Seasonal and diurnal variations in atmospheric pressure

The Laplace idea of the description of tides is used for the representation of seasonal-diurnal variations in atmospheric pressure. The variations are represented as the sum of pure periodic processes whose frequencies coincide with combinations of astronomical frequencies and whose amplitudes and phases are determined with the use of spectral analysis of observed variations. Combinations of the frequencies of the Earth’s rotation and orbital motion are used as the astronomical frequencies. The idea is tested on the data of atmospheric pressure and temperature observations at the Ternei site. These data are compared to the observations of atmospheric tides associated with the gravitational pull of the Moon. It is found that the pressure and temperature seasonal variations associated with solar radiation exceed solar tides by tens of times and can be used for the description of such phenomena as cyclones and season changes. Analysis of atmospheric lunar tides has shown that these tides are also responsible for atmospheric temperature variations, which are in antiphase with pressure variations. The ratios of the phases of temperature and pressure variations are the same in seasonal and tidal variations. It seems likely that seasonal variations and tides propagate along the Earth’s surface as a wave that accompanies the surface motion of the spherical projection of the Sun in the first case and the Moon in the second case.