Amplitude and phase of the 11-yr term in sea-level: Europe

The 1 I-yr solar cycle term in sea-level is further elucidated by singleand two-channel high resolution signal processing techniques applied to 37 European height H of sea-level records. In agreement with earlier analysis the period and amplitude are 10.6k0.3yr and 10.3k4.8mm. New results are as follows: in view of the recently detected 11-yr term in Earth rotation A T = ET -UT, cross-spectra of the H records with AT were computed. At the solar cycle period H lags A T by 0.7 t 0.5 yr; since A T lags the change in length of day A(1od) by 2.7yr the result is that H lags A(1od) by 3.4k0.5 yr. The continuum spectrum of H and A T has a high coherency and zero phase from the solar cycle down to a period of 40yr, although this relation cannot be causal. We propose that the circumpolar vortex of westerly winds is the common forcing function for the H and A T discrete solar cycle signal and a significant portion of the long-period continuum in European waters.