THE ATMOSPHERIC TIDES AT WAKE ISLAND

Abstract

Twelve years of hourly surface observations from Wake Island are analyzed to isolate the atmospheric tides and to study possible relations between the tides and weather over a very small land mass. In addition to determining the solar diurnal and the solar semidiurnal variation of temperature and pressure, the study demonstrates that the lunar semidiurnal pressure oscillation can be satisfactorily determined while the lunar semidiurnal temperature variation cannot be isolated with 12 years of hourly observations. The frequency of occurrence of precipitation shows only a slight suggestion of a lunar tidal period; however, the lunar semidiurnal precipitation component has the same relation to the lunar semidiurnal pressure wave as the solar semidiurnal precipitation wave has to the solar semidiurnal pressure wave. There is some evidence for a solar semidiurnal variation of cloudiness and a relationship between cloudiness and the semidiurnal pressure wave rather than between cloudiness and the predominantly diurnal temperature wave. A pronounced observational bias in sky cover associated with the moon's position makes it impossible to conduct any valid study of the relationship between sky cover and the lunar tidal period.