Solar Activity and the Semidiurnal Component of Lunar Daily Variation in H at Alibag

Lunar daily geomagnetic variation in different phases of solar activity, derived from the long series of horizontal intensity at Alibag, has been separated into parts of oceanic and ionospheric origin. The results show that the ionospheric part of L, becomes dominant over the other harmonics and it correlates poorly with sunspot number, considered here as the index of solar activity