publisher = {Reimer},

abstract = {In a regional study based upon a large set of sea-level data and meteorological data, the long-period variations in sea-level and the fluctuations of meteorological parameters have been investigated for the Norwegian coast. In the period range between 1 and 20 years, the sea-level is found to be dominated by a few distinct signals. The interaction between meteorological parameters and sea-level is discussed. The sea-level is found to respond to long-period air pressure variations as an inverse barometer. Most of the sea-level signals with periods between 1 and 5 years are at least partly due to similar signals in air pressure and/or wind stress. In the Chandler band, the meteorological parameters contain at least two distinct signals. The oceanic pole tide signal is masked by the atmospheric forcing of the sea-level. This leads to temporal variations in the apparent pole tide, which are uncorrelated with the temporal variations of the Chandler wobble. The air pressure corrected pole tide is still not an equilibrium tide, but the large deviations in phase from equilibrium may well be due to unaccounted effects of wind stress and temperature. The Chandler wobble in polar motion is important as the driving force of the pole tide. In an extensive numerical investigation, the simple and physically reasonable model of a single frequency, damped, harmonic oscillation, which is frequently excited at random times and with random amplitude is found to explain all features of the observed Chandler and annual wobbles. Comparing the results from the numerical investigations to the results from analyses of the polar motion gives strong evidence for the Chandler wobble period to be either 428.5± 1.0 days or 437.2±0.8 days and not the usually assumed period of ≈434 days. No final decision can be made which of the two periods is the true Chandler period, though the shorter one is favoured by several facts. The signals in meteorological parameters can all be related to the variations in sunspot numbers. A non-linear response of the atmosphere to the annual solar forcing, which is modulated by the sunspot cycles explains the observed frequency patterns. The excess of the observed sunspot effects in surface air temperature over those predicted from simple climate models by a factor of 10 indicates the existence of strong positive feedback mechanisms, which are responsible for the signals in air pressure and wind stress, too. The 18.6-year nodal tide lags the equilibrium tide by 0.8 radian, while the amplitudes exceed the equilibrium amplitudes by a factor of 3 to 5. At most parts of the coast, the nodal modulation of the amplitude of the fortnightly lunar tide Mf also lags the equilibrium modulation by 0.5 to 0.7 radian. The amplitude of the nodal modulation is close to equilibrium, except for Oslo and Bergen. At the latter stations, resonance effects may modify the modulation. Mf itself is found to have an amplitude of two to three times the equilibrium amplitude and a phase lag of slightly more than π. Determining the land uplift at the Norwegian coast from the trend in sea-level leads to a varying pattern of isolines, with the land uplift gradient being perpendicular to the general direction of the coast line, and being rather large at parts of the coast. At most parts of the coast, the zero line is further out in the sea than given on other published charts.},
note = { \url {http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/11707}},
note = { \url {http://dx.doi.org/10.23689/fidgeo-6047}},
}