A Combined Modeling and Measurement Approach to Assess the Nodal Tide Modulation in the North Sea

The correct representation of the 18.61-year nodal tide is essential for an interpretation evolution mean sea level, as errors cause misleading bias. currently estimated by applying correction factors in harmonic analysis, which are derived from equilibrium tide. From tide, values f amplitude and u phase determined, alter lunar tidal constituents, depending on cycle. This approach has proven to be valid many gauges, even though impact shelf seas been shown differ their theoretical value. Hence, constituents records North Atlantic region were analyzed lag with a new multiple, nonlinear regression approach, able approximate modulation quantitatively its agreement Results show overestimation M2 N2 more than 2.7% Wadden Sea, while O1 K2 underestimated 1–4.6%, would produce error 2–5 cm example, German Sea. Additionally, process-based model Sea was applied at diurnal minimum maximum cycle calculate spatial distribution u. confirm spatially varying satellite friction dominated, shallow water regions.