Fengjue Wang

1 month ago | agupubs.onlinelibrary.wiley.com | Yuyang Huang |Space science |Chao Xiong |Fengjue Wang

1 Introduction In 1922, an abnormally large deflection of the northward component of the Earth's magnetic field was detected by the magnetometers at the Huancayo equatorial Observatory in Peru. After that, this phenomenon gained significant attention from researchers (Bartels & Johnston, 1940; S. Chapman, 1948; Egedal, 1947, 1948). Chapman (1951) attributed this deflection to an intense, narrow ionospheric current that flows on the dayside above the magnetic dip equator in the E region.