CONSISTENCY OF INTRA-CENTENNIAL OSCILLATIONS IN LENGTH OF DAY AND OCEANIC CHARACTERISTICS

The paper presents analysis of intra-centennial (inter-decadal and multidecadal) variations of the length of day (LOD) and some oceanic parameters such as sea surface temperature (SST) and sea level (SL). Methods of multivariate regression analysis and correlation analysis are used. Results of the regression analysis show a spatially coherent response of SST to LOD variations on the multidecadal time scale. The earlier response is peculiar to the north and tropical Atlantic where the multidecadal SST variations are approximately opposite to the LOD variations. In the most remaining parts of the oceans, except especially in the Ni & ntilde;o 3.4 region of the equatorial east Pacific, the multidecadal SST variations are generally lagged relative to the antiphase variations of the LOD. Smoothing of SST averaged over di ff erent areas and of the global mean SL shows that the intra-annual variations include inter-decadal, 20-30 -year, multidecadal, 60-70 -year, components that correspond to similar oscillation components in the LOD. The most striking correspondence of the two components is observed between the LOD and SST averaged over the Ni & ntilde;o 3.4 region. Generally, there are significant correlations of the intra-centennial variations on the averaged and smoothed SST series and global mean SL with the LOD variations. We propose that angular momentum exchange processes involving oceanic circulation and interactions between the Earth's core and the mantle play probably a part in the observed relationships of intra-centennial variations in oceanic parameters with variations in the LOD.