Fig. 4
From: Influence of geomagnetic storms on the quality of magnetotelluric impedance
Variations in the magnetic field amplitude and the hat matrix's diagonal elements in the period of 101Â s using the data observed at site 163 from 00:00 on October 29 to 00:00 on November 4. a Shows the hat matrix's diagonal elements normalized by the expected value 2/N. b, c Show the magnetic fields normalized by the standard deviation in the x- and y-directions, respectively. The variation in the hat matrix's diagonal elements has the same trend as the magnetic field amplitude