Variation ofS q-ranges andL 2 (H) with the dip latitude in Indian region

Summary A modified method of computing theS _q -range in terms ofR _x inH, D andZ has been suggested. Mean quiet-day daily rangesR _x , have been computed for five Indian stations usingH, D andZ data for selected years. The seasonal and latitudinal variation ofR _x (H), R _x (Z) andR _x (D) are discusses. Thee-season maximum inR _x (H) andR _x (Z) is attributed to the decrease in the distance between the foci during equinoxes; the electrojet and theS _q -foci movement with seasons have little influence onS _q (D). It is inferred that the electrojet current is independent of the worldwideS _q current system and stands with its own return currents.The variation of lunar semi-diurnal tide inHL ₂ (H)] with the dip latitude in Indian region shows a secondary peak at 9° N dip latitude. This secondary peak in theL ₂ (H) is termed as Lunar secondary electrojet, and it is suggested that this is possibly produced by magneto-acoustic oscillations due to the drift motion of the charged particles that produce the primary jet in a direct transverse to itself.