A new look at the ionosphelic current system

The paper describes some regional anomalies in the solar daily variations of the northward X and eastward Y geomag netic field by examining the data from indivi dual stations during the International Geophysical Year (IGY) 1957-58. Around 30-40oN dip lati tude the daily range of X showed a minimum and the range of Y a maximum, which is the chara cteristic of the Sq focus. No definite indic ations of stich phenomenon were seen in the southern hemis phere. The low latitude maximum of fjj( around noon changed to midd ay minimum at high latitudes. not through a flat daily variation at focus latitudes. A fore noon minimum and an afternoon maximum of !!X occurred at northern focus latitudes. A reverse feature occurred al southern focus latitude. It is suggested that the mid-latitude Sq cun'ent system is greatly aff ected by