LUNAR BAROMETRIC TIDE, ITS GLOBAL DISTRIBUTION AND ANNUAL VARIATION

The global distribution of the lunar barometric tide L2 is investigated by spherical harmonic analysis, based on 104 stations for the annual mean, and on 85 stations for the three seasons. The main wave of L2 is the one with wave number 2, but for a detailed study of the irregularities of the global distribution of L2, waves with other wave numbers have also to be considered. Even the main wave of L2 is asymmetric to the equator with the two lunar-daily pressure maxima occurring earlier in the Southern than in the Northern Hemisphere. The amplitudes at the same distances from the equator are greater in the Southern than in the Northern Hemisphere. These hemispheric differences are most pronounced during the D season. As found in earlier investigations the phase consiant of L2 is always greater during the J season than during the D season. But the amplitudes are greatest during the J season only north of 30oS. Farther south the amplitude maximum occurs during the D season. © 1969 Birkhäuser Verlag.