Luni-solar tidal oscillations in horizontal magnetic intensity H and in ƒ₀F2 at Huancayo during low solar activity period

Abstract

The article describes lunar daily and lunar monthly oscillations in ƒ₀F2 and H at Huancayo for the period 1951-1955. Chapman's Phase Law L = Σ⁴ _n-1 C_nsin{n_Φ + (n-2)v + α_n} for H is shown to be valid for ƒ₀F2 also. The average phase difference between lunar daily oscillations in ƒ₀F2 and H is 165° for the first and 140° for the second harmonic. The lunar semi-monthly tide in H starts increasing with sunrise and is maximum around noon, while the tide in ƒ₀F2 starts increasing about 2 hr after sunrise and has a broad maximum from 10.00-16.00 hr. The maximum deviation due to lunar semi-diurnal or semi-monthly tide averaged over the whole year occurs at about 8 local hr for H and at about 41. hr for ƒ₀F2. The lunar tides in H or ƒ₀F2 are strongest during December Solstices and weakest during June Solstices.