Tides of Norway: insights from a dense coastal tide gauge network

Abstract. Tide gauges provide highly precise observations of coastal sea-level variability, yet their spatial sparsity remains a fundamental limitation in regions characterised by complex coastal geometry. This study utilises an extensive archive of 250 short-duration tide-gauge deployments by the Norwegian Mapping Authority (Kartverket) between 2009 and 2026 to characterise tides along the Norwegian coast. We characterise the major tidal constituents and several tidal datums along the entire coastline, including the maximum tidal range and high-tide durations. Further, these data provide a unique source for global model validation, as shown by comparisons against five state-of-the-art tide models, yielding median errors of 2.4 to 3.3 cm that scale with model spatial resolution. Collectively, these results provide a high-density in situ characterisation of Norwegian tides, reveal fine-scale tidal variability that is unresolved by sparse permanent networks, and establish an observational basis for future spaceborne investigations of tidal dynamics in Norway's fjords and coastal waters.