Astronomic link to anomalously high mean sea level in the northern Adriatic Sea

Abstract Annual mean sea-level records over nearly 130 yr in the northern Adriatic Sea indicate a combined influence of lunar precessions and solar activity in causing their interannual variability. Sea-level indices of variability at Venice and Trieste were obtained by removing trends and filtering variations shorter than 5 yr. Inspired by reconstructions with Fourier coefficients, the sea-level indices were restored with harmonics related to solar activity, lunar precessions and their interference. Harmonics were fit to indices, explaining more than 75% of the indices’ variance with skills greater than 0.93, at both sites. Fits also allowed projections of interannual variability of mean sea level in the northern Adriatic for the rest of the 21st century. Elevated mean sea levels are expected to be centered around 2022–23, 2049–50, 2066–67, and 2090–91. It was also found that mean sea levels have been anomalously high in the northern Adriatic during at least 75% of the last 12 highs in the solar cycles.