Magnetometer and radar observations of magnetohydrodynamic cavity modes in the Earth's magnetosphere

摘要: Night and early morning data from the Johns Hopkins University, Applied Physics Laboratory HF radar at Goose Bay magnetometers in Canadian CANOPUS array often show structured spectra with distinct spectral peaks 1.3, 1.9, 2.6 mHz. These frequencies are very stable vary by less than ±5% for 6 days of we have analysed. The measurements F-region drift velocities indicate that these associated field line resonances shear Alfven wave, seen lower latitudes as frequency increases. magnetometer magnetohydrodynamic (MHD) waves westward phase velocities. We shall observations compatible formation MHD cavity modes nightside magnetosphere, between magnetopause, approximately 14.5 RE, turning points dipolar outside plasmasphere. Likely sources energy compressional pul...