2020023
