Lunar nodal tide in the Baltic Sea

The nodal tide in the Baltic Sea was studied on the basis of the Stockholm tide-gauge readings for 1825–1984; data from the tide gauge at Świnoujście for the same period provided comparative material. The Stockholm readings are highly accurate and are considered representative of sea levels in the whole Baltic; hence, the final computations were performed for the readings from this particular tide gauge for the period 1888–1980. The tidal amplitude obtained from measurements uncorrected for atmospheric pressure or wind field was compared with that forced only by atmospheric effects. The amplitude of the recorded nodal tide was the same as the equilibrium tide amplitude calculated for Stockholm. Calculations for equilibrium tide amplitudes were also performed for the extreme latitudes of the Baltic basin.