LUNAR COMPONENTS IN LUNPING SCINTILLATIONS

Fourteen consecutive years of 15-min scintillation index values observ ed at Lunping, Taiwan, by Huang have been analyzed by the lunar age su perposition method. Analysis covers 24 hours per day and is performed separately for each of the four seasons. The analysis method is explai ned briefly. Statistically significant first and second lunar harmonic s have been found at all seasons, but the largest and most significant occur in the summertime data (141 days, centered on the June solstice ). During the daytime the probability of scintillations at Lunping is significantly correlated with f0E(s) (the ordinary wave top frequency of sporadic E). We conclude that our lunar harmonics probably result f rom the modulation, in the E region, of neutral winds of solar thermal origin by upward propagating lunar tides. The nighttime scintillation s are larger, and tidal neutral air velocities seem to play a role in the production mechanism(s). There is clear evidence for both the summ ertime temperate latitude type of scintillations observed in Japan and the scintillations, mainly equinoctial, arising from the equatorial b ubble mechanism. Four distinct, statistically significant summertime s cintillation periods are found; plus one each in the autumnal and wint er data. At attempt is made to identify the production mechanism assoc iated with each. The prominent role of lunar tides in both equatorial and temperate latitude types of scintillation is noted, and the statis tical significance of the results is discussed briefly. The potential value of analyzing numerous existing data bases by this method is ment ioned.