Are multi-decadal sea-level oscillations augmenting rates of mean sea level?

There is evidence to show sea-level change is accelerating, with a departure from Holocene rates in the late-19th century, to more than a doubling of the rate of global mean sea-level change over the past 25-years. Although the effect of anthropogenic forcing on sea level is certain, the influence of natural internal variability on augmenting rates of change remains an important area of research. This is especially significant at ocean-climate response timescales (>30-years). Using tide-gauge data, we apply empirical mode decomposition (EMD) to separate both the global and regional sea-level records into a series of intrinsic mode functions (IMFs) that are quasi-periodic in character. From them, we identify the dominant modes of variability that are common to each ocean basin, and compare these to recognised modes of climate variability to determine the causal factors of sea-level oscillations. We also conduct a sensitivity analysis with sub-sampled tide-gauge data to test the feasibility of this approach with high-resolution proxy-based sea-level reconstructions.