A study of the longest tide gauge sea-level record in Greenland (Nuuk/Godthab, 1958–2002)

We study the longest tide gauge record available from Greenland, that is the Nuuk/Godthab site in southwest Greenland, for the time period 1958-2002. Standard regression methods and the application of the Ensemble Empirical Mode Decomposition technique reveal a rate of sea-level rise of ≈ 2 mm/yr, two complete cycles of the 18.6-years lunar nodal tide, and a negligible acceleration. Using previous assessments for the globally averaged sea-level rise during that period, glacial isostatic adjustment modeling and sea-level “fingerprinting” of the mass loss of continental ice sources, terrestrial water sources and oceanic steric effects, we evaluate the various contributions to local sea-level rise at the tide gauge location. The misfit between the observed and the modeled sea-level trend is unlikely to reflect tectonic deformations but, more intriguingly, may indicate that the mass balance of the Greenland ice sheets was, during the second half of the last century, somehow closer to balance than suggested by previous investigations.