Lunar tides in noon electron density at fixed real heights in the ionosphere over Puerto Rico and Huancayo

Lunar semi-monthly oscillations in the electron density at fixed real heights of the ionosphere at noon over Puerto Rico and Huancayo during the periods March 1959 to December 1961 and January 1960 to December 1961 respectively, have been computed. The amplitude of the tide, M2, for both the stations is found to increase monotonically with height during each of the seasons, there being about 50 times enhancement of tidal amplitude from the base to the peak of the F2-region. At any fixed height, the amplitude is largest during November-February months and least during May-August months. The phase of the tide seems to remain constant with height at Huancayo but it varies considerably with height at Puerto Rico. During any of the seasons the tides at about 180 km above Huancayo and Puerto Rico are almost in the same phase