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Separation of the semidiurnal tidal effect on individual days and some equatorial features of the geomagnetic lunar tide

1963; American Geophysical Union; Volume: 68; Issue: 9 Linguagem: Inglês

10.1029/jz068i009p02425

2156-2202

A. Onwumechilli,

Solar and Space Plasma Dynamics

A method of estimating the lunar effect on individual days is reported. Calculations are carried out to demonstrate how it may help in the study of some aspects of the L field. The contribution of the L field to the diurnal variation of the geomagnetic horizontal field (H) at Ibadan is found to be large, but it is not clear whether ‘big-L days’ of the type reported by Bartels and Johnston [1940] from Huancayo really exist. The evidence is such that, if the existence of big-L days is accepted, the existence of small-L days and even inverse-L days has to be accepted. The results rather indicate that the magnification of L may vary from hour to hour on the same day. The asymmetry in the variation of H near the magnetic equator (defined by Onwumechilli [1959]) is found not to arise from the L field.